JP2010041123A - Image data processor, image recorder and image data processing method - Google Patents

Abstract

An increase in data size due to re-encoding is prevented.
An image data processing apparatus, a recording condition generator for determining a recording mode of the compressed moving image stream in accordance with program information corresponding to the compressed moving image stream, a re-encoded stream that re-encodes the compressed moving image stream A re-encoding unit for obtaining the compressed video stream, and when the recording mode is a re-encoding mode for re-encoding and recording the compressed video stream, the compressed video stream is output to the re-encoding unit; A stream controller that outputs the compressed moving image stream so as not to pass through the re-encoding unit in a stream recording mode in which the compressed moving image stream is recorded without being re-encoded.
[Selection] Figure 1

Description

  The present invention relates to a process for recording a moving image, and more particularly to a process for recording a compressed moving image stream.

  In recent years, DVD (Digital Versatile Disc) / HDD (Hard Disk Drive) recorders for recording television programs have become widespread. When recording a television program, a moving image is encoded by a method such as MPEG (Moving Picture Experts Group). When encoding, it is necessary to determine encoding conditions such as an average bit rate and a screen size. The optimal encoding conditions differ depending on the type of program such as a sports program, a drama program, or a news program.

Therefore, for example, Patent Document 1 discloses an apparatus that determines an encoding condition from the type of a television program and encodes an analog television signal according to the encoding condition. Since an analog television signal is input, encoding is always performed in this apparatus.
JP-A-11-55626

  When recording a program on a DVD / HDD recorder or the like, encoding is performed so as to reduce the data size in order to record a large number of programs in a limited storage capacity. When receiving digital television broadcasting in recent years, re-encode the received bit stream (that is, after decoding already encoded data, a highly efficient encoding method) In this case, the data size is reduced by performing the encoding again.

  However, in the case of digital broadcasting, the received video is already compressed, so even if it is re-encoded, the data size will not be smaller than the data size of the original compressed video stream, or the data size will increase. May end up. Examples of such cases include: (1) Sports programs with fast video movements, and programs that are difficult to compress, such as song programs with rapid changes in video brightness, (2) Stream is a highly efficient code In the case where the image data is already largely compressed by a conversion method (MPEG-4 AVC (Advanced Video Coding) /H.264, etc.).

  An object of the present invention is to prevent an increase in the data size of a compressed video stream due to re-encoding.

  In order to solve the above problems, an image data processing apparatus according to the present invention includes a recording condition generator for determining a recording mode of the compressed moving image stream according to program information corresponding to the compressed moving image stream, and re-encoding the compressed moving image stream. A re-encoding unit for obtaining a re-encoded stream; and when the recording mode is a re-encoding mode for re-encoding and recording the compressed video stream, the compressed video stream is output to the re-encoding unit. A stream controller that outputs the compressed video stream so as not to pass through the re-encoding unit when the recording mode is a stream recording mode in which the compressed video stream is recorded without being re-encoded.

  According to this, since re-encoding is not performed when the recording mode is the stream recording mode, an increase in the data size of the compressed moving image stream can be prevented.

  An image recording apparatus according to the present invention includes a recording condition generator that determines a recording mode of the compressed moving image stream according to program information corresponding to the compressed moving image stream, a re-encoding stream, and a re-encoded stream. A re-encoding unit to obtain, and when the recording mode is a re-encoding mode for re-encoding and recording the compressed video stream, the compressed video stream is output to the re-encoding unit, and the recording mode is A stream controller that outputs the compressed video stream so as not to pass through the re-encoding unit when the compressed video stream is recorded in a stream recording mode without re-encoding, and the re-encoded stream or the stream And a data recording device for recording the compressed moving image stream output from the controller.

  The image data processing method according to the present invention includes a recording condition generation step for determining a recording mode of the compressed moving image stream according to program information corresponding to the compressed moving image stream, re-encoding the compressed moving image stream, and re-encoding the stream. The recording mode is the compressed video so that the re-encoding step is performed when the recording mode is a re-encoding mode for re-encoding and recording the compressed video stream. A stream control step for controlling the compressed moving image stream so that the re-encoding step is not performed in the stream recording mode in which the stream is recorded without being re-encoded.

