JP2009260436A - Information processing unit and information processing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information processing unit and an information processing method, capable of compressing data with high quality and efficiency, and to provide a program. <P>SOLUTION: The information processing unit has: a frame unit bit rate calculation circuit 202 for subtracting a rate distribution value obtained by performing variable-rate compression to audio data from the maximum transfer rate of primary video data and audio data to calculate a bit rate in frame units; and a primary video compression processing circuit 206 for compressing the primary video data based on the bit rate in frame units. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information processing apparatus, an information processing method, and a program for compressing content data.

  2. Description of the Related Art Conventionally, an authoring apparatus used in the production site of a recording medium such as an optical disc performs encoding processing (compression encoding processing) using, for example, MPEG (Moving Picture Experts Group) standards on video data, audio data, and the like. . Then, the authoring device multiplexes each encoded data obtained as a result of each encoding process, and records this multiplexed stream on a recording medium.

  Such an authoring apparatus distributes the bit amount that can be recorded on the recording medium to video data, audio data, and the like, and performs an encoding process on each data so as to be within the allocated bit amount.

  As a video data encoding method, so-called “two-pass encoding” is known (see, for example, Patent Document 1). Two-pass encoding is a technique that includes temporary (preliminary) encoding processing and actual encoding processing.

  Hereinafter, the temporary encoding process is referred to as a first pass encoding process, the actual encoding process is referred to as a second pass encoding process, and an outline of the two pass encoding will be described.

  The encoder performs a first-pass encoding process in which the encoding condition is kept constant for a series of video data to be encoded. At this time, various data obtained in the encoding process of the first pass, for example, the amount of generated bits is sequentially detected in units of frames.

  Next, the encoder allocates bits to each of the frames constituting the video data based on the generated bit amount for each frame detected in this way. That is, the target bit amount used in the second pass encoding process is set in units of frames.

  Further, the encoder assigns a picture type used in the second pass encoding process. The assignment of the picture type indicates that an encoding type is assigned to each frame.

  Specifically, in MPEG, each frame is encoded with any encoding type of I picture (Intra-Picture), P picture (Predictive-Picture), and B picture (Bidirectionally Predictive-Picture). The An I picture indicates an encoding type in which image data for one frame is encoded as it is without using image data of other frames. In other words, the I picture refers to an encoding type such as an intra-frame encoding process. P picture and B picture indicate an encoding type such as an inter-frame encoding process. That is, a P picture basically calculates a difference (prediction error) between image data for one frame and image data of a predicted frame of an I picture or a P picture that precedes it in time. Encoding type such as encoding. The B picture is basically a difference (prediction error) between the image data for one frame and the image data of the predicted frame of the I picture or P picture that precedes or follows in time. An encoding type that encodes the difference.

  Therefore, picture type assignment refers to assigning each frame to one of three encoding types such as an I picture, a P picture, and a B picture. In other words, it can be said that the picture type assignment is a setting of each GOP (Group Of Picture) structure.

  In this way, after the first pass encoding process, setting of the target bit amount and picture type assignment are performed on a frame basis using the processing result.

  Next, an encoding condition including at least the picture type and the target bit amount for each frame is set, and the second pass encoding process is executed according to the encoding condition.

  That is, the encoder performs the second pass encoding process on the same video data as the first pass, and outputs the encoded video data obtained as a result. Specifically, the encoder sequentially encodes the data of each frame constituting the video data so as to be data of an assigned picture type and a target bit amount. As a result, a bit stream formed by continuously arranging encoded frame data of any one of I, B, and P pictures is output from the encoder as encoded video data.

  Other video data encoding methods are also disclosed in Patent Document 2 and Patent Document 3, for example.

  The technique disclosed in Patent Document 2 is a technique in which the following first to third processes are executed in that order. That is, the first process is a process for performing the first pass encoding process on all sections of the video data. The second process is a process of performing the second pass encoding process on only a part of specific sections of the video data. In the third process, only the data in a specific section of the encoded video data of the first pass is replaced with the encoded video data of the second pass, and the resulting data is output as final encoded video data. It is processing.

  The technique disclosed in Patent Document 3 is the following technique. In other words, the target bit amount is set so that the allocated amount of the section in which there is no problem even if the bit amount of the encoded video data in the first pass is reduced is allocated to another section where the problem occurs. Japanese Patent Application Laid-Open No. H10-228688 discloses a method of performing the second pass encoding process according to the target bit amount.

JP 2000-278042 A JP 2002-326864 A JP 2001-53570 A JP 2006-74461 A

  By the way, audio standards defined for Blu-Ray (trademark) discs include TureHD, DTS-HD, and the like capable of variable rate (VBR) transfer. The maximum transfer rate of DTS-HD is specified as 24.5 Mbps, and the maximum transfer rate of TrueHD is specified as 18 Mbps. As for video standards, the maximum transfer rate is defined as 40 Mbps, and the maximum transfer rate of secondary video data is defined as 8 Mbps. The maximum transfer rate of the Blu-Ray disc itself is specified as 54 Mbps.

  In the disc production process that uses variable rate transfer for audio, secondary video, etc., for example, a process that minimizes the difference between the maximum rate and the minimum rate for variable-rate audio data in order to keep the transfer rate of the Blu-Ray standard. In addition, the audio transfer bandwidth of Blu-Ray discs was reduced. Also, the secondary video data is encoded with an average rate suppressed so as to be within the maximum transfer rate of the secondary video, or encoded at a uniform rate (CBR: Constant Bit Rate).

  In actual operation, the average rate and maximum rate of the variable rate of audio or secondary video are calculated and encoded so as to be within the maximum transfer rate of the Blu-Ray disc.

  However, in these methods, since the maximum rate of variable rates such as audio and secondary video becomes a reference for calculation, the compression rate band of the primary video data is limited by the peak of the variable rate. For this reason, the transfer rate according to the disk standard has not been fully utilized, and the high quality and efficiency that is the purpose of the original variable rate has not been realized.

  The present invention has been proposed in view of such conventional circumstances, and provides an information processing apparatus, an information processing method, and a program capable of compressing data with high quality and high efficiency.

  An information processing apparatus according to the present invention includes a calculation unit that subtracts a rate distribution value obtained by variable rate compression of the sub data from a maximum transfer rate of main data and sub data to calculate a bit rate in units of frames, and A compression unit that compresses the main data based on the bit rate of each frame.

