[FFmpeg-devel] [PATCH] DVCPRO HD - revised two-part patch

Dan Maas dmaas
Fri Jan 4 08:05:32 CET 2008


Thanks for your comments. After taking another look at the 
find_macroblock functions, I've decided to withdraw that part of the 
patch. The lookup tables are not as big as I thought (a few tens of KB) 
and it was not hard to produce them for DV100. We can always switch to 
functions later if it clearly improves performance.

(I kept the 16-bit lookup tables for DV25/50 and added 32-bit tables for 
DV100. If this is too ugly we could make the DV25/50 tables into 32-bits 
or find another approach, let me know.)

The new DVCPRO HD patch is in two parts. The first patch (attached) 
makes all of the code changes necessary to support DVCPRO HD, and the 
second patch (URL below) adds the macroblock lookup tables.
http://largefiles.maasdigital.com/largefiles/maas-dv100-2B-tables.diff.gz

Changes since my original 3-part post:
- macroblock lookup tables kept as described above
- tab and spacing issues fixed
- the few // comments switched to /* */

You guys have better eyes for micro-optimizations than I do; if there 
are more examples like Michael pointed out in the find_macroblock 
functions, please let me know.

One more thing I wanted to ask about - I have a compile-time #define for 
changing a quality-speed tradeoff in the DV100 encoder. It would be 
nicer to do this as a run-time switch, but I'm not sure how best to get 
a quality-speed parameter down at the codec level. Any help would be 
appreciated.

Regards,
Dan

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