[Ffmpeg-devel] Re: [PATCH] DVCPRO50 support

Dan Maas dmaas
Fri Mar 3 22:51:36 CET 2006

> Really ? I though that the spec required different quantization
> (JPEG-like) and different bit distribution techniques to be used.

Yes, but that just means DV100 needs an alternate version of the two
functions set_class_number() and guess_qnos(). Bit distribution is the
same as DV25/50, just with 8 blocks per macroblock instead of 6.

In my internal codebase, the equivalents of encode_video_segment() and
encode_ac() are shared between DV25 and DV100. There may be a tiny
efficiency advantage to separating them (fewer if() statements) but
that's about all.

Perhaps I emphasized the differences between DV25/50 and DV100 too
much in last year's discussion, and glossed over the similarities :)


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