JP4867872B2 - Image processing apparatus, control method for the image processing apparatus, and program - Google Patents

Description

  The present invention relates to an image processing apparatus that processes image data that has been encoded by the MPEG method, a control method for the image processing apparatus, and a program.

  Baseband digital video signals are used in devices that perform processing to record image signals captured by a video camera or the like on a recording medium such as a magnetic recording tape, optical disk, or hard disk drive. In order to reduce and record efficiently, the captured image signal is subjected to encoding processing and decoding processing in accordance with the MPEG (Moving Picture Experts Group) system.

  A bitstream in which an image signal is encoded in conformity with this MPEG system must satisfy the restrictions imposed through an image buffering verifier defined in Recommendation H.262 (ISO / IEC 13818-2). .

  That is, in the encoding processing method in which the generated code amount varies in the time axis direction as in the MPEG system, in order to accurately decode the bit stream recorded on the recording medium at the time of reproduction, the content in the input buffer in the decoding processing system The data occupation amount must always be grasped in the encoding processing system.

  For this reason, in the MPEG system, the generated code amount is controlled assuming a VBV (Video Buffering Verifier) buffer in the encoding processing system as a virtual buffer corresponding to the input buffer in the decoding processing system. That is, in the encoding processing system, the generated code amount per unit time is controlled so that the VBV buffer does not fail, in other words, the VBV buffer does not underflow or overflow.

  Therefore, in the MPEG system, it is necessary to consider the size of the VBV buffer even when a bit stream to be newly recorded is connected to a bit stream previously recorded on a recording medium. In other words, the encoding processing system is applied to the size of the VBV buffer so that the decoding process can be performed without breaking the input buffer even if the preceding and succeeding edit points to be continuously recorded are reproduced. Data occupancy must be set.

  As a technique for satisfying such a requirement and performing joint recording, Patent Document 1 discloses a copy picture that repeatedly displays a picture displayed immediately before this edit point at an edit point of a bit stream to be newly connected and recorded. A method of inserting stuffing bytes has been proposed.

  Also, in Patent Document 2, if the VBV buffer occupancy is extremely small in relation to the generated code amount of the next picture displayed immediately after the edit point to be recorded continuously, an underflow of the VBV buffer occurs during the encoding process. In order to prevent the occurrence of image quality, a method has been proposed for avoiding image quality degradation caused by restrictions on the amount of codes generated in the next picture.

JP 11-205734 A JP 2004-48104 A

  However, the prior art including the above-described Patent Documents 1 and 2 merely indicates that the failure of the VBV buffer is prevented by inserting a copy picture during splice recording.

  The present invention has been proposed in view of such circumstances, and records new encoded image data by inserting a copy picture while maintaining good image quality before and after the edit point of splice recording. An object is to provide an image processing apparatus that performs processing, a control method of the image processing apparatus, and a program.

As means for solving the above-described problems, an image processing apparatus according to the present invention is an image processing apparatus that processes image data that has been encoded by the MPEG method, and stores the first image data. The picture displayed immediately before the edit point is repeatedly displayed on the edit point on the recording medium according to the bit occupancy of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. The copy picture to be displayed is inserted as control information, and the second image data is recorded on the recording medium, and the first image is inserted from the editing point according to the scanning method of the first image data. The picture structure of the copy picture is set, and the copy picture is inserted on the editing point on the recording medium, and the second image A control means for controlling said recording means so as to record over data, said control means, when scanning method of the first image data is interlaced is inserted into the first sheet from the editing point above you and sets the copy picture field structure.
An image processing apparatus according to the present invention is an image processing apparatus that processes image data that has been encoded by the MPEG method, on an editing point on a recording medium on which the first image data is recorded. A copy picture that repeatedly displays the picture displayed immediately before the edit point is inserted as control information in accordance with the bit occupancy of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. A recording means for recording the second image data on the recording medium, and a picture structure of the copy picture to be inserted first from the editing point according to the scanning method of the first image data, The recording unit is configured to record the second image data by inserting the copy picture on an editing point on the recording medium. And when the first image data scanning method is a progressive method, the control means sets the copy picture to be inserted after the first image from the editing point in a frame structure. It is characterized by.

