JP2007089213A - Recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording and reproducing device that can minimize increase in the number of seeks without reading useless data, even in a fast-forward reproduction mode. <P>SOLUTION: In a recording and reproducing device which has an HDD 7, records and reproduces a stream onto the HDD 7, a stream is recorded onto the HDD 7 in a first unit of blocks and is read from the HDD 7 in a second unit of blocks. In a fast-forward reproduction mode, the second unit of blocks is made into a unit of a single picture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording / reproducing apparatus that records and reproduces a stream using a randomly accessible recording medium such as a hard disk.

  When a television broadcast is digitized, a broadcast program can be recorded as a digital signal using a randomly accessible recording medium such as a hard disk. When a recording / reproducing apparatus using such a randomly accessible recording medium appears, it is possible to realize a function of recording a previously recorded stream at the same time as recording a video information stream such as a broadcast program.

  In general, in this type of recording / reproducing apparatus, a data processing unit (hereinafter referred to as a writing block) in which data is written to a recording medium in one seek and processing of data read in one seek. The unit (hereinafter referred to as a read block) is controlled to be equal.

  Therefore, in such a recording / reproducing apparatus, when a previously recorded stream is fast-forwarded while recording a video information stream such as a broadcast program, one block is set to a size including a plurality of pictures. In such a case, only a part of the read block is used for fast-forward playback, and there is a problem that there is data that is not used for playback even if read out. In particular, when the playback speed in fast forward playback is increased, this reduction in playback efficiency becomes significant, and either the data writing process required for recording or the data reading process required for playback may not be sufficiently performed. May occur.

On the other hand, it is considered that the size of one block is reduced so that unnecessary data is not read out as much as possible.
JP-A-8-138318 JP-A-6-62369 Japanese Patent Laid-Open No. 11-259958 JP-A-11-69279 JP 7-322213 A

  However, if the size of one block is reduced, useless data can be prevented from being read, but the number of seeks for writing as well as reading increases, and the reproduction efficiency decreases due to the increase in the number of seeks. It becomes a problem.

  Therefore, the present invention has been made in view of such problems, and provides a recording / reproducing apparatus capable of minimizing the increase in the number of seeks without reading useless data even in fast-forward reproduction. The purpose is to do.

  The recording / reproducing apparatus of the present invention includes a randomly accessible recording medium, and records and reproduces the stream on the recording medium, and writes the stream in the first block unit to the recording medium. Control means for controlling to read the stream in units of second blocks, and the control means sets the size of the second block unit in the first block when the normal playback mode is set. When the fast-forward playback mode is set, control is performed so that the unit size is the same as the unit size, and the size of the second block unit is set to one picture unit, and control is performed to read the stream from the recording medium in units of one picture. It is characterized by that.

  By adopting such a configuration, it is possible to selectively read out only necessary pictures in the fast-forward playback mode, and unnecessary data is not read out, thereby improving read efficiency.

  Further, the image processing apparatus further includes data amount detection means for detecting a data amount of a picture included in the stream, and the control means detects the data amount of the picture detected by the data detection means when the fast-forward playback mode is set. Based on the above, it is controlled to read a stream from the recording medium in units of one picture.

  In addition, the recording / reproducing apparatus of the present invention includes a randomly accessible recording medium, and in the recording / reproducing apparatus for recording and reproducing the stream on the recording medium, the data amount detection for detecting the data amount of the picture included in the stream And writing the stream in the first block unit to the recording medium, and the stream from the recording medium in one picture unit based on the data amount for each picture detected by the data amount detecting unit. Control means for controlling to read out, and the amount of data included in the first block is larger than the average value of the amount of data for each picture.

  According to the present invention, the stream is written in the first block unit on the recording medium, read out in the second block unit, and the second block unit is set as one picture unit in the fast-forward playback mode. Thus, not only the number of seeks to the recording medium can be reduced, but also only necessary pictures can be selectively read out in the fast-forward playback mode. As a result, the number of seeks is reduced, unnecessary reading of data in fast-forward playback and the like is eliminated, and writing / reading efficiency with respect to the recording medium is improved, so that it is possible to improve the processing capability of the recording / reproducing apparatus. .

