JP4251297B2 - Recording apparatus and recording method - Google Patents

Description

  The present invention relates to a recording apparatus and a recording method, and more particularly, to a recording apparatus and a recording method suitable for use when recording an image or the like, for example.

  With recent increases in CPU (Central Processing Unit) speed, higher functionality, increased memory, hard disk and other recording media (storage media), and lower hardware costs including these, An inexpensive and highly functional computer that can be purchased by individuals has been realized.

  With the widespread use of low-cost and high-functional computers as described above, the user can easily perform various processes such as recording, reproduction, editing, and the like for enormous amounts of data that have been difficult in the past, for example, images. There is an increasing demand for operations.

  The present invention has been made in view of such a situation, and makes it possible to perform various processes in response to user requests with simple operations.

A recording apparatus according to one aspect of the present invention is a recording apparatus that records moving image data on a data recording medium, and includes a recording time for recording the moving image data, and bit rate information related to a bit rate of the moving image data. Setting means for setting, calculation means for calculating a necessary capacity, which is a recording capacity necessary for recording the moving image data, based on the recording time and bit rate information set by the setting means; and the data a recording medium, I the required capacity more recording regions der, and securing means for securing a necessary area and a capacity for the required capacity and index as a file, the file is the required region, the moving picture and image data, and the index records the data indicating the position at which the scene change according to the output of the scene change detecting circuit And a recording means.

  The securing means may be configured to release a non-recorded area of the necessary area after recording the moving image data by the recording means.

  Presenting means for presenting the necessary area secured by the securing means to a user can be further provided.

  The securing means can secure the necessary area when an instruction to start recording is given.

A recording method according to an aspect of the present invention is a recording method for recording moving image data on a data recording medium, the recording time for recording the moving image data, and bit rate information related to the bit rate of the moving image data. Based on the set recording time and bit rate information, a required capacity, which is a recording capacity necessary for recording the moving image data, is calculated, and the recording capacity exceeding the required capacity is recorded on the data recording medium. What regions der to secure the necessary space and a capacity for the required capacity and index as a file, the a necessary area the file, and the moving image data, and the index, the scene change detecting circuit Recording the data indicating the position where the scene change has been made in response to the output of .

In the present invention, a recording time for recording moving image data and bit rate information regarding the bit rate of the moving image data are set, and the moving image data is recorded based on the set recording time and bit rate information. A required capacity, which is a recording capacity required for the recording, is calculated. Then, the data recording medium, I required capacity more recording regions der and necessary area and a capacity for the required capacity and indexes are reserved as a file, the file becomes the moving image data, the index The data indicating the position where the scene change has been made is recorded in accordance with the output of the scene change detection circuit .

  According to the present invention, it is possible to record the moving image data instructed to be recorded without ending in the middle.

  1 and 2 show a configuration example of an embodiment of a personal computer to which the present invention is applied.

  The personal computer includes a main body 31, a keyboard 21 and a mouse 22 that are operated when a command is input to the main body 31, and a display 51 that displays an image.

  The main body 31 is of a so-called mini tower type, and has a width of 225 mm, a height of 367.9 mm, and a depth of 451.5 mm, for example. Further, a surface 32 and a surface 33 are formed between the front surface and the side surface of the main body 31 so as to connect the two at an angle. A power button 34 that is operated when the power of the main body 31 is turned on or off is disposed on one of the surfaces 32.

  In addition, when a peripheral device connected to the main body 31 is placed on the upper surface of the main body 31, the leg portions of the peripheral device are stably arranged on the upper surface of the main body 31. A recess 35 is formed at a position corresponding to.

  A lower panel 36 and an upper panel 37 are provided on the front surface of the main body 31. The lower panel 36 is constantly urged so as to protrude outward by a spring (not shown), and the user presses the lower panel 36 against the urging force of the spring and from the protruded state, The main body 31 can be recessed. The upper panel 37 is guided by left and right guides 45 and is movable in the vertical direction. The upper panel 37 is restricted from moving downward when the lower panel 36 is in a protruding state.

  When using the main body 31, the user presses the lower panel 36 against the urging force of the spring toward the main body 31 to make it depressed. Accordingly, the restriction on the downward movement of the upper panel 37 is released, and the upper panel 37 moves downward along the guide 45. As a result, as shown in FIG. 2, an FDD (floppy disk drive) 41, a CD-ROM (Compact Disc-Read Only Memory) / CD-R (Recordable) drive (hereinafter referred to as CD Drive 42) and AV (Audio Visual) terminal portion 43 are exposed.

  In addition, the main body 31 is further provided with an expansion portion 44 so that other predetermined devices can be attached.

  When stopping the use, the user puts his / her finger on the recess 38 formed in the upper part of the upper panel 37 and moves the upper panel 37 upward. When the upper panel 37 moves upward along the guide 45 to a predetermined position, the lower panel 36 protrudes outward in accordance with the urging force of the spring, and restricts the downward movement of the upper panel 37.

  As described above, the main body 31 is formed with the tapered surfaces 32 and 33 at the front and side corners in order to make the width narrow. In addition, a slidable panel (upper panel 37) is provided on the front side to protect internal devices, and when not in use, the upper panel 37 is closed so that the internal devices are not exposed. A flat and simple design image is realized.

  In consideration of the potential for future AV equipment, the upper panel 37 is designed so that it can be changed in a drawer type or a rotary type.

  The display 51 basically includes a pedestal 52 and a display unit 53 that is movably coupled to the pedestal 52 in the horizontal direction (pan direction) and the vertical direction (tilt direction). A recess 54 is provided in front of the pedestal 52.

  For example, a CRT (Cathode Ray Tube) 55 constituting a high-definition 17-type trinitron monitor is disposed on the front surface of the display unit 53, and two oblique surfaces 56 and 57 on the left and right sides have two inside. Speakers 59 and 60 are arranged so that high-quality images and powerful stereo high-quality sound reproduction can be realized.

  A microphone (microphone) 24 for capturing the voice uttered by the user is attached in front of the upper surface of the display unit 53. For example, a so-called hands-free phone is connected by the microphone 24 and the above-described speakers 59 and 60. It can be realized.

  A groove 58 is formed in the center of the upper surface of the display unit 53. In addition to accommodating the cord of the microphone 24 in this groove 58, for example, when a TV camera for constituting a videophone is placed on the display 51, the cord can be accommodated. .

  FIG. 3 shows a detailed configuration example of the front surface of the main body 31.

  A power lamp 61 is provided above the power button 34. The power lamp 61 is turned on or off when the power of the main body 31 is turned on or off. A hard disk access lamp 63 is provided below the power button 34. As will be described later, the main body 31 has a built-in hard disk 212 (FIG. 5), and the hard disk lamp 63 lights in orange, for example, when the hard disk 212 is being accessed.

  The FDD 41 is for, for example, a 3.5-inch FD (1.44 MB (megabyte) /1.2 MB / 720 KB (kilobyte)), and a floppy disk drive access lamp 64 and a floppy disk eject button 66 are provided on the front thereof. And are provided. The floppy disk drive access lamp 64 is lit when the FD is being accessed, and the floppy disk eject button 66 is pressed when the FD is taken out from the FDD 41.

  The CD drive 42 reads data from a CD-ROM disk (not shown) and reads / writes data from / to a CD-R (CD-R FS) disk 211 (FIG. 5). In the CD drive 42, for example, reading is performed at 8 × speed and writing is performed at 2 × speed.

  On the front surface of the CD drive 42, an eject button 68, an eject hole 69, and an access lamp 70 are provided. The eject button 68 is operated when the tray of the CD drive 42 is pulled out, and the eject hole 69 is pointed when the tray is manually pulled out when the tray cannot be pulled out by the eject button 68. It is operated by. The access lamp 70 is lit when the CD-ROM disc or the CD-R disc 211 is being accessed.

  The AV terminal unit 43 is provided with an S video input terminal, a composite signal video input terminal, and two audio input terminals (pin jacks) of L (Left) and R (Right) channels. When editing an image or sound recorded by a video camera or VTR (Video Tape Recorder), the image and sound are input from these terminals.

  FIG. 4 shows a detailed configuration example of the back surface of the main body 31.

  A power input terminal 71 is provided on the upper right of the back surface of the main body 31, and power is supplied to the main body 31 by connecting a power cord (not shown) thereto.

  In addition, a keyboard terminal 72 and a mouse terminal 73 are provided on the upper left of the back surface, and the keyboard 21 or the mouse 22 is connected to the keyboard terminal 72 or the mouse terminal 73, respectively. A USB (Universal Serial Bus) terminal 74 is provided below the mouse terminal 73, and a device conforming to the USB standard is connected thereto. Further, a printer terminal 75 and two serial terminals 76 are provided at the lower part thereof. A printer or an image scanner is connected to the printer terminal 75. The serial terminal 76 is connected to, for example, an infrared communication adapter. That is, in this embodiment, by connecting an infrared communication adapter, which is an interface for infrared communication, to the serial terminal 76, infrared communication can be performed between the main body 31 and another device. ing.

  A game terminal 77 is provided below the printer terminal 75. For example, a joystick or a MIDI (Musical Instrument Digital Interface) device is connected to the game terminal 77.

  Below the serial terminal 76, a headphone terminal 78, a line input terminal 79, and a microphone terminal 80 are sequentially provided. For example, an external speaker is connected to the headphone terminal 78, an audio device is connected to the line input terminal 79, and a microphone 24 (FIGS. 1 and 2) is connected to the microphone terminal 80.

  On the right side of the above terminals, a picture showing what is connected to each terminal is displayed.

  Below the microphone terminal 80, a video output terminal 81 for composite signals, an S video output terminal 82, and a monitor terminal 83 are provided. From the video output terminal 81 or the S video output terminal 82, a composite video signal or S video is output. The monitor terminal 83 is connected to the display 51.

  An AV terminal portion 84 is provided below the video output terminal 81, the S video output terminal 82, and the monitor terminal 83. Similar to the front AV terminal 43, the AV terminal 84 is provided with an S video input terminal, a video input terminal for composite signals, and audio inputs for L and R channels.

  An antenna terminal 85 is provided on the right side of the AV terminal portion 84 so that, for example, television signals in a VHF (Very High Frequency) band and a UHF (Ultra High Frequency) band can be received. Has been made.

  Furthermore, a line jack 86 and a telephone jack 87 are provided at the lower part of the back surface. The line jack 86 is connected to a telephone line, and the telephone jack 87 is connected to, for example, a telephone or a facsimile.

  Next, FIG. 5 shows an example of the electrical configuration of the computer shown in FIGS.

  In the present embodiment, the computer incorporates a moving picture experts group (MPEG) 1 real-time encoder board 213 incorporating a TV (Television) tuner 213A, and as application programs, image editing, recording, reproduction, MPEG decoding, It is equipped as standard equipment for performing other image processing. This enables editing of images and audio captured by the video camera 214, and production of a video CD that records the edited image and audio. It has been made easy to do. In addition, a television broadcast program received by the TV tuner 213A can be recorded, and further, while the recording is being performed, an arbitrary scene of a recorded video (image) can be easily reproduced. ing.

  That is, the microprocessor 201 records various application programs recorded on the hard disk 212 under the control of an operating system such as Microsoft Windows 95 (Windows (registered trademark) 95). By executing the above, for example, image recording, reproduction, editing, decoding processing, and other predetermined processing are performed. As the microprocessor 201, for example, Pentium (registered trademark) II processor (266 MHz, built-in secondary cache memory obtained by adding optimization to MMX technology and 16-bit code to Pentium (registered trademark) Pro manufactured by Intel Corporation. (Not shown) 512 KB) and the like are adopted so that even when processing a large amount of data such as images and sounds, high performance can be exhibited (Pentium (registered trademark)). MMX is a trademark).

  The main memory 202 stores programs executed by the microprocessor 201 and data necessary for the operation of the microprocessor 201. Here, the main memory 202 is mounted, for example, as standard by 32 MB, so that processing of an image with a large amount of data can be performed at high speed. The main memory 202 can be expanded up to, for example, 128 MB.

  The bus bridge 204 controls data exchange between the internal bus and an expansion bus such as a PCI (Peripheral Component Interconnect) local bus or an ISA (Industry Standard Architecture) bus.

  The microprocessor 201, the main memory 202, and the bus bridge 204 are connected to each other via an internal bus, and the remaining blocks are connected to each other via an expansion bus. The bus bridge 204 is connected to both the internal bus and the expansion bus.

  The modem 206 is a DSVD / DATA / FAX modem of 33.6 Kbps (bit per second), for example, and controls communication via a telephone line. In the modem 206, for example, an image or sound can be received from the Internet or the like, and this can be a target of processing such as encoding or editing. Further, the modem 206 can also transmit images and sounds that have been edited and encoded to the outside. In addition, the modem 206 transmits the voice input to the microphone 24, receives the transmitted voice, and outputs it from the speakers 59 and 60, thereby realizing a hands-free phone. When the modem 206 is used as a FAX modem, the transfer rate is set to 14.4 Kbps, for example.

  An I / O (Input / Output) interface 207 functions as an interface that outputs an operation signal corresponding to the operation of the keyboard 21 and the mouse 22 and receives an audio signal as an electric signal output from the microphone 24.

  The auxiliary storage interface 210 reads / writes data from / to a CD-R (Compact Disc Recodable) disk 211, a CD-ROM disk (not shown), a hard disk (HD (Hard Disk)) 212, an FD (not shown), and the like. To act as an interface for

  On the CD-R disc 211, for example, images and sounds encoded by the encoder board 213 are recorded, so that a user-original video CD can be produced. Note that the CD drive 42 also supports CD-R FS. Further, here, for example, about 650 MB (about 520 MB at the time of CD-R FS) can be written to the CD-R disc 211 at the maximum.

  The hard disk 212 is, for example, 4.3 GB (gigabyte) compatible with high-speed bus master IDE (Integrated Drive Electronics) transfer, and includes, for example, data compressed and encoded by the encoder board 213 and processing of the microprocessor 201. The necessary data etc. are recorded. In addition, a SCSI (Small Computer System Interface) board can be attached to the main body 31, whereby a hard disk (drive) having a SCSI interface can be added.