  The information processing method according to the present invention includes a calculation step of subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and the sub data to calculate a bit rate in units of frames. And a compression step of compressing main data based on the bit rate of the frame unit.

  Further, the program according to the present invention includes a calculation step of subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and sub data to calculate a bit rate in units of frames, And causing the computer to execute a compression step of compressing the main data based on the bit rate of each frame.

  According to the present invention, a bit rate for each frame is calculated by subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and the sub data, and based on this bit rate for each frame. Since the main data is compressed, the data can be compressed with high quality and high efficiency by making maximum use of the maximum transfer rate. Therefore, it is possible to manufacture a high-quality and efficient disk.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Here, the overall configuration of the authoring apparatus will be described first, and then the information processing apparatus that compresses video data will be described.

〔overall structure〕
FIG. 1 shows a configuration example of an authoring apparatus installed on the studio side (hereinafter referred to as “studio-side authoring apparatus”) to which the present invention is applied.

  The studio authoring device 11 includes a menu signal processing device 21, a subtitle signal processing device 22, an audio signal processing device 23, a video signal processing device 24, a multiplexer 25, a downloader 26, a file server 27, and an authoring. The application execution apparatus 28 is connected to each other via a network 29. Further, a DLT (Digital Linear Tape) 31, a HDD (Hard Disk Drive) 32, and a network 33 are connected to the downloader 26 via a writer 30. Hereinafter, each of the menu signal processing device 21 to the downloader 26 is also referred to as an “internal device”.

  The studio-side authoring device 11 generates a multiplexed stream to be recorded on the optical disc as a file and outputs it to at least one of the DLT 31, the HDD 32, and the network 33. For example, when data is output to the network 33, the data is transferred to another device connected to the network 33, for example, the plant-side authoring device 101 in FIG. 5 described later, and the data is held in the other device. (Remember).

  In the studio-side authoring device 11, the menu signal processing device 21 is controlled by the authoring application execution device 28, performs an encoding process on the video data of the menu screen supplied from, for example, a video tape recorder, and the result is obtained. The encoded video data is stored in the file server 27.

  The subtitle signal processing device 22 is controlled by the authoring application execution device 28 and performs encoding processing on video data such as a title supplied from an external video tape recorder, for example, and the resulting encoded video data is file server 27.

  The audio signal processing device 23 is controlled by the authoring application execution device 28, performs an encoding process on audio data supplied from, for example, a video tape recorder, and stores the encoded audio data obtained as a result in the file server 27.

  The video signal processing device 24 is controlled by the authoring application execution device 28, performs an encoding process on the video data supplied from, for example, a video tape recorder, and stores the encoded video data obtained as a result in the file server 27. The video data is the main data among editing objects (data) to be recorded on the optical disc. A detailed configuration example of the video signal processing device 24 will be described later with reference to FIG.

  The multiplexer 25 is controlled by the authoring application execution device 28, multiplexes the encoded audio data and encoded video data stored in the file server 27, and generates the resulting multiplexed stream as a file (hereinafter referred to as "multiplexed"). Referred to as a stream file). The multiplexed stream file generated by the multiplexer 25 is supplied to the downloader 26 via the network 29.

  The downloader 26 outputs the multiplexed stream file to at least one of the DLT 31, the HDD 32, and the network 33 via the writer 30. This multiplexed stream file is supplied as disk image data, for example, to the plant-side authoring apparatus 101 of FIG. Further explanation of the plant-side authoring apparatus 101 will be described later.

  The file server 27 is composed of, for example, a computer having a network management function and a disk array that can be accessed at high speed. The file server 27 stores encoded video data and encoded audio data supplied from each internal device via the network 29. The file server 27 outputs the stored encoded video data and encoded audio data to the multiplexer 25 and the like via the network 29 in response to a request from the multiplexer 25 and the like.

  The authoring application execution device 28 is constituted by, for example, a computer that can execute authoring application software. The authoring application software refers to software for controlling the overall operation of the studio authoring apparatus 11. That is, the authoring application execution device 28 controls the operation of each internal device as described above, for example, according to various conditions set by the operator.

  Next, an operation example of the studio-side authoring apparatus 11 will be described with reference to the flowchart of FIG.

  In step S1, the authoring application execution device 28 notifies each internal device such as the video signal processing device 24 of the editing target by notifying each internal device of the edit list in accordance with the operation of the operator.

  Here, the editing target includes at least video data to be processed by the video signal processing device 24, for example. In addition, if necessary, any number of audio data to be processed by the audio signal processing device 23, video data to be processed by the subtitle signal processing device 22, and video data to be processed by the menu signal processing device 21. The so-called material (data) including any kind of data.

  In step S2, the authoring application execution device 28 generates various types of information necessary for the encoding process, and notifies the internal device of an encoded file that is collectively included in a predetermined file.

  Specifically, the authoring application execution device 28 acquires, for example, the recordable data amount of the optical disc on which the editing target is to be recorded, and based on the data amount, assigns the data amount allocated to each data constituting the editing target. Calculate each. Then, the authoring application execution device 28 includes each of the calculated data amounts in the encoded file, and notifies the corresponding internal device among the internal devices.

  For example, when the encoded file is notified to the video signal processing device 24, the authoring application execution device 28 notifies the video data to be processed by the video signal processing device 24. That is, the amount of data allocated to video data excluding menus and titles to be edited (hereinafter referred to as “data amount that can be allocated to video data”) is included in the encoded file and notified to the video signal processing device 24. .

  Further, for example, the authoring application execution device 28 encodes chapter time information (hereinafter referred to as “access (chapter) point”) set by the operator for video data excluding menus and titles to be edited. It is included in the file and notified to the video signal processing device 24. A chapter refers to a frame to which intra-frame coding processing (I picture) is forcibly assigned. An apparatus capable of handling an optical disk can confirm the recorded contents by performing a track jump with this chapter as a target.

  Further, for example, the authoring application execution apparatus 28 encodes the maximum number of GOP display frames (for example, 15 frames) and the encoding processing array in each GOP for video data excluding menus and titles to be edited. To the video signal processing device 24.

  Further, for example, the authoring application execution device 28 notifies the video signal processing device 24 of a multi-angle processing target, if necessary, in the encoded file. Multi-angle refers to a process in which a plurality of video materials are time-division multiplexed and recorded on an optical disc so that, for example, a train traveling scene can be viewed from different shooting locations according to a user's selection.

