[FFmpeg-devel] 16:9 DV AVI not detected

Roman Shaposhnik rvs
Thu Jan 3 05:58:30 CET 2008

On Jan 1, 2008, at 2:39 PM, Michael Niedermayer wrote:

> On Mon, Dec 31, 2007 at 12:57:41PM -0800, Roman Shaposhnik wrote:
> [...]
>>>>     The only possible workaround that I know of is to
>>>> do what is done for AVI type 1 DV, but it'll be more
>>>> trouble than it is worth. IMHO.
>>> if the dv decoder knows the aspect ratio,
>>    It doesn't right now. That logic is in  the DV demuxer. btw, would
>> you agree that things like SAR/DAR signaling are actually part
>> of the container, not codec info?
> some codecs store aspect ratio, some containers store aspect ratio
> we currently have just AVCodecContext.sample_aspect_ratio, and both
> demuxers and decoders use that ...

   Is it just me, or does it sound messy? Kind of reminds me of the  
with DV audio and AVI-type-2 containers. These two tracks usually
disagree and users get bitten by it. Something is telling me that the  
ratio from the container would disagree with the aspect ratio from  
the codec
even more frequently. Which one should take precedence?

    Oh, well -- I guess life is messy :-(

> we could add AVStream.sample_aspect_ratio if having just one variable
> turns out to be insufficient ...

   I'm not really proposing this.

> for the specific case of DV, i think the aspect ratio is part of the
> codec stream, but thats surely debatable as dv mixes codec and  
> container
> stuff

    So, what would be your advice -- have DV codec always set it (and  
override the value that came from the container)?

> but maybe i missunderstood your question, due to having no russian  
> stuff
> here ;)

   I think you answered exactly the question that I asked.


P.S. the stuff is all gone on my side of the wire as well. It was  
good while
it lasted  -- now back to work ;-)

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