  According to the present invention, it is possible to prevent an increase in the data size of a compressed moving image stream due to re-encoding. Further, it is possible to record a moving image with an appropriate image quality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an image recording apparatus according to an embodiment of the present invention. The image recording apparatus in FIG. 1 includes a stream controller 12, a recording condition generator 14, a data recording controller 16, a re-encoding unit 20, and a data recording apparatus 32. The re-encoding unit 20 includes a video / audio stream separator 22, a video signal re-encoder 24, an audio signal re-encoder 26, and a multiplexer 28. The stream controller 12, the recording condition generator 14, the data recording controller 16, and the re-encoding unit 20 constitute an image data processing apparatus.

  In digital broadcasting, a video stream that has been compression-encoded with a method such as MPEG-2 or MPEG-4 AVC for video and an audio stream that has been compression-encoded (a description of the audio stream is omitted) are multiplexed. A compressed video stream STR is broadcast. The recording condition generator 14 extracts program information about the recording target program transmitted by the compressed video stream STR from the program information INF input from the outside, determines the recording mode according to the extracted information, and is determined The recording mode is output to the stream controller 12, the video signal re-encoder 24, and the audio signal re-encoder 26. The stream controller 12 outputs a compressed video stream STR that is a multiplexed stream to the video / audio stream separator 22 or the data recording controller 16 according to the recording mode determined by the recording condition generator 14.

  The video / audio stream separator 22 separates the compressed video stream STR into a video stream and an audio stream, and outputs the video stream to the video signal re-encoder 24 and the audio stream to the audio signal re-encoder 26. The video signal re-encoder 24 includes a video signal decoder and a video signal encoder (not shown). The video signal decoder decodes the video stream, and the video signal encoder re-encodes (recompresses) the obtained decoding result according to the recording mode determined by the recording condition generator 14. The audio signal re-encoder 26 includes an audio signal decoder and an audio signal encoder (not shown). The audio signal decoder decodes the audio stream, and the audio signal encoder re-encodes the obtained decoding result according to the recording mode determined by the recording condition generator 14.

  The video signal re-encoder 24 and the audio signal re-encoder 26 can perform re-encoding by various methods. In particular, the video signal encoder of the video signal re-encoder 24 performs re-encoding with a high-efficiency encoding method. Here, as an example, MPEG-4 AVC / H. It shall be re-encoded with H.264. The multiplexer 28 remultiplexes the re-encoded video stream and the re-encoded audio stream, and outputs the re-encoded stream.

  The data recording controller 16 outputs the re-encoded stream or the compressed moving image stream STR directly received from the stream controller 12 to the data recording device 32, and the data recording device 32 records the received stream on the recording medium. The data recording device 32 is specifically a recording device such as a DVD drive or HDD, and records the stream on a recording medium such as a DVD or hard disk.

  The image recording apparatus of FIG. 1 records in the stream recording mode in which the input compressed video stream STR is recorded as it is without being re-encoded, and in the re-encoding mode in which the compressed video stream STR is re-encoded and recorded. Can be recorded. In the case of the stream recording mode, the stream controller 12 outputs the input compressed video stream STR to the data recording controller 16 so as not to pass through the re-encoding unit 20 and causes the data recording device 32 to record it. It is possible to record while maintaining the video quality of the broadcast wave.

  On the other hand, in the re-encoding mode, the stream controller 12 outputs the input compressed moving image stream STR to the re-encoding unit 20, re-encodes it, and records it in the data recording device 32. Therefore, if the moving image of the compressed moving image stream STR is a moving image suitable for re-encoding, it is possible to suppress the data size of the re-encoded stream while suppressing deterioration in image quality.

  FIG. 2 is a flowchart showing an example of the flow of processing in the image recording apparatus of FIG. The program information INF input to the recording condition generator 14 includes program information corresponding to the compressed video stream STR, and the program information corresponding to the compressed video stream STR corresponds to the compressed video stream STR. The type of program to be recorded and keywords are included.

  In step S12 in FIG. 2, the recording condition generator 14 determines the type of program to be recorded (program genre) corresponding to the compressed video stream STR from the program information corresponding to the compressed video stream STR in the input program information INF. ). The program information INF may be, for example, program information (EPG (Electronic Program Guide)) transmitted by broadcast waves, or may be program information (iEPG) downloaded via the Internet. Further, the program information INF may be program information included in an MPEG-2 TS (Transport Stream) packet constituting the compressed moving image stream STR. Examples of the program type include a news program, a sports program, and a song program.

