Hint based adaptive encoding

• US 9,154,804 B2
• Filed: 09/30/2011
• Issued: 10/06/2015
• Est. Priority Date: 06/04/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Concion, Davide
• Primary Examiner(s): Rao, Andy
• Assistant Examiner(s): WALKER, JARED T
• Application Number:
  US13/251,089
• Publication Number:
  US 20120307887A1
• Time in Patent Office: 1,467 Days
• Field of Search: 37524001-24027
• US Class Current: 1/1
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/167 Position within a video image, e.g. region of interest [ROI]
• CPC Class Codes: H04N 19/23 with coding of regions that are present throughout a whole video segment, e.g. sprites, background or mosaic
• CPC Class Codes: H04N 19/507 using conditional replenishment

Abstract

A device for encoding video image data includes a data receiver that receives a current image frame to be compressed, the current image frame being composed of a plurality of current macroblocks. An information receiver receives metadata that includes information that identifies static areas within the received current image frame. An encoder encodes each of the plurality of current macroblocks. The encoder encodes a current macroblock that is entirely within the static areas as having no difference from a corresponding preceding macroblock in a preceding frame by using an encoded macroblock that is created without comparing the current macroblock to the corresponding preceding macroblock. The metadata may include information that identifies regular video and graphics within the received current image frame and the encoder may make different compression decisions according to the inclusion of regular video and graphics within the current macroblock.

Claims

1. A device for encoding video image data, the device comprising:

a data receiver that receives a current image frame to be compressed, the current image frame being composed of a plurality of current macroblocks;

an information receiver that receives metadata that includes information that identifies static areas within the received current image frame;

an encoder that encodes each of the plurality of current macroblocks, wherein when the metadata identifies a current macroblock as being entirely within the static areas, the encoder codes the current macroblock using the metadata as having no difference from a corresponding macroblock in a preceding frame, the encoded macroblock being generated without comparing the current macroblock to the corresponding preceding macroblock.

2. The device of claim 1 wherein the encoded macroblock fulfills one of the following conditions:

the encoded macroblock is a frame macroblock and a reference index value 0 refers to the preceding frame;

the encoded macroblock is a frame macroblock, the reference index value 0 refers to a complementary field pair in decoding order, and a preceding field in decoding order is not a non-paired field;

the encoded macroblock is a field macroblock and the reference index value 0 refers to the preceding field in decoding order of a same parity.

3. The device of claim 1 wherein the encoder further encodes a current macroblock that is not entirely within the static areas by comparing the current macroblock to the corresponding preceding macroblock.

4. The device of claim 3 wherein the metadata further includes information that identifies regular video and graphics within the received current image frame and the encoder further makes different compression decisions according to the inclusion of regular video and graphics within the current macroblock.

13. The device of claim 1, wherein the video image data and metadata are generated from a common source.

14. The device of claim 1, wherein the metadata is generated prior to video processing of the encoder.

15. The device of claim 1, wherein the metadata is generated prior to video processing of the encoder.

16. The device of claim 1, wherein the encoder assigns a SKIP coding mode to the macroblock that is coded as having no difference from the corresponding macroblock in the preceding frame.

17. The device of claim 1, wherein when the metadata identifies a current macroblock is not entirely within the static area, the encoder codes the respective macroblock according to a default coding process of the encoder.

18. The host device of claim 1, wherein a first non-static area corresponds to a video display section and a second non-static area corresponds a cursor display section.

20. The device of claim 1, wherein the encoder scales each of the plurality of current macroblocks to produce image data of an appropriate size for a remote device.

21. The device of claim 1, wherein static areas correspond to computer generated video, and non-static areas correspond to non-computer generated video.

5. A method for encoding video image data, the method comprising:

receiving a current image frame to be compressed, the current image frame being composed of a plurality of current macroblocks;

receiving metadata that includes information that identifies static areas within the received current image frame;

encoding each of the plurality of current macroblocks, wherein when the metadata identifies a current macroblock as being entirely within the static areas, encoding the current macroblock using the metadata as having no difference from a corresponding macroblock in a preceding frame, the encoded macroblock being generated without comparing the current macroblock to the corresponding preceding macroblock.

6. The method of claim 5 wherein the encoded macroblock fulfills one of the following conditions:

the encoded macroblock is a frame macroblock and a reference index value 0 refers to the preceding frame;

the encoded macroblock is a frame macroblock, the reference index value 0 refers to a complementary field pair in decoding order, and a preceding field in decoding order is not a non-paired field;

the encoded macroblock is a field macroblock and the reference index value 0 refers to the preceding field in decoding order of a same parity.

7. The method of claim 5 further comprising encoding a current macroblock that is not entirely within the static areas by comparing the current macroblock to the corresponding preceding macroblock.

8. The method of claim 7 wherein the metadata further includes information that identifies regular video and graphics within the received current image frame and encoding the current macroblock that is not entirely within the static areas uses different compression decisions according to the inclusion of regular video and graphics within the current macroblock.

9. A device for encoding video image data, the device comprising:

means for receiving a current image frame to be compressed, the current image frame being composed of a plurality of current macroblocks;

means for receiving metadata that includes information that identifies static areas within the received current image frame;

means for encoding each of the plurality of current macroblocks, wherein when the metadata identifies a current macroblock as being entirely within the static areas, encoding the current macroblock using the metadata as having no difference from a corresponding macroblock in a preceding frame, the encoded macroblock being generated without comparing the current macroblock to the corresponding preceding macroblock.

10. The device of claim 9 wherein the encoded macroblock fulfills one of the following conditions:

the encoded macroblock is a frame macroblock and a reference index value 0 refers to the preceding frame;

the encoded macroblock is a frame macroblock, the reference index value 0 refers to a complementary field pair in decoding order, and a preceding field in decoding order is not a non-paired field;

the encoded macroblock is a field macroblock and the reference index value 0 refers to the preceding field in decoding order of a same parity.

11. The device of claim 9 further comprising means for encoding a current macroblock that is not entirely within the static areas by comparing the current macroblock to the corresponding preceding macroblock.

12. The device of claim 11 wherein the metadata further includes information that identifies regular video and graphics within the received current image frame and the means for encoding the current macroblock that is not entirely within the static areas uses different compression decisions according to the inclusion of regular video and graphics within the current macroblock.

19. A video coding system, comprising:

a video source providing a video sequence to be coded and metadata identifying a region within a frame of the video sequence that contains static image content, each frame of the video sequence having been parsed into a plurality of blocks for coding;

an encoder that encodes each of the blocks of a frame, wherein

when the metadata identifies that a block is located entirely within the region of static content, the encoder codes the respective block as having no difference from a corresponding block of a preceding frame without comparing the respective block to the corresponding block of the preceding frame, and

when the metadata identifies that block is not located entirely within the region of static content, the encoder codes the respective block according to a default coding process of the encoder.