  The hard disk 212 stores an operating system, and further, an application program for causing the microprocessor 201 to execute image recording, reproduction, editing, decoding, and other processing.

  That is, here, a so-called “Slipclip” (slip clip) is incorporated as an application program for image recording, playback, editing, and other so-called video production.

  Here, “Slipclip” is composed of five application programs called “slip recorder”, “clip editor”, “clip viewer”, “video CD creator”, and “video CD copy tool”.

  The “slip recorder” is used when recording images and sounds, and reproducing recorded images and sounds. The “clip editor” is used when editing a recorded image (and sound accompanying it). The “clip viewer” is used when managing recorded images and sounds. The “video CD creator” is used when an edited image or the like is recorded on the CD-R disc 211 to produce a video CD. The “video CD copy tool” is used when producing a copy of the same video CD as the previously produced video CD.

  In this embodiment, in order to prevent the production of a so-called pirated board of a video CD, the production and copying of the video CD can be performed only for images that have been edited in the main body 31. ing.

  Here, in the following, among “Slip Recorder”, “Clip Editor”, “Clip Viewer”, “Video CD Creator”, and “Video CD Copy Tool” “ “Slip Recorder”, “Clip Editor”, and “Clip Viewer” will be explained.

  The hard disk 212 further records, as an application program for causing the microprocessor 201 to decode data encoded by the encoder board 213, for example, a program that performs decoding based on the MPEG1 standard. That is, here, image encoding is realized by hardware, and decoding thereof is realized by software. Note that image encoding can be realized by software, and decoding can also be realized by hardware.

  The encoder board (MPEG1 real-time encoder board) 213 encodes images and sound in real time in accordance with, for example, the MPEG1 standard. For example, encoding and transmission at a high bit rate for high-quality recording. For example, encoding in four types of recording modes such as encoding at a low bit rate can be performed. Here, as will be described later, there are four types of recording modes called “High”, “Normal”, “Long”, and “Network” in descending order of bit rate. The recording mode “Normal” conforms to the video CD standard, and when encoding is performed in this mode, recording can be performed for about 100 minutes per 1 GB.

  As described above, the encoder board 213 includes the TV tuner 213A that receives a television broadcast program, and MPEG-encodes the program received by the TV tuner 213A. The encoder board 213 is data supplied via the expansion bus, data supplied via the AV processing circuit 215 (for example, an image reproduced by the VTR 216), and an external device. The data supplied from the video camera 214 can also be encoded.

  The TV tuner 213A can set, for example, 62 channels from 1 to 62, and the audio can receive, for example, stereo and bilingual.

  In the video camera 214, for example, an image is taken and supplied to the encoder board 213. Note that the encoder board 213 has an interface with the video camera 214, so that an image and sound captured by the video camera 214 can be input to the encoder board 213.

  The AV processing circuit 215 includes, for example, a VGA (Video Graphics Array), a three-dimensional accelerator (none of which is shown), and performs processing necessary for graphics and other displays on the display 51. Further, the AV processing circuit 215 performs processing necessary for audio output to the speakers 59 and 60. Also, the AV processing circuit 215 has a built-in NTSC encoder 215A. For example, when outputting an image to the VTR 216, the NTSC encoder 215A outputs the image after converting the image into one conforming to the NTSC system. .

  Furthermore, the AV processing circuit 215 is connected to the encoder board 213 via, for example, an AMC bus. The encoder board 213 temporarily stores an MPEG-encoded image in a frame memory 110 (FIG. 6), which will be described later. When instructed to monitor an MPEG-encoded image, the frame memory 110 The image stored in is supplied from the encoder board 213 to the AV processing circuit 215 via the AMC bus, whereby the display 51 displays the image.

  The AV processing circuit 215 performs drawing on a VRAM (Video RAM (Random Access Memory)) 203 and outputs the drawing contents to the display 51 to display an image.

  The VTR 216 records images and sounds output from the AV processing circuit 215 as necessary.

  Next, FIG. 6 shows a configuration example of the encoder board 213 of FIG. In FIG. 6, only blocks related to MPEG encoding are shown, and other blocks, that is, blocks constituting the TV tuner 213, for example, are omitted. Further, FIG. 6 shows only blocks related to MPEG encoding of images, and illustration of blocks related to MPEG encoding of audio is omitted.

  One frame of digital image data composed of a predetermined number of pixels is supplied to the input terminal 101 at a rate of, for example, about 30 frames per second.

  The image data supplied to the input terminal 101 is stored in a frame memory 110 capable of storing a plurality of images (for example, 27 frames) for temporarily storing the image data and switching them in a predetermined order. Are transferred to the block divider 111 and the motion detector 120. The block divider 111 divides the frame of the image data supplied from the frame memory 110 into, for example, blocks of 8 × 8 pixel luminance components and chroma components Cb and Cr. Here, a total of six blocks including four luminance component blocks and one corresponding chroma component Cb, Cr block constitute a macro block (MB).

  Image data is supplied from the block divider 111 to the differentiator 112 in units of macroblocks. The differentiator 112 takes a difference between image data from the block divider 111 and inter-frame prediction image data described later, and uses the difference value as data of a frame on which inter-frame prediction encoding described later is performed. 113 to the switched terminal b. Further, the image data output from the block divider 111 is supplied to the switched terminal a of the changeover switch 113 as data of a frame to be subjected to intra-frame encoding described later.

  The change-over switch 113 selects either the terminal a or b, and the image data supplied to the terminal selected thereby is supplied to a DCT (Discrete Cosine Transform) circuit 14 in units of blocks. The DCT circuit 114 performs DCT processing on the image data input thereto, and outputs the resulting DCT coefficient to the quantizer 115. The quantizer 115 quantizes the DCT coefficient from the DCT circuit 114 at a predetermined quantization step, and outputs the resulting quantized coefficient to the zigzag scan circuit 116.

  The zigzag scan circuit 116 performs, for example, zigzag scan on the block-unit quantization coefficients, and outputs them to the VLC (variable length coding) circuit 117 in that order. The VLC circuit 117 performs VLC processing on the quantization coefficient from the zigzag scan circuit 116 and supplies variable length encoded data obtained as a result to the output buffer 118. The output buffer 118 has a storage capacity of 160 KB, for example, temporarily stores the variable-length encoded data from the VLC circuit 117, smooths the output data amount, and outputs it from the output terminal 102. . Data output from the output terminal 102 is supplied to the hard disk 212 and recorded, for example.

  Further, the output buffer 118 outputs the data accumulation amount to the quantization step controller 119. The quantization step controller 119 sets a quantization step based on the data accumulation amount from the output buffer 118 so that the output buffer 118 does not overflow and underflow, and outputs the quantization step to the quantizer 115. In the quantizer 115 described above, quantization is performed according to the quantization step supplied from the quantization step controller 119 in this way.

  On the other hand, the quantization coefficient output from the quantizer 115 is supplied not only to the zigzag scan circuit 116 but also to the inverse quantizer 126. The inverse quantizer 126 dequantizes the quantization coefficient from the quantizer 115 to obtain a DCT coefficient and outputs the DCT coefficient to the inverse DCT circuit 125. The inverse DCT circuit 125 performs inverse DCT processing on the DCT coefficient, and supplies the resultant data to the adder 124. Furthermore, the adder 124 is also supplied with inter-frame prediction image data output from the motion compensator 121 via a change-over switch 123 that is turned on when processing a frame of inter-frame prediction encoding. . The adder 124 adds these data and supplies the data to the frame memory 122 for storage.

  Then, the motion compensator 121 performs motion compensation on the data stored in the frame memory 122 in accordance with the motion vector supplied from the motion detector 120, and the inter-frame prediction image data obtained as a result is switched to the difference unit 112 and the switching unit. Supply to switch 123.

  Here, the frames constituting the encoding target image (moving image) are arranged in the display order, and from the head, I0, B1, B2, P3, B4, B5, P6, B7, B8, I9, B10, B11, It describes as B12, .... The above I, P, and B indicate that the frame is an I picture, a P picture, and a B picture, and the numbers following I, P, and B indicate the display order.

  In MPEG, an image I0 is first encoded. Next, the image P3 is encoded, but the image P3 itself is not encoded, but the difference between the images P3 and I0 is encoded. Further, next, the image B1 is encoded, but the image B1 itself is not encoded, but the image B1 and one of the images I0 and P3, or the average value of both are calculated. The difference is encoded. In this case, of the average values of the images I0, P3, or both, the one that minimizes the so-called prediction residual (the one that minimizes the amount of data obtained by encoding) is selected and the difference from the image B1 Are encoded.

  After the image B1 is encoded, the image B2 is encoded, but the image B2 itself is not encoded, and the image B2 and either the image I0 or the image P3, or both The difference from the average value is encoded. Also in this case, the average of the images I0 and P3, or both of them is selected which minimizes the prediction residual, and the difference between the image B2 and the image B2 is encoded.

  Thereafter, the image P6 is encoded, but the image P6 itself is not encoded, but the difference between the images P6 and P3 is encoded. Thereafter, encoding is performed in the same procedure.

Here, the correspondence relationship between the image to be encoded and the image to be a partner that takes the difference at that time is shown below in the order of encoding.
Coding order Image to be encoded Image to be the partner of difference (1) I0 −
(2) P3 I0 or P3
(3) B1 I0 or P3
(4) B2 I0 or P3
(5) P6 P3
(6) B4 P3 or P6
(7) B5 P3 or P6
(8) P9 P6
(9) B7 P6 or P9
(10) B8 P6 or P9
(11) I9 −
(12) P12 I9
(13) B10 I9 or P12
(14) B11 I9 or P12
・
・
・

  As described above, the encoding order is I0, P3, B1, B2, P6, B4, B5, P9, B7, B8, I9, P12, B10, B11,. Become. The encoded data is output in this order.

  As described above, the difference between the P picture and the B picture is usually encoded with another image. However, encoding the image itself is more preferable than encoding the difference. When the amount of data decreases, the image itself is encoded.

  In the encoder board 213 of FIG. 6, encoding is performed as described above.

  Therefore, at the time of encoding the first image I0, the image data is read from the frame memory 110 and supplied to the block divider 111 to be blocked. As a result of the block division by the block divider 111, the image data is divided into the four luminance blocks described above and the Cb and Cr blocks, which are sequentially output. At the time of encoding an I picture, the changeover switch 113 selects the switched terminal a, so that the image data output from the block divider 111 is supplied to the DCT circuit 114 via the changeover switch 113. The The DCT circuit 114 performs two-dimensional vertical and horizontal DCT processing on the block unit image data supplied thereto, thereby converting the image data on the time axis into DCT coefficients as data on the frequency axis. Is done.

  This DCT coefficient is supplied to the quantizer 115, where it is quantized according to the quantization step from the quantization step controller 119 to obtain a quantized coefficient. The quantized coefficients are zigzag scanned by the zigzag scan circuit 116 and output in that order.

  The quantization coefficient output from the zigzag scan circuit 116 is supplied to the VLC circuit 117, where variable length encoding processing such as so-called Huffman coding is performed. The variable length encoded data obtained as a result is temporarily stored in the output buffer 118 and then output at a constant bit rate. Therefore, the output buffer 118 serves as a buffer memory so that irregularly generated data can be output at a constant bit rate.

  As described above, the image I0 that is an I picture (Intra Picture) is encoded by itself, but such encoding is called intra-frame (Intra) encoding. Note that the decoding of the intra-coded image is performed in the reverse procedure described above.

  Next, encoding of the second image P3 will be described. The second and subsequent images can also be encoded as an I picture, but this reduces the compression rate. Therefore, the second and subsequent images are encoded as follows using the fact that there is a correlation between consecutive images.

  That is, the motion detector 120 detects, for each macroblock constituting the second image P3, a portion that closely resembles the macroblock from the first image I0, and the corresponding macroblock. A vector representing a positional shift relative to the block is detected as a motion vector. Here, for a motion vector detection method, for example, ISO / ISC 11172-2 annex D.D. Since it is disclosed in 6.2 etc., the description thereof is omitted here.

  For the second image P3, the block obtained from the first image I0 by performing motion compensation according to the motion vector for each block, instead of supplying the block to the DCT circuit 114 as it is. Is calculated by the differentiator 112 and supplied to the DCT circuit 114.

  Here, if the correlation between the block obtained by motion compensation of the first image I0 according to the motion vector and the block of the second image P3 is high, the difference between them becomes small. The amount of data obtained as a result of the encoding is smaller when the difference is encoded than when the block of the eye image P3 is intra-encoded.

  The method of encoding the difference in this way is called inter-frame (Inter) encoding.

  Note that encoding the difference does not always reduce the amount of data, and depending on the complexity of the image to be encoded and the level of correlation with the previous and subsequent frames, it may be more than the inter encoding that encodes the difference. The compression rate may be higher when intra coding is performed. In such a case, intra coding is performed. Whether to perform intra coding or inter coding can be set for each macroblock.

  By the way, in order to perform inter-coding, it is necessary to obtain a decoded image obtained by decoding previously encoded data.

  Therefore, the encoder board 213 is provided with a so-called local decoder. That is, the motion compensator 121, the frame memory 122, the changeover switch 123, the adder 124, the inverse DCT circuit 125, and the inverse quantizer 126 constitute a local decoder. Note that the image data stored in the frame memory 122 is called local decoded picture or local decoded data. On the other hand, the image data before encoding is called original picture (Original Picture) or original data (Original Data).

  At the time of encoding the first image I0, the output of the quantizer 115 is locally decoded through the inverse quantizer 126 and the inverse DCT circuit 125 (in this case, the changeover switch 123 is turned off, As a result, the adder 124 does not substantially perform processing) and is stored in the frame memory 122.

  Note that the image stored in the frame memory 122 is not the original picture, but is the same as the image obtained on the decoder side, which is encoded and further locally decoded. Therefore, the image in the frame memory 122 is slightly deteriorated in image quality as compared with the original picture by the encoding and decoding processes.