  Also, for example, the authoring application execution device 28 includes “automatic scene change detection (ON / OFF)”, “disk capacity of the optical disk”, “VTR start and end times”, etc. in the encoded file as necessary. To the video signal processing device 24.

  In step S3, each internal device encodes corresponding data in the editing target based on various information included in the encoded file, and stores each encoded data obtained as a result in the file server 27. . Specifically, for example, the video signal processing device 24 executes “video data generation processing” in FIG. 4 to be described later.

  In step S4, the multiplexer 25 generates a multiplexed stream file by multiplexing each encoded data stored in the file server 27 in the process of step S3, and supplies the multiplexed stream file to the downloader 26.

  In step S <b> 5, the downloader 26 outputs the multiplexed stream file to at least one of the DLT 31, the HDD 32, and the network 33 via the writer 30. Thereby, the process of the studio side authoring apparatus 11 is complete | finished.

  Next, a detailed configuration example of the video signal processing device 24 in the studio-side authoring device 11 will be described with reference to FIG.

  As shown in FIG. 3, the video signal processing device 24 includes, for example, a video tape recorder 51, a main controller 52, an encoder 53, and a monitor device 54.

  The edit list is supplied from the authoring application execution device 28 to the video signal processing device 24 by the processing in step S1 described above. Specifically, the edit list is supplied to the main controller 52 as shown in FIG. 3 and then supplied to the video tape recorder 51. That is, the edit list is supplied to the video tape recorder 51 via the main controller 52.

  The video tape recorder 51 reproduces the magnetic tape in accordance with this edit list, thereby outputting the video data D1 to be processed and supplying it to the encoder 53.

  The encoder 53 switches its operation according to various encoding conditions set by the main controller 52, and performs encoding processing according to, for example, the MPEG standard on the video data D1 output from the video tape recorder 51. At this time, the setting of various encoding conditions is variably controlled by the main controller 52 so that the amount of bits generated from the encoder 53 is controlled.

  Further, the encoder 53 notifies the main controller 52 of the result of the encoding process. As a result, the main controller 52 can detect the picture type used in the encoding process of the encoder 53 and the generated bit amount in the encoding process in units of frames.

  In addition, when performing so-called two-pass encoding, the encoder 53 performs both the first-pass and second-pass encoding processes.

  Specifically, the encoder 53 performs a first pass encoding process, for example, a part of the process of step S22 in FIG. 4 to be described later in order to set in advance the encoding conditions used in the second pass encoding process. Perform some encoding process. Specifically, the encoder 53 allocates a picture type by its own internal processing. Then, the encoder 53 performs the first pass encoding process on the video data D1 using the picture type allocated in this way, and the result of the first pass encoding process is, for example, the picture type of each frame. And the generated bit amount and the like are notified to the main controller 52.

  In the second pass encoding process, the encoder 53 executes, for example, an encoding process in step S30 in FIG. That is, the encoder 53 performs the second pass encoding process on the video data D1 using the picture type and the target bit amount set by the main controller 52, and the encoded video data obtained as a result thereof. D2 is stored in the file server 27 via the network 29. At this time, the encoder 53 notifies the main controller 52 of the data amount of the video data D2 stored in the file server 27.

  The monitor device 54 is configured by a display device, for example, and displays video corresponding to the encoded video data D2 output from the encoder 53 based on control through the encoder 53 of the main controller 52. That is, the encoder 53 decodes the encoded video data D2 and supplies the resulting video signal to the monitor device 54. The monitor device 54 displays a video corresponding to the supplied video signal, that is, a video corresponding to the encoded video data D2.

  Thereby, the operator can confirm the processing result of the encoder 53 on the monitor device 54 as necessary. That is, the video signal processing device 24 can preview the processing result of the encoder 53 using the monitor device 54. Further, the operator can finely change each of the various encoding conditions by operating the main controller 52 based on the preview result.

  The main controller 52 is constituted by, for example, a computer assigned to the video signal processing device 24. The main controller 52 controls the overall operation of the video signal processing device 24 by performing data communication with the authoring application execution device 28 via the network 29.

  Therefore, for example, as shown in FIG. 3, the main controller 52 includes a graphical user interface (GUI) 61, a video tape recorder (VTR) control unit 62, a bit assign unit 63, and An encoding control unit 64 is provided.

  That is, the main controller 52 receives the control from the authoring application execution device 28 and the operation of the operator by the management of the GUI 61. In addition, the VTR control unit 62, the bit assign unit 63, and the encode control unit 64 managed by the GUI 61 are used to control the operations of the video tape recorder 51, the encoder 53, and the monitor device 54.

  Accordingly, the main controller 52 can set various encoding conditions based on the encoded file notified from the authoring application execution device 28, for example. Hereinafter, in order to distinguish from the encoded file supplied to other internal devices, the encoded file supplied to the video signal processing device 24 is referred to as an encoded file VENC.XML together with the description of FIG. Called.

  Further, as described above, the main controller 52 accepts operator settings via the GUI 61, and can thereby update, for example, various encoding condition settings.

  The main controller 52 controls, for example, that the encoder 53 performs encoding processing on the video data D1 to be processed in accordance with various encoding conditions set or updated as described above.

  The main controller 52 can receive the result of the encoding process notified from the encoder 53 and notify the authoring application execution apparatus 28 of the result of the encoding process.

  The VTR control unit 62 controls the operation of the video tape recorder 51 in accordance with the edit list notified from the authoring application execution device 28 to reproduce the video data D1 to be edited from the video tape recorder 51.

  For example, the bit assigning unit 63 sets various encoding conditions according to the encoded file VENC.XML notified from the authoring application execution device 28, and notifies the encoding control unit 64 of control data corresponding to the encoding conditions. At this time, the bit assigning unit 63 can change the setting of various encoding conditions in accordance with, for example, the operator's operation of the GUI 61.

  The encoding conditions set by the bit assigning unit 63 include, for example, the first encoding condition used in the first pass encoding process and the second encoding condition used in the second pass encoding process. . The first encoding condition includes, for example, various conditions necessary for setting the picture type in the internal process when the encoder 53 executes the first pass encoding process. On the other hand, the second encoding condition includes, for example, the picture type and the target bit amount of each frame used in the second pass encoding process.

  For example, the encoding control unit 64 controls each encoding process of the first pass and the second pass of the encoder 53 according to the control file notified from the bit assigning unit 63.