  A configuration of a digital television broadcast recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

  In the present embodiment, FIG. 1 is a block diagram showing a schematic configuration of a digital TV broadcast recording / reproducing apparatus, and FIG. 2 is a flowchart for explaining write / read operations of a hard disk drive device in the digital TV broadcast recording / reproducing apparatus of FIG. FIG. 3 is an explanatory diagram for explaining the contents of data stored in the picture address management table in the digital TV broadcast recording / reproducing apparatus of FIG.

  As shown in FIG. 1, the digital TV broadcast recording / reproducing apparatus 1 in this embodiment demodulates the broadcast signal received by the antenna 1 and the antenna 2 that receive the digital broadcast signal, and demultiplexes the demodulated signal. A tuner 2 that acquires the TS (Transport Stream) and EPG (Electronic Program Guide) of the channel selected by the viewer, and an HDD (Hard Disk Drive Device) 7 that conforms to the IDE standard for recording the TS obtained by the tuner 2; , A decoding unit 9 that decodes the TS read from the HDD 7, and a display device 10 that displays video by the decoded signal decoded by the decoding unit 9.

  The digital TV broadcast recording / playback apparatus also includes a picture length detection unit 3 that detects the amount of data for each picture configured based on the TS obtained by the tuner 2, and a picture length obtained by the picture length detection unit 3. And a picture address management table 8 for storing the head sector number in the HDD 7 of each picture.

  Information for identifying the head of a picture is included in the header of the TS, and the picture length detection unit 3 refers to this identification information, so that the data amount of each picture Pn from the TS that is continuously input Dn is obtained, and the data amount Dn of the obtained picture Pn is converted into the number of sectors Sn in the HDD 7. Here, since the HDD 7 conforming to the IDE standard is used, 1 sector = 512 bytes, and the number of sectors Sn required to store the picture Pn of the data amount Dn in the HDD 7 is Sn> Dn / 512. It is calculated as the smallest integer that satisfies.

  Then, based on the number of sectors Sn of the picture Pn obtained by the picture length detection unit 3, the first sector number Zn + 1 of the picture Pn + 1 is obtained by the following formula 1, and the picture address management table 8 as shown in FIG. Stored.

  The digital TV broadcast recording / reproducing apparatus further includes an input buffer 4 for temporarily storing the TS obtained by the tuner 2 and an output buffer 5 for temporarily storing the TS read from the HDD 7.

  In addition, each part in the digital TV broadcast recording / reproducing apparatus mentioned above is controlled by CPU6.

  The input buffer 4 sequentially stores the TS obtained by the tuner 2 and transfers the stored TS to the HDD 7 in a predetermined N-byte block unit, whereby the TS is written into the HDD 7. Is called. Note that a value sufficiently larger than the average value of the number of bytes constituting one picture is used for this N-byte block.

  The output buffer 5 refers to the head sector number of each picture on the HDD 7 stored in the picture address management table 8 so as to store the TS read out in units of pictures from the HDD 7 and sequentially decode the stored TS. It supplies to the part 9.

  In the recording / reproducing apparatus having such a configuration, a TS writing / reading operation for the HDD 7 when the received program is recorded and the program recorded in the HDD 7 is reproduced will be described below.

  As shown in FIG. 3, when the viewer uses a remote controller (not shown) or the like to instruct the playback of the program recorded on the HDD 7 while recording the received program, the input buffer 4 is first sent to the HDD 7. It is determined whether there is a block to be transferred, that is, whether the TS of the received program is stored in N bytes or more (step S01).

  When TS of N bytes or more is stored in the input buffer 4, N bytes of data are immediately transferred from the input buffer 4 to the HDD 7 and a writing process is performed (step S02).

  When the process of writing N bytes of data to the HDD 7 is completed, it is determined whether a TS to be transferred to the decoding unit 9 is stored in the output buffer 5 (step S03).

  If there is a TS to be transferred to the decoding unit 9 in the output buffer 5, it is determined that it is not necessary to read data from the HDD 7, and the process returns to step S 01 to execute the writing routine for the HDD 7 in the input buffer 5. If there is no TS to be transferred to the decoding unit 9 in the output buffer 5, that is, if a TS necessary for reproduction is not read out from the HDD 7 within a period necessary for reproduction, at least the TS It is determined that the picture including the TS cannot be reproduced, and the complementing process is performed.