The image processing apparatus control method according to the present invention is an image processing apparatus control method for processing image data that has been encoded by the MPEG method, and the recording means records the first image data. A picture displayed immediately before the editing point is displayed on the editing point on the recording medium, in accordance with the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. A copy picture to be repeatedly displayed is inserted as control information, and a recording process for recording the second image data on the recording medium and a control means, from the editing point according to the scanning method of the first image data. The recording means is controlled to set the picture structure of the copy picture to be inserted into the first picture and to record it on the recording medium. Comprising a control step, in the control step, when scanning method of the first image data is interlaced to and sets the copy pictures to be inserted into the first sheet from the editing point on the field structure The
Also, the control method of the image processing apparatus according to the present invention is the control method of the image processing apparatus that processes the image data encoded by the MPEG method, wherein the first image data is recorded by the recording means. According to the bit occupancy of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the above encoding process, the picture displayed immediately before the editing point is repeated on the editing point on the recording medium. The copy picture to be displayed is inserted as control information, and the second image data is recorded on the recording medium, and the first image is inserted from the editing point according to the scanning method of the first image data. A control step of controlling the recording means to set the picture structure of the copy picture and record it on the recording medium; The serial control step, when scanning method of the first image data is a progressive method, and sets the copy pictures to be inserted into the first sheet after the above edit point in the frame structure.

The program according to the present invention is a program for causing a computer to execute image processing for processing image data encoded by the MPEG method, and the first image data is recorded by the recording means. The picture displayed immediately before the editing point is repeatedly displayed on the editing point on the recording medium according to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. The copy picture to be displayed is inserted as control information, the second image data is recorded on the recording medium, and the first image is inserted from the editing point according to the scanning method of the first image data. Controlling the recording means to set the picture structure of the copy picture to be recorded on the recording medium Comprising a that control step, in the control step, when scanning method of the first image data is interlaced and characterized by setting the copy pictures to be inserted into the first sheet from the editing point on the field structure is a program for executing to that image processing in a computer.
Further, the program according to the present invention is a program for causing a computer to execute image processing for processing image data encoded by the MPEG system, and the first image data is recorded by the recording means. On the edit point on the recording medium, the picture displayed immediately before the edit point is repeatedly displayed according to the bit occupancy of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. The copy picture to be inserted is inserted as control information, and the second image data is recorded on the recording medium, and the first image data is inserted from the editing point according to the scanning method of the first image data. Control the recording means so that the picture structure of the copy picture is set and recorded on the recording medium A control step, wherein, when the scanning method of the first image data is a progressive method, the copy picture to be inserted after the first image from the editing point is set in a frame structure. Is a program for causing a computer to execute image processing.

  According to the present invention, the picture displayed immediately before the editing point is repeated on the editing point on the recording medium on which the first image data is recorded, according to the bit occupancy of the VBV buffer. A copy picture to be displayed is inserted as control information, the second image data is recorded on the recording medium, and a copy picture to be inserted into the first sheet by the control means according to the scanning method of the first image data Since the recording means is controlled so that the picture structure is set and recorded on the recording medium, new encoded image data is inserted by inserting a copy picture while maintaining good image quality before and after the edit point of splice recording. Can be recorded.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  An image processing apparatus to which the present invention is applied is an apparatus that processes image data that has been encoded by the MPEG method. As an example of such an image processing apparatus, image data, audio data, and attached data encoded by the MPEG system as shown in FIG. 1 are recorded on the magnetic tape 2 as recording media and recorded on the magnetic tape 2. The following description will be given using the camcorder 1 that reproduces the image data.

  The camcorder 1 encodes an image pickup signal read from the image pickup device and records it on the magnetic tape 2 as an encoding processing system, an input unit 11, an A / D conversion unit 12, an encoding processing unit 13, and data multiplexing. Unit 14, variable speed reproduction data generation unit 15, error correction code addition unit 16, recording amplifier 17, and recording rotary head 18. The camcorder 1 also serves as a decoding processing system that decodes and reproduces image data recorded on the magnetic tape 2, a reproducing rotary head 19, a reproducing amplifier 110, an error correction unit 111, and a data separation processing unit 112. A variable speed reproduction memory 113, a switching unit 114, a decoding processing unit 115, a D / A conversion unit 116, and an output unit 117. The camcorder 1 also includes a controller 118 that controls each processing unit related to the encoding processing system and the decoding processing system.

  The input unit 11 inputs an analog imaging signal read by an imaging element such as a CCD, and supplies the input imaging signal to the A / D conversion unit 12.

  The A / D conversion unit 12 converts the analog imaging signal input to the input unit 11 into digital image data, and supplies the converted image data to the encoding processing unit 13.

