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

Michael Niedermayer michaelni
Fri Mar 3 13:47:36 CET 2006


On Thu, Mar 02, 2006 at 07:57:23PM -0500, Dan Maas wrote:
> With regards to Baptiste's question of "why not a different codec?"-
> DV25 and DV50 share so much code (probably 95%) that I don't see a
> reason to split them up. In the future I may add DV100 (DVCPRO HD) to
> the mix as well. You can determine the flavor of DV unambiguously just
> by looking at the resolution and pixel format.

for encoding, the supported pixel formats are a field of AVCodec, now if
dv would support 2 pixel formats and independant of that one or more
resolutions then a single codec_id would be fine but dv has a very strict
small set of supported resolution-pix_fmt-framerate, other mixes arent
allowed and in case of resolution-pix_fmt would need some new tables to
be invented

so while a single codec_id for encoding would work fine, the end user
would be much more happy i think if you would add several so an application
like ffmpeg.c could automatically select a supported pix_fmt and framerate
from the codec_id, note, the only change for this is to duplicate your
AVCodec structure and fill in the pix_fmt/framerate/name and register that
AVCodec no need to touch or split any of th actual code, and for decoding
you will probably use a single codec_id for for all ...

iam not sure what to do at the remuxing side, but it seems the mov muxer
will still have to check for resolution/framerate/... to find a valid
codec_tag as in case of remuxing the codec_id would be the generic dv
decoder one

if anyone, mans? has another suggestion for how the same end user
friendliness could be achived then speak up ...


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