[FFmpeg-devel] [PATCH] lavfi/vf_vpp_qsv: fix the infinite loop while framerate lower than input

[Fu, Linjie]

> From: Zhong Li <lizhong1008 at gmail.com>
> Sent: Tuesday, April 21, 2020 17:10
> To: Fu, Linjie <linjie.fu at intel.com>
> Cc: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH] lavfi/vf_vpp_qsv: fix the infinite loop
> while framerate lower than input
> 
> > > 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.
> IIRC, it is not necessary to insert hwdownload/upload to use fps filter. No ？
Ahh, you are right, the native fps filter would be fair enough for this case.

Thanks for the elaborations.