  In accordance with a control command from the controller 118, the encoding processing unit 13 performs encoding processing conforming to the MPEG system on the image data supplied from the A / D conversion unit 12 as follows. Then, the encoded image data is supplied to the data multiplexing unit 14 and the variable speed reproduction data generation unit 15.

  Specifically, as illustrated in FIG. 2, the encoding processing unit 13 sets each picture as one of an I picture, a P picture, and a B picture, for example, in units of 15 GOPs (Group Of Pictures). Encode according to type. Here, the I picture is a picture type that is encoded using only image information of the current picture. Further, the P picture is a picture type that is predictively encoded using image information of a picture that is previously located in the display order. Further, the B picture is a picture type that is predictively encoded using image information of a plurality of pictures that are located bidirectionally with respect to the display order.

  That is, as shown in FIG. 1-No. The data stream obtained by performing the encoding process according to each picture type by switching the 15 pictures in the decoding process order is supplied to the data multiplexing unit 14 and the variable speed reproduction data generation unit 15.

  The data multiplexing unit 14 multiplexes system data such as audio data and subcodes into image data supplied from the encoding processing unit 13 and a variable speed reproduction data generation unit 15 described later in accordance with a control command from the controller 118. To do. The data multiplexing unit 14 also performs processing for inserting a copy picture and a stuffing byte, which will be described later, as system data in accordance with a control command from the controller 118. Then, the data multiplexing unit 14 supplies the multiplexed bit stream to the error correction code adding unit 16. In the normal operation of the camcorder 1, the image data encoded by the encoding processing unit 13 is directly supplied to the data multiplexing unit 14.

  The variable speed reproduction data generation unit 15 generates variable speed reproduction image data from the image data supplied from the encoding processing unit 13, and supplies the generated image data to the error correction code addition unit 16.

  The error correction code adding unit 16 adds an error correction code to the bit stream supplied from the data multiplexing unit 14 in accordance with a control command from the controller 118 and supplies the bit stream to the recording amplifier 17.

  The recording amplifier 17 performs amplification processing after converting the bit stream supplied from the error correction code adding unit 16 into serial data. Then, the recording amplifier 17 supplies the amplified image data to the recording rotary head 18.

  The recording rotary head 18 records the image data supplied from the recording amplifier 17 on the magnetic tape 2 rotated through a rotating drum (not shown).

  The reproducing rotary head 19 reads the image data recorded on the magnetic tape 2 and supplies the read image data to the reproducing amplifier 110.

  The reproduction amplifier 110 performs amplification processing on the image data supplied from the reproduction rotating head 19 and supplies the image data subjected to the amplification processing to the error correction unit 111.

  The error correction unit 111 performs error correction processing on the image data supplied from the reproduction amplifier 110. Then, the reproduction amplifier 110 supplies the image data subjected to the error correction processing to the data separation processing unit 112 and the variable speed reproduction memory 113, respectively.

  The data separation processing unit 112 separates audio data and system data from the image data supplied from the error correction unit 111. Then, the data separation processing unit 112 supplies the image data from which the audio data and the system data are separated to the decoding processing unit 115 via the switching unit 114. Further, the data separation processing unit 112 supplies the separated system data to the controller 118. Here, the system data includes background information described later.

  The variable speed reproduction memory 113 temporarily stores the image data supplied from the error correction unit 111 in the memory area for variable speed reproduction. The data stored in the variable speed reproduction memory 113 is read out by the decoding processing unit 115 via the switching unit 114 at every timing corresponding to the variable speed reproduction.

  The switching unit 114 electrically connects one of the data separation processing unit 112 and the variable speed reproduction memory 113 to the input terminal of the decoding processing unit 115 in accordance with a control command from the controller 118. In the normal operation mode of the camcorder 1, the switching unit 114 is electrically connected to the input terminals of the data separation processing unit 112 and the decoding processing unit 115.

  In response to a control command from the controller 118, the decoding processing unit 115 performs decoding processing in conformity with the MPEG system on image data supplied from either the data separation processing unit 112 or the variable speed reproduction memory 113. The decoded image data is supplied to the D / A converter 116.

  The D / A converter 116 converts the image data supplied from the decoding processor 115 into an analog image signal. Then, the D / A conversion unit 116 supplies the converted image signal to the output unit 117.

  The output unit 117 outputs the image signal supplied from the D / A conversion unit 116 to, for example, a display device.

  The controller 118 controls the operation of each processing unit of the encoding processing system and the decoding processing system.