  The second image P3 is stored in the frame memory 122 as a result of local decoding of the first image I0. The second image P3 is sent from the frame memory 110 via the block divider 111 to the differentiator 112 in units of blocks. Supplied. By this time, the motion detector 120 needs to finish detecting the motion vector of the image P3.

  On the other hand, the motion detector 120 supplies the motion compensator 121 with the motion vector detected in units of macroblocks for the second image P3. The motion compensator 121 performs motion compensation (MC (Motion Compensation)) on the image I0 that has already been locally decoded and stored in the frame memory 122 in accordance with the motion vector from the motion detector 120, and the motion compensation obtained as a result. Data (MC data) (one macroblock) is supplied to the differentiator 112 as inter-frame prediction image data.

  In the differentiator 112, the difference between corresponding pixels between the original data of the image P3 supplied via the block divider 111 and the inter-frame prediction image data supplied from the motion compensator 121 is calculated. Then, the difference value obtained as a result is supplied to the DCT circuit 114 via the changeover switch 113 and is encoded in the same manner as in the case of the I picture. Accordingly, in this case, the changeover switch 113 selects the switched terminal b.

  As described above, the image P3 which is a P picture (Predicted Picture) is basically obtained by motion compensation of the reference image using the I picture or P picture encoded immediately before as the reference image. The difference from the predicted image is encoded.

  That is, for the P picture, for the macro block (inter macro block) in which the amount of data becomes smaller when inter coding is performed, the switched terminal b is selected by the changeover switch 113 and the inter coding is performed. In addition, for a macroblock (intra macroblock) whose data amount is smaller when intra-encoding is performed, the switched terminal a is selected by the change-over switch 113 and intra-encoding is performed.

  Of the macro blocks of the P picture, the intra-coded one is locally decoded in the same manner as the I picture and stored in the frame memory 122. In addition, the inter-coded data is added via the inverse quantizer 126 and the inverse DCT circuit 125 and the inter-frame prediction image data supplied via the changeover switch 123 turned on is an adder 124. Is locally decoded and stored in the frame memory 122.

  Next, encoding of the third image B1 will be described.

  At the time of encoding the image B1, which is a B picture, the motion detector 120 uses two images for an I picture or P picture displayed immediately before the image B1 and an I picture or P picture displayed immediately after that. A motion vector is detected. Accordingly, here, motion vectors for the images I0 and P3 of the image B1 are detected. Here, the motion vector for the image I0, which is the I picture displayed immediately before the image B1, is a forward vector (Forward Vector), and the motion vector for the image P3, which is the P picture displayed immediately thereafter, is a backward vector (Backward). Bector).

  Regarding the image B1, (1) a difference from inter-frame prediction image data obtained by performing motion compensation on a locally decoded image I0 according to a forward vector, and (2) a locally decoded image P3 as a backward vector Therefore, the difference from the inter-frame prediction image data obtained by motion compensation, (3) the difference from the average value of the two inter-frame prediction image data obtained in (1) and (2) above, and (4) the image B1 Of these four, the one with the smallest data amount is selected and encoded.

  When any data of (1) to (3) is encoded (when inter encoding is performed), a necessary motion vector is supplied from the motion detector 120 to the motion compensator 121, Data obtained by performing motion compensation according to the motion vector is supplied to the differentiator 112. Then, the difference unit 112 obtains the difference between the original data of the image B 1 and the data from the motion compensator 121, and this is supplied to the DCT circuit 114 via the changeover switch 113. Therefore, in this case, the changeover switch 113 selects the switched terminal b. On the other hand, when the data of (4) is encoded (when intra encoding is performed), the data, that is, the original data of the image B1 is supplied to the DCT circuit 114 via the changeover switch 113. . Accordingly, in this case, the changeover switch 113 selects the switched terminal a.

  As for the image B1, which is a B picture, since the images I0 and P3 that have been encoded and locally decoded are stored in the frame memory at the time of encoding, the encoding as described above is possible.

  For the fourth image B2, a process is performed in which B1 is replaced with B2 in the description when the image B1 is encoded.

  For the fifth image P6, the processing in which P3 is replaced with P6 and I0 is replaced with P3 in the description when the image P3 is encoded is performed.

  Since the sixth and subsequent images are repeated as described above, description thereof is omitted.

  By the way, in the encoder board 213, the picture of each screen is set to any picture type (Picture Type) of I picture, P picture, or B picture, and the macro block type ( As described above, whether to encode with Macro Block Type) is selected based on the amount of data generated as a result of the encoding. However, the amount of data depends on the image to be encoded. If you don't try, you won't know the exact value.

  However, the bit rate of the bit stream obtained by performing MPEG encoding needs to be basically constant. As a method for this, for example, the quantization step (quantization scale) in the quantizer 115 is controlled. There is a way to do it. That is, if the quantization step is increased, coarse quantization is performed, and the data amount (generated code amount) can be reduced. Further, if the quantization step is reduced, fine quantization is performed, and the generated code amount can be increased.

  Specifically, the quantization step is controlled as follows, for example.

  That is, in the encoder board 213, an output buffer 118 is provided at its output stage, and by temporarily storing the encoded data here, a change in the amount of generated code is absorbed to some extent, and its output bit The bit rate of the stream can be made constant.

  However, if the generation of encoded data (variable length encoded data) at a rate exceeding the predetermined bit rate continues, the amount of data stored in the output buffer 118 increases and overflows. Conversely, if the generation of encoded data continues at a rate that is lower than the predetermined bit rate, the amount of data stored in the output buffer 118 will decrease and underflow will occur.

  Therefore, as described above, the data accumulation amount (code amount) of the output buffer 118 is fed back to the quantization step controller 119, and the quantization step controller 119 determines the output buffer 118 based on the data accumulation amount. The quantization step is controlled so that neither overflow nor underflow occurs.

  That is, the quantization step controller 119 increases the quantization step when the data storage amount of the output buffer 118 is close to its capacity and is likely to overflow, thereby reducing the generated code amount. Also, the quantization step controller 119 reduces the quantization step when the data accumulation amount of the output buffer 118 is close to 0 and is likely to underflow, thereby increasing the generated code amount.

  By the way, the generated code amount also changes depending on whether the image is intra-frame encoded or inter-frame encoded.

  In general, when intra-frame coding is performed, a large amount of generated code is generated. Therefore, when the amount of data stored in the output buffer 118 is large, it is necessary to set a considerably large quantization step. However, in this case, the output buffer 118 may overflow even if the maximum quantization step is set. In addition, when quantization is performed in a large quantization step, basically, the image quality of the decoded image deteriorates, and thus the image quality of the image encoded / decoded using the decoded image as a reference image also deteriorates. It will be. Therefore, when performing intra-frame coding, it is necessary to secure a sufficient free space in the output buffer 118 in order to prevent overflow of the output buffer 118 and to prevent deterioration of the image quality of the decoded image. There is.

  Therefore, the quantization step controller 119 recognizes in advance the order in which intraframe coding and interframe coding are performed based on the signal from the compression method selection circuit 132, and when intraframe coding is performed, the output buffer The quantization step is also controlled so that a sufficient free area is secured in 118.

  By the way, from the viewpoint of the image quality of the decoded image, it is necessary to quantize a complex image with a small quantization step and a flat image with a large quantization step, but only buffer feedback. This is not considered in the quantization step set based on the above. If the quantization step is not an appropriate value from the viewpoint of image complexity, an unreasonably large amount of bits is allocated to the image to be encoded, or a small amount of bits is allocated. Will be. If an illegal bit allocation is performed on a certain image in this manner, it affects the bit allocation amount for another image, which is not preferable.

  Therefore, the quantization step controller 119 sets the quantization step in accordance with not only the feedback of the data accumulation amount from the buffer 118 (buffer feedback) but also the complexity of the image to be encoded. Has been made.

  That is, in the encoder board 213, the picture evaluation circuit 130 reads out the picture to be encoded stored in the frame memory 110, calculates the evaluation value representing the complexity thereof, and calculates the scene change detection circuit 131, the compression method. This is supplied to the selection circuit 132 and the quantization step controller 119.

  The quantization step controller 119 supplies the quantization step actually used for encoding the image, the data amount obtained by performing the quantization in the quantization step (generated code amount), and the image evaluation circuit 130. The relationship between the evaluation values corresponding to the complexity of the image is learned, and based on the learning result, a basic quantization step that is a basis for setting the next quantization step is obtained.

  That is, the quantization step actually used for encoding the image, the data amount obtained by performing the quantization in the quantization step (generated code amount), and the evaluation value corresponding to the complexity of the image Learning is performed by using the regression analysis and graphing the regression analysis result. From the graph, an evaluation value for the complexity of the image to be encoded next is used as an argument to predict a basic quantization step that is most suitable for encoding the image.

  Then, the quantization step controller 119 changes this basic quantization step according to the buffer feedback, and sets the value as the quantization step.

  The basic quantization step can be accurately predicted by learning, and the value takes into account the complexity of the image, so the quantization step is obtained from such a basic quantization step. Thus, it is possible to improve the image quality of the decoded image as compared with the case where the quantization step is controlled based only on the buffer feedback.

  The scene change detection circuit 131 detects whether or not a scene change has occurred based on the evaluation value from the image evaluation circuit 130, and supplies the detection result to the compression method selection circuit 132. The compression method selection circuit 132 selects an image compression method using the evaluation value from the image evaluation circuit 130 and, if necessary, the output of the scene change detection circuit 131. That is, in the compression method selection circuit 132, for example, an image is encoded as any picture type of I picture, P picture, or B picture, the number of pictures constituting the GOP, and the macroblock is encoded as an intra-frame code. A compression method is selected for a macroblock type or the like regarding whether to perform encoding or interframe encoding.

  When a compression method is selected, the compression method selection circuit 132 controls the change-over switches 113 and 123 based on whether the macroblock is subjected to intraframe encoding or interframe encoding. That is, as described above, when performing intra-frame coding, the changeover switch 113 is switched to the switched terminal a, and the changeover switch 123 is turned off. When interframe coding is performed, the changeover switch 113 is switched to the switched terminal b, and the changeover switch 123 is turned on.

  Further, the compression method selection circuit 132 notifies the quantization step controller 119 whether to perform intraframe encoding or interframe encoding. Based on this notification, the quantization step controller 119 recognizes the order in which intraframe coding and interframe coding are performed as described above.

  Here, when the compression method selection circuit 132 selects to encode an image as a P picture or a B picture continuously for a long time, the P picture and the B picture are basically inter-frame codes. Therefore, if an image with a low correlation between frames is generated due to a scene change or the like, the amount of generated code increases, and the image quality of the decoded image deteriorates.

  Therefore, as described above, the scene change detection circuit 131 is supplied with the scene change detection result to the compression method selection circuit 132, and the compression method selection circuit 132 indicates that the scene change has occurred. When received, the picture after the scene change is forcibly selected to be an I picture.

  As described above, for a method of obtaining a basic quantization step by learning and setting the quantization step from the basic quantization step, see, for example, Japanese Patent Application Laid-Open No. 8-102951 filed earlier by the present applicant. The details are disclosed.

  Next, in the image evaluation circuit 130, the following two parameters representing the complexity of the image are calculated by referring to the frame memory 110 as evaluation values for evaluating the image to be encoded. Has been made.

  That is, as the first parameter, the generated code amount when the image is intra-frame encoded (the generated code amount when the image is encoded as an I picture) can be predicted (estimated), and the image itself An evaluation value representing the amount of information is calculated. Specifically, as the first parameter, for example, the sum total of DCT coefficients obtained by performing DCT processing on an image for each block, and other statistics can be used. Further, for example, for each block, an absolute value sum of values obtained by subtracting the average value of the pixel values from each pixel value (hereinafter referred to as an average absolute value sum as appropriate) is obtained, and the total sum of the average absolute value sums of the blocks It is also possible to use the first parameter as the first parameter. Note that obtaining the sum of absolute values in this way can relatively reduce the circuit scale of the image evaluation circuit 130 and reduce the load, compared to obtaining the sum of the DCT coefficients.

  Here, the image evaluation circuit 130 obtains, for example, the sum of the average absolute value sum as the first parameter as follows.

That is, for example, for a certain block S that constitutes an image to be encoded, the pixel value of the pixel at the i-th position in the right direction and the j-th position in the lower direction from the upper left corner of the block is represented by S _{i. , j} , an average absolute value sum MAD (Mean Absolute Difference) for each block is obtained according to the following equation (here, for example, all luminance blocks and chrominance blocks are obtained, for example: It is also possible to obtain only the luminance block).

・・・（１）
但し、式（１）において、Ｓ_AVEは、ブロックＳの画素値の平均値を表す。

... (1)
However, in the formula (1), S _AVE represents an average value of the pixel values of the block S.

  Then, according to the following equation, the sum of average absolute values SMAD is obtained as the first parameter.

SMAD = ΣMAD
... (2)
However, in Formula (2), Σ represents the summation for all the blocks constituting the image.

  Note that the image evaluation circuit 130 also obtains the sum of the average absolute value sum MAD expressed by the equation (1) in units of macroblocks. This is, for example, whether each macroblock, which is performed in the compression method selection circuit 132, is intra-frame encoded or inter-frame encoded (forward prediction encoding, backward prediction encoding, or bidirectional prediction encoding). Used to determine

  The second parameter represents the information amount of the difference between the image capable of predicting the generated code amount when the image is inter-frame encoded and the reference image used when inter-frame encoding is performed. An evaluation value is calculated. Specifically, as the second parameter, for example, an absolute value sum of differences between an image and a predicted image (obtained by motion compensation of a reference image) (hereinafter, referred to as difference absolute value sum as appropriate). Can be obtained in units of blocks, and the sum of absolute difference sums of each block can be used.

  Here, the sum of absolute differences is obtained when the motion detector 120 detects a motion vector. Therefore, the image evaluation circuit 130 obtains, for example, the sum of absolute difference sums as the second parameter using the motion detection result by the motion detector 120.

That is, for example, regarding a reference image, consider a block composed of 8 × 8 pixels in the horizontal and vertical directions, and the pixel at the i-th position in the right direction and the j-th position in the lower direction from the upper left of the block. Is expressed as R _{i, j} . Further, regarding the image to be encoded, the x-axis or y-axis is considered from the top left to the right or the bottom, respectively, and the block having the point (x, y) as the top left pixel is i from the top left to the right. The pixel value of the pixel at the j-th position in the downward direction is represented as S _{x + i, y + j} .