  In step S14, the recording condition generator 14 determines whether or not it is difficult to re-encode the compressed video stream STR, that is, the extracted type is a predetermined type of program that is difficult to encode (for example, video motion). Is a fast sports program or a song program in which the luminance of the video changes rapidly over time). If applicable, the recording condition generator 14 determines that it is difficult to re-encode the compressed video stream STR, and advances the process to step S16. If not, the process proceeds to step S18.

  In step S16, the recording condition generator 14 determines the recording mode to be the stream recording mode, and outputs this recording mode to the stream controller 12, the video signal re-encoder 24, and the audio signal re-encoder 26. In this case, the stream controller 12 outputs the compressed moving image stream STR to the data recording controller 16, and the data recording controller 16 causes the data recording device 32 to record this stream. That is, stream recording (direct recording) without re-encoding is performed.

  In step S18, the recording condition generator 14 determines the recording mode as a recording mode designated in advance by the user, and this recording mode is determined by the stream controller 12, the video signal re-encoder 24, and the audio signal re-encoder. 26. In this case, when the re-encoding mode is designated in advance as the recording mode, the stream controller 12 outputs the compressed moving image stream STR to the video / audio stream separator 22. This stream is re-encoded by the video signal re-encoder 24 and the audio signal re-encoder 26, and the result is re-multiplexed by the multiplexer 28 and output to the data recording controller 16. The data recording controller 16 causes the data recording device 32 to record the re-encoded stream obtained by the multiplexer 28. That is, recording in the re-encoding mode is performed. When the stream recording mode is designated in advance as the recording mode, stream recording is performed as in step S16.

  FIG. 3 is a flowchart showing another example of the processing flow in the image recording apparatus of FIG. In step S22 of FIG. 3, the recording condition generator 14 extracts the keyword of the recording target program corresponding to the compressed moving image stream STR from the program information corresponding to the compressed moving image stream STR in the input program information INF. Examples of the keyword include “news” included in a program title and the like, a sports name (such as “baseball”), a specific song program name, a specific singer name, and the like. The keyword may be any data associated with the program.

  In step S24, the recording condition generator 14 determines whether it is difficult to re-encode the compressed video stream STR, that is, whether the extracted keyword corresponds to a keyword of a program that is difficult to encode. Judging. If applicable, the recording condition generator 14 determines that it is difficult to re-encode the compressed video stream STR, and advances the process to step S26. If not, the process proceeds to step S28. In step S26, stream recording is performed as in step S16 of FIG. In step S28, recording is performed in the recording mode designated by the user, as in step S18 of FIG.

  As described above, since the image recording apparatus of FIG. 1 automatically determines the recording mode according to the program information, the program can be recorded in an appropriate recording mode. For a program that is difficult to re-encode, the input compressed video stream STR is recorded as it is without re-encoding, so that the program can be recorded without degrading the image quality.

  If the recording condition generator 14 determines from the program information INF that it is difficult to re-encode the compressed video stream STR, the recording condition generator 14 enters a re-encoding mode in which re-encoding is performed at an encoding bit rate equal to or higher than a predetermined value. The recording mode may be determined. In this case, stream recording is not performed, and the re-encoding unit 20 re-encodes the compressed moving image stream STR at this encoding bit rate. Then, for example, a compressed moving image stream of a program having a lot of moving images can be re-encoded while suppressing deterioration in image quality.

  FIG. 4 is a block diagram showing a configuration of a first modification of the image recording apparatus of FIG. The image recording apparatus in FIG. 4 is different from the image recording apparatus in FIG. 1 in that a recording condition generator 214 is provided instead of the recording condition generator 14. The recording condition generator 214 outputs message data for displaying a message for the user to the display 36, and determines the recording mode according to not only the input program information INF but also the setting information UST by the user. However, it is different from the recording condition generator 14 of FIG. The display 36 displays a message according to the message data from the recording condition generator 214. The display 36 may be external to the image recording apparatus of FIG. 4 (for example, as a television receiver), or the image recording apparatus of FIG.

  FIG. 5 is an explanatory diagram showing an example of display on the display 36 of FIG. The recording condition generator 214 starts recording in the determined recording mode and outputs message data indicating the recording mode to the display 36.