  In the camcorder 1 configured as described above, image data obtained by performing an encoding process on the image signal input from the input unit 11 is recorded on the magnetic tape 2, and the image data is read from the magnetic tape 2 and decoded. The processed image signal is output from the output unit 117 to the outside.

  In the following, among the operations performed by the camcorder 1 described above, data relating to a recording process in which image data input to the input unit 11 is connected and recorded from any editing point of image data previously recorded on the magnetic tape 2. The following description will be made with particular attention to the operations of the multiplexing unit 14 and the controller 118.

  When recording the overwrite image data supplied from the decoding processing unit 115 on the magnetic tape 2 on which the underlying image data is recorded, the data multiplexing unit 14 performs VBV at the editing point where the overwrite image data is recorded. A copy picture and a stuffing byte are inserted so as not to break the buffer.

  This is due to the relationship between the amount of generated codes related to pictures before and after the edit point to be recorded jointly. If the data occupancy VBV_occupancy of the VBV buffer is extremely small, the VBV buffer underflow does not occur in the encoding process. This is because the amount of generated code of a picture located immediately after the point is limited and the image quality deteriorates.

  For example, the delay time (hereinafter referred to as VBV_delay) from when a picture is input to the VBV buffer until it is output is the final display picture (background Last) of the background image data and the display start picture (overwrite Top) of the overwrite image data. ), The data occupancy VBV_occupancy may fall below a predetermined set value as shown in FIG.

  Therefore, the data multiplexing unit 14 specifically inserts, as control information, a copy picture that repeatedly displays a picture (background Last) displayed immediately before the editing point in accordance with the control command of the controller 118 as follows. Thus, as shown in FIG. 3B, the VBV_delay of the display start picture (overwrite Top) of the overwritten image data is lengthened so that the data occupancy VBV_occupancy exceeds a predetermined set value.

  The controller 118 that controls the data multiplexing unit 14 that performs copy picture and stuffing byte insertion processing includes, for example, header size header size, VBV_delay, among the system data acquired from the data separation processing unit 112 when performing splice recording processing. The data occupancy VBV_occupancy at the start of writing of the display start picture of the overwritten image data is calculated from the background information including the frame interval and the scanning method. Then, when the data occupancy VBV_occupancy at the start of writing falls below a predetermined set value, the controller 118 detects the copy picture to be inserted immediately after the edit point, that is, in order to suppress the image quality deterioration at the beginning of the joint of the image data. Calculate the number of inserts. That is, the controller 118 calculates the number of inserted sheets so that the data occupation amount VBV_occupancy of the overwritten data after inserting the copy picture is equal to or larger than the set value.

  Specifically, when the value of (VBV_delay + header size) is different between the background image data and the overwrite data, the controller 118 causes the data multiplexing unit 14 to insert a copy picture and a stuffing byte.

  That is, the controller 118 uses the value of (VBV_delay + header size) of the background image data as the target value V_cur, and calculates the number N of copy pictures to be inserted and the stuffing byte data amount S under the following conditions. However, when the value of (VBV_delay + header size) of the background image data is below the minimum value, the set value is set as the target value.

When V_cur-f (0) ≦ 0, N = 0, S = (f (0) −V_cur)
When V_cur−f (0)> 0, N satisfying f (N−1) <V_cur ≦ f (N), S = (f (N−V_cur))
Here, f (N) is the value of (VBV_delay + header size) of the overwritten image data when N copy pictures are inserted.

  Note that there are two types of copy pictures generated by the background image data, that is, a field structure and a frame structure, and therefore the value differs every time one is inserted.

  Next, processing steps for calculating the amount of generated copy pictures and stuffing bytes will be described with reference to the flowchart shown in FIG.

  As a premise, in the processing steps according to the flowchart shown in FIG. In this processing step, the value vbv_1 of the (VBV_delay + header size) of the background image data and the value vbv_2 of the (VBV_delay + header size) of the overwrite image data are used as arguments. Also, in this processing step, the number of stuffing bytes to be generated StuffByte is used as a wide-area variable. Furthermore, in this processing step, the number of bytes FIELD_SIZE per field structure copy picture and the number of bytes FRAME_SIZE per frame structure copy picture are used as constant values.

  In step S1, the controller 118 sets the number of inserted copy pictures to the initial value 0, and proceeds to step S2.

  In step S2, the controller 118 converts the value of vbv_2 with respect to vbvd_1 into bytes, holds the calculated value as sub_vbvd, and proceeds to step S3.