  In this complementary processing, when a picture that cannot be reproduced is an I picture or a P picture, reading of the picture is stopped and reading of the next picture is started with reference to the picture address management table 8. During this time, the reproduced image is complemented with the picture reproduced immediately before the next I picture is read from the HDD 7. If the picture that could not be reproduced is a B picture, reading of the picture is stopped and reading of the next picture is started with reference to the picture address management table 8. During this time, the reproduced image is complemented with the picture reproduced immediately before the next picture is read from the HDD 7 regardless of the type of picture. Thus, even when the reading process from the HDD 7 cannot catch up with the reproduction process for displaying on the display device 10, the display screen is not disturbed, and only a small amount of still reproduction is performed. It is possible to minimize degradation of the display image quality (step S04).

  On the other hand, if no TS of N bytes or more is stored in the input buffer 4 in step S01, the picture data management table 8 is referred to calculate the data amount of the picture to be read next from the HDD 7. This calculation is easily obtained by multiplying the first sector number of the next picture following the picture to be read by the first sector number of the picture to be read and the data amount of 512 bytes per sector (step S05). ).

  Next, it is determined whether the output buffer 5 has enough free space to store a picture to be read from the HDD 7 (step S06).

  If there is no free space in the output buffer 5 for storing a picture to be read from the HDD 7, the process returns to step S01 to perform a writing routine for the HDD 7 in the input buffer 5, and the output buffer 5 should be read from the HDD 7. If there is free space for storing pictures, the TS for one picture is immediately read from the HDD 7 and stored in the output buffer 5 (step S07).

  Then, the pointer of the picture address management table 8 is updated to the next picture after the read picture, and the process returns to step S01 to execute a writing routine for the HDD 7 of the input buffer 5 (step S08).

  As described above, in the present embodiment, a picture address management table is provided for writing to the HDD 7 in units of blocks of a predetermined size and for reading out in units of pictures, and for storing sector numbers of each picture on the HDD 7. Therefore, not only can the number of seeks of the HDD 7 be reduced by enlarging the block during the writing process, but also only the pictures necessary for fast-forward playback can be selectively read out. . As a result, the number of seeks is reduced, unnecessary data is not read out during fast-forward playback, etc., and writing / reading efficiency with respect to the HDD 7 is improved, so that the processing capability of the digital TV broadcast recording / playback apparatus can be improved. It becomes possible. Na

  In the present embodiment, when the writing process from the input buffer 4 to the HDD 7 is possible, the writing process is performed immediately, and when the writing process is not possible, the reading process from the HDD 7 is performed. Because of the control, the writing process to the HDD 7 is performed with priority over the reading process from the HDD 7. As a result, the writing process to the HDD 7 can be surely performed, and the reliability in the recording process can be improved.

  Further, in the present embodiment, there is no TS to be transferred to the decoding unit 9 in the output buffer 5, that is, as many TSs as necessary for reproduction are not read from the HDD 7 within a period necessary for reproduction. In this case, since the previous picture is used instead of the unread picture, the display screen of the display device 10 is not disturbed and still reproduction is performed for a very short period. . As a result, it is possible to minimize the degradation of the image quality of the display image.

  In addition, since the still reproduction control associated with the complementary processing is switched according to the picture type of the picture for which the TS 7 reading process has not been completed in time, the optimum still reproduction period is set for each picture type. Become.

  In the present embodiment, the case where a program transmitted to a digital TV broadcast is encoded according to the MPEG standard has been described, but other compression encoding methods can be supported.

  In the present embodiment, since the writing process to the HDD 7 is given priority over the reading process, the HDD 7 outputs the output buffer to the HDD 7 during a period in which TS cannot be transferred from the input buffer 4 in block units (N bytes). Although the case of controlling to read TS to 5 has been described, the present invention is not limited to this. For example, a threshold value is set in advance for the free capacity of the input buffer 4, and when the free capacity of the input buffer 4 exceeds the threshold value, control is performed so that reading processing from the HDD 7 to the output buffer 5 is performed. Also good. In this case, the threshold value may be set to a value sufficiently larger than the amount of data written from the tuner 2 to the input buffer 4 during the period required for the reading process from the HDD 7 to the output buffer 5.

