Deblocker for postprocess deblocking

1. A decoder system for deblocking video data, said decoder system comprising:

a video decoder for decoding video data comprising portions that are predicted from deblocked pictures;

a video decoder for decoding video data comprising portions that are predicted from undeblocked pictures; and

a deblocker for deblocking the video data comprising portions that are predicted from deblocked pictures and for deblocking the video data comprising portions that are predicted from undeblocked pictures, wherein the deblocker further comprises:

a first filter for filtering edges in the video data; and

a second filter for filtering edges in the video data.

2. The decoder system of claim 1 , wherein the first filter is a stronger filter than the second filter.

3. The decoder system of claim 2 , wherein the deblocker selects the first filter or the second filter on the basis of pixel gradients.

4. The decoder system of claim 2 , wherein the deblocker selects the first filter or the second filter on the basis of whether a current macroblock and neighboring macroblock are field or frame coded.

5. The decoder system of claim 1 , wherein the deblocker converts quantization parameters for the video data comprising portions that are predicted from undeblocked pictures to quantization parameters in accordance with quantization parameters for video data that comprises portions that are predicted from deblocked pictures.

6. The decoder system of claim 1 , wherein the deblocker determines neighboring pixels for a block, based on whether the block and a neighboring block are field or frame coded.

7. The decoder system of claim 1 , wherein the deblocker deblocks a skipped macroblock.

8. A decoder system for deblocking video data, said decoder system comprising:

a video decoder operable to decode video data comprising portions that are predicted from deblocked pictures;

a video decoder operable to decode video data comprising portions that are predicted from undeblocked pictures; and

a deblocker operably coupled to the video decoder operable to decode video data comprising portions that are predicted from deblocked pictures, and to the video decoder operable to decode video data comprising portions that are predicted from undeblocked pictures, said deblocker operable to deblock the video data comprising portions that are predicted from deblocked pictures and deblock the video data comprising portions that are predicted from undeblocked pictures, wherein the decoder further comprises:

a first filter operable to filter edges in the video data; and

a second filter operable to filter edges in the video data, wherein the first filter is a stronger filter than the second filter.

9. The decoder system of claim 8 , wherein the deblocker comprises:

a boundary strength detector connected to the first filter and the second filter, the boundary strength detector operable to measure pixel gradients; and

wherein the deblocker selects the first filter or the second filter on the basis of the measured pixel gradients.

10. The decoder system of claim 9 , wherein the deblocker selects the first filter or the second filter on the basis of whether a current macroblock and neighboring macroblock are field or frame coded.

11. The decoder system of claim 8 , wherein the deblocker converts quantization parameters for the video data comprising portions that are predicted from undeblocked pictures to quantization parameters for the video data comprising portions that are predicted from deblocked pictures.

12. The decoder system of claim 8 , wherein the deblocker determines neighboring pixels for a block, based on whether the block and a neighboring block are field or frame coded.

13. The decoder system of claim 8 , wherein the deblocker deblocks a skipped macroblock.