[FFmpeg-user] Issue with hwaccel cuvid

[Dennis Mungai]

On Wed, 8 Apr 2020 at 19:13, 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
>

And another suggestion:

Try using a newer FFmpeg build. Your binary was compiled in ~2019. Retry
with a new build and report back.
On this mailing list, only ffmpeg git tip builds are supported.

For up to date static builds, see:
1. Jon Van Sickle's builds (Linux):  https://johnvansickle.com/ffmpeg/
2. For Windows, Zeranoe's: https://ffmpeg.zeranoe.com/builds/