  In the present embodiment, the video information included in the broadcast signal is recorded on the HDD 7 and reproduced. However, the present invention is not limited to this, and audio information, data broadcast information, and the like are recorded on the HDD 7. You may replay it.

  For example, when data broadcasting information is stored in the HDD 7, a data broadcasting memory for separating and storing the data broadcasting information from the TS output from the tuner 2 is first provided, and the data broadcasting information is previously stored in the data broadcasting memory. Record it.

  Then, the data broadcast information stored in the data broadcast memory is written in an area reserved in the innermost periphery of the HDD 7 in advance, and read out from there for reproduction.

  Here, the data broadcast information recorded in the data broadcast memory is determined that the input buffer 4 is sufficiently free and the TS to be transferred to the decoding unit 9 of the output buffer 5 has reached a sufficient amount. Is recorded from the data broadcast memory to the HDD 7. In this case, the threshold is set to a value that is sufficiently larger than the amount of data written to the input buffer 4 and the amount of data transferred from the output buffer 5 to the decoding unit 9 during the period of writing from the data broadcasting memory to the HDD 7. You just have to. When the transfer from the data broadcast memory to the HDD 7 is completed, the data broadcast information separation process is started again, and this process is repeated. In this manner, the data broadcast can be separated and recorded in the HDD 7 without stopping the video information stream even during the recording process, the reproduction process, or the simultaneous recording / reproduction process.

  Further, when data broadcast information is transferred from the data broadcast memory to the HDD 7 at the above timing, there is sufficient time in transferring the data broadcast information. It is good to write. By collecting data broadcast information on the inner periphery, it is possible to collect video information streams that require real-time performance on the outer periphery, thereby improving the processing capability of the digital TV recording / reproducing apparatus.

  When reading from the HDD 7 in order to use the data broadcast information already recorded in the HDD 7, the data broadcast information recorded in the HDD is transferred to the decoding unit 9 of the output buffer 5 because the input buffer 4 is sufficiently free. When it is determined that the TS to be reached has reached a sufficient amount, the data is read from the HDD 7 to the data broadcasting memory. In this case, the threshold is set to a value that is sufficiently larger than the amount of data written to the input buffer 4 and the amount of data transferred from the output buffer 5 to the decoding unit 9 during the period of reading from the HDD 7 to the data broadcasting memory. Just keep it. This data broadcast memory is an area allocated for using data broadcast information. As described above, the data broadcast information can be read from the HDD 7 without stopping the video stream even during the recording process, the reproduction process, or the simultaneous recording / reproduction process.

  Next, another embodiment will be described. FIG. 4 is a block diagram showing a schematic configuration of a digital TV broadcast recording / reproducing apparatus according to another embodiment. FIG. 5 is a flowchart for explaining write / read operations of the hard disk drive device in the digital TV broadcast recording / reproducing apparatus of FIG. is there.

  In FIG. 4, the same components as those in FIG. Here, the difference from the above embodiment is that when the viewer uses the remote control or the like to instruct to play the program recorded on the HDD 7 while recording the received program, the mode to be played is different. The point is that it has instruction means 11 for setting the normal reproduction mode or the fast-forward reproduction mode. Here, the fast-forward playback mode is a case of playback at 3 × speed or higher, and the normal playback mode is a case of playback at 1 × speed or 2 × speed.

  Then, when the normal reproduction mode is set by the instruction means 11, the CPU 6 controls to read from the HDD 7 in blocks of N bytes and store the read TS in the output buffer 5. Also, when the fast-forward playback mode is set by the instruction means 11, control is performed so that the TS is read from the HDD 7 in units of pictures and stored in the output buffer 5 as described in the first embodiment. is doing.

  Next, TS writing / reading operations with respect to the HDD 7 in the recording / reproducing apparatus having such a configuration will be described with reference to the flowchart of FIG.

  Here, in the flowchart of FIG. 2 described in the first embodiment, steps S01 to S04 are the same as steps S11 to S14 of FIG.

