[FFmpeg-devel] More H.264 predictive lossless

Jason Garrett-Glaser darkshikari
Tue Oct 7 22:42:06 CEST 2008

On mplayerhq, mixedqps_lossless.h264 is now available.  This test clip
uses the following features in addition to predictive lossless:

1. Deblocking
3. B-frames (pyramidal, with weights)
4. All macroblock types, including 8x8dct and PCM.
5. Random distribution of QPs, with 50% lossless and 50% ranging from 1 to 31.

CoreAVC plays it correctly.

The clip is also notable for breaking the patch we previously
considered for adding predictive lossless support, due to the fact
that negative residuals added to a zeroed block end up being stored as
zeros due to clipping.

Since x264 has committing Predictive Lossless replacing the old
lossless mode (which was removed from the spec), we're going to need
to support this mode soon enough.

Michael, any comments or ideas?

Dark Shikari

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