[FFmpeg-user] Issue with hwaccel cuvid

[Dennis Mungai]

On Wed, 8 Apr 2020 at 19:46, Andy Sheimo <asheimo at gmail.com> wrote:

> Dennis, Thank you. Lesson learned, check latest builds before submitting
> questions. Using the latest static build has resolved the issue.
>
> Cheers, -Andy
>
> On Wed, Apr 8, 2020 at 12:14 PM Dennis Mungai <dmngaie at gmail.com> wrote:
>
> > On Wed, 8 Apr 2020 at 19:04, Andy Sheimo <asheimo at gmail.com> wrote:
> >
> > > This still produces the same error;
> > >
> > > ffmpeg -threads 1 -loglevel verbose -hwaccel cuvid
> > > -hwaccel_output_format cuda -c:v mpeg2_cuvid -extra_hw_frames 3 -i
> > > "l:\welter_originals\gamera the brave\Latatude Zero-trailer.mkv" -c:a
> > copy
> > > -c:v h264_nvenc test.mkv
> > >
> > > But this works to complete the job;
> > >
> > > ffmpeg -threads 1 -loglevel verbose -hwaccel cuda
> > > -hwaccel_output_format cuda -extra_hw_frames 3 -i
> > > "l:\welter_originals\gamera the brave\Latatude Zero-trailer.mkv" -c:a
> > copy
> > > -c:v h264_nvenc test.mkv
> > >
> > > By not specifying  -c:v mpeg2_cuvid do we know what decoder is being
> > used?
> > > Is the process still completely in hardware? Do you think this is a
> > > limitation of the cuvid decoder?
> > >
> > > Thanks for your help. -Andy
> > >
> >
> > NVDEC (an alias to the CUDA hwaccel) handles GPU memory quite differently
> > from CUVID, and when its' in use, the decoder is not specified.
> > CUVID, however, was never a true hwaccel, but rather a "wrapper" that
> > "brings up"/initializes a specific decoder by name passed to it via -c:v,
> > in a similar fashion to the bring-up seen with QuickSync (-hwaccel qsv).
> >
> > I cannot speak much about why CUVID is failing on your end. I migrated
> all
> > my workflows to NVDEC an year ago.
> >
> > Perhaps omitting the hwacccel_output_format with CUVID will help?
> >
> > Try this:
> >
> > ffmpeg -threads 1 -loglevel verbose -hwaccel cuvid
> > -c:v mpeg2_cuvid -extra_hw_frames 3 -i
> > "l:\welter_originals\gamera the brave\Latatude Zero-trailer.mkv" -c:a
> copy
> > -c:v h264_nvenc test.mkv
> >
> > Then report back.
>
>
Thanks, and welcome.