PARALLEL ENCODING DEVICE, RECORDING MEDIUM, AND IMAGING DATA ENCODING METHOD

• US 20110069761A1
• Filed: 09/14/2010
• Published: 03/24/2011
• Est. Priority Date: 09/18/2009
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: SUGITA, HIROAKI
• Application Number:
  US12/881,357
• Publication Number:
  US 20110069761A1
• Time in Patent Office: Days
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

According to one embodiment, a device includes a storage unit, a processing unit, a detection unit, a control unit. The storage unit stores control information indicating progress states of process modes for encoding with respect to process blocks. The processing unit parallelly executes executable process modes for executable process blocks, based on the control information and a dependency relationship between the process modes for the process blocks. The detection unit detects error occurring in processing of the processing unit. The control unit updates to a re-executable state, if the error occurring is detected, the progress state of an error process block and the progress state of a process block dependent on the error process block in the control information.

Claims

1. A parallel encoding device comprising:

a storage unit which stores control information indicating progress states of process modes for encoding with respect to process blocks, the process blocks being obtained by dividing image data;

a parallel processing unit which parallelly executes executable process modes for executable process blocks, based on the control information stored in the storage unit and a predetermined dependency relationship between the process modes for the process blocks;

a detection unit which detects error occurring in processing executed by the parallel processing unit; and

a control unit which updates to a re-executable state, if the detection unit detects the error occurring, the progress state of an error process block and the progress state of a process block dependent on the error process block in the control information stored in the storage unit.

2. A device according to claim 1, wherein

each process block includes a macroblock or sequence macroblocks,

the process modes include motion vector search, intra-frame encoding, entropy encoding, and reference image generation, and

the dependency relationship includes a case in which after a first process mode of the process modes for a first process block of the process blocks is completed, a second process mode of process modes for a second process block of the process blocks is executed.

3. A device according to claim 1, wherein

a motion vector search unit included in the parallel processing unit searches for, based on the control information and a first dependency relationship associated with motion vector search processing, a first process block on which the motion vector search processing is executable, and then executes the motion vector search processing on the first process block,

a mode determination unit included in the parallel processing unit searches for, based on the control information and a second dependency relationship associated with mode determination processing, a second process block on which the mode determination processing is executable, and then executes the mode determination processing on the second process block,

an encoding unit included in the parallel processing unit searches for, based on the control information and a third dependency relationship associated with encoding processing, a third process block on which the encoding processing is executable, and then executes the encoding processing on the third process block, and

a reference image generation unit included in the parallel processing unit searches for, based on the control information and a fourth dependency relationship associated with reference image generation processing, a fourth process block on which the reference image generation processing is executable, and then executes the reference image generation processing on the fourth process block.

4. A device according to claim 1, wherein

the image data is moving image data,

the parallel processing unit parallelly executes motion vector search processing, mode determination processing, entropy encoding processing, and reference image generation processing within one of frames included in the moving image data or among the frames,

the detection unit detects the error occurring in the entropy encoding processing, and

if the detection unit detects the error occurring, the control unit cause the parallel processing unit to re-execute a part or all of the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing for an error frame and a subsequent frame, in setting in which the same error does not occur.

5. A device according to claim 4, wherein the control unit cause the parallel processing unit to re-execute the mode determination processing, the entropy encoding processing, and the reference image generation processing for an error process block and the subsequent process block among process blocks included in the error frame, and re-execute the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing from the beginning of each frame succeeding to the error frame.

6. A device according to claim 4, wherein the control unit cause the parallel processing unit to re-execute the motion vector search processing only for a process block referring to a re-execution part in the error frame, with respect to a frame succeeding to the error frame.

7. A device according to claim 4, wherein if the detection unit detects the error occurring, the control unit cause the parallel processing unit to re-execute the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing from the beginning of the error frame, and re-execute the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing from the beginning of each frame succeeding to the error frame.

8. A device according to claim 4, wherein

the process modes include motion vector search, intra-frame encoding, entropy encoding, and reference image generation, and

the setting in which the same error does not occur are to cancel the intra-frame encoding.

9. A device according to claim 1, wherein the control information indicates a completed process mode of the process modes for each of the process blocks.

10. A device according to claim 1, wherein the encoding complies with an H.264 standard.

11. A device according to claim 10, wherein the detection unit detects, as the error block, a process block including a macroblock having a size not less than a predetermined size or a process block corresponded to HRD underflow occurring.

12. A device according to claim 1, wherein the detection unit compares a set time assumed to be necessary for re-encoding due to the error with a time limit for the error frame for ensuring real time outputting, and only if the set time is short enough with respect to the output time limit, detects the error occurring.

13. A device according to claim 1, wherein the parallel processing unit, the detection unit, and the control unit are implemented by a multiprocessor.

14. A non-transitory computer-readable recording medium recording a computer program which causes at least one processor to execute processing including:

accessing control information which is stored in a storage unit, and indicates progress states of process modes for encoding with respect to process blocks, the process blocks being obtained by dividing image data;

parallelly executing executable process modes for executable process blocks, based on the control information stored in the storage unit and a predetermined dependency relationship between the process modes for the process blocks;

detecting error occurring in the parallel execution; and

updating to a re-execution state, if the error occurring is detected, the progress state of an error process block and the progress state of a process block dependent on the error process block in the control information stored in the storage unit.

15. A non-transitory recording medium according to claim 14, wherein

each process block includes a macroblock or sequence macroblocks,

the process modes include motion vector search, intra-frame encoding, entropy encoding, and reference image generation, and

the dependency relationship includes a case in which after a first process mode of the process modes for a first process block of the process blocks is completed, a second process mode of process modes for a second process block of the process blocks is executed.

16. A non-transitory recording medium according to claim 14, wherein

the image data is moving image data,

the parallelly executing is parallelly executing motion vector search processing, mode determination processing, entropy encoding processing, and reference image generation processing within one of frames included in the moving image data or among the frames,

the detecting is detecting the error occurring in the entropy encoding processing, and

if the error occurring is detected, the updating includes causing the parallelly executing to re-execute a part or all of the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing for an error frame and a subsequent frame, in setting in which the same error does not occur.

17. An encoding image data method being executed by a processor, the method comprising:

accessing control information which is stored in a storage unit, and indicates progress states of process modes for encoding with respect to process blocks, the process blocks being obtained by dividing the image data;

parallelly executing executable process modes for executable process blocks, based on the control information stored in the storage unit and a predetermined dependency relationship between the process modes for the process blocks;

detecting error occurring in the parallel execution; and

updating with a re-execution state, if the error occurring is detected, the progress state of an error process block and the progress state of a process block dependent on the error process block in the control information stored in the storage unit.

18. A method according to claim 17, wherein

each process block includes a macroblock or sequence macroblocks,

the process modes include motion vector search, intra-frame encoding, entropy encoding, and reference image generation, and

the dependency relationship includes a case in which after a first process mode of the process modes for a first process block of the process blocks is completed, a second process mode of process modes for a second process block of the process blocks is executed.

19. A method according to claim 17, wherein

the image data is moving image data,

the parallelly executing is parallelly executing motion vector search processing, mode determination processing, entropy encoding processing, and reference image generation processing within one of frames included in the moving image data or among the frames,

the detecting is detecting the error occurring in the entropy encoding processing, and

if the error occurring is detecting, the updating includes causing the parallelly executing to re-execute a part or all of the motion vector search processing, the mode determination processing, the entropy encoding processing, and the reference image generation processing for an error frame and a subsequent frame, in setting in which the same error does not occur.