  Further, the encoding control unit 64 detects the difficulty level required for the encoding process and the picture type from the result of the first pass encoding process by the encoder 53 in units of frames, and the detection result is sent to the bit assigning unit 63. Notice. Then, the bit assignment unit 63 sets the second encoding condition used in the second pass encoding process using the notified difficulty level and picture type for each frame. The difficulty level will be described later.

  Further, the encoding control unit 64 controls the encoded video data D2 obtained as a result of the final second-pass encoding process of the encoder 53 to be stored in the file server 27 via the network 29.

  Next, an example of the operation of the video data generation process in the video signal processing device 24 will be described with reference to the flowchart of FIG.

  The authoring application execution device 28 notifies the edit list (edit target) in the process of step S1 of FIG. 2 described above, and the encoded file VENC.XML is supplied in the process of step S2. Further, when the start of the “video data generation process” is instructed, the VTR control unit 62, the bit assignment unit 63, and the encoding control unit 64 are activated by the management of the GUI 61, and this “video data generation process” Is started. That is, the process proceeds to step S3 in FIG. 2, and this “video data generation process” is started as the process of the video signal processing device 24 in the process of step S3.

  In step S21, the main controller 52 acquires various types of information necessary for the encoding process of the video data D1 to be edited from the encoded file VENC.XML supplied from the authoring application execution device 28.

  Specifically, for example, “access (chapter) points”, “scene change automatic detection (ON / OFF)”, “disk capacity”, “VTR start and end times” included in the encoded file VENC.XML, Various types of information such as “amount of data that can be allocated to the video data D1” are acquired.

  In step S22, the main controller 52 controls the video tape recorder 51 and the encoder 53 to perform the first pass encoding process according to the first encoding condition set by the various information acquired in the process of step S21. Is applied to the video data D1 to be edited. Then, the main controller 52 detects the difficulty level required for the encoding process and the picture type for each frame from the first encoded video data obtained as a result of the first pass encoding process.

  Specifically, the encoder 53 processes the video data D1 to be edited reproduced by the video tape recorder 51 as follows.

  The encoder 53 sets each picture type of each frame constituting the video data D1. That is, the encoder 53 sets the frame designated by the instruction from the main controller 52 as an I picture. Furthermore, when “automatic scene change detection” acquired in the process of step S21 is set to ON (when notified from the main controller 52), the encoder 53 correlates the frames before and after that. A frame determined to be a scene change from the relationship is forcibly set as an I picture. Then, the encoder 53 executes a process of setting a frame group from the frame set as the I picture to the frame immediately before the next I picture as the GOP.

  Further, the encoder 53 sequentially performs the first pass encoding process by the fixed quantization step on each of the frames constituting the video data D1 using the picture type set in this way. . The encoder 53 notifies the main controller 52 of the amount of bits generated at that time, that is, the amount of generated bits when each frame is encoded, and the picture type of each frame to the main controller 52. Notice.

  Then, the main controller 52 detects each of the difficulty level and the picture type in units of frames based on this notification from the encoder 53. That is, the main controller 52 detects the picture type of each frame notified from the encoder 53 as the picture type of each frame as it is. Further, the main controller 52 detects (measures) each generated bit amount of each frame notified from the encoder 53 as each difficulty level of each frame.

  As described above, the difficulty level in the present specification refers to the data amount of each frame after the encoding process when the encoding process by the fixed quantization step is performed on the video data D1 to be edited. .

  In other words, in the inter-frame encoding process (P or B picture encoding type), the prediction error (difference) from the prediction frame becomes large at a portion where the motion is intense, and much data is required to reduce the image quality degradation accordingly. It becomes. In addition, in the intra-frame encoding process (I-picture encoding type), when there are many high frequency components, high-order coefficient data is generated by the discrete cosine transform process. A large amount of data is required. Therefore, when the encoding process by the fixed quantization step is performed on the video data D1, a large amount of data is detected in a portion (frame) that requires a large amount of data to reduce image quality degradation. Become. From the above, the data amount of each frame data constituting the encoded video data obtained as a result of the encoding process by the fixed quantization step being applied to the video data D1 to be edited is the respective data amount of each frame. Will refer to the degree of difficulty.

  In step S23, the main controller 52 sets the target bit amount in units of frames by executing “bit allocation calculation processing” using the difficulty level and the picture type detected in units of frames in the process of step S22. .

  The “bit allocation calculation process” refers to the following process, for example. In other words, the encoded video data D2 obtained when the second pass encoding process is performed on the video data D1 to be edited using the difficulty level and the picture type of each frame detected in the process of step S22. A calculation process for allocating the entire target bit amount to each frame is a “bit allocation calculation process”.

  Hereinafter, the “bit allocation calculation process” will be described in more detail.

That is, the main controller 52 executes the arithmetic processing of the following equation (1), and calculates the total bit amount TOTAL_SUPPLY that can be actually allocated to the video data D1 (encoded data D2).
TOTAL_SUPPLY = TOTAL_BYTES − TOTAL_HEADER (1)
In equation (1), TOTAL_BYTES indicates the “data amount that can be allocated to the video data D1” acquired in the process of step S21, and the target data of the entire encoded video data D2 recorded in the file server 27 on the network 29. It corresponds to the amount. Further, TOTAL_HEADER indicates the data amount of accompanying data such as a header in the encoded video data D2, and is the data amount specified by the total number of GOPs.

  Therefore, the main controller 52 actually allocates the data amount that can be allocated to the data excluding the incidental data of the encoded video data D2 to the video data D1 by the arithmetic processing of the equation (1). The total amount of bits that can be allocated is calculated as TOTAL_SUPPLY.

  Next, the main controller 52 distributes the total bit amount TOTAL_SUPPLY that can be actually allocated to the video data D1 to each encoding processing unit (encoding unit). Hereinafter, the data amount of each encoding unit distributed in this way is referred to as a target bit amount of the corresponding encoding unit and is described as SUPPLY_BYTES. Further, the main controller 52 calculates, for each encode unit, the total sum of the difficulty levels of the frames belonging to the corresponding encode unit (difficulty levels detected in the process of step S22). Hereinafter, the difficulty level of each frame is described as DIF, and the sum of the difficulty levels DIF is described as DIF_SUM.