  The difference from the flowchart of FIG. 3 is that in step S11, it is determined whether there is a block to be transferred to the HDD 7 in the input buffer 4, that is, whether the TS of the received program is stored in N bytes or more. If no TS of N bytes or more is stored in the buffer 4, the process proceeds to step S15, and it is determined whether or not the mode set by the instruction means 11 is the normal playback mode.

  When it is determined that the normal playback mode is selected, N bytes of TS are immediately read from the HDD 7 and stored in the output buffer 5 (step S16).

  On the other hand, if it is determined in step S15 that the fast-forward playback mode is selected, the picture data amount to be read next from the HDD 7 is calculated with reference to the picture address management table 8 as in step S5 of FIG. (Step S17).

  In step S18, it is determined whether the output buffer 5 has enough free space to store the picture to be read from the HDD 7, and the output buffer 5 has no free space to store the picture to be read from the HDD 7. In this case, the process returns to step S11. On the other hand, if the output buffer 5 has a free capacity for storing a picture to be read from the HDD 7, a TS for one picture is immediately read from the HDD 7 and stored in the output buffer 5. (Step S19).

  Then, the pointer in the picture address management table 8 is updated to the picture next to the read picture, and the process returns to step S20 to execute a writing routine for the HDD 7 of the input buffer 5 (step S08).

  As described above, in the second embodiment, writing is performed in units of blocks of a predetermined size with respect to the HDD 7, and in the normal playback mode, reading is performed in the same block units as writing, while in the fast forward playback mode, pictures are read. Since the picture address management table for storing the sector number of each picture on the HDD 7 is provided in addition to reading in units, it is possible to reduce the number of seeks of the HDD 7 by increasing the block size during the writing process. In addition, the number of readings does not increase at the time of normal reproduction where most data read processing is required for reproduction, while only necessary pictures can be selectively read at the time of fast-forward reproduction. This reduces the number of seeks, eliminates unnecessary data reading in fast-forward playback, and improves the writing / reading efficiency with respect to the HDD 7, thereby improving the processing capability of the digital TV broadcast recording / playback apparatus. It becomes.

It is a block diagram which shows schematic structure of the digital TV broadcast recording / reproducing apparatus in one embodiment of this invention. 2 is a flowchart for explaining a write / read operation of a hard disk drive device in the digital TV broadcast recording / reproducing apparatus of FIG. 1. It is explanatory drawing explaining the content of the data stored in the picture address management table in the digital TV broadcast recording / reproducing apparatus of FIG. It is a block diagram which shows schematic structure of the digital TV broadcast recording / reproducing apparatus in other embodiment of this invention. 5 is a flowchart for explaining write / read operations of a hard disk drive device in the digital TV broadcast recording / reproducing apparatus of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Tuner 3 Picture length detection part 4 Input buffer 5 Output buffer 6 CPU
7 Hard disk drive (HDD)
8 Picture address management table 9 Decoding unit 10 Display device 11 Instruction means

Claims (3)

In a recording / reproducing apparatus that has a randomly accessible recording medium and records and reproduces a stream on the recording medium,
Control means for writing the stream to the recording medium in units of first blocks and controlling to read the stream in units of second blocks;
When the normal reproduction mode is set, the control means controls the size of the second block unit to be the same as the size of the first block unit,
When the fast-forward playback mode is set, the recording / reproducing apparatus is characterized in that the size of the second block unit is set to one picture unit, and control is performed to read a stream from the recording medium in units of one picture. A data amount detecting means for detecting a data amount of a picture included in the stream;
When the fast-forward playback mode is set, the control means controls to read a stream from the recording medium in units of one picture based on the data amount of the picture detected by the data detection means. The recording / reproducing apparatus according to claim 1. In a recording / reproducing apparatus that has a randomly accessible recording medium and records and reproduces a stream on the recording medium,
A data amount detecting means for detecting a data amount of a picture included in the stream;
The stream is written to the recording medium in units of a first block, and control is performed to read the stream from the recording medium in units of pictures based on the data amount for each picture detected by the data amount detection unit. Control means for
The recording / reproducing apparatus according to claim 1, wherein the data amount included in the first block is larger than an average value of the data amount for each picture.

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