[Libav-user] HW Accelerator in Windows: DXVA2 with new API

[Hector Alonso]

I've changed the size and number of the slices from the source and it shows
perfectly the video.
What is the relation between the slices and the DXVA2 ?




2014-08-26 10:58 GMT+02:00 Hector Alonso <hector.alonso.aparicio at gmail.com>:

> Hi,
>
> I've modified my initialization code: supressed flags, and enabled
> thread_safe_callbacks, but the result is the same, lots of "Missing
> reference picture, default is __" error messages and avcodec_decode_video2
> returns -1094995529 "Invalid data found when processing input" half the
> time.
> The video is showing very very poorly with tons of compression artifacts.
> I've read the extradata comment in ffmpeg code and it seems that is not
> really used with H264 codec. I've run my ffmpeg-not-HWaccel decoder and the
> extradata is not used at all indeed.
>
> This is the new initialization:
>
> #ifdef DXVA2_DECODER_ENABLED
>
> // Create and populate Input Stream structure:
>  InputStream* ist = new InputStream();
> ist->hwaccel_id = HWACCEL_AUTO;
> ist->hwaccel_device = "dxva2";
>  ist->dec = _pCodec;
> ist->dec_ctx = _pCodecCtx;
>
> // Set Known width and height
>  _pCodecCtx->coded_width  = 1280;
> _pCodecCtx->coded_height = 720;
>
> // Set Input Stream structure as ancillary data into codec
> _pCodecCtx->opaque = ist;
>  // Initialize DXV2 context
> dxva2_init(_pCodecCtx);
>
> // Set DXVA2 callbacks to codec context
> _pCodecCtx->get_buffer2 = ist->hwaccel_get_buffer;
>  _pCodecCtx->get_format = get_format;
> _pCodecCtx->thread_safe_callbacks = 1;
>
> #endif
>
> Remember: dxva2_init is a call to the analogue method from ffmpeg_dxva.c
> file modified by me into a .h and a .cpp attached in a previous mail (I
> don't know if that's a common practice in this mail list or you do it in
> another way).
>
> Regarding the next step (using the DX surface directly as an OpenGL
> texture), it can be done
> using: WGLEW_NV_DX_interop, wglDXOpenDeviceNV, wglDXSetResourceShareHandleNV, wglDXRegisterObjectNV,
> make current, lock, etc.
>
> Look at WiDiSample code -> RenderOpenGL.cpp bind texture (Intel Media SDK
> video decoder example), and this page:
> http://halogenica.net/sharing-resources-between-directx-and-opengl/
>
> ...but for now I'm more worried about getting the DXVA2 to work properly
> with FFMPEG.
>
> What am I missing?
>
>
>
>
> 2014-08-25 17:53 GMT+02:00 wm4 <nfxjfg at googlemail.com>:
>
> On Mon, 25 Aug 2014 15:23:20 +0200
>> Hector Alonso <hector.alonso.aparicio at gmail.com> wrote:
>>
>> > Hi,
>> > I've rebuilt ffmpeg using these instructions
>> > https://trac.ffmpeg.org/wiki/CompilationGuide/MSVC from the Visual
>> Studio
>> > Console, installing MinGW directly from the link with the flags
>> --enable-dxva2
>> > and --enable-hwaccel=h264_dxva2 and is almost working but I get a lot
>> > of errors:
>> > -1094995529 "Invalid data found when processing input"
>> > from avcodec_decode_video2 a lot of artifacts and a very poor and
>> > inconsistent image quality.
>> > This is my dxva initialization code:
>> >
>> > _pCodecCtx->flags|= CODEC_CAP_DR1;
>> > _pCodecCtx->flags|= CODEC_CAP_HWACCEL;
>> >
>> > InputStream *ist = new InputStream ();
>> > ist->hwaccel_id = HWACCEL_AUTO;
>> > ist->hwaccel_device = "dxva2";
>> > ist->dec = _pCodec;
>> > ist->dec_ctx = _pCodecCtx;
>> > _pCodecCtx->coded_width  = 1280;
>> > _pCodecCtx->coded_height = 720;
>> > _pCodecCtx->opaque = ist;
>> > dxva2_init(_pCodecCtx);
>> > _pCodecCtx->opaque  = ist;
>> > _pCodecCtx->get_buffer2 = ist->hwaccel_get_buffer;
>> > _pCodecCtx->get_format = get_format;
>> > _pCodecCtx->thread_safe_callbacks = 0;
>> >
>> > before  calling
>> >
>> >  if (avcodec_open2(_pCodecCtx , _pCodec, 0) < 0)  ...
>> >
>> > Where get_format is:
>> >
>> > static enum AVPixelFormat get_format(AVCodecContext *s, const enum
>> > AVPixelFormat *pix_fmts)
>> > {
>> > InputStream* ist = (InputStream*)s->opaque;
>> > ist->active_hwaccel_id = HWACCEL_DXVA2;
>> > ist->hwaccel_pix_fmt   = AV_PIX_FMT_DXVA2_VLD;
>> > return ist->hwaccel_pix_fmt;
>> > }
>> >
>> > Find attached my modified ffmpeg_dxva2.cpp and ffmpeg_dxva2.h files from
>> > the original ffmpeg_dxva2.c and the InputStream declaration from
>> ffmpeg.h
>> >
>> > For getting the decoded frame I call: dxva2_retrieve_data_call, and
>> then I
>> > convert it to YUV420p (I make the final conversion via pixel shader with
>> > OpenGL texture).
>> >
>> > Also, with my old CPU decoder I had 3-6% CPU usage and 5-10% GPU usage
>> (as
>> > I said, I'm converting and painting with OpenGL) and now with the "GPU
>> > Accelerated" one I have 5-13% CPU and 6-12% GPU.
>>
>> PS: nevcairiel mentioned:
>> http://developer.download.nvidia.com/opengl/specs/WGL_NV_DX_interop.txt
>>
>> Unfortunately, it's marked as experimental, and other drivers probably
>> don't provide it.
>>
>> > Any thoughts?
>> >
>> > Thank you!
>> >
>> _______________________________________________
>> Libav-user mailing list
>> Libav-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/libav-user
>>
>
>
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