  In step S3, the controller 118 determines whether the value of sub_vbvd is 0 or less. Here, the controller 118 proceeds to step S4 when the value of sub_vbvd is 0 or less, and proceeds to step S6 when the value of sub_vbvd is not 0 or less.

  In step S4, the controller 118 sets the number of inserted copy pictures to 0, and proceeds to step S5.

  In step S5, the controller 118 sets the value of StuffByte to-(sub_vbvd), and proceeds to step S18.

  In step S6, the controller 118 increments the number of inserted copy pictures, that is, updates the value to 1, and proceeds to step S7.

  In step S7, the controller 118 determines whether or not the value of sub_vbvd is equal to or less than the value of FIELD_SIZE. Here, the controller 118 proceeds to step 8 when it is equal to or smaller than the value of FIELD_SIZE, and proceeds to step S11 when not smaller than the value of FIELD_SIZE.

  In step S8, the controller 118 determines whether or not the background image data scanning method is progressive. Here, the controller 118 proceeds to step S9 when it is progressive, and proceeds to step S10 when it is not progressive, that is, when interlaced.

In step S9, the controller 118 calculates StuffByte from the following equation, and proceeds to step S18.
StuffByte = FRAME_SIZE-sub_vbvd

In step S10, the controller 118 calculates StuffByte from the following equation, and proceeds to step S18.
StuffByte = FIELD_SIZE-sub_vbvd

  In step S6, the controller 118 determines whether or not the background image data scanning method is progressive. Here, the controller 118 proceeds to step S12 when it is progressive, and proceeds to step S13 when it is not progressive, that is, when interlaced.

  In step S12, the controller 118 updates the value obtained by subtracting FRAME_SIZE from sub_vbvd as sub_vbvd, and proceeds to step S14.

  In step S13, the controller 118 updates the value obtained by subtracting FIELD_SIZE from sub_vbvd as sub_vbvd, and proceeds to step S14.

  In step S14, the controller 118 determines whether or not the value of sub_vbvd is greater than 0. When the value is greater than 0, the controller 118 proceeds to step S15. Further, the controller 118 repeats the processes of steps S15 and S16 described later until the condition that the value of sub_vbvd is greater than 0 is not satisfied, and then proceeds to step S17.

  In step S15, the controller 118 increments the number of inserted copy pictures, and proceeds to step S16.

  In step S16, the controller 118 updates the value obtained by subtracting FIELD_SIZE from sub_vbvd as sub_vbvd, and returns to step S14.

  In step S17, the controller 118 sets the value of StuffByte to-(sub_vbvd), and proceeds to step S18.

  In step S18, the controller 118 calculates the inserted number of copy pictures as a return value, and ends this processing step.

  When one or more copy pictures are inserted by the above processing steps, the controller 118 specifically sets the picture structure of the copy picture according to the scanning method of the background image data according to the flowchart shown in FIG. Set.

  In step 21, the controller 118 acquires background information including the header size header size, VBV_delay, frame interval, and scanning method, and then proceeds to step S22.

  In step S22, the controller 118 obtains the number of inserted copy pictures obtained as a return value of the processing steps in steps S1 to S18 described above, and proceeds to step S23.

  In step S23, the controller 118 repeats the processing related to steps S24 to S29 described later for the number of copies of the copy picture obtained in step S22, and thereafter ends the present processing step.

  In step 24, the controller 118 determines whether or not the current copy picture to be processed is the first copy picture with respect to the editing point. Here, the controller 118 proceeds to step S25 when it is the first copy picture, and proceeds to step S28 when it is not the first copy picture.

  In step S25, the controller 118 determines whether or not the background image data scanning method is progressive. Here, the controller 118 proceeds to step S26 when it is progressive, and proceeds to step S27 when it is not progressive, that is, when it is interlaced.

  In step S26, the controller 118 sets the picture structure of the target copy picture to the frame structure, and proceeds to step S29.

  In step S27, the controller 118 sets the picture structure of the target copy picture to the field structure, and proceeds to step S29.

  In step S28, the controller 118 sets the picture structure of the target copy picture to the frame structure, and proceeds to step S29.

  In step S29, the controller 118 counts up the target copy picture and returns to step S23.