  In this case, in the motion detector 120, d (x, y) represented by the following equation is obtained by changing each of x and y by one.

・・・（３）

... (3)

  Then, in the motion detector 120, (x, y) that minimizes d (x, y) in Equation (3) is detected as a motion vector, and further, the minimum d (x, y) is the difference absolute value. Calculated as sum AD.

  The image evaluation circuit 130 uses the absolute difference value AD for each block obtained by the motion detector 120 as described above, and obtains the sum of absolute differences SAD as the second parameter according to the following equation. .

SAD = ΣAD
... (4)
However, also in Formula (4), Σ represents the summation for all the blocks constituting the image.

  Note that the image evaluation circuit 130 also obtains the total sum of the absolute difference value AD expressed by Expression (3) in units of macroblocks. This is, for example, whether each macroblock, which is performed in the compression method selection circuit 132, is intra-frame encoded or inter-frame encoded (forward prediction encoding, backward prediction encoding, or bidirectional prediction encoding). Used to determine

  The first parameter SMAD and the second parameter SAD obtained by the image evaluation circuit 130 are supplied to the scene change detection circuit 131, the compression method selection circuit 132, and the quantization step controller 119.

  As described above, the scene change detection circuit 131 detects whether or not a scene change has occurred based on the output of the image evaluation circuit 130, and the compression method selection circuit 132 further determines the evaluation value from the image evaluation circuit 130, If necessary, an image compression method is selected using the output of the scene change detection circuit 131. Further, the quantization step controller 119 sets the quantization step as described above.

  The scene change detection circuit 131 obtains, for example, a ratio between the second parameters SAD for consecutive images, and detects whether there is a scene change based on the magnitude of the ratio.

  Further, the scene change detection circuit 131 generates index data to be described later. This index data is supplied to the microprocessor 201 and used to generate an index file described later.

  Further, in the compression method selection circuit 132, for example, for the P picture and the B picture, the total sum in macroblock units of the average absolute value sum MAD and the difference absolute value sum AD supplied from the image evaluation circuit 130 is compared. Based on the magnitude relation, it is determined whether the macroblock is to be intra-frame encoded or inter-frame encoded. That is, for the macroblock, the sum of the average absolute value sum MAD is smaller than the sum of the difference absolute value sum AD. Therefore, if it is expected that the amount of generated codes will be smaller when intra-frame coding is performed, Intra coding is selected. In addition, when the sum of the average absolute value sum MAD is larger than the sum of the difference absolute value sums AD, and it is expected that the amount of generated code is reduced by performing inter-frame coding, the inter-frame coding is performed. It is chosen to do.

  In FIG. 6, the controller 133 monitors the data amount of the data stored in the output buffer 118, and controls the encoding process in the encoder board 213 corresponding to the data amount. . This will be described later.

  Next, “Slipclip” recorded on the hard disk 212 as an application program for video production will be described.

  When the power button 34 of the main body 31 is operated to turn on the power, the operating system recorded on the hard disk 212, that is, the Windows (registered trademark) 95 here is started as described above. After starting Windows (registered trademark) 95, clicking the [Start] button on the task bar displays the [Start] menu.

  In the present embodiment, for example, [VAIO] is one item of the [Start] menu, and a predetermined application including “Slipclip” is registered therein.

  As described above, “Slipclip” consists of “Slip Recorder”, “Clip Editor”, “Clip Viewer”, “Video CD Creator”, and “Video CD Copy Tool”, and [Slipclip] in [VAIO] The five application programs are registered. Therefore, when the item [Slipclip] is clicked by operating the mouse 22, for example, five items of [Slip Recorder], [Clip Editor], [Clip Viewer], [Video CD Creator], and [Video CD Copy Tool] are displayed. The item is displayed.

  When the user clicks on any item in accordance with the work purpose, an application program corresponding to the item is activated.

  For example, when a material used for production of a video CD is shot by the video camera 214 and captured (recorded), or when a television broadcast program is recorded by the VTR 216 or the like, it is simply recorded. In such cases, “slip recorder” is activated. In this case, for example, a slip recorder main window 301 as shown in FIG. 7 is displayed.

  The slip recorder main window 301 includes various displays and buttons.

  That is, the recording state is displayed on the recording indicator 302. Specifically, in a state where a recording reservation is made and waiting for the start of recording, the display of the recording indicator 302 is, for example, “TIMER”. Further, in the state where the reserved recording is being performed, the display of the recording indicator 302 is, for example, “TEMER REC”. Further, when recording is started by operating the recording button 309, the display of the recording indicator 302 is, for example, “REC”. When the pause button 310 or the stop button 308 is operated and the recording is paused or stopped, the display of the recording indicator 302 is, for example, “PAUSE” or “STOP”, respectively.

  The scene change indicator 303 has a flag shape, and is displayed only when a scene change of a recorded image is detected. That is, the scene change indicator 303 is not normally displayed, and is displayed only for a predetermined time when a scene change is detected, thereby notifying the user of the scene change.

  In the current time display 304, the current time is displayed in a so-called 24-hour system. Here, for example, the time managed by [Date and time] in the control panel of Windows (registered trademark) 95 is displayed as it is.

  The recording time display 305 displays the elapsed time from the start of recording or the remaining time until the end of recording (or the remaining time until the end of the tape described later). Which time is displayed can be switched by operating a recording time display change button (TIME button) 311. When recording is not performed, the recording time display 305 is “00:00:00”, for example.

  The timer standby indicator 306 displays a status regarding reserved recording. That is, in a state where a recording reservation is made and waiting for the start of the reserved recording, the fact that the reserved recording is waited and the start time of the reserved recording are displayed. Specifically, for example, when the reservation recording from time 14:55 is on standby, as shown in FIG. 7, “ON” indicating that the reservation recording is on standby and the start time “14:55” Is displayed. In addition, when the reserved recording is being performed, the fact and the end time are displayed. Specifically, for example, when a scheduled recording that ends at time 21:43 is being performed, “OFF” to that effect and an end time “21:43” are displayed.

  When recording other than scheduled recording (hereinafter referred to as normal recording as appropriate) is performed, the same display as when scheduled recording is performed is performed even when the end time is set.

  During normal recording in which no end time is set, the display of the timer standby indicator 306 is, for example, “-:-”.

  Further, in cases other than those described above, nothing is displayed on the timer standby indicator 306.

  In the endless recording display 307A, a display corresponding to the type of tape described later is made. In other words, when the tape type is “endless”, the endless recording display 307A is “E” as shown in FIG. When the tape type is “normal”, nothing is displayed on the endless recording display 307A.

  In the input source display 307B, an input selected as a recording target is displayed. That is, when the input from the AV terminal unit 84 on the back surface of the main body 31 or the input from the AV terminal unit 43 on the front surface is selected, the input source display 307B becomes “Video 1” or “Video 2”, respectively. When the output of the TV tuner 213A is selected, the input source display 307B becomes “TV-O”. Note that the channel selected by the TV tuner 213A is displayed in the circled portion. In FIG. 7, the input source display 307B is “TV-1”, and accordingly, a program broadcast on one channel is selected as a recording target.

  A stop button 308, a recording button 309, or a pause button 310 is operated when recording is stopped, when recording is started, or when recording is paused. When the pause button 310 is operated (clicked) to stop the recording, the recording can be resumed by operating the pause button 310 again.

  The recording time display change button 311 is operated when the recording time display 305 is changed as described above. Each time the recording time display change button 311 is operated, the elapsed time and the remaining time are alternately displayed in the recording time display 305.

  An input switching button (INPUT button) 312 is operated when switching an input to be recorded. That is, every time the input switching button 312 is operated, the input from the AV terminal 84 on the back of the main body 31, the input from the AV terminal 43 on the front, and the output of the TV tuner 213A are cyclic. Selected. In accordance with the operation of the input switching button 312, the input source display 307B is also changed.

  The up / down button 313 changes the channel from the currently selected channel to the next channel or the previous channel displayed on the channel button 314 when the output of the TV tuner 213A is selected as an input. Is operated when. The channel button 314 is operated when selecting the channel when the output of the TV tuner 213A is selected as an input. The number (channel) display of the channel button 314 can be set to an arbitrary channel in the range of 1 to 62 in the item [Channel setting] in the [Option] menu of the slip recorder main window 301. It is made like that.

  In the state in which the slip recorder main window 301 configured as described above is displayed, for example, the input switching button 312 is operated (further, the up / down button 312 or the channel button 314 is operated as necessary) By selecting the input and operating the recording button 309, the recording of the image (and the sound accompanying it) as the selected input is started. It is necessary to set the tape used for recording.

  That is, when recording is instructed by operating the recording button 309 or the like, an image to be recorded is encoded by the encoder board 213 and converted into encoded data, which is then recorded on the hard disk 212. However, if recording is simply performed on the hard disk 212, recording may not be possible due to insufficient free space on the hard disk 212.

  By the way, for example, when recording on a video tape by a VTR or the like, the recording can be freely performed from the beginning to the end of the video tape. This can be considered that the recording capacity corresponding to the video tape is secured in advance.

  Therefore, even with “Slipclip”, the recording capacity necessary for normal recording (minimum recording capacity for preventing the recording from ending in the middle when the hard disk 212 runs out of space) (hereinafter, referred to as “Slipclip”) A recording area (hereinafter referred to as “required capacity” as appropriate) is secured in the hard disk 212, and encoded data or the like is recorded in the required area.

  That is, in the present embodiment, when recording an image, a file having a size necessary for recording an MPEG system stream obtained as a result of MPEG encoding by the encoder board 213 (hereinafter referred to as an MPEG file as appropriate), as will be described later. A file having a size necessary for recording an index or the like (hereinafter, referred to as an index file as appropriate) is generated and recorded on the hard disk 212, whereby encoded data (MPEG system stream) is recorded. ) And the like are reserved in the hard disk 212 in advance.

  That is, an MPEG file and an index file that are larger than the necessary capacity are written in the free area of the hard disk 212.

  Here, the contents of the MPEG file and the index file immediately after being written to the hard disk 212 have no particular meaning. Therefore, when recording with a VTR, it corresponds to preparing a new video tape. In "slip recorder", it is called a tape.

  This tape setting can be performed, for example, in a tape setting dialog box 321 as shown in FIG.

  That is, as one of items in the [Edit] menu displayed at the top of the slip recorder main window 301 (FIG. 7), there is [Standard tape setting]. By clicking there, a tape setting dialog box 321 is displayed. Is displayed.

  In the tape setting dialog box 321, a name to be given to the tape is input in the name column 322. In the embodiment of FIG. 8, “Tape” is input. Here, the names entered in the name column 322 are the file names of the MPEG files and index files that make up the tape. Note that, for example, MPG or SCX is used as the extension of the MPEG file or the index file. Therefore, for example, “Tape” is input as the name of the tape in the name column 322. In this case, the file name of the MPEG file or index file constituting the tape is basically Tape.MPG or Tape.SCX, respectively.

  The write prohibition check box 323 is checked when writing to the tape is prohibited. In the type column 324, the type of tape is set.

  Here, in the “slip recorder”, two types of tape, “normal” (normal tape) and “endless” (endless tape), are prepared.

  When the normal tape is selected, an MPEG file and an index file are created as the minimum tape necessary for recording for the recording time set in the recording time column 325 described later. That is, for example, when 1 hour is set as the recording time in the recording time column 325, a tape capable of recording for 1 hour is created as shown in FIG.

  On the other hand, when an endless tape is selected, a fixed recording time, for example, a tape capable of recording for 15 minutes (hereinafter, referred to as a fixed tape as appropriate) has a total recording time of the recording time column 325. It will be created as long as the recording time set in. That is, here, a tape capable of recording for 15 minutes has a recording time set in the recording time column 325 (in the present embodiment, for example, set in units of 15 minutes as described later), 15 A number obtained by adding 1 to the quotient divided by the minutes is created. Specifically, for example, when 1 hour is set as the recording time in the recording time column 325, five fixed tapes are created as shown in FIG. A tape capable of recording for 15 minutes is created).

  Here, the normal tape is composed of one MPEG file and an index file, but the endless tape may be composed of a plurality of MPEG files and index files as described above. For this reason, the MPEG file and the index file constituting the endless tape are given a file name in which a symbol # and a serial number are added to the name of the tape.

  In other words, in the case shown in FIG. 9B, five MPEG files and index files are created, and the file names are Tape # 1.MPG and Tape # from the top tape. 1.SCX, Tape # 2.MPG and Tape # 2.SCX, Tape # 3.MPG and Tape # 3.SCX, Tape # 4.MPG and Tape # 4.SCX, Tape # 5.MPG and Tape # 5. SCX.

  Recording on a normal tape starts from the beginning and ends when it reaches the end. Note that if an instruction to stop recording is given before reaching the end, recording is ended at that point. In this case, the portion where the MPEG file and the index file are not recorded is discarded (released as a free area).

  On the other hand, recording on the endless tape starts from the beginning of the first fixed tape among the plurality of fixed tapes. When the end of the first fixed tape is reached, the recording on the first fixed tape is finished, and the recording on the second fixed tape is started. In the same manner, the third, fourth,..., Recording on the last fixed tape is sequentially performed, and when the end of the last fixed tape is reached, recording on the first fixed tape is again performed (overwriting). Is done.

  That is, in the case shown in FIG. 9B, when the recording on all the first to fifth fixed tapes is completed, the recording on the first fixed tape is started again until the end of the recording is commanded. Such a cyclic recording is continued in an endless manner (for example, until the stop button 308 is operated).

  When the end of recording is instructed, the recording is ended at that time. In this case, in “Slipclip”, a range that is traced back by the recording time set in the recording time column 325 from the point of time when the recording ends is set as a reproducible range.

  That is, for example, in FIG. 9B, when the end of recording is instructed when 10 minutes of recording is performed on the fifth fixed tape, as shown in FIG. The reproducible range is one hour from the tenth position of the first (first) fixed tape to the tenth position of the fifth fixed tape.