  As described with reference to FIGS. 2 and 3, the recording condition generator 214 determines that it is difficult to re-encode the compressed video stream STR from the program information, that is, the type of the recording target program is the code. When the program type is difficult to convert, or when the keyword of the program to be recorded corresponds to the keyword of a program that is difficult to encode, the stream recording mode is set to the recommended mode recommended as the recording mode, and the recording mode is set to This recommended mode is determined. In this case, the recording condition generator 214 starts stream recording (direct recording) and outputs message data indicating that stream recording is performed to the display 36 as shown in FIG. Thereby, the user can know the current recording mode (recommended mode) from the display on the display 36.

  Note that the recording condition generator 214 may change the mode for re-encoding at an encoding bit rate equal to or higher than a predetermined value to the recommended mode.

  FIG. 6 is an explanatory diagram showing another example of display on the display 36 of FIG. When the stream recording mode is set to the recommended mode, the recording condition generator 214 performs display for recommending the recommended mode (stream recording mode) and processing in the recommended mode (stream recording) as shown in FIG. Message data for performing a display for the user to select whether or not may be output to the display 36.

  After the display of FIG. 6, the recording condition generator 214 determines the recording mode according to the setting information UST indicating the user's selection. When the user selects “Yes”, the recording condition generator 214 determines the recording mode to be the stream recording mode. In this case, the stream controller 12 causes the data recording device 32 to directly record the compressed moving image stream STR without going through the re-encoding unit 20. If the user selects “No”, the recording condition generator 214 determines the recording mode to be a re-encoding mode, and the re-encoding unit 20 re-encodes the compressed video stream STR and then the data recording device 32.

  FIG. 7 is an explanatory view showing still another example of display on the display 36 of FIG. As shown in FIG. 7, the recording condition generator 214 outputs message data for displaying the recommended mode (stream recording mode) and displaying a plurality of selectable recording mode candidates to the display 36. May be.

  After the display of FIG. 7, the recording condition generator 214 determines the recording mode according to the setting information UST indicating the user's selection. When the user selects the “high compression re-encoding mode”, the recording condition generator 214 determines the recording mode as the high compression re-encoding mode. In this case, the video signal re-encoder 24 and the audio signal re-encoder 26 compress the compressed video stream so that the data size of the re-encoded stream after re-encoding is minimized within the range where the image quality is acceptable. Re-encode the STR. The data recording device 32 records the obtained re-encoded stream.

  When the user selects “high image quality re-encoding mode”, the recording condition generator 214 determines the recording mode to be the high image quality re-encoding mode. In this case, the video signal re-encoder 24 and the audio signal re-encoder 26 re-encode the compressed video stream STR so that the bit rate of the re-encoded stream after re-encoding is equal to or higher than a predetermined value. . The data recording device 32 records the obtained re-encoded stream. When the user selects “stream recording mode”, the recording condition generator 214 determines the recording mode as the stream recording mode. In this case, the stream controller 12 causes the data recording device 32 to directly record the compressed moving image stream STR without going through the re-encoding unit 20.

  Thus, according to the image recording apparatus of FIG. 4, the user is notified of the current recording mode as shown in FIG. 5, the user is allowed to select whether or not to perform processing in the recommended mode as shown in FIG. As shown in FIG. 7, the user can be notified of selectable recording modes and selected. Therefore, the recording according to the user's preference can be realized.

  FIG. 8 is a block diagram showing a configuration of a second modification of the image recording apparatus of FIG. The image recording apparatus in FIG. 8 is different from the image recording apparatus in FIG. 4 in that a recording condition generator 314 and a re-encoding unit 320 are provided instead of the recording condition generator 214 and the re-encoding unit 20. The re-encoding unit 320 is different from the re-encoding unit 20 in that it includes a video / audio stream separator 322 and a multiplexer 328 instead of the video / audio stream separator 22 and the multiplexer 28. .

  The recording condition generator 214 determines the recording mode and outputs the determined recording mode to the video / audio stream separator 322 as well. It is assumed that the recording condition generator 214 can also select a recording mode in which only audio is re-encoded. When the recording mode is a recording mode in which only audio is re-encoded, the video / audio stream separator 322 outputs the video stream to the multiplexer 328 and the audio stream to the audio signal re-encoder 26. As in FIG. 1, the audio signal re-encoder 26 decodes and re-encodes the audio stream. The multiplexer 328 remultiplexes the video stream output from the video / audio stream separator 322 and the re-encoded audio stream, and outputs the re-encoded stream.