  With the above processing steps, the controller 118 changes the picture structure of the first copy picture from the editing point to a field structure, that is, a structure composed of a macroblock structure of field DCT coding when the scanning method of the background image data is interlaced. The picture structure of the second and subsequent copy pictures is set to a frame structure, that is, a structure composed of a macroblock structure of frame DCT coding. Also, when the background image data scanning method is progressive, the controller 118 sets the picture structure of the first and subsequent copy pictures from the editing point to a frame structure, that is, a structure composed of a macroblock structure of frame DCT coding.

  Then, according to the control information relating to the copy picture set by the controller 118, the data multiplexing unit 14 uses the control data relating to the copy picture held in the internal memory as system data, and the PES (Packetized Elementary Stream) of the overwritten image data. ) A process of multiplexing the other audio data or the like on the overwritten image data is added to the header.

  In the camcorder 1, in addition to executing the splice recording process by the data multiplexing unit 14 and the controller 118 configured by hardware, for example, an image processing program stored on the hard disk is read on the RAM and used for general purpose. It is also possible to perform the joint recording process by mounting with the processor of FIG.

  Through the processing described above, the controller 118 sets the picture structure of the copy picture to be inserted by associating the background mode of the background image data with the recording mode of the overwrite image data, as shown in FIG. is doing.

  That is, in the specific example shown in FIG. 6, the number of effective scanning lines of the background image data and the overwrite image data is 1080. Further, in the specific example shown in FIG. 6, an interlace mode 60i consisting of 60 fields per second, a progressive mode 30p consisting of 30 frames per second, a progressive mode 24p consisting of 30 frames per second, and 50 fields per second. The interlace mode 50i, the progressive mode 25p consisting of 25 frames per second is used as the base mode and the recording mode. Note that FIG. 6 shows a relationship in which connection recording cannot be performed between the modes indicated by −.

  When the background mode is interlace, the controller 118 sets the copy picture to be inserted into the first frame from the editing point without regard to the recording mode, and sets the copy picture to be inserted after the second frame into the frame structure. In addition, when the background mode is progressive, the controller 118 sets the copy picture to be inserted from the editing point to the first and subsequent frames in the frame structure regardless of the recording mode.

  The controller 118 acquires background information regarding each background mode as shown in FIG. 7 by referring to ECCTB stored in the background image data.

  Next, an example of the joint recording process will be described.

  First, as a first embodiment, FIG. 8 and FIG. 9 show picture arrangements in the recording area of the magnetic tape 2 when the overlaid image data in the interlace mode 60i is connected to the background image data in the interlace mode 60i.

  8A and 8B show picture arrays arranged in the order of decoding processing in units of frames. Specifically, FIG. 8A shows an arrangement of pictures constituting the base image data before the joint recording process. FIG. 8B shows an arrangement of pictures in which the overwrite image data is connected and recorded so as to overwrite the pictures P8, B6, and B7 and later in the background image data.

  FIGS. 9A and 9B show the arrangement of pictures arranged in the order of display in field units including a top field t and a bottom field b. Specifically, FIGS. 9A and 9B show the arrangement of the pictures shown in FIGS. 8A and 8B in field units and display order, respectively.

  As shown in FIGS. 8 and 9, the controller 118 selects two edit pictures and inserts two copy pictures so as to be overwritten from the I picture or P picture of the background image data. By doing so, the controller 118 can perform continuous recording without breaking the correspondence between the decoding order and the display order.

  This is because when the editing point is selected so that it is overwritten from the B picture of the background image data, the picture displayed earlier with the picture displayed after the I picture or P picture remaining as the background remains overwritten. This is to prevent this.

  Next, as a second embodiment, FIG. 10 and FIG. 11 show the picture arrangement in the recording area of the magnetic tape 2 when overwriting image data in the progressive mode 24p is connected to the background image data in the progressive mode 24p. .

  FIGS. 10A and 10B show picture arrays arranged in the order of decoding processing in units of frames. Specifically, FIG. 10A shows an arrangement in the decoding processing order of the pictures constituting the background image data before the joint recording process. FIG. 10B shows an arrangement in the decoding processing order of pictures in which overwrite image data is connected and recorded so that pictures I2, B0, and B1 and later in the background image data are overwritten.

  In this joint recording process, the controller 118 inserts a frame-structured copy picture because the background image data is in the progressive mode 24p. Here, a frame structure copy picture composed of frame DCT coding macroblocks has a smaller amount of generated code than a field structure copy picture composed of field DCT coding macroblocks. Therefore, the controller 118 can reduce the data occupancy VBV_occupancy of the VBV buffer with a smaller number of inserted copy pictures, and as a result, a smaller number of copy pictures can be inserted in the first picture of overwritten image data. Can be increased efficiently. That is, the controller 118 can perform the joint recording process by shortening the state where the image is stopped on the editing point while maintaining good image quality.

