[Ffmpeg-devel] [PATCH] remove special nuv wav tags

[Måns Rullgård]

Baptiste Coudurier <baptiste.coudurier at smartjog.com> writes:

> Reimar D?ffinger wrote:
>> Hello,
>> On Sun, Nov 05, 2006 at 09:13:14PM +0000, M?ns Rullg?rd wrote:
>>> Also, setting AVCodecContext.codec_tag in nuv.c seems a little
>>> questionable, given that most of the code treats it as RIFF codec tag,
>>> which it is not in this case.
>> 
>> Either codec_tag is supposed to be riff tags then it should be removed
>> or it is supposed to avoid information loss when doing stream copy then
>> this is the correct use IMO.
>
> codec_tag is not riff tag, mov sets it too, and seriously I don't see
> why demuxer should not set it to what's in the container.

Well, I guess I'm OK with demuxers setting codec_tag to whatever value
the format uses, on the odd chance that something has a use for that
piece of information.  I still find it a little strange putting
format-specific data in AVCodecContext.  Don't we usually try to
separate codecs from containers?  Besides, the codec_id field is
meaningless without knowing which format it came from.

> Now lavf exports CODEC_ID which is unique and accurate. That means that
> applications using lavf should use CODEC_ID, not codec_tag.
> codec_tag is NOT accurate NOR unique.

Yes, I've never found codec_id insufficient.

-- 
M?ns Rullg?rd
mru at inprovide.com