  When the recording mode is a recording mode for re-encoding video, the video / audio stream separator 322 outputs the video stream to the video signal re-encoder 24. As described with reference to FIG. 1, the video signal re-encoder 24 re-encodes the video stream, and the multiplexer 328 re-multiplexes the re-encoded video stream and the audio stream.

  As described above, the image recording apparatus of FIG. 8 re-encodes the audio stream, but can record the stream of the video stream. Therefore, it is possible to perform recording with an emphasis on video quality.

  FIG. 9 is a block diagram showing the configuration of the third modification of the image recording apparatus of FIG. The image recording apparatus in FIG. 9 is different from the image recording apparatus in FIG. 4 in that a recording condition generator 414 and a re-encoding unit 420 are provided instead of the recording condition generator 214 and the re-encoding unit 20. The re-encoding unit 420 is different from the re-encoding unit 20 in that it further includes a bit number comparator 429 as a re-encoding comparator.

  FIG. 10 is a flowchart showing an example of the flow of processing in the image recording apparatus of FIG. FIG. 11A is a timing chart showing an example of a recording mode when only one channel can be recorded. FIG. 11B is a timing chart showing an example of a recording mode when two channels can be recorded. In step S32 of FIG. 10, the recording condition generator 414 notifies the stream controller 12, the video signal re-encoder 24, and the audio signal re-encoder 26 that the recording mode is the re-encoding mode RE. Then, recording of the re-encoded stream in the re-encoding mode RE is executed (CH1 in FIGS. 11A and 11B).

  In step S34, the recording condition generator 414 determines whether or not stream recording is possible at the same time as re-encoded recording (that is, simultaneous recording of two channels is possible). If yes, go to Step S36, otherwise go to Step S38. In step S36, the recording condition generator 414 instructs the stream controller 12 to perform the stream recording, and causes the stream recording in the stream recording mode DR to be performed simultaneously with the recording in the re-encoding mode RE (FIG. 11 ( b) CH2).

  In step S38, the bit number comparator 429 receives the re-encoded stream after multiplexing from the multiplexer 28, and the bit number of a part of the re-encoded stream (for example, within a predetermined length period) It is determined whether the number of bits of the corresponding portion of the compressed video stream before re-encoding output from the controller 12 is smaller and the difference between these numbers is equal to or greater than a predetermined value, and the determination result R1 Is output to the recording condition generator 414. The recording condition generator 414 returns the process to step S32 when the number of bits of the re-encoded stream is less than the number of bits of the compressed moving image stream and the difference between these numbers is greater than or equal to a predetermined value. In the case of, the process proceeds to step S40.

  In step S40, the recording condition generator 414 determines whether stream recording is being performed simultaneously. If they are being executed simultaneously, the process proceeds to step S42, and if they are not being executed simultaneously, the process proceeds to step S44.

  In step S42, the recording condition generator 414 notifies the video signal re-encoder 24 and the audio signal re-encoder 26 to stop recording in the re-encoding mode RE. Recording in the re-encoding mode RE is stopped, and recording in the stream recording mode DR is continued (CH1 in FIG. 11B). In step S44, the recording condition generator 414 notifies the stream controller 12, the video signal re-encoder 24, and the audio signal re-encoder 26 to stop recording in the re-encoding mode RE. Recording in the re-encoding mode RE is stopped, and thereafter, the stream controller 12 outputs a compressed moving image stream, and recording is performed in the stream recording mode DR (FIG. 11 (a)).

  As described above, the image recording apparatus in FIG. 9 determines which one should be recorded according to the re-encoded stream and the compressed moving image stream before re-encoding, that is, the optimum recording mode, so that the program information cannot be used. Even so, optimal image recording can be realized.

  FIG. 12 is a block diagram showing a configuration of a fourth modification of the image recording apparatus of FIG. The image recording apparatus in FIG. 12 is different from the image recording apparatus in FIG. 4 in that a recording condition generator 514 and a re-encoding unit 520 are provided instead of the recording condition generator 214 and the re-encoding unit 20. The re-encoding unit 520 is different from the re-encoding unit 20 in that it further includes a deterioration determination unit 529 as a re-encoding comparator.