  In this case, the range from the beginning of the first fixed tape to the position of 10 minutes and the range of the fifth fixed tape from the position of 10 minutes to the end are not reproducible ranges. From the viewpoint of efficient use of 212, both should be discarded, but here, only the range from the 10-minute position to the end of the fifth fixed tape is discarded, and the beginning of the first fixed tape. The range from 10 to 10 minutes is not discarded. This is due to the following reason.

  That is, information necessary for decoding MPEG encoded data, such as a system header, is arranged at the beginning of the MPEG file that constitutes the fixed tape. This is because it becomes difficult.

  Accordingly, the range from the beginning of the first fixed tape to the position of 10 minutes can be reproduced by directly accessing the MPEG file constituting the fixed tape.

  As described above, the endless tape is not composed of a plurality of fixed tapes, but is composed of one tape as in the case of the normal tape. A method is conceivable in which, after starting recording and reaching the end, recording (overwriting) from the beginning is repeated again. However, as described above, since a system header or the like is written at the beginning of the MPEG file, if it is overwritten, decoding becomes difficult. Therefore, the endless tape is preferably composed of a plurality of fixed tapes.

  Returning to FIG. 8, a recording time (recording time) for recording is input in the recording time column 325. Here, for example, a maximum of 12 hours can be set in units of 15 minutes. Note that the recording time is input separately for hours and minutes.

  The automatic index check box 326 is checked when an index as a mark indicating the position of a scene change of an image is automatically added during recording. When the automatic index check box 326 is not checked, a scene change pointer and a scene change parameter, which will be described later, are not recorded in the index file.

  In the recording mode column 327, a recording mode (bit rate information) is set. Here, four recording modes of “High”, “Normal”, “Long”, and “Network” are prepared in descending order of bit rate.

  Here, FIG. 10 shows the frame size (number of horizontal pixels × vertical number of pixels), the bit rate of the system stream obtained as a result of MPEG encoding (system bit rate), and the result of MPEG encoding of the image for each recording mode. The bit rate (video rate), frame rate, audio MPEG encoding result bit rate (audio bit rate), settable recording mode, and time available for recording on a 1 GB tape are shown.

  In the recording mode “High”, the recording time for the tape having the same recording capacity is the shortest, but a high-quality decoded image can be obtained. In the recording mode “Normal”, as described above, a system stream compliant with the video CD (VCD) standard can be obtained. The recording mode “Long” is suitable for, for example, a case where a high-quality decoded image is not required but recording is performed for a relatively long time. The recording mode “Network” has a bit rate that can be transmitted in real time by, for example, ISDN (Integrated Services Digital Network), and is suitable for such transmission.

  Note that in the recording mode “Long”, the number of pixels constituting one frame is about 1/4 compared to the recording modes “High” and “Normal”, and in the recording mode “Network”, the number of pixels is further reduced. ing. In the recording modes “High”, “Normal”, and “Long”, the number of frames per second (frame rate) is 30 frames. In the recording mode “Network”, the number of frames is 1/3, which is 10 frames. It has become.

  Returning to FIG. 8 again, the recording mode is set in the recording mode column 328. Here, three recording modes of two channels (dual), stereo, and monaural (single) are prepared.

  As shown in FIG. 10, here, when “High” or “Long” is set as the recording mode, the recording mode can be selected from either two channels or stereo. It is said that. When “Normal” is set as the recording mode, the recording mode is fixed to 2 channels. Further, when “Network” is set as the recording mode, the recording mode is fixed to monaural.

  The clip creation folder automatic check box 329 is checked when a folder for creating a clip is set in advance. Here, the clip is composed of a set of MPEG files and index files. That is, a set of an MPEG file and an index file is called a tape in the “slip recorder” and a clip in the “clip editor” and the “clip viewer”. When the tape is a normal tape, the clip and the tape are synonymous. However, when the tape is an endless tape, the tape may correspond to a plurality of clips (a plurality of sets of MPEG files and index files).

  The clip creation folder reference button 330 is operated when a folder for creating a clip is designated.

  The information column 331 displays the size of the decoded image, the frame rate, the video bit rate, the audio bit rate, and the like when encoding is performed according to the recording mode set in the recording mode column 327. That is, the size shown in FIG. 10 is displayed corresponding to the recording mode.

  Furthermore, the information column 331 encodes the recording mode set in the recording mode column 327, and the resulting MPEG system stream is recorded only for the recording time set in the recording time column 325. The size (recording capacity) (disk area) of the tape secured in the hard disk 212 is also displayed.

  Here, the size of the tape is calculated as follows, for example.

  That is, the system bit rate of the recording mode set in the recording mode column 327 is multiplied by the recording time set in the recording time column 325, thereby obtaining the size of the MPEG file. Further, for example, 0.1% of the size of the MPEG file is set as the size of the index file. The sum of the MPEG file size and the index file size is the tape size.

  The system bit rate in each recording mode basically uses the value shown in FIG. 10, but the recording mode “Normal” is based on the system bit rate (1,411,200 bps) shown in FIG. A smaller value is also used. That is, the system bit rate of the recording mode “Normal” in FIG. 10 represents a value when the MPEG system stream is recorded on the video CD. This is based on the video CD standard in the pack constituting the MPEG system stream. The bit rate of the bit stream to which a specified sync or header is added (the bit rate specified in the video CD standard). When an MPEG system stream is recorded on the hard disk 212, such a sync or header is unnecessary, and from the viewpoint of effective use of the hard disk 212, such unnecessary data is not recorded on the hard disk 21 here. I am doing so.

  Therefore, for the recording mode “Normal”, the size of the tape is calculated using 1,394,400 bps, which is the bit rate of the MPEG system stream composed only of packs.

  Specifically, for example, in the embodiment of FIG. 8, “Normal” is set as the recording mode, and “1 hour” is set as the recording time. Here, if the type of tape is “normal”, an increase of 0.1% of the value obtained by multiplying the bit rate of 1,394,400 bps by the recording time of 1 hour is the tape size. Become. However, in FIG. 8, “endless” is set as the tape type. As described above, the recording time for the endless tape is 15 minutes longer than the recording time set in the recording time column 325. Therefore, the tape size is increased by 0.1% of the value obtained by multiplying the bit rate of 1,394,400 bps by the recording time of 1 hour 15 minutes, that is, 748.76 MB. In FIG. 8, this value is displayed in the information column 331.

  The OK button 332 is operated when the setting items in the tape setting dialog box 321 are confirmed to be newly input and the tape setting dialog box 321 is closed. The cancel button 333 is operated when the setting items in the tape setting dialog box 321 are held in the previously determined state and the tape setting dialog box 321 is closed. The help button 334 is operated to display an explanation (help) about the tape setting dialog box 321.

  Next, recording processing by the “slip recorder” will be described with reference to the flowcharts of FIGS. 11 and 12.

  When recording, the user first opens the tape setting dialog box 321 (FIG. 8) and sets the tape as described above.

  For example, when recording a television broadcast program, the input switching button 312 of the slip recorder main window 301 (FIG. 7) is operated, and the output of the TV tuner 213A (FIG. 5) is selected as an input. Further, the channel of the program to be recorded is selected by operating the up / down button 313 or the channel button 314.

  Further, for example, when recording (dubbing) an image (and accompanying sound) recorded by the video camera 214, the video output terminal and the audio output terminal (not shown) of the video camera 214 are connected to the back of the main body 31. The AV terminal portion 84 or the front AV terminal portion 43 is connected. Then, the input switching button 312 is operated to select an input from the AV terminal 84 or 43 as an input.

  After the above work, when the user operates the recording button 309 of the slip recorder main window 301, the microprocessor 1 performs recording processing according to the flowchart of FIG. 11 or FIG.

  That is, when a normal tape is set as the tape used for recording, first, as shown in the flowchart of FIG. 11, it is first determined in step S1 whether or not a tape can be created.

  Here, simply by setting a tape in the tape setting dialog box 321, a tape, that is, a recording area necessary for recording, is not secured on the hard disk 212. That is, the tape is secured after the recording button 309 is operated and the start of recording is instructed. This is because it is not preferable to secure a tape before recording starts from the viewpoint of efficient use of the hard disk 212.

  The determination process in step S1 is performed by checking whether the size of the tape is calculated as described above and a recording area of that size can be secured in the hard disk 212.

  If it is determined in step S1 that a tape cannot be created, that is, if the hard disk 212 does not have enough free space to secure the set tape, for example, this is displayed and the recording process is terminated. Therefore, in this case, recording is not performed.

  If it is determined in step S1 that the tape can be created, that is, if the MPEG file and the index file constituting the set tape can be written to the hard disk 212, the process proceeds to step S2. The MPEG file and the index file are written to the hard disk 212. As described above, no particularly meaningful information is written in the MPEG file and the index file at this time.

  Thereafter, the process proceeds to step S3, where an MPEG file as a tape is opened, and the process proceeds to step S4. In step S4, the encoder board 213 is controlled so as to encode the input selected by operating the input switching button 312. Thus, the encoder board 213 performs MPEG encoding of the recording target.

  In step S5, the MPEG system stream obtained as a result of the MPEG encoding is transferred to the hard disk 212 and written in the MPEG file secured in step S2. Thereafter, the process proceeds to step S6, in which it is determined whether the MPEG system stream has been written to the end of the MPEG file or the end of recording has been instructed by operating the stop button 308. If it is determined in step S6 that the MPEG system stream has not been written to the end of the MPEG file, and it is determined that the stop button 308 has not been operated, the process returns to step S4 to encode and record the recording target. Continued.

  On the other hand, if it is determined in step S6 that the MPEG system stream has been written to the end of the MPEG file, or if it is determined that the end of recording has been instructed by operating the stop button 308, step S7 is performed. Then, the MPEG file is closed and the recording process is terminated.

  Next, when the tape used for recording is an endless tape, a recording process according to the flowchart of FIG. 12 is performed.

  That is, in step S11 or S12, processing similar to that in step S1 or S2 in FIG. 11 is performed. In step S12, as described above, an endless tape composed of a plurality of fixed tapes (FIG. 9B) is created.

  After step S12, the process proceeds to step S13, where the MPEG file on the first fixed tape (first fixed tape) constituting the endless tape is opened, and the process proceeds to step S14. In step S14, the encoder board 213 is controlled to encode the input selected by operating the input switching button 312, and the encoder board 213 performs MPEG encoding of the recording target.

  In step S15, the MPEG system stream obtained as a result of the MPEG encoding is transferred to the hard disk 212 and written in the MPEG file. Thereafter, the process proceeds to step S16, and it is determined whether or not the end of the recording is instructed by operating the stop button 308, for example. If it is determined in step S16 that the end of recording has not been instructed, the process proceeds to step S17 to determine whether or not the MPEG system stream has been written to the end of the MPEG file constituting the fixed tape. If it is determined in step S17 that the MPEG system has not been written to the end of the MPEG file constituting the fixed tape, the process returns to step S14 to continue encoding and recording of the recording target.

  If it is determined in step S17 that the MPEG system stream has been written to the end of the MPEG file constituting the fixed tape, the process proceeds to step S18, the MPEG file is closed, and the process proceeds to step S19. In step S19, the MPEG file constituting the next fixed tape is opened, and the process proceeds to step S14. Therefore, after this, the MPEG system stream is written to the MPEG file constituting the next fixed tape.

  If the MPEG system stream has been written to the end of the MPEG file constituting the last fixed tape, in step S19, the MPEG file constituting the first fixed tape is opened again, and the MPEG system stream is opened there. The stream is overwritten. Therefore, the MPEG system stream is written endlessly until it is determined in step S16 that the end of recording has been instructed.

  For example, when the stop button 308 is operated, it is determined in step S16 that the end of recording has been instructed. In this case, the process proceeds to step S20, the opened MPEG file is closed, and the recording process is terminated.

  Next, at the time of recording, as described above, the MPEG system stream is recorded in the MPEG file constituting the tape. At the same time, predetermined data is also recorded in the index file constituting the tape. .

  The flowchart in FIG. 13 shows an index recording process for recording data in an index file.

  When recording is started, first, in step S30, the index file is opened and the recording start time (current time when recording is started) (hereinafter referred to as the start time as appropriate), recording mode ( The header in which the tape setting dialog box 321 (set in the tape setting dialog box 321 (FIG. 8)) is arranged is recorded, and the process proceeds to step S31. In step S31, the microprocessor 201 determines whether index data has been transmitted from the scene change detection circuit 131 (FIG. 6) of the encoder board 213. If it is determined that the index data has not been transmitted, steps S32 to S38 are performed. Is skipped and the process proceeds to step S39.

  If it is determined in step S31 that index data has been transmitted from the scene change detection circuit 131 (FIG. 6), the microprocessor 201 receives the index data, and proceeds to step S32.

  Here, FIG. 14 shows an example of the format of the index data output from the scene change detection circuit 131.

  As shown in the figure, in the index data, a 4-bit area in which various flags are arranged and a 28-bit area in which the second parameter SAD described in Expression (4) is arranged are sequentially arranged. It consists of a total of 32 bits. As the flag, for example, a flag indicating the picture type of the frame for which the second parameter SAD is calculated (hereinafter referred to as a picture type flag as appropriate), or the presence or absence of a scene change detection in the scene change detection circuit 131 is indicated. Things (hereinafter referred to as scene change flags as appropriate) are arranged.

  Returning to FIG. 13, in step S32, the microprocessor 201 determines whether or not the index data received from the scene change detection circuit 131 is for an I picture or a P picture. This determination is performed with reference to, for example, a picture type flag arranged in the index data.

  If it is determined in step S32 that the index data is not for an I picture or a P picture, that is, for a B picture, steps S33 to S38 are skipped, Proceed to S39. If it is determined in step S32 that the index data is for an I picture or a P picture, the process proceeds to step S33 to determine whether a scene change has been detected in the I picture or P picture. Whether or not the microprocessor 201 determines. This determination is made with reference to a scene change flag arranged in the index data, for example.

