[FFmpeg-devel] Adding AMD OpenVideo Decode acceleration

[Leith Bade]

Thanks for that.

I copied the DXVA code and modified it to use OpenVideo Decode.

I now want to test it but I cannot figure out how you are supposed to use
get/reget/release_buffer with hwaccel contexts from the application side.

Is there some existing open source application that uses FFmpeg's DXVA
hwaccel so I can see how to do this?

One more question, if I didn't want ffmpeg to depend on the OVD library,
what would be the best way to create a callback system in end_frame? (So the
host application takes the filled buffers and calls OVD itself...)

Thanks,
Leith Bade
leith at leithalweapon.geek.nz



On 8 January 2011 09:21, Vitor Sessak <vitor1001 at gmail.com> wrote:

> On 01/07/2011 02:26 PM, Leith Bade wrote:
>
>> Hi
>>
>> I am new to FFmpeg.
>>
>> I would like to use FFmpeg to drive AMD's new OpenVideo Decode API (which
>> interops with OpenCL and OpenGL) with H264.
>>
>> I have been learning the API, but the documentation is very poor (lots of
>> typos, mistakes, vague or missing descriptions).
>>
>> As far as I can tell the API's structures are very similar to DXVA, but
>> simplified a bit. (I have used DXVA docs to fill in the gaps in the OVD
>> docs).
>>
>> I tried decoding only I-frames by using h264bistream library, but I am not
>> very familiar with H264 and the spec is incredibly complex and hard to
>> follow.
>>
>> I have not managed to get anything out of OVD except zero filled NV12
>> buffers :-( (despite the API returning success code for the decode call).
>>
>> I read that FFmpeg has DXVA support now, and the H264 parser works
>> correctly.
>>
>> How much effort would it be to add a custom hardware acceleration module
>> for
>> H264? I want it to interop with my OpenCL context, and output to a OpenCL
>> memory buffer rather than a CPU memory buffer (like the default API does).
>>
>> What files should I look at?
>>
>
> Probably the best thing is to look at the commit who added DXVA to ffmpeg:
> http://lists.mplayerhq.hu/pipermail/ffmpeg-cvslog/2010-January/026854.html.
>
> -Vitor
>
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