  FIG. 13 is a flowchart illustrating an example of a processing flow in the image recording apparatus of FIG. The image recording apparatus of FIG. 12 determines whether or not to continue recording in the re-encoding mode RE based on the image quality of the image of the re-encoded video stream, not the number of bits generated by re-encoding.

  The flowchart of FIG. 13 is different from the flowchart of FIG. 10 in that step S58 is provided instead of step S38, and only step S58 will be described. The video signal re-encoder 24 decodes the compressed video stream (video stream) before re-encoding and performs inter-screen differential encoding on the result to obtain a re-encoded stream. The decoding result SP of the stream and the decoding result RP of the re-encoded video stream obtained at the time of re-encoding can be output.

  In step S58, the degradation determination unit 529 receives the decoding result SP of the compressed video stream before re-encoding and the decoding result RP of the re-encoded video stream from the video signal re-encoder 24, and receives the decoding result RP. Determines whether the image is deteriorated by a predetermined degree or more from the decoding result SP, and outputs the determination result R2 to the recording condition generator 514. The recording condition generator 514 returns the process to step S32 if the decoding result RP is deteriorated by a predetermined degree or more than the decoding result SP, and otherwise proceeds to step S40. The recording condition generator 514 is the same as the recording condition generator 414 in FIG.

  The degradation determination unit 529 may use, as the degree of degradation of the decoding result, for example, a value obtained by adding the absolute values of the pixel level differences between the two decoding results for the entire screen, for example. PSNR (Peak Signal-to-Noise Ratio), which is an index of the above, may be used.

  An image based on the decoding result RP and an image based on the decoding result SP are displayed on the display 36, and the user who sees the display determines whether or not to continue recording in the re-encoding mode RE, and the recording condition The generator 514 may be instructed.

  Each functional block of each of the above image recording apparatuses is typically realized as an LSI (Large-Scale Integration) which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all except for the data recording device 32 and the display 36.

  Although referred to as LSI here, it may be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacture, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI after manufacture may be used. Furthermore, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Biotechnology can be applied as a possibility.

  Further, the present invention can be realized as a method using the characteristic means possessed by each of the above image recording apparatuses as steps, or as a program for causing a computer to execute these steps. Such a program can be distributed via a recording medium such as a CD-ROM (Compact Disc-Read Only Memory) or a transmission medium such as the Internet.

  As described above, the present invention can prevent an increase in the data size of a compressed moving image stream, and thus is useful for an image data processing device or the like.

1 is a block diagram illustrating a configuration of an image recording apparatus according to an embodiment of the present invention. 3 is a flowchart illustrating an example of a processing flow in the image recording apparatus of FIG. 1. 6 is a flowchart illustrating another example of a processing flow in the image recording apparatus in FIG. 1. It is a block diagram which shows the structure of the 1st modification of the image recording device of FIG. It is explanatory drawing which shows the example of the display on the indicator of FIG. It is explanatory drawing which shows the other example of the display on the indicator of FIG. It is explanatory drawing which shows the further another example of the display on the indicator of FIG. It is a block diagram which shows the structure of the 2nd modification of the image recording device of FIG. It is a block diagram which shows the structure of the 3rd modification of the image recording device of FIG. 10 is a flowchart illustrating an example of a process flow in the image recording apparatus of FIG. 9. (A) is a timing chart showing an example of a recording mode when only one channel can be recorded. (B) is a timing chart showing an example of a recording mode when two channels can be recorded. It is a block diagram which shows the structure of the 4th modification of the image recording device of FIG. 13 is a flowchart illustrating an example of a process flow in the image recording apparatus in FIG. 12.

Explanation of symbols

12 Stream controller 14, 214, 314, 414, 514 Recording condition generator 16 Data recording controller 20, 320, 420, 520 Re-encoding unit 32 Data recording device 36 Display 429 Bit number comparator (re-encoding comparison) vessel)
529 Degradation determiner (re-encoding comparator)

Claims (18)