  If it is determined in step S33 that no scene change has been detected, steps S34 to S37 are skipped and the process proceeds to step S38. If it is determined in step S33 that a scene change has been detected, the process advances to step S34, and the microprocessor 201 calculates a scene change parameter. That is, the microprocessor 201 divides the SAD arranged in the index data received this time by the previous SAD stored in step S38, which will be described later, and uses the division result as a scene change parameter.

  Here, the scene change parameter represents the degree of scene change (the degree to which the screen is switched), and the larger the degree, the larger the value. The scene change parameters are not limited to those described above, and other physical quantities representing the degree of scene change can be adopted.

  After the calculation of the scene change parameter, the process proceeds to step S35, and the microprocessor 201 determines whether or not the scene change parameter is larger than a predetermined threshold ε (for example, 3). If it is determined in step S35 that the scene change parameter is not greater than the predetermined threshold ε, steps S36 and S37 are skipped and the process proceeds to step S38.

  If it is determined in step S35 that the scene change parameter is larger than the predetermined threshold ε, the process proceeds to step S36, and the encoded data of the frame in which the scene change parameter indicates the degree of scene change is written in the MPEG file. A scene change pointer as position information regarding the determined position is obtained and associated with the scene change parameter. Further, an identification flag to be described later is added to these and written in the index file.

  As the scene change pointer, for example, a byte position indicating the byte number where the encoded data is written from the head of the MPEG file can be adopted.

  Here, hereinafter, an appropriate combination of the scene change parameter and the scene change pointer with an identification flag is referred to as an index. The index serves as a mark indicating the position of the scene change in the image.

  As described above, the index attached (written to the index file) by the microprocessor 201 at the time of recording is called an automatic index. The index can also be attached by the user performing a predetermined operation, and the index attached by the user is called a manual index. The identification flag described above is, for example, a 1-bit flag indicating whether the index is an automatic index or a manual index.

  After step S36, the process proceeds to step S37, where the scene change indicator 303 of the slip recorder main window 301 (FIG. 7) is displayed for a predetermined time, thereby notifying the user that a scene change has been detected. The In step S38, the SAD arranged in the index data received this time is stored in the main memory 202 in place of the previously stored SAD, and the flow advances to step S39. In step S39, it is determined whether or not the recording of the MPEG system stream to the MPEG file has been completed. If it is determined that the recording has not ended, the process returns to step S31, and the same processing is repeated thereafter.

  If it is determined in step S39 that the recording of the MPEG system stream to the MPEG file has been completed, the index file is closed and the index recording process is terminated.

  Here, in the embodiment of FIG. 13, when the scene change flag indicates that a scene change has been detected by the scene change detection circuit 131, the index is changed only when the scene change parameter is larger than a predetermined threshold value ε. However, it is also possible to record the index regardless of the size of the scene change parameter. However, in this case, an index is added to a frame that does not change so much, and as a result, the number of indexes increases.

  Next, it is convenient if an arbitrary scene of an already recorded image can be reproduced while an image (and sound accompanying it) is being recorded. That is, for example, if you are looking away while recording and you miss a certain scene, it is convenient if you can play back to that scene.

  Therefore, in the “slip recorder”, as described above, while recording an image (and accompanying sound), that is, without interrupting the recording, an arbitrary scene of the already recorded image can be reproduced. It is made to be able to. Here, such reproduction is hereinafter referred to as slip reproduction as appropriate.

  When performing the slip reproduction, the user selects the item “slip” from the “reproduction” menu at the top of the slip recorder main window 301 of FIG. In this case, for example, a playback window 341 as shown in FIG. 15 is displayed.

  In the reproduction window 341, the reproduced image is displayed in the image display field 342. The playback indicator 343 displays the current playback state. That is, for example, “PLAY” during playback, “PAUSE” during pause, “STOP” during stop, “SLOW” during slow playback, “F.SKIP” during forward skip, While skipping in the reverse direction, “R.SKIP” is displayed on the playback indicator 343, respectively.

  In the playback time display 344, as shown in FIG. 16, the elapsed time from the recording start time (start time) to the position subject to slip playback (hereinafter referred to as a playback point as appropriate), playback The remaining time from the point to the recording target position (hereinafter referred to as the recording point as appropriate) (however, for a recorded tape, the time until the end of the tape), or the image at the playback point (encoding) Time information of one of the times when the (data) is recorded (hereinafter referred to as recording time as appropriate) is displayed. Which time information is displayed can be selected by operating a reproduction time display change button 353.

  Here, when slip playback is performed, the relative position relationship between the playback point and the recording point (distance between the playback point and the recording point) unless the playback point is moved by operating a slider 354 described later. Does not change. Accordingly, when the remaining time is selected as time information in the playback time display 344 during slip playback, the remaining time is displayed (approximately constant) (time corresponding to the distance between the playback point and the recording point). .

  Note that the playback window 341 is not only used when slip playback is instructed, but also when monitoring input selected by operating the input switching button 312 of the slip recorder main window 301 or when recording is performed. It is also opened when instructed to play a finished tape. When the playback window 341 is opened for monitoring, the playback time display 344 becomes “-:-:-”. In addition, when the playback window 341 is opened for playback of a tape for which recording has been completed, when the remaining time is selected as time information to be displayed on the playback time display 344, the time from the playback point to the end of the tape is selected. Is displayed.

  The voice mode display 345 displays the current voice mode. There are three types of audio modes, for example, stereo audio output, output from left and right speakers only for the L channel, and output from both left and right speakers only for the R channel, and by operating the audio switching button 357, It has been made so that you can choose. When stereo sound output, L channel only output, and R channel only output are selected, for example, “STEREO”, “L ONLY”, and “R ONLY” are respectively displayed as the audio mode display 345. Is displayed.

  The stop button 346, the playback button 347, or the pause button 348 is operated when the playback is stopped, when the playback is started, or when the playback is paused. The skip button 349 or 350 is operated when performing a backward skip or a forward skip, respectively. The index button 351 or 352 is operated when skipping from the playback point to the closest frame in the reverse or forward direction from the frames to which the index is attached.

  The reproduction time display change button 353 is operated when selecting time information to be displayed on the reproduction time display 344. Each time the playback time display change button 353 is operated, the display of the playback time display 344 changes, for example, as elapsed time → remaining time → recording time → elapsed time →. .

  The slider 354 is operated when changing the playback point. That is, the slider 354 can be moved, for example, by dragging with the mouse 22, and the playback point is changed corresponding to the position of the slider 354. The slider 354 can be moved from the left end to the right end of the slider groove 354A. The left end of the slider groove 354A corresponds to the recording start position (the beginning of the MPEG file), and the right end corresponds to the recording point. Accordingly, by operating the slider 354, the user can reproduce an arbitrary screen from when recording is started until immediately before the screen on which recording is currently performed.

  However, in the encoder board 213, as described above, the image before encoding is temporarily stored in the frame memory 110, and the encoding result is temporarily stored in the output buffer 118. Furthermore, a certain amount of time is required to write the MPEG encoding and the encoding result. For this reason, in reality, the target of slip reproduction is the screen that is back about 10 to 15 seconds from the screen that is currently being recorded.

  The slider 354 moves when operated by the user, and also moves corresponding to playback points that change sequentially as playback is performed. The slider 354 is also moved when the playback point is changed by operating the skip buttons 349 and 350, the index buttons 351 and 352, and the like.

  When the slider 354 is moved and the playback point is changed, the time information in the playback time display 344 is also changed in accordance with the change.

  The frame advance button 355 is operated when the frame is advanced (when the next frame is displayed in the image display field 342) when the playback is paused by operating the pause button 348. The The slow playback button 356 is operated when performing slow playback. The voice switching button 357 is operated when switching the voice mode. Each time the audio switching button 357 is operated, the audio mode changes, for example, as follows: stereo audio output → L channel only output → R channel only output → stereo audio output →. It has become.

  Next, the slip reproduction process by the “slip recorder” will be described with reference to the flowchart of FIG.

  When the slip reproduction is instructed (commanded) and the reproduction window 341 is opened, in step S40, the microprocessor 201 reads the MPEG system stream from the head of the MPEG file that constitutes the tape that is currently written. In step S41, the microprocessor 201 executes an application program (MPEG1 software decoder 201A (FIG. 18), which will be described later) recorded in the hard disk 212 for performing MPEG decoding, thereby reading the MPEG system read in step S40. The decoding result is output in step S42, that is, the image of the decoding result is displayed in the image display field 342 of the playback window 341, and the sound of the decoding result is Are output from the speakers 59 and 60.

  In step S43, time information corresponding to the position of the MPEG system stream read in step S40 is displayed in the playback time display 344 of the playback window 341. Here, as the time information, information selected by operating the reproduction time display change button 353 among the above three types is displayed. Further, the time information is obtained in the microprocessor 201 as follows.

  That is, as described above, since the MPEG system stream has a fixed rate, the elapsed time corresponding to the position of the MPEG system stream read in step S40 is the recording position of the MPEG system stream (what is from the beginning of the MPEG file)? It can be determined by whether it is recorded in the byte). The remaining time can be obtained from the number of bytes from the position of the MPEG system stream read in step S40 to the position of the MPEG system stream currently recorded. Furthermore, since the recording start time is recorded at the head of the index file constituting the tape as described above, the recording time can be obtained by adding the elapsed time to the start time.

  The time information at each position of the MPEG system stream recorded in the MPEG file can be obtained as described above. For example, the recording time at each position can be recorded and obtained from the recording time. It is.

  After the process of step S43, the process proceeds to step S44, for example, whether the playback point has been changed by moving the slider 354, operating the skip buttons 349, 350, the index buttons 351, 352, or the like. Is determined by the microprocessor 201. If it is determined in step S44 that the playback point has not been changed, the process returns to step S40, the continuation of the previously read MPEG system stream is read from the MPEG file, and the same processing is repeated thereafter.

  If it is determined in step S44 that the playback point has been changed, the process proceeds to step S45, where the position for reading the MPEG system stream from the MPEG file is changed in accordance with the change of the playback point, and the process returns to step S40. In this case, in step S40, the MPEG system stream is read from the changed position, and the same processing is repeated thereafter.

  Note that the slip regeneration process ends when, for example, the regeneration window 341 is closed or the stop button 346 is operated.

  As described above, when recording, while continuing the recording, the image (and accompanying sound) already recorded on the hard disk 212 can be reproduced from an arbitrary position. You can watch the scene you want at any time without interrupting the recording.

  Furthermore, since the time information is displayed in the playback time display 344 of the playback window 341, it is possible to find a desired scene relatively quickly by looking at the time information.

  In the case of performing slip reproduction, in the hard disk 212, data writing and reading are performed in a time-sharing manner. The scheduling for writing and reading data is performed under the control of Windows (registered trademark) 95, which is an OS (operating system), for example, and “Slipclip”, which is an application program, Not involved. However, this scheduling can also be performed in the application program “Slipclip”.

  In other words, the read / write time of data on a hard disk currently in practical use is sufficiently fast, and slip playback is basically performed by simply reading / writing data to / from the hard disk under OS input / output (I / O) control. Recording can be performed without interruption.

  Further, as shown in FIG. 15, the image reproduced by the slip reproduction can be displayed not only in the image display field 342 in the reproduction window 341 but also in a so-called full screen display. That is, the image display field 342 can be enlarged and displayed on the entire screen of the display 51.

  Next, the process of the “slip recorder” will be further described with reference to FIG.

  In the recording process by the “slip recorder”, an MPEG system stream obtained by MPEG-encoding an image (and an accompanying sound) on the encoder board 213 is converted into an MPEG file that constitutes a tape created in advance on the hard disk 212. To be recorded. Further, a scene change parameter is calculated from the index data output from the encoder board 213, and is recorded together with a scene change pointer and an identification flag in an index file constituting a tape created in advance on the hard disk 212.

  Here, as shown in FIG. 18, a header (H) in which a start time, which is a time when recording starts, a recording mode, etc., is recorded at the head of the index file.

  Further, as described above, the identification flag, the scene change pointer, and the scene change parameter indicate that the scene change flag included in the index data indicates that a scene change has been detected, and as shown in FIG. This is recorded when the scene change parameter is larger than a predetermined threshold value ε. As shown in FIG. 18, the scene change pointer recorded in the index file represents the position where the encoded data of the frame having the scene change is recorded.

  On the other hand, in the slip reproduction process by the “slip recorder”, the MPEG system stream is already recorded in the MPEG file in the MPEG1 software decoder 201A realized by the microprocessor 201 executing the application program for performing MPEG decoding. Data is read out and decoded from an arbitrary position within the range (the filled area in FIG. 18).

  Here, at the time of recording, the MPEG file is configured to be opened in a so-called shared state that allows access from a plurality of application programs, whereby the encoder board 213 outputs the MPEG file. Both the writing of the MPEG system stream and the reading of the MPEG system stream to the decoder 201A can be performed.

  When the tape is an endless tape, as described above, since the endless tape is composed of a plurality of fixed tapes, the MPEG system stream output from the encoder board 213 is written into the MPEG system stream instructed to perform the slip reproduction. In some cases, it is recorded on a fixed tape different from the fixed tape (MPEG file). In this case, the MPEG file in which the MPEG system stream instructed for the slip reproduction is recorded is opened and read separately from the MPEG file in which the MPEG system stream output from the encoder board 213 is written (after the reading is completed). Is closed).

  As described above, in this embodiment, the MPEG system stream is recorded separately in the MPEG file, and the index (identification flag, scene change pointer, and scene change parameter) is separately recorded in the index file. The content of the MPEG file conforms to the MPEG standard, and therefore can be used in other applications.

  The MPEG system stream and the index can be recorded in one file. However, in this case, it is difficult to use the file in another application.

  If the automatic index check box 326 is not checked in the tape setting dialog box 321 of FIG. 8, as described above, the index is not recorded in the index file. That is, in this case, the index file is composed only of the header.

  Here, the fact that the above-described image recording and reproduction can be performed in parallel will be described. Here, it is assumed that “Normal” is set as the recording mode, and in order to simplify the explanation, the calculation of the data amount is performed not for the MPEG system stream but for the video elementary stream. Shall.