Subsequently, the main controller 52 calculates an evaluation function for performing bit allocation in GOP units for each encoding unit. The evaluation function here is expressed by the following equation (2), for example.
Y = BX (2)
In Expression (2), Y represents the target bit amount SUPPLY_BYTES of the encoding unit to be calculated, and X represents the total DIF_SUM of the difficulty levels DIF of each frame belonging to the encoding unit to be calculated.

When the main controller 52 sets the evaluation function of the expression (2) in this way, in other words, when the coefficient B in the evaluation function of the expression (2) is calculated, the following uses the coefficient B for each encoding unit. The calculation process of Equation (3) is sequentially executed.
GOP_TGT = B × GOP_DIF_SUM (3)
In Expression (3), GOP_DIF_SUM indicates the sum of the difficulty levels DIF of each frame belonging to the GOP to be calculated. GOP_TGT indicates the target bit amount of the GOP to be calculated.

  That is, the target bit amount GOP_TGT of the calculation target GOP is allocated to the calculation target GOP from the target bit amount SUPPLY_BYTES of the encoding unit including the calculation target GOP according to the difficulty level GOP_DIF_SUM of the calculation target GOP. Refers to the amount of data.

  Then, the main controller 52 sets the target bit amount of each frame by executing, for each GOP, the process of allocating the target bit amount GOP_TGT of the target GOP to each of the frames belonging to the target GOP. .

  As described above, in the “bit allocation calculation process” in step S23, the second encoding condition used in the second pass encoding process is set based on the first pass encoding process result (the process result in step S22). One, that is, a target bit amount is set.

  In step S24, the main controller 52 determines the target bit amount for each frame set by the immediately preceding “bit allocation calculation process” (in this case, the “bit allocation calculation process” in step S23) and the process in the immediately preceding step S22. The second encoding condition including at least the picture type of each frame detected in step (b) is set.

  Next, in step S25, the main controller 52 performs the second encoding that should be obtained when the second pass encoding process according to the second encoding condition is performed on the video data D1 to be edited. A preview process of the video data D2 is executed.

  The preview processing in step S25 indicates, for example, the following series of processing. That is, the video tape recorder 51 reproduces the video data D1 to be edited and supplies it to the encoder 53 in response to the operator's operation of the GUI 61, that is, in response to the control of the main controller 52. The encoder 53 once encodes the video data D1 according to the second encoding condition, re-decodes the resulting encoded video data D2, and supplies the resulting video signal to the monitor device 54. The monitor device 54 displays an image corresponding to this video signal. That is, the video corresponding to the second encoded video data D2 that should be obtained when the second pass encoding process according to the second encoding condition is performed on the video data D1 to be edited is displayed on the monitor device. 54 is displayed as a preview image. The series of processes described above is the preview process in step S25.

  In step S26, the main controller 52 determines whether or not the image quality evaluation of the operator is “O.K”.

  That is, the operator evaluates the image quality of the preview image displayed on the monitor device 54 by the process of step S25, that is, the image corresponding to the encoded video data D2, and operates the GUI 61 to display the evaluation result as the main controller. 52 can be input.

  For example, when the operator is satisfied with the image quality and operates the GUI 61 to instruct the start of the second pass encoding process, it is determined in step S26 that the operator's image quality evaluation is “OK”, and the process proceeds to step S30. Proceed to

  In step S30, the main controller 52 controls the video tape recorder 51 and the encoder 53 to perform the second pass encoding process in accordance with the second encoding condition set in the immediately preceding step S24. This is applied to the video data D1. Further, the second encoded video data D2 obtained as a result is stored in the file server 27.

  Specifically, for example, the video tape recorder 51 reproduces the video data D1 to be edited based on the control of the main controller 52 and supplies it to the encoder 53. The encoder 53 performs the second-pass encoding process according to the second encoding condition instructed from the main controller 52 on the video data D1, and uses the resulting second encoded video data D2 as the main controller. Based on the control of 52, it is stored in the file server 27 via the network 29.

  Thereafter, in step S31, the main controller 52 executes post-processing such as notifying the authoring application execution device 28 of the result of the second pass encoding process. This completes the “video data generation process”.

  On the other hand, is the operator satisfied with the image quality of the preview video displayed on the monitor device 54 by the preview processing in step S25, that is, the video corresponding to the encoded video data D2 before being stored in the file server 27? To evaluate. If the operator is not satisfied with the image quality, for example, if the customization process is selected by operating the GUI 61, it is determined in step S26 that the image quality evaluation of the operator is not “O.K”, and the process proceeds to step S27.

  In step S27, the main controller 52 determines whether or not an instruction to change the picture type is given.

That is, the operator operates the GUI 61 to give an instruction to change the picture type of one or more frames constituting the video data D1 to be edited from B or P picture to I picture. The data can be input to the controller 52.
If there is no such instruction from the operator, it is determined in step S27 that there is no instruction to change the picture type, and the process proceeds to step S28.

  In step S <b> 28, the main controller 52 executes “customization processing”. The “customization process” here refers to a process of partially changing the image quality by partially changing the encoding condition in response to the operator's operation of the GUI 61, for example.

  Further, in the subsequent step S29, the main controller 52 re-executes the “bit distribution calculation process” similar to step S23 described above, thereby updating the setting of the target bit amount. That is, the process of step S29 is basically the same process as the process of step S23 described above. However, the process of step S29 is different from the process of step S23 in that the result of the “customization process” of the immediately preceding step S28 is used.

  When the process of step S29 ends, the process returns to step S24, and the subsequent processes are repeated.

  On the other hand, if there is an instruction to change the picture type from the operator, it is determined in step S27 that an instruction to change the picture type is given, the process returns to step S21, and the subsequent processes are repeated.

  That is, the frame instructed by the operator to change the picture type is regarded as a scene change point, and as a result, a series of processes after the above-described various information acquisition process in step S21 is performed again.

  As described above, the video signal processing device 24 can set the second encoding condition used in the second pass encoding process based on the difficulty level and the picture type for each frame. Further, the video signal processing device 24 can change the second encoding condition in response to the operation of the operator. As a result, the video data D1 is finally encoded under the second encoding condition satisfied by the operator, and the encoded video data D2 obtained as a result is stored in the file server 27.

  Thereafter, as described above, in the studio-side authoring apparatus 11 of FIG. 1, the encoded video data D2 is multiplexed with other encoded video data and encoded audio data, and the resulting multiplexed stream file is converted into a DLT 31. , HDD 32, and network 33.

