[FFmpeg-devel] [PATCH 1/4] lavc/mpeg*: drop the XvMC hwaccel code

[Anton Khirnov]

Quoting Soft Works (2022-02-07 03:18:54)
> I sometimes wonder whether there exists a single API user who
> really understands this (very special) kind of logic and
> would make decisions based on that understanding.
> 
> When it's not even fully understood internally, how should it
> be understood externally? 

The rule for API users is simple: you are not allowed to assume a
specific component (like a decoder, demuxer or hwaccel) will be
available at runtime*. You are supposed to check for it using the APIs
provided for this purpose. In this case, AV_PIX_FMT_XVMC will just stop
being offered in get_format().

Not to mention that I very much doubt there are any users of xvmc left,
besides the original mplayer.

* unless you are running with a very specific verified build, in which
  case a removal like this should be caught at the build stage

-- 
Anton Khirnov