[Libav-user] Hardware Accelerated Decoding

[wm4]

On Fri, 29 Nov 2013 17:04:56 +0500
Safi ud Din Khan <safiuddinkhan at gmail.com> wrote:

> Hello i am interested in doing hardware accelerated decoding for my 
> ffmpeg based multimedia program using VA API .... i am kind of a 
> beginner and does not understand very well as how VAAPI interacts with 
> ffmpeg libraries .... what i have seen from the source code of ffmpeg is 
> that some parts of VAAPI (decoding parts) are already implemented inside 
> ffmpeg source code (libavcodec/vaapi.c and others) ......

It's complicated. ffmpeg.c now supports hardware decoding too (it's
mostly an "example"), see:

   http://git.videolan.org/?p=ffmpeg.git;a=blob;f=ffmpeg_vdpau.c

For VAAPI is relatively similar, but the patches for ffmpeg.c vaapi
support have not been merged yet, but see the series of patches
starting here:

   http://lists.libav.org/pipermail/libav-devel/2013-November/053307.html

(Note that these just read the decoded video back to CPU RAM, which is
of course inefficient and only serves as a way to somehow use the
decoded data within the ffmpeg.c/avconv.c utilities.)