  As described above, the multiplexed stream file output to at least one of the DLT 31, the HDD 32, and the network 33 is the disk image data, for example, the authoring apparatus (hereinafter, referred to as FIG. 5) installed on the plant side. (Referred to as plant-side authoring device).

  FIG. 5 shows a configuration example of a plant-side authoring apparatus to which the present invention is applied.

  As shown in FIG. 5, the plant-side authoring device 101 includes, for example, a premastering device 111, a formatter 112, and a cutting device 113.

  Here, with reference to the flowchart of FIG. 6, the process example of this plant side authoring apparatus 101 is demonstrated.

  In step S41, the premastering apparatus 111 acquires disk image data (multiplexed stream file including the encoded video data D2 in FIG. 3).

  Next, in step S42, the premastering device 111 encrypts the disk image data using copy protection data given from the outside, and supplies the encrypted data obtained as a result to the formatter 112.

  In step S 43, the formatter 112 performs various processes such as a signal level conversion process on the encrypted data, and supplies the resulting signal to the cutting device 113.

  In step S44, the cutting device 113 creates a master disc 114 (an optical disc master 114 on which disc image data is recorded) based on the signal supplied from the formatter 112. Thereby, the process of the plant side authoring apparatus 101 is complete | finished.

  As described above, in the first pass encoding process for the video data D1 in FIG. 3 described above, the picture type optimized for the video material is set and used, and the target of each frame based on the picture type is used. The bit amount is set. Thereafter, the same picture type as in the first pass is used, and the target bit amount set in the first pass is used, and the second pass encoding process is performed on the video data D1, As a result, encoded video data D2 is obtained. Then, the disk image data including the encoded video data D2 is supplied to the plant-side authoring apparatus 101 and recorded on the optical disk 114.

  Accordingly, by notifying the studio-side authoring apparatus 11 in FIG. 1 in advance of the usable disk capacity of the optical disk 114, the video signal processing apparatus 24 in FIG. 3 sets a target bit amount corresponding to the notification. Is possible. As a result, it is possible to prevent the data amount of the disk image data recorded on the optical disk 114 from becoming insufficient or excessive as compared to the usable disk capacity of the optical disk 114. As a result, the disc capacity of the optical disc 114 can be fully used, and as a result, the image quality of the video data recorded on the optical disc 114 is improved.

  By the way, the series of processes described above can be executed by hardware, but can also be executed by software.

  In this case, the entire studio-side authoring apparatus 11 shown in FIG. 1 or a part of the studio-side authoring apparatus 11 can be configured, for example, as a computer described later. The part of the studio-side authoring apparatus 11 may be, for example, the entire video signal processing apparatus 24 of FIG. 1, or may be a part of the video signal processing apparatus 24, for example, the main controller 52 of FIG. Sometimes.

  Similarly, the whole plant-side authoring apparatus 101 in FIG. 5 or a part thereof can be configured as a computer to be described later, for example. The part of the plant-side authoring apparatus 101 may be, for example, the entire cutting apparatus 113, as in the studio-side authoring apparatus 11, or may be a part of the cutting apparatus 113 (not shown). is there.

[Video data compression processing]
Next, an information processing apparatus that compresses video data will be described. The information processing apparatus shown as a specific example uses the maximum transfer rate of main data and sub data to the maximum to distribute the video data of the main data with high quality and high efficiency. Note that the information processing apparatus corresponds to the bit assigning unit 63, the encoding control unit 64, and the encoder 53 of the video signal processing device 24 described above.

  FIG. 7 is a block diagram illustrating a configuration of an information processing apparatus that compresses video data based on a variable rate distribution value of an audio stream. This information processing apparatus includes a rate distribution conversion circuit 201, a frame unit bit rate calculation circuit 202, a consistency detection circuit 203, a picture type generation circuit 204, a color space conversion circuit 205, and a primary video compression processing circuit 206. It has.

  The rate allocation conversion circuit 201 converts the variable rate allocation value of the audio stream from a sampling unit to a frame unit. That is, the rate distribution conversion circuit 201 converts the bit rate assigned to the sampling unit on the time axis.

  The frame unit bit rate calculation circuit 202 calculates the frame unit bit rate by subtracting the variable rate distribution value of the audio stream in units of frames from the standard maximum transfer rate. For example, by subtracting the variable rate distribution value from 54 Mbps, which is the maximum transfer rate of the Blu-Ray disc, the bit rate on the time axis, that is, the frame unit of the primary video is derived.

  FIG. 8 is a schematic diagram showing bit distribution of primary video based on audio variable rate distribution values. As shown in Fig. 8, the maximum transfer rate of Blu-Ray discs is subtracted from the maximum transfer rate of 54 Mbps, which is the maximum transfer rate specified for Blu-Ray discs. It is possible to produce higher-quality content. Note that audio standards capable of variable rate (VBR: Variable Bit Rate) transfer include, for example, TrueHD and DTS-HD. The maximum transfer rate of DTS-HD is defined as 24.5 Mbps, and the maximum transfer rate of TrueHD is defined as 18 Mbps.

  The consistency detection circuit 203 receives the assigned picture type of the primary video. The frame unit calculated by the frame unit bit rate calculation circuit 202 at the frame position of the I picture (intra-frame encoded image: Intra-Picture) or P picture (inter-frame forward prediction encoded image: Predictive-Picture) It is determined whether the bit rate exceeds the picture type change reference value.

  When the consistency detection circuit 203 determines that the picture change reference value has not been exceeded, the picture type generation circuit 204 reconstructs a GOP (Group Of Picture) structure as will be described later, and assigns the assigned picture type at the time of encoding. To decide. This GOP reconstruction is performed as part of the above-described “bit allocation calculation process”.

  The color space conversion circuit 205 converts the color space of the primary video data that is the material to be encoded and outputs it to the primary video compression processing circuit 206. Note that YUV = 4: 2: 2 is obtained by sampling the luminance in 8 bits for each pixel in 4 pixels in the horizontal direction, averaging the color difference for every 2 pixels, and sampling in 8 bits, and the amount of information is 16 bits in average for each pixel. is there. YUV = 4: 2: 0 is a format in which the luminance information is left as it is after sampling with YUV = 4: 2: 2, and the color difference information is averaged (subsampled) by two pixels in the vertical direction and recorded. Yes, the amount of information is an average of 12 bits per pixel.

