On Wed, 2022-06-08 at 11:13 +0000, Soft Works wrote: > > -----Original Message----- > > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Xiang, > > Haihao > > Sent: Wednesday, June 8, 2022 10:42 AM > > To: ffmpeg-devel@ffmpeg.org > > Cc: Wu, Tong1 <tong1...@intel.com>; Chen, Wenbin <wenbin.c...@intel.com> > > Subject: Re: [FFmpeg-devel] [PATCH] avcodec/qsvenc: make QSV encoder encode > > VAAPI and D3D11 frames directly > > > > On Wed, 2022-06-08 at 05:08 +0000, Soft Works wrote: > > > > -----Original Message----- > > > > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Tong > > > > Wu > > > > Sent: Tuesday, June 7, 2022 11:22 AM > > > > To: ffmpeg-devel@ffmpeg.org > > > > Cc: Tong Wu <tong1...@intel.com>; Wenbin Chen <wenbin.c...@intel.com> > > > > Subject: [FFmpeg-devel] [PATCH] avcodec/qsvenc: make QSV encoder encode > > > > VAAPI > > > > and D3D11 frames directly > > [..] > > > > > 2.35.1.windows.2 > > > > > > Hi, > > > > > > thanks for submitting this patch. Though, I'm afraid, but this > > > > > > - fundamentally contradicts the logic of ffmpeg's handling of hw > > > > acceleration, > > > hw device and hw frames contexts > > > - adds code to an encoder, doing things an encoder is not supposed to do- > > > > qsv > > > encoders and decoders have their own context => QSV > > > > nvdec and nvenc have CUDA but nvenc can also support D3D11va, it sounds make > > sense for me to support D3D11va/vaapi in qsvenc too as d3d11va/vaapi are > > used > > internally in MediaSDK. > > Can you please post a command line showing nvenc working with input > from a D3D11VA decoder and without using any hwmap/hwupload/hwdownload > filters? >
According to the code below, nvenc may accept d3d11 frames directly, https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/nvenc.c#L46-L72 so the command below should work $> ffmpeg -y -hwaccel_output_format d3d11 -hwaccel d3d11va -i input.mp4 -c:v hevc_nvenc out.mp4 > > > > > > - is not safe/guaranteed to work always > > > there are different requirements for QSV than for other other cases > > > like VAAPI - for example: QSV requires a fixed-size frame pool > > > and encoders often need a larger frame pool than VAAPI > > > > > > > Encoders in MediaSDK don't need a fixed pool, probably we may relax this > > limitation in QSV. > > Well - I think they do: > > Common > The QSV hw frames context implementation is using a fixed pool size and > changing that would be anything but trivial. > > D3D11 > The decoders are using and allocating a D3D11 array textures which cannot > be resized. When the surface count is too low, QSV encoding will fail. > > VAAPI > See vaapi_frames_init(): there is support for dynamically sized pools, but > not as render targets. > > > The actual problem though is not about fixed vs dynamic pool size - it's > about whether the number of frames will be sufficient for encoding. > And when try to use the (d3d11va) decoder's output frames and supply them > to the encoder, they may very likely be insufficient. > > > QSV encoding always requires quite a number of surfaces. > You might remember all the extra_hw_frames parameters in the sample > command lines: > > https://trac.ffmpeg.org/wiki/Hardware/QuickSync > > ------------- > > Did you ever test this with a D3D11VA decoder on Windows? > I'm not sure whether this can work at all (feeding decoder frames > into the encoder) due to the differing bind_flags requirements. > > In case you did test that - could you please post the command line? vaapi on Linux: $ ffmpeg -y -hwaccel vaapi -hwaccel_output_format vaapi -i input.mp4 -c:v hevc_qsv out.mp4 d3d11va on Windows: $ ffmpeg.exe -y -hwaccel d3d11va -hwaccel_output_format d3d11 -i input.mp4 -c:v h264_qsv -y out.mp4 Thanks Haihao _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