  Further, when a copy picture is inserted into the background image data in the progressive mode as in this embodiment, if a copy picture having a field structure composed of macro blocks of field DCT coding is put in the first edit point, the field Since a copy picture composed of DCT coding macroblocks creates a frame image only from the final display picture of the background image data consisting of the bottom field, the resolution drops to half.

  On the other hand, the background image data in the progressive mode originally has the resolution of the frame, and the controller 118 according to the second embodiment uses the picture in the frame DCT mode in consideration of such resolution characteristics. Thus, since the first and subsequent copy pictures are inserted, it is possible to perform joint recording processing in a state in which the image quality of the joint on the edit point at the time of reproduction is kept good.

  FIG. 11 shows an arrangement of pictures arranged in the display order in the splice recording process according to the second embodiment, applied to unit field intervals.

  Here, since both the background image data and the overwritten image data are in the progressive mode 24p, when applied to the unit field interval, an array in which frames of three field periods and frames of two field periods are alternately arranged. That is, the sequence is 3-2.

  In contrast to the picture arrangement structure described above, in the second embodiment, as shown in FIG. 11, in the second embodiment, the controller 118 sets editing points in units of GOPs with 24 pictures as one unit. Overwrite image data is connected and recorded from the next picture of the frame assigned in the order of the top field t and the bottom field b in the data. Here, the controller 118 inserts one or more copy pictures assigned in the order of the top field t and the bottom field b in order to improve the image quality or match the VBV_delay. As a result, the controller 118 destroys the 3-2 sequence structure in the progressive mode 24p, but the time for the image to stop at the editing point is shortened, and the appearance when reproduced is improved.

  Further, in the controller 118 that performs such splice recording processing, between different streams, specifically, a mixed stream of the progressive mode 24p and the progressive mode 30p, a mixed stream of the progressive mode 30p and the progressive mode 24p, and the progressive mode 24p. In the mixed stream of the interlace mode obtained by pulling down 3-2 and the interlace mode 60i or the like, it is possible to perform the joint recording process while maintaining good image quality during reproduction.

  As in the first and second embodiments described above, in the camcorder 1, the data multiplexing unit 14 causes the bit occupancy of the VBV buffer on the edit point on the magnetic tape 2 on which the background image data is recorded. Depending on the rate, a copy picture that repeatedly displays the picture displayed immediately before the editing point is inserted as control information, and the image data is multiplexed so as to record the overwritten image data on the magnetic tape 2, and the controller 118, the data multiplexing unit 14 is controlled to set the picture structure of the copy picture to be inserted into the first image and record it on the magnetic tape 2 according to the scanning method of the background image data. It is possible to perform a process of recording a new encoded image data by inserting a copy picture in a state where the image quality before and after the dot is kept good.

  The present invention is not limited to the camcorder 1 that performs recording processing by connecting the magnetic recording tape 2 described above as a recording medium, but also two encoded images such as an image processing program executed by a computer and a dedicated editing machine. It can also be used when connecting bitstreams made of data without re-encoding.

1 is a block diagram showing an overall configuration of a camcorder to which the present invention is applied. It is a figure which shows the arrangement | sequence process of the picture which concerns on an encoding process. It is a figure which shows the change of the data occupation rate of the VBV buffer by copy picture insertion. 10 is a flowchart for explaining a process for calculating the number of inserted copy pictures. It is a flowchart with which it uses for description of the setting process which sets the picture structure of a copy picture. It is a figure which shows the picture structure of the copy picture matched with background | background mode and recording mode. It is a figure which shows the structure of ECCTB stored in background image data. It is a figure which shows the picture arrangement | sequence in the recording area of the magnetic tape 2 in a frame unit when the overwrite image data of the interlace mode 60i is connected and recorded on the background image data of the interlace mode 60i. It is a figure shown in the picture arrangement field unit in the recording area of the magnetic tape 2 when the overwrite image data of the interlace mode 60i is connected and recorded on the background image data of the interlace mode 60i. It is a figure which shows the picture arrangement | sequence in the recording area of the magnetic tape 2 at the time of carrying out recording by connecting the overwrite image data of progressive mode mode 24p to the background image data of progressive mode 24p. It is a figure which shows the picture arrangement | sequence in the recording area of the magnetic tape 2 at the time of 3-2 pull-down when the overwrite image data of progressive mode mode 24p is connected and recorded on the background image data of progressive mode 24p.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Camcorder, 2 Magnetic tape, 11 Input part, 12 A / D conversion part, 13 Encoding process part, 14 Data multiplexing part, 15 Variable speed reproduction | regeneration data generation part, 16 Correction code addition part, 17 Recording amplifier, 18 Rotating head for recording, 19 Rotating head for reproduction, 110 Amplifier for reproduction, 111 Error correction unit, 112 Data separation processing unit, 113 Variable speed reproduction memory, 114 Switching unit, 115 Decoding processing unit, 116 D / A conversion unit, 117 Output unit, 118 controller

