> From: Zhong Li <lizhong1...@gmail.com> > Sent: Sunday, April 19, 2020 23:00 > To: Fu, Linjie <linjie...@intel.com> > Cc: FFmpeg development discussions and patches <ffmpeg- > de...@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH] lavfi/vf_vpp_qsv: fix the infinite loop > while framerate lower than input > > Fu, Linjie <linjie...@intel.com> 于2020年2月29日周六 下午5:35写道: > > > > > -----Original Message----- > > > From: Zhong Li <lizhong1...@gmail.com> > > > Sent: Saturday, February 29, 2020 13:14 > > > To: FFmpeg development discussions and patches <ffmpeg- > > > de...@ffmpeg.org> > > > Cc: Fu, Linjie <linjie...@intel.com> > > > Subject: Re: [FFmpeg-devel] [PATCH] lavfi/vf_vpp_qsv: fix the infinite > loop > > > while framerate lower than input > > > > > > Linjie Fu <linjie...@intel.com> 于2020年2月28日周五 下午11:34写 > 道: > > > > > > > > There are frame droppings in frc while converting into a lower > framerate, > > > > and MSDK returns ERROR_MORE_DATA which should be ignored. > > > > > > Should be fixed in MSDK instead of working around in FFmpeg? > > > > MSDK made decision regarding frame rate conversion. If it's the framerate > down case, > > FRC would skip frame without producing an output [1], and request a new > input frame. > > I can't see the benefit to use MSDK framerate conversion function. Is > it a good idea to drop it and use ffmpeg native fps filter instead?
The implementation of FRC inside MSDK is quite straight-forward or simple currently since it just drops or repeats frames, hence I think using native fps filter is a good idea for decoding + FRC or FRC + encoding. However, for a pure hardware transcoding pipeline, there may be some performance issues if inserting a software filter, extra memory copy would be introduced in hwdownload/hwupload between system memory and video memory, which would impact a lot for large resolutions. Took a simple tests for 4K 10bit HEVC transcoding: # inserting a fps filter in the transcoding: 20 fps $ ffmpeg -hwaccel qsv -c:v hevc_qsv -i ../Exodus_UHD_HDR_Exodus_draft.mp4 -vf "hwdownload,format=p010le,fps=fps=60,hwupload=extra_hw_frames=40" -c:v hevc_qsv out.mp4 # using msdk framerate conversion: 33 fps $ ffmpeg -hwaccel qsv -c:v hevc_qsv -i ../Exodus_UHD_HDR_Exodus_draft.mp4 -vf "vpp_qsv=framerate=60" -c:v hevc_qsv out.mp4 - Linjie _______________________________________________ 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".