  In the recording mode “Normal”, one frame image is composed of 352 pixels × 240 pixels as shown in FIG. Now, each pixel is composed of, for example, an 8-bit luminance signal Y and a total of 12 bits of 2-bit color difference signals Cb and Cr in terms of one pixel, and 1 GOP is composed of 15 frames, for example. Then, the data amount of 1 GOP (data amount before encoding) is 1856 KB from the following equation.

      352 pixels × 240 pixels × 12 bits × 15 frames / 8 bits = 1856 KB

  Further, when the recording mode is “Normal”, as shown in FIG. 10, the bit rate (video rate) of the video elementary stream in the encoder board 213 is 1,151,929 bps, and the frame rate is Since it is 30 frames / second, image data of 1 GOP (here, 15 frames as described above) is compressed to a data amount represented by the following equation.

      1,151,929 / 30 frames x 15 frames / 8 bits = 70.3KB

  Therefore, in this case, the image data is compressed to 1 / 26.4 (= 70.3 KB / 1856 KB).

  By the way, when the present inventor measured the transfer rate of a certain HDD, it was about 4 MB / second. In this case, the compressed data of 1 GOP of 70.3 KB described above is written in about 17.2 ms (= 70.3 / (4 × 1024)).

  Therefore, even if 20 ms, which is a considerably slow time as the head seek time of the HDD, is considered, writing of 1 GOP compressed data can be performed in about 37.2 ms (= 17.2 ms + 20 ms).

  On the other hand, the transfer rate when reading data from the HDD is generally faster than when writing data, but here it is the same as when writing, and the head seek time is 20 ms as in the above case. The reading of 1 GOP compressed data from the HDD can be performed in about 37.2 ms.

  Here, 1 GOP is composed of 15 frames, and thus corresponds to about 0.5 seconds. Since writing and reading of compressed data of 1 GOP can be performed in about 74.4 ms (= 37.2 ms + 37.2 ms), image recording and recording can be performed during a period of 1 GOP (about 0.5 seconds). Playback can be performed in parallel.

  When the recording mode is “Long”, the data amount of 1 GOP (before compression) is 394 KB, and becomes 22.9 KB by encoding. That is, it is compressed to about 1 / 17.2. In this case, assuming that the HDD specifications are the same as those described above, the time required to write and read 22.9 KB of compressed data is about 25.6 ms, which is again a period of 1 GOP (about 0.5 G Recording and playback of images can be performed in parallel.

  By the way, since Windows (registered trademark) 95 is an OS having a multitask function, there is a case where other processing is performed while waiting for writing of the MPEG system stream to the hard disk 212. Therefore, if the user performs an operation requesting another process during the slip reproduction, the requested process may be performed even if the writing to the hard disk 212 is set to the highest priority. For this reason, it is preferable not to perform an operation that performs such other processing during slip reproduction, but it is difficult to ensure that all users do so.

  On the other hand, when waiting for writing of the MPEG system stream to the hard disk 212 occurs and the writing is not in time, the MPEG system stream breaks down. In this case, since the decoding becomes difficult, it is absolutely necessary to avoid the failure of the MPEG system stream.

  Therefore, when it becomes difficult to write the MPEG system stream to the hard disk 212, the encoder board 213 stops the encoding, and this control is performed by the controller 133 (FIG. 6). Has been made to be done by.

  That is, as described above, the controller 133 monitors the data amount of the output buffer 118. As shown in the flowchart of FIG. 20, first, in step S51, whether or not the data amount is larger than 100 KB, for example. Determine. If it is determined in step S51 that the data amount of the output buffer 118 is not larger than 100 KB, the process proceeds to step S52, and the controller 133 performs MPEG encoding on each block constituting the encoder board 213 as usual. Control and return to step S51. That is, the storage capacity of the output buffer 118 is 160 KB as described above, and encoding is continued when there is a margin (free capacity) of 60 KB or more.

  If it is determined in step S51 that the amount of data in the output buffer 118 is greater than 100 KB, the process proceeds to step S53, and the controller 133 interrupts (stops) the encoding process. That is, for example, the controller 133 prevents the image from being stored in the frame memory 110 and prevents the image from being read out therefrom. Accordingly, the writing of the MPEG system stream to the hard disk 212 is awaited (the device driver for the hard disk 212 does not request the MPEG system stream), and the data amount of the output buffer 118 exceeds 100 KB, and the margin is 60 KB. If it becomes less than the encoding, the encoding is interrupted.

  In step S54, the controller 133 determines whether the data amount in the output buffer 118 is less than 50 KB, for example. If it is determined in step S54 that the data amount in the output buffer 118 is not less than 50 KB, the process returns to step S54. If it is determined in step S54 that the data amount in the output buffer 118 has become less than 50 KB, that is, the waiting write processing to the hard disk 212 is performed, whereby the data amount in the output buffer 118 is reduced to 50 KB. When it becomes less than, it progresses to step S55 and the controller 133 restarts an encoding process, and returns to step S51. That is, for example, the controller 133 starts reading an image from the frame memory 110 and also starts storing an image there.

  As described above, since the encoding is interrupted when the writing of the MPEG system stream to the hard disk 212 is unlikely to occur in time, the failure of the MPEG system stream can be avoided.

  Since the image input to the encoder board 213 during the interruption of the encoding is not stored in the frame memory 110 as described above, the image not stored is not recorded, but the number of frames is not so much. It is not expected to be much, so it is not a big problem compared to the failure of the MPEG system stream.

  In the above case, encoding is interrupted when the margin of the output buffer 118 is less than 60 KB. This is due to the following reason. That is, MPEG encoding can be interrupted only on a frame basis. Therefore, even if the encoding is interrupted after the encoding of a certain frame is started, it cannot be interrupted until the encoding of the frame is completed. On the other hand, in MPEG encoding, the largest amount of data occurs when intra coding is performed. In general, the amount of data generated by intra coding is expected to be about 40 KB.

  From the above, even if the encoding is to be interrupted, about 40 KB of data may be input to the output buffer 118. Therefore, at least the data can be stored as the free capacity of the output buffer 118. It is necessary to secure free space.

  Therefore, in this embodiment, a 20 KB margin is seen in the 40 KB, and the encoding is interrupted when the margin of the output buffer 118 is less than 60 KB.

  Next, when editing an image recorded by the “slip recorder”, the “clip editor” is activated. In this case, for example, a clip editor main window 361 as shown in FIG. 21 is displayed.

  After the clip editor main window 361 is displayed, a clip to be edited is designated.

  Here, as described above, the clip and the tape are basically synonymous, and the “clip editor” uses the clip. Therefore, a clip is composed of an MPEG file and an index file.

  When a clip is designated, a source window 362 is displayed in the clip editor main window 361, and an index screen for the designated clip is further displayed.

  That is, the microprocessor 201 reads the encoded data of the frame recorded at the position pointed to by the scene change pointer recorded in the index file constituting the designated clip in the MPEG file constituting the designated clip. The MPEG1 software decoder 201A (FIG. 18) decodes the data. Then, the microprocessor 201 displays the decoded frame (a reduced screen thereof) on the source window 362 as an index screen.

  Here, on the index screen, a name for identifying the index screen is displayed at the top thereof. In the embodiment of FIG. 21, for example, Auto0, Index1, Auto2, Auto3, etc. are given as names of index screens.

  Here, the index screen corresponding to the automatic index has a number “Auto” with a number, and the index screen corresponding to a manual index has a number “Index” with a number. It is given as the default name.

  As described above, the automatic index is attached at the time of recording. The manual index is operated at an arbitrary position on the source window 362 (for example, by operating an index addition button 366A on the toolbar of the clip editor main window 361). However, here, it can be attached to the top of the GOP).

  In the [Index] menu of the clip editor main window 361, there is an item [Change to manual index], and by clicking there, the automatic index can be changed to a manual index. (In this case, the name of the index screen is left as it is, for example (the letters “Auto” are not “Index”)). This change is performed by changing the identification flag constituting the index.

  In the clip editor main window 361, the index screen corresponding to the automatic index and the index screen corresponding to the manual index are displayed in different colors in the display portions of the names. Can be easily distinguished.

  Furthermore, both the automatic index and the manual index can be deleted by operating a delete button 366B on the toolbar of the clip editor main window 361.

  A timeline 363 as a time axis is displayed at the bottom of the source window 362. The index screen is displayed, for example, so that the left end thereof coincides with the position of the corresponding time on the timeline 363 (recording time of the index screen with respect to the time when recording is started).

  The index screen is basically the first frame for switching scenes. Therefore, from an index screen to just before the next index screen, there is basically one scene. Therefore, the user can easily find a desired scene.

  When the user wants to check the image after the index screen is displayed, drag the mouse 22 on the timeline 363 only in the range to be checked. In this case, the dragged range is shown as R in FIG. Then, for example, when the playback button 367 on the toolbar of the clip editor main window 361 is clicked, the playback range R is played back.

  That is, in this case, for example, the reproduction window 341 shown in FIG. 15 is opened. Then, the MPEG system stream corresponding to the reproduction range R is decoded by the MPEG1 software decoder 201A and displayed in the image display field 342.

  Therefore, the user can easily confirm the scene.

  The user looks at the index screen or further confirms the scene, determines the scene to be used for editing, and clicks the edit point file creation button 368 on the toolbar of the clip editor main window 361. In this case, an output window 369 is displayed below the source window 362 in the clip editor main window 361 as shown in FIG.

  After the output window 369 is displayed, the user drags a range to be copied as a new clip scene in the source window 362. In this case, the range from the index screen immediately before the dragged range in the source window 362 to the frame immediately before the index screen immediately after the range is set as a copy target range to be copied to a new clip. On the time line 363 of the source window 362, a start point mark 364L and an end point mark 364R are displayed at positions corresponding to the start point and end point of the copy target range, respectively. Further, the background portion of the source window 362 and the portion of the timeline 363 corresponding to the copy target range are changed to other colors.

  When the cursor (not shown) of the mouse 22 is moved into the copy target range and the mouse 22 is dragged at that position, the cursor is changed from, for example, an arrow shape to a shape symbolizing the index screen. The In this state, when the cursor is moved to the output window 369 and the drag is released, the copy target range is copied to the output window 369. In the embodiment of FIG. 21, one scene having the index frame with the name “Auto0” as the first frame and one scene having the index screen with the name “Auto2” as the first frame are output. Copied to window 369.

  When the copy target range is copied to the output window 369, all the automatic indexes in the copy target range are deleted in the output window 369. Further, when an automatic index is added to the first frame of the copy target range, the automatic index is changed to a manual index.

  Here, the reason why the automatic index in the copy target range copied to the output window 369 is deleted is as follows. That is, according to the “video CD creator” described above, which is one of the application programs included in “Slipclip”, a video CD in which the scene copied to the output window 369 is recorded can be produced. In the “Video CD creator”, when producing a video CD, an index in the standard of the video CD is set at the position of the scene change pointer recorded in the index file.

  On the other hand, the automatic index is intended to make it easy for the user to find a desired scene, and basically a considerable number is recorded. Therefore, if the automatic index is not deleted, such a large number of indexes are set on the video CD.

  The reason why the automatic index of the first frame in the copy target range is changed to the manual index is as follows. That is, the first frame in the copy target range corresponds to a so-called editing point, and it is preferable to set an index at the editing point even in the video CD. However, the automatic index is deleted, so that it is not deleted by changing to the manual index.

  Therefore, in the output window 369, only the index screen corresponding to the manual index is displayed. Therefore, when it is desired to leave an index at the position of the automatic index, it is necessary to change the automatic index to a manual index as described above before copying to the output window 369. .

  Even if the copy target range is copied to the output window 369, it is possible not to delete the automatic index. Further, it is possible to prevent the automatic index of the first frame in the copy target range from being changed to the manual index.

  The user copies a desired scene to the output window 369 as described above. In addition, the scene copied to the output window 369 can be moved, deleted, rearranged, and the like, and such work is performed as necessary.

  Then, after arranging the desired scenes in the output window 369 in the desired order, when it is desired to create a new clip composed of such scenes, for example, in the clip editor main window 361 The build start button 370 on the toolbar is operated.

  In this case, in the microprocessor 201, the encoded data corresponding to each scene arranged in the output window 369 is read from the MPEG file while referring to the index file. Then, the elementary data (elementary stream) of the read encoded data is used as it is, and after necessary processing at the connection point (edit point) is performed, only system encoding is performed again. This encoding result is recorded on the hard disk 212 as a new MPEG file.

  At this time, an index file corresponding to the index screen displayed in the output window 369 (this index file is a manual index and does not include an automatic index from the above description) is also newly created, This and the newly created MPEG file are recorded on the hard disk 212 as a new clip.

  Next, as described above, an index screen corresponding to the automatic index recorded in the index file is displayed in the source window 362. For example, many index screens are displayed without much interval. In some cases, the user is prevented from searching for a scene.

  Therefore, in this embodiment, a certain condition is set for the display of the index screen corresponding to the automatic index recorded in the index file, and only the index screen that matches the condition (hereinafter referred to as display condition as appropriate) is displayed. It is made to be able to let you.

  That is, FIG. 22 shows an index display level setting dialog box 381 for setting display conditions.

  For example, in the [Display] menu of the clip editor main window 361 in FIG. 21, there is [Index display level setting] as an item. By clicking there, an index display level setting dialog box 381 is displayed. The

  The all display column 382 is selected (clicked) when setting display conditions for displaying index screens corresponding to all automatic indexes recorded in the index file. The level column 383 is selected when setting a display condition for displaying an index screen corresponding to an automatic index having a scene change parameter equal to or greater than a certain threshold. The threshold value is set to the value input in the threshold value input field 383A.

  The number display field 384 is selected when setting display conditions for displaying index screens corresponding to a predetermined number of automatic indexes in descending order of scene change parameters. The predetermined number is set to the value input in the number input field 385.

  The maximum level display field 386 is selected when setting a display condition for displaying an index screen corresponding to an automatic index having the largest scene change parameter within a certain time interval. The time interval is set to the value input in the time input field 387.