  The primary video compression processing circuit 206 compresses video data based on a bit rate in units of frames. The primary video compression processing circuit 206 performs compression processing according to the assigned picture type determined by the picture type generation circuit 204 and outputs compressed data.

  Thus, by subtracting the variable rate distribution value of the audio stream in frame units from the maximum transfer rate to calculate the bit rate in frame units, the maximum transfer rate can be utilized to the maximum. Similarly, the maximum transfer rate can be maximally utilized based on the variable rate distribution value of the secondary video.

  FIG. 9 is a block diagram illustrating a configuration of an information processing apparatus that compresses primary video data based on a variable rate distribution value of secondary video. This information processing apparatus includes a frame unit bit rate calculation circuit 211, a consistency detection circuit 212, a picture type generation circuit 213, a color space conversion circuit 214, and a primary video compression processing circuit 215.

  The frame unit bit rate calculation circuit 211 calculates a frame unit bit rate by subtracting the variable rate distribution value of the secondary video in frame units from the standard maximum transfer rate. For example, the bit rate of the frame unit of the primary video is derived by subtracting the variable rate distribution value from 40 Mbps which is the maximum transfer rate of the video standard of the Blu-Ray disc.

  FIG. 10 is a schematic diagram showing bit distribution of the primary video based on the variable rate distribution value of the secondary video. As shown in Fig. 10, by subtracting the secondary video variable rate distribution value from the maximum transfer rate of 40 Mbps for the Blu-Ray disc video standard, the maximum transfer rate of the Blu-Ray disc can be used effectively. It is possible to produce higher-quality content. As for the video standard, the maximum transfer rate is defined as 40 Mbps, and the maximum transfer rate of secondary video data is defined as 8 Mbps. The maximum transfer rate of the Blu-Ray disc itself is specified as 54 Mbps.

  In addition, the consistency detection circuit 212, the picture type generation circuit 213, the color space conversion circuit 214, and the primary video compression processing circuit 215 are respectively included in the consistency detection circuit 203, the picture type generation circuit 204, the color space conversion circuit 205, and the primary video compression processing circuit 215. Since this is the same as the video compression processing circuit 206, the description thereof is omitted.

  Thus, by subtracting the variable rate distribution value of the secondary video from the maximum transfer rate of the video standard, the maximum transfer rate can be utilized to the maximum.

  In the above description, variable-rate audio and variable-rate secondary video are processed by separate information processing apparatuses. However, primary video data can be compressed by using a single information processing apparatus. Is possible.

  Next, processing of the consistency detection circuits 203 and 212, picture type generation circuits 204 and 213, color space conversion circuits 205 and 214, and primary video compression processing circuits 206 and 215 will be described with specific examples.

  FIG. 11 is a diagram illustrating an example of the picture type determination result in accordance with the difficulty level of the material. This picture type determination is performed by the primary video compression processing circuits 206 and 215. Specifically, for example, the encoder 53 of the video signal processing device 24 determines the picture type from the degree of difficulty required for the encoding process detected by the first pass encoding.

  FIG. 12 is a diagram illustrating an example of the rate distribution value of the primary video set based on the variable rate distribution value of the secondary video. In this case, the distribution value of the primary video is set by subtracting the variable rate distribution value of the secondary video from 40 Mbps, which is the maximum transfer rate of the video standard of the Blu-Ray disc.

  FIG. 13 is a diagram illustrating a determination example of the consistency detection circuit 203 when 35 Mbps is set as the picture type change reference value. The consistency detection circuits 203 and 212 determine whether the bit rate of the primary video exceeds the picture type change reference value at the frame position of the I picture or P picture. In the example shown in FIG. 13, frames 02, 05, and 11 that do not exceed the picture type change reference value are detected.

  If the picture type change reference value is not exceeded at the frame position of the I picture or P picture, it is difficult to assign an I picture or P picture that greatly affects image quality.

  Therefore, the picture type generation circuits 204 and 213 reconstruct a GOP (Group Of Picture) structure. Specifically, as shown in FIG. 14, an I picture or a P picture that does not exceed the picture type change reference value is changed to a B picture (bidirectional predictive-picture), and a picture type change reference. Change the picture type greater than the value to I picture or P picture. Thus, by determining the assigned picture type at the time of encoding, it is possible to produce a Blu-Ray disc with higher quality.

  FIG. 15 is a flowchart showing video data compression processing in the information processing apparatus. First, in step S101, a transfer rate distribution value other than the primary video is input to the information processing apparatus.

  In step S102, the information processing apparatus determines whether or not the input transfer rate distribution value is a secondary video. If the transfer rate distribution value is that of the secondary video, the process proceeds to step S103, and if the transfer rate distribution value is not that of the secondary video, the process proceeds to step S104.

  In step S103, the frame unit bit rate calculation circuit 211 subtracts the secondary video rate distribution value from the maximum transfer rate of the video standard to calculate the frame rate of the primary video.

  In step S104, the rate distribution conversion circuit 201 converts the rate distribution value in the audio sampling unit into the rate distribution value in the frame unit.

  In step S105, the frame unit bit rate calculation circuit 202 subtracts the audio rate distribution value from the maximum transfer rate of the Blu-Ray disc to calculate the frame unit bit rate of the primary video.

  In step S106, the consistency detection circuits 203 and 212 determine whether the bit rate of the primary video is greater than or equal to the picture type change reference value at the frame position of the I picture or P picture. If the picture type change reference value is not satisfied, the process proceeds to step S107. If the picture type change reference value is greater than or equal to the picture type change reference value, the process proceeds to step S108.

  In step S107, the picture type generation circuits 204 and 213 reconstruct a GOP (Group Of Picture) structure. Specifically, the reconstruction process is repeatedly performed until the I picture or P picture reaches or exceeds the picture type change reference value. By reconstructing the GOP structure in this way, it is possible to determine an assigned picture type with high image quality.

  In step S108, the primary video compression processing circuits 206 and 215 compress the primary video data based on the bit rate and the assigned picture type in units of frames.

  In this way, the information processing apparatus inputs the rate distribution value other than the encoding target and determines the encoding target rate distribution value by subtracting the non-encoding rate distribution value from the maximum transfer rate, thereby maximizing the transfer rate. It can be used as much as possible.

