[FFmpeg-user] ffmpeg cuvid not transcoding properly

[Andy]

Unfortunately lowering threads did not help and resulted in the same error.
I noticed that all inputs that im having issues with are mpegts...

On Sun, Nov 17, 2019 at 12:33 AM Dennis Mungai <dmngaie at gmail.com> wrote:

> Hey there,
>
> Lower your decoder threads and retest:
>
> ffmpeg -threads 1 -vsync 1 -hwaccel cuvid -c:v h264_cuvid -deint 1
> -drop_second_field 1 -i 'http://0.0.0.0:4603' -c:v h264_nvenc -vb
> 1000k -preset:v medium -c:a aac -ac 2 -ar 48k -ab 96k test.mp4
>
> Now with the yadif_cuda filter:
>
> ffmpeg -threads 1 -vsync 1 -hwaccel nvdec -hwaccel_output_format cuda -i
> 'http://0.0.0.0:4603' -vf "yadif_cuda" -c:v h264_nvenc -vb 1000k
> -preset:v medium -c:a
> aac -ac 2 -ar 48k -ab 96k test.mp4
>
> For usage see:
>
> ffmpeg -h filter=yadif_cuda
>
> For what to expect, see
>
> https://stackoverflow.com/questions/55687189/how-to-use-gpu-to-accelerate-the-processing-speed-of-ffmpeg-filter/55747785#55747785
>
> Running the nvdec & cuvid decoders with multiple threads is the
> fastest way to land in hot water.
> Infact, the decoder will warn you if threads (either in auto mode or
> manually set) exceed 16. These hwaccels do not implement threading.
>
> You can confirm that by running:
>
> ffmpeg -h decoder=h264_cuvid
>
> And see that threading is not a reported capability.
>
> I also changed your commands to -vsync 1 as the MP4 muxer
> implelentation in libav supports CFR only, and NALU HRD stuffing isn't
> supported.
> Even if you're using libx264, do not use
>
> -x264-params "nal-hrd=cbr"
>
> When generating (f)mp4 content as you'll generate invalid output, with
> audio predominantly out of sync.
> If you truly require VFR output as part of your workflow, then stick
> to either mpegts (also supported in chunks via HLS or segment muxer)
> OR matroska (mkv).
>
> Cheers,
>
> Dennis M.
>
> On Sat, 16 Nov 2019 at 20:37, Ted Park <kumowoon1025 at gmail.com> wrote:
> >
> > How is the stream