Bitplane coding and decoding for AC prediction status information

1. A method comprising:

selecting a bitplane mode from a group of plural available bitplane modes; and

processing a bitplane according to the selected bitplane mode, wherein the bitplane indicates AC prediction status information for plural macroblocks of a first video picture;

wherein a second video picture includes one or more intra macroblocks and one or more inter macroblocks, and wherein a per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

2. The method of claim 1 wherein the AC prediction status information indicates for each of the plural macroblocks of the first video picture whether or not the macroblock is coded using AC prediction.

3. The method of claim 1 wherein the first video picture is a progressive intra frame, an interlaced intra frame, or an interlaced intra field.

4. The method of claim 1 wherein the processing comprises encoding.

5. The method of claim 1 wherein the processing comprises decoding.

6. A computer-readable medium having stored thereon computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 1 .

7. A method comprising:

encoding a bitplane that indicates AC prediction status information for plural macroblocks of a first video picture; and

signaling the encoded bitplane;

wherein a second video picture includes one or more intra macroblocks and one or more inter macroblocks, and wherein a per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

8. The method of claim 7 wherein the bitplane includes one AC prediction status bit for each of the plural macroblocks of the first video picture to indicate whether or not the macroblock is coded using AC prediction.

9. The method of claim 7 wherein the encoded bitplane is signaled at field or frame layer in a bitstream.

10. A computer-readable medium having stored thereon computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 7 .

11. A method comprising:

receiving an encoded bitplane; and

decoding the bitplane, wherein the bitplane indicates AC prediction status information for plural macroblocks of a first video picture;

wherein a second video picture includes one or more intra macroblocks and one or more inter macroblocks, and wherein a per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

12. The method of claim 11 wherein the bitplane includes one AC prediction status bit for each of the plural macroblocks of the first video picture to indicate whether or not the macroblock is coded using AC prediction.

13. The method of claim 11 wherein the encoded bitplane is signaled at field or frame layer in a bitstream.

14. A computer-readable medium having stored thereon computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 11 .

15. A method comprising:

selecting a bitplane mode from a group of plural available bitplane modes;

processing a bitplane according to the selected bitplane mode, wherein the bitplane indicates AC prediction status information for plural macroblocks of a video picture; and

for a second video picture, for each of at least one but not all of plural macroblocks of the second video picture, processing an AC prediction status bit signaled at macroblock layer;

wherein the second video picture includes one or more intra macroblocks and one or more inter macroblocks, wherein the AC prediction status bit is a per macroblock AC prediction status bit, and wherein the per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

16. A method comprising:

selecting a bitplane mode from a group of plural available bitplane coding/decoding modes, wherein the plural available bitplane coding/decoding modes include row-skip, column-skip, pair-wise VLC, group-of-six VLC, and one or more differential modes; and

processing a bitplane according to the selected bitplane coding/decoding mode, wherein the bitplane indicates AC prediction status information for plural macroblocks of a video picture.

17. A method comprising:

encoding a bitplane that indicates AC prediction status information for plural macroblocks of a video picture;

signaling the encoded bitplane; and

for each of one or more intra macroblocks of a second video picture, signaling a per macroblock AC prediction status bit at macroblock layer;

wherein the second video picture includes one or more intra macroblocks and one or more inter macroblocks, and wherein the per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

18. The method of claim 17 wherein the second video picture is a motion-compensated picture.

19. A method comprising:

receiving an encoded bitplane;

decoding the bitplane, wherein the bitplane indicates AC prediction status information for plural macroblocks of a video picture; and

for each of one or more intra macroblocks of a second video picture, receiving a per macroblock AC prediction status bit at macroblock layer;

wherein the second video picture includes one or more intra macroblocks and one or more inter macroblocks, and wherein the per macroblock AC prediction status bit is signaled for each of the one or more intra macroblocks but not for any of the one or more inter macroblocks.

20. The method of claim 19 wherein the second video picture is a motion-compensated picture.