  Further, after determining the rate distribution value, the information processing apparatus determines whether the rate distribution value at the frame position of the I picture or P picture that greatly affects the image quality of the encoding assigned picture type is equal to or greater than the set reference value. do. And if it is below the setting standard, the GOP structure is reconfigured and the allocation picture type is changed to B picture allocation, so that the transfer rate of the Blu-Ray disc can be fully utilized to achieve higher quality image quality. Blu-Ray disc production becomes possible.

  The series of processes described above can be executed by hardware, but can also be executed by software. In this case, the information processing apparatus illustrated in FIGS. 7 and 9 can be configured as a computer.

  FIG. 16 is a block diagram illustrating a configuration of a computer. A CPU (Central Processing Unit) 301 executes various processes according to a program recorded in a ROM (Read Only Memory) 302 or a program loaded from a storage unit 308 to a RAM (Random Access Memory) 303. The RAM 303 also appropriately stores data necessary for the CPU 301 to execute various processes.

  The CPU 301, ROM 302, and RAM 303 are connected to each other via a bus 304. An input / output interface 305 is also connected to the bus 304.

  An input unit 306, an output unit 307, a storage unit 308, and a communication unit 309 are connected to the input / output interface 305. A drive 310 is connected to the input / output interface 305 as necessary, and a removable recording medium 311 made of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is appropriately installed, and a computer read from them is read. The program is installed in the storage unit 308 as necessary.

  The input unit 306 includes input devices such as a touch panel that also serves as a display unit of the output unit 307, a keyboard, a remote controller including a light receiving unit, and a mouse.

  The output unit 307 includes, for example, a display unit such as a display, a sound output unit such as a speaker or a headphone output terminal, or a combination thereof.

  The storage unit 308 is configured with, for example, a hard disk. The communication unit 309 includes, for example, a modem, a terminal adapter, a wireless communication device, and the like, and controls communication with other information processing apparatuses.

  When an information processing apparatus that compresses the above-described primary video using such a computer is configured, it can be configured by a combination of programs executed by the input unit 306, the output unit 307, and the CPU 301.

  As mentioned above, although an example of embodiment was shown, it is not a thing limited to the above-mentioned embodiment, Various modifications based on the technical idea of this invention are possible.

  For example, when the above-described series of processing is also executed by software, a program constituting the software is installed from a network or a recording medium into a computer incorporated in dedicated hardware. Or it installs in a general purpose personal computer etc. which can perform various functions by installing various programs.

  Further, a recording medium including such a program is distributed to provide a program to the user separately from the apparatus main body. For example, a magnetic disk (including a floppy disk) on which a program is recorded, an optical disk (including a compact disk-read only memory (CD-ROM), a DVD (digital versatile disk)), a magneto-optical disk (MD (mini-disk) )), And a removable recording medium (package medium) made of a semiconductor memory or the like. Further, it may be configured by a ROM, a hard disk, or the like that is provided to the user in a state of being pre-installed in the apparatus main body and in which a program is recorded.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the order, but is not necessarily performed in chronological order, either in parallel or individually. The process to be executed is also included.

It is a block diagram which shows the structural example of a studio side authoring apparatus. It is a flowchart which shows the process example of a studio side authoring apparatus. It is a block diagram which shows the structural example of the video signal processing apparatus among studio side authoring apparatuses. It is a flowchart which shows the example of the "video data generation process" which a video signal processing apparatus performs. It is a block diagram which shows the structural example of a plant side authoring apparatus. It is a flowchart which shows the process example of a plant side authoring apparatus. FIG. 3 is a block diagram illustrating a configuration of an information processing apparatus that compresses video data based on a variable rate distribution value of an audio stream. It is a schematic diagram which shows bit distribution of the primary video based on the variable rate distribution value of audio. It is a block diagram which shows the structure of the information processing apparatus which compresses primary video data based on the variable rate distribution value of secondary video. It is a schematic diagram which shows bit allocation of the primary video based on the variable rate allocation value of secondary video. It is a figure which shows an example of the picture type determination result according to the difficulty of a raw material. It is a figure which shows an example of the rate distribution value of the primary video set based on the variable rate distribution value of secondary video. It is a figure which shows the example of a detection of a consistency detection circuit. It is a figure which shows an example which changes the picture type more than a picture type change reference value into an I picture or a P picture. It is a flowchart which shows the video data compression process in information processing apparatus. It is a block diagram which shows the structure of a computer.

Explanation of symbols

  11 Studio-side authoring device, 21 Menu signal processing device, 22 Subtitle signal processing device, 23 Audio signal processing device, 24 Video signal processing device, 25 Multiplexer, 26 Downloader, 27 File server, 28 Authoring application execution device, 29 Network, 30 Writer, 31 DLT, 32 HDD, 33 Network, 51 Video tape recorder, 52 Main controller, 53 Encoder, 54 Monitor device, 61 GUI, 62 VTR control unit, 63 Bit assignment unit, 64 Encode control unit, 101 Plant side authoring device 111 pre-mastering device, 112 formatter, 113 cutting device, 114 optical data Disk device, 201 rate distribution conversion circuit, 202 frame unit bit rate calculation circuit, 203 consistency detection circuit, 204 picture type generation circuit, 205 color space conversion circuit, 206 primary video compression processing circuit, 211 frame unit bit rate calculation circuit, 212 Consistency Detection Circuit, 213 Picture Type Generation Circuit, 214 Color Space Conversion Circuit, 215 Primary Video Compression Processing Circuit

Claims (5)

A calculation unit for subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and the sub data to calculate a bit rate in units of frames;
An information processing apparatus comprising: a compression unit that compresses main data based on the bit rate of the frame unit. The main data is video data,
When the bit rate of the frame position of the intra-frame encoded image or the inter-frame forward prediction encoded image in the video data is equal to or less than a predetermined rate distribution value, the compression unit bi-predictively encodes the picture type of the frame position The information processing apparatus according to claim 1, wherein the information processing apparatus is changed to an image. The sub data is audio data,
The information processing apparatus according to claim 1, further comprising: a conversion unit that converts the variable rate distribution value in sampling units into a variable rate distribution value in frame units. A calculation step of subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and sub data to calculate a bit rate in units of frames;
A compression step of compressing main data based on the bit rate of each frame. A calculation step of subtracting a rate distribution value obtained by variable rate compression of the sub data from the maximum transfer rate of the main data and sub data to calculate a bit rate in units of frames;
A program for causing a computer to execute a compression step of compressing main data based on the bit rate of each frame.

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