  When any one of the above display conditions is selected, the number of indexes to be displayed / total number of indexes field 388 displays the total number of automatic indexes recorded in the index file and the automatic indexes. The number of items that meet the selected display condition is displayed.

  The OK button 389 is operated when the setting items in the index display level setting dialog box 381 are confirmed to be newly input and the index display level setting dialog box 381 is closed. The cancel button 390 is operated when the setting items in the index display level setting dialog box 381 are held in the previously determined state and the index display level setting dialog box 381 is closed. The help button 391 is operated when displaying help for the index display level setting dialog box 381.

  The display of the index screen in the source window 362 shown in FIG. 21 is performed according to the display conditions set as described above.

  That is, as shown in the flowchart of FIG. 23, first, in step S61, it is determined whether or not the display column 382 for all is selected. If it is determined that the column is selected, the process proceeds to step S62. An index screen corresponding to all of the automatic indexes recorded in the file is displayed in the source window 362, and the process ends.

  If it is determined in step S61 that the all display column 382 is not selected, the process proceeds to step S63, and it is determined whether or not the level column 383 is selected. If it is determined in step S63 that the level field 383 is selected, the process proceeds to step S64, and among the automatic indexes recorded in the index file, a scene change parameter equal to or greater than the value input in the threshold value input field 383A is selected. What is possessed is retrieved and the process proceeds to step S68. In step S68, an index screen corresponding to the searched automatic index is displayed in the source window 362, and the process ends.

  If it is determined in step S63 that the level column 383 is not selected, the process advances to step S65 to determine whether the number display column 384 is selected. If it is determined in step S65 that the number display field 384 is selected, the process proceeds to step S66, and the corresponding automatic index is searched. That is, when the value input in the number input field 385 is n, in step S66, the top n number having the largest scene change parameter is searched from the automatic index recorded in the index file, and the process proceeds to step S68. In step S68, an index screen corresponding to the searched n automatic indexes is displayed in the source window 362, and the process ends.

  On the other hand, when it is determined in step S65 that the number display column 384 is not selected, that is, none of the all display column 382, the level column 383, and the number display column 384 is selected. Accordingly, when the maximum level display field 386 is selected, the process proceeds to step S67, and the automatic index having the maximum scene change parameter is set in the index file for each time interval set in the time input field 387. Retrieved from In step S68, an index screen corresponding to the automatic index searched within each time is displayed in the source window 362, and the process ends.

  As described above, since the number of index screens to be displayed can be limited in accordance with the size of the scene change parameter, the user can easily find a desired scene.

  Here, in the present embodiment, when the level column 383 is selected, the value (scene change parameter threshold value) input to the threshold value input column 383A is not required to open the index display level dialog box 381. 21 can be changed by operating the lower button 365A and the up button 365B on the toolbar of the clip editor main window 361 in FIG. That is, each time the lower button 365A is operated, the threshold value of the scene change parameter is decremented by one. Therefore, in this case, the number of index screens to be displayed increases. Further, when the up button 365B is operated, the threshold value of the scene change parameter is incremented by one. Therefore, in this case, the number of index screens to be displayed is decreased.

  Note that here, the index screens that are limited to display according to the above display conditions are limited to automatic indexes, but the display of index screens corresponding to manual indexes can be similarly limited. It is.

  Next, create a clip (tape) in the “Slip Recorder”, and create a new clip by editing the clip in the “Clip Editor”. When the number of clips increases, for example, to which clip It is difficult to determine what is recorded just by looking at the file name. Therefore, “Slipclip” provides “Clip Viewer” as an application program for managing clips.

  When “Clip Viewer” is activated, for example, a clip viewer main window 401 as shown in FIG. 24 is displayed.

  The clip list 402 displays a representative screen of clips registered in the clip collection.

  Here, the clip collection is a folder for grouping clips, and the representative screen is a certain screen constituting a clip. For example, the initial screen of the clip is set as the representative screen by default, but it can be changed.

  The name given to the clip collection is displayed on the tab 402A. Therefore, in the embodiment of FIG. 24, there are three folders as a collection of clips of “summer trip”, “ski tournament”, and “Christmas”. The clip collection can be selected by clicking the tab 402A, and the clip list 402 displays a representative screen of clips registered in the selected clip collection. In the embodiment of FIG. 24, the clip collection “summer trip” is selected, and a representative screen of three clips registered there is displayed in the clip list 402.

  In the index list 403, when a representative screen displayed in the clip list 402 is clicked and a clip is selected, an index screen of the selected clip is displayed.

  In the image display field 404, a playback image of the clip selected in the clip list 402 is displayed. In the title column 405, the title of the clip selected in the clip list 402 is displayed. That is, in the “clip viewer”, a title can be given to the clip, and the title is displayed in the title column 405.

  A stop button 406, a playback button 407, a pause button 408, skip buttons 409 and 410, index buttons 411 and 412, a slider 414, a frame advance button 415, and a slow playback button 416 are a stop button 346 in the playback window 341 in FIG. The play button 347, the pause button 348, the skip buttons 349 and 350, the index buttons 351 and 352, the slider 354, the frame advance button 355, and the slow play button 356 are respectively corresponded.

  The full screen button 413 is operated when displaying the image display field 404 in full screen. The explanatory note column 417 displays the explanatory note of the clip selected in the clip list 402. That is, in the “clip viewer”, an explanatory note can be attached to the clip, and the explanatory note is displayed in the explanatory note column 413.

  In this embodiment, the image is encoded (compressed) and recorded. However, the image recording can be applied to a case where the image is recorded as it is without being encoded. However, whether or not the slip reproduction can be performed depends on the transfer speed and head seek time of the hard disk 212 and the data amount (data rate) of the image data to be recorded.

  That is, for example, as the transfer speed or the head seek time of the hard disk 212, 4 Mbps or 20 ms is considered as described above.

  Then, if recording and playback are performed on the same image as that in the recording mode “Normal”, that is, the above-mentioned 1856 KB image with the data amount of 15 frames, the hard disk 212 is recorded. It takes about 453 ms (= 1856 [KB] / 4 × 1024 [KB / s]) to write and read 1856 KB of data to and from, respectively. If the head seek time of 20 ms is taken into consideration, it takes about 473 ms for writing or reading. Therefore, in this case, it takes about 946 ms (= 473 ms + 473 ms) to read and write the image data of 15 frames in parallel, and it is performed during the time corresponding to 15 frames, that is, about 0.5 seconds. Will not be able to.

  On the other hand, when recording and playback is performed on the same image as that in the recording mode “Long”, that is, the above-described 394 KB image with the data amount of 15 frames, the hard disk 212 is recorded. It takes about 96.2 ms (= 394 [KB] / 4 × 1024 [KB / s]) to write and read 394 KB of data to and from each other. If the head seek time of 20 ms is taken into consideration, it takes about 116.2 ms for writing or reading. Therefore, in this case, the reading / writing of the image data of 15 frames is completed in about 232.4 ms (= 116.2 ms + 116.2 ms), so during the time corresponding to 15 frames, that is, about 0.5 seconds, Reading and writing can be done in parallel.

  In this embodiment, the image is encoded in accordance with the MPEG1 standard, which is one of the fixed-rate encoding methods. However, the image encoding method conforms to the MPEG1 standard. In addition, the image can be encoded at a variable rate. However, when encoding an image at a variable rate, for example, when performing slip reproduction, it is difficult to detect the position where encoded data is recorded from the number of bytes from the recording start position. Become.

  In the present embodiment, the slip reproduction is performed on the image (and the sound accompanying it), but the slip reproduction can be performed on other data. Similarly, securing a tape can be performed for data other than images and sound.

It is a perspective view which shows the example of an external appearance structure of the personal computer to which this invention is applied. It is a perspective view which shows the example of an external appearance structure of the personal computer to which this invention is applied. 3 is a front view of a main body 31. FIG. 4 is a rear view of the main body 31. FIG. FIG. 3 is a block diagram showing an example of the electrical configuration of the personal computer of FIG. 1 (FIG. 2). 3 is a block diagram illustrating a configuration example of an MPEG1 real-time encoder board 213. FIG. It is a figure which shows the slip recorder main window. FIG. 6 is a diagram showing a tape setting dialog box 321. It is a figure for demonstrating a normal tape and an endless tape. It is a figure for demonstrating the specification of each video recording mode. It is a flowchart for demonstrating the recording process which made the normal tape object. It is a flowchart for demonstrating the video recording process for endless tape. It is a flowchart for demonstrating an index recording process. It is a figure which shows the format of index data. It is a figure which shows the reproduction | regeneration window 341. FIG. It is a figure for demonstrating elapsed time, remaining time, and recording time. It is a flowchart for demonstrating slip reproduction | regeneration processing. It is a block diagram for demonstrating the process of application program "slip recorder." It is a figure which shows the time change of a scene change parameter. 4 is a flowchart for explaining processing of a controller 133. It is a figure which shows the clip editor main window 361. FIG. It is a figure which shows the index display level setting dialog box 381. FIG. 10 is a flowchart for explaining an index screen display process for displaying an index screen in a source window 362. It is a figure which shows the clip viewer main window.

Explanation of symbols

  21 keyboard, 22 mouse, 24 microphone, 31 body, 32, 33 face, 34 power button, 35 recess, 36 lower panel, 37 upper panel, 41 FDD, 42 CD drive, 43 AV terminal part, 44 extension part, 45 guide , 51 display, 52 pedestal, 53 display section, 54 recess, 55 CRT, 56, 57 face, 58 groove, 59, 60 speaker, 61 power lamp, 63 hard disk access lamp, 64 floppy disk drive access lamp, 66 floppy disk eject Button, 68 Eject button, 69 Eject hole, 70 Access lamp, 71 Power input terminal, 72 Keyboard terminal, 73 Mouse terminal, 74 USB terminal, 75 Printer terminal, 76 Serial terminal, 77 game terminal, 78 headphone terminal, 79 line input terminal, 80 microphone terminal, 81 video output terminal, 82 S video output terminal, 83 monitor terminal, 84 AV terminal, 85 antenna terminal, 86 line jack, 87 telephone Jack, 101 input terminal, 102 output terminal, 110 frame memory, 111 block divider, 112 differentiator, 113 changeover switch, 114 DCT circuit, 115 quantizer, 116 zigzag scan circuit, 117 VLC circuit, 118 output buffer, 119 Quantization step controller, 120 motion detector, 121 motion compensator, 122 frame memory, 123 selector switch, 124 adder, 125 inverse DCT circuit, 126 Quantizer, 130 Image evaluation circuit, 131 Scene change detection circuit, 132 Compression method selection circuit, 133 Controller, 201 Microprocessor, 202 Main memory, 203 VRAM, 204 Bus bridge, 206 Modem, 207 I / O interface, 210 Auxiliary Storage interface, 211 CD-R disk, 212 hard disk, 213 MPEG1 real-time encoder board, 213A TV tuner, 214 video camera, 215 AV processing circuit, 215A NTSC encoder, 216 VTR, 301 slip recorder main window, 302 recording indicator, 303 scene Change indicator, 304 Current time display, 305 Recording time display, 30 Timer standby indicator, 307A endless recording display, 307B input source display, 308 stop button, 309 recording button, 310 pause button, 311 recording time display change button, 312 input switching button, 313 up / down button, 314 channel button, 321 tape setting Dialog box, 322 name field, 323 write protection check box, 324 type field, 325 recording time field, 326 automatic index check box, 327 recording mode field, 328 recording mode field, 329 automatic check box, 330 Button, 331 information field, 332 OK button, 333 cancel button, 334 help button, 341 playback window, 34 Image display field, 343 playback indicator, 344 playback time display, 345 audio mode display, 346 stop button, 347 playback button, 348 pause button, 349, 350 skip button, 351, 352 index button, 353 playback time display change button, 354 Slider, 354A Slider groove, 355 Frame advance button, 356 Slow playback button, 357 Audio switching button, 361 Clip editor main window, 362 Source window, 363 Timeline, 364L Start point mark, 364R End point mark, 365A Lower button, 365B Raise Button, 366A Add index button, 366B Delete button, 367 Play button, 368 Create edit point file , 369 Output window, 370 Build start button, 381 Index display level setting dialog box, 382 All display column, 383 level column, 383A Threshold input column 383A, 384 Number display column, 385 Number input column, 386 Maximum level display Field, 387 time input field, 388 number of displayed indexes / total number of indexes field, 389 OK button, 390 cancel button, 391 help button, 401 clip viewer main window, 402 clip list, 402A tab, 403 index list, 404 Image display field, 405 Title field, 406 Stop button, 407 Play button, 408 Pause button, 409, 410 Skip button, 411 12 Index button, 413 full-screen button, 414 slider, 415 frame advance button, 416 slow playback button 417 described sentence column

Claims (5)

A recording device for recording moving image data on a data recording medium,
Setting means for setting a recording time for recording the moving image data and bit rate information relating to the bit rate of the moving image data;
Calculation means for calculating a necessary capacity, which is a recording capacity necessary for recording the moving image data, based on the recording time and bit rate information set by the setting means;
In the data recording medium, the required capacity more recording regions der, and securing means for securing a necessary area and a capacity for the required capacity and index as a file,
A recording apparatus comprising: recording means for recording the moving image data and data indicating a position where a scene change has been made according to an output of a scene change detection circuit, which is the index , in the file which is the necessary area. The recording apparatus according to claim 1, wherein after the recording of the moving image data by the recording unit, the securing unit releases an unrecorded area of the necessary area. The recording apparatus according to claim 1, further comprising a presentation unit that presents the necessary area secured by the securing unit to a user. The recording apparatus according to claim 1, wherein the securing unit secures the necessary area when an instruction to start recording is given. A recording method for recording moving image data on a data recording medium,
Set a recording time for recording the moving image data and bit rate information related to the bit rate of the moving image data,
Based on the set recording time and bit rate information, calculate a necessary capacity that is a recording capacity necessary to record the moving image data,
Wherein the data recording medium, I the required capacity more recording area der to secure the necessary space and a capacity for the required capacity and index as a file,
A recording method comprising: recording the moving image data and data indicating the position where a scene change has been made according to an output of a scene change detection circuit, into the file, which is the necessary area.

Images