Claims (6)

In an image processing apparatus for processing image data encoded by the MPEG system,
On the editing point on the recording medium on which the first image data is recorded, immediately before the editing point according to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. A copy means for repeatedly displaying a picture displayed on the display as control information and recording second image data on the recording medium;
The picture structure of the copy picture to be inserted first from the edit point is set according to the scanning method of the first image data, and the copy picture is inserted on the edit point on the recording medium to Control means for controlling the recording means so as to record the second image data ;
The control means, when scanning method of the first image data is an interlace method, the image processing apparatus you and sets the copy pictures to be inserted into the first sheet from the editing point on the field structure. In an image processing apparatus for processing image data encoded by the MPEG system,
On the editing point on the recording medium on which the first image data is recorded, immediately before the editing point according to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process. A copy means for repeatedly displaying a picture displayed on the display as control information and recording second image data on the recording medium;
The picture structure of the copy picture to be inserted first from the edit point is set according to the scanning method of the first image data, and the copy picture is inserted on the edit point on the recording medium to Control means for controlling the recording means so as to record the second image data;
2. The control unit according to claim 1, wherein when the scanning method of the first image data is a progressive method, the copy picture inserted after the first image from the editing point is set in a frame structure. Image processing apparatus. In a control method of an image processing apparatus for processing image data encoded by the MPEG method,
According to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process on the editing point on the recording medium on which the first image data is recorded by the recording unit, A recording step of repetitively displaying a picture displayed immediately before the editing point as control information and recording second image data on the recording medium;
A control step of controlling the recording means so as to set the picture structure of the copy picture inserted from the editing point to the first image according to the scanning method of the first image data and to record the picture structure on the recording medium; ,
In the above control process, the scanning method of the first image data when it is interlaced image processing apparatus you and sets the copy pictures to be inserted into the first sheet from the editing point on the field structure Control method. In a control method of an image processing apparatus for processing image data encoded by the MPEG method,
  According to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process on the editing point on the recording medium on which the first image data is recorded by the recording unit, A recording step of repetitively displaying a picture displayed immediately before the editing point as control information and recording second image data on the recording medium;
  A control step of controlling the recording means so as to set the picture structure of the copy picture inserted from the editing point to the first image according to the scanning method of the first image data and to record the picture structure on the recording medium; ,
  In the control step, when the scanning method of the first image data is a progressive method, the copy picture inserted after the first image from the editing point is set in a frame structure. Control method. In a program for causing a computer to execute image processing for processing image data encoded by the MPEG method,
According to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process on the editing point on the recording medium on which the first image data is recorded by the recording unit, A recording step of repetitively displaying a picture displayed immediately before the editing point as control information and recording second image data on the recording medium;
A control step of controlling the recording means so as to set the picture structure of the copy picture inserted from the editing point to the first image according to the scanning method of the first image data and to record the picture structure on the recording medium; ,
In the above control process, the time scanning method of the first image data is interlaced computer image processing you and sets the copy pictures to be inserted into the first sheet from the editing point on the field structure A program to make it run. In a program for causing a computer to execute image processing for processing image data encoded by the MPEG method,
  According to the bit occupancy rate of the VBV (Video Buffering Verifier) buffer used in the decoding process corresponding to the encoding process on the editing point on the recording medium on which the first image data is recorded by the recording unit, A recording step of repetitively displaying a picture displayed immediately before the editing point as control information and recording second image data on the recording medium;
  A control step of controlling the recording means so as to set the picture structure of the copy picture inserted from the editing point to the first image according to the scanning method of the first image data and to record the picture structure on the recording medium; ,
  In the control step, when the scanning method of the first image data is a progressive method, the copy picture inserted after the first image from the editing point is set in a frame structure. A program to make it run.

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