A recording condition generator for determining a recording mode of the compressed video stream according to program information corresponding to the compressed video stream;
A re-encoding unit that re-encodes the compressed video stream to obtain a re-encoded stream;
When the recording mode is a re-encoding mode that re-encodes and records the compressed video stream, the compressed video stream is output to the re-encoding unit, and the recording mode re-encodes the compressed video stream. An image data processing apparatus comprising: a stream controller that outputs the compressed moving image stream so as not to pass through the re-encoding unit when the recording mode is a stream recording mode without recording. The image data processing apparatus according to claim 1,
The recording condition generator is
An image data processing apparatus, wherein when the program information determines that it is difficult to re-encode the compressed moving image stream, the recording mode is determined as the stream recording mode. The image data processing apparatus according to claim 2,
The recording condition generator is
An image data processing apparatus, wherein when the type of program corresponding to the compressed moving image stream is a predetermined type, it is determined that re-encoding of the compressed moving image stream is difficult. The image data processing apparatus according to claim 2,
The recording condition generator is
An image data processing apparatus, wherein when a keyword included in program information corresponding to the compressed moving image stream is a predetermined keyword, it is determined that re-encoding of the compressed moving image stream is difficult. The image data processing apparatus according to claim 1,
The recording condition generator is
When it is determined from the program information that it is difficult to re-encode the compressed video stream, the recording mode is determined to be a re-encoding mode for re-encoding at an encoding bit rate equal to or higher than a predetermined value,
The re-encoder is
An image data processing apparatus, wherein re-encoding is performed at an encoding bit rate equal to or greater than the predetermined value. The image data processing apparatus according to claim 1,
The recording condition generator is
An image data processing apparatus that obtains a recommended mode recommended as the recording mode in accordance with the program information and outputs data for displaying the recommended mode. The image data processing apparatus according to claim 6.
The image data processing apparatus, wherein the recommended mode is the stream recording mode. The image data processing apparatus according to claim 6.
The recommended mode is a mode in which re-encoding is performed at an encoding bit rate equal to or higher than a predetermined value. The image data processing apparatus according to claim 6.
The recording condition generator is
An image data processing apparatus, wherein the recording mode is determined as the recommended mode. The image data processing apparatus according to claim 6.
The recording condition generator is
An image data processing apparatus that outputs data for performing display for selecting whether or not to perform processing in the recommended mode, and determines the recording mode according to the selected result. The image data processing apparatus according to claim 6.
The recording condition generator is
An image data processing apparatus that outputs data for displaying a plurality of candidates for the recording mode, and determines the recording mode for a candidate selected from the plurality of candidates. The image data processing apparatus according to claim 11.
The image data processing apparatus, wherein the plurality of candidates include the stream recording mode and the re-encoding mode. The image data processing apparatus according to claim 1,
The re-encoder is
Of the audio stream and video stream included in the compressed video stream, the audio stream is re-encoded, and the video stream is not re-encoded. The image data processing apparatus according to claim 1,
The re-encoder is
A re-encoding comparator that compares the compressed video stream with a re-encoding result by the re-encoder and outputs the result as a determination result;
The recording condition generator is
An image data processing apparatus that causes the re-encoder to stop re-encoding according to the comparison result. The image data processing apparatus according to claim 14, wherein
The re-encoding comparator is
An image characterized by being a bit number comparator that obtains a relationship between the number of bits of a part of the re-encoding result and the number of bits of a corresponding part of the compressed video stream and outputs the result as the determination result Data processing device. The image data processing apparatus according to claim 14, wherein
The re-encoding comparator is
It is a deterioration determiner that determines whether or not the decoding result of the re-encoding result has deteriorated by a predetermined degree or more as an image from the decoding result of the compressed moving image stream, and outputs the result as the determination result. Image data processing device. A recording condition generator for determining a recording mode of the compressed video stream according to program information corresponding to the compressed video stream;
A re-encoding unit that re-encodes the compressed video stream to obtain a re-encoded stream;
When the recording mode is a re-encoding mode that re-encodes and records the compressed video stream, the compressed video stream is output to the re-encoding unit, and the recording mode re-encodes the compressed video stream. A stream controller that outputs the compressed video stream so as not to go through the re-encoding unit when the recording mode is a stream recording mode without recording,
An image recording apparatus comprising: a data recording apparatus that records the re-encoded stream or the compressed moving image stream output from the stream controller. A recording condition generating step for determining a recording mode of the compressed video stream according to program information corresponding to the compressed video stream;
Re-encoding the compressed video stream to obtain a re-encoded stream; and
When the recording mode is a re-encoding mode for re-encoding and recording the compressed video stream, the recording mode does not re-encode the compressed video stream so that the re-encoding step is performed. An image data processing method comprising: a stream control step for controlling the compressed moving image stream so that the re-encoding step is not performed in a stream recording mode for recording.

Images