[FFmpeg-devel] [PATCH 2/6] vaapi: Remove H.264 baseline profile

[Mark Thompson]

On 09/10/17 22:48, Carl Eugen Hoyos wrote:
> 2017-10-09 13:21 GMT+02:00 wm4 <nfxjfg at googlemail.com>:
> 
>> Shouldn't trying to decode baseline video just fall back to sw decoding?
> 
> Given that software doesn't support the specific features of baseline either,
> I don't think this helps.
> I was under the impression the only sane thing to do when reading
> baseline H.264 is printing a warning and continue as if constraint
> baseline was detected.

At least with software decode we would know that it has failed - an inconvenient property of many hardware decoders is their reluctance to report errors usefully or at all.

Hence the warning on using the ALLOW_PROFILE_MISMATCH flag, which does allow the attempt to decode baseline profile streams with hardware:
"""
If the stream is actually not supported then the behaviour is
undefined, and may include returning entirely incorrect output
while indicating success.
"""

I think the behaviour we have now with this option to continue if the user really wants (and is aware of the possible consequences) is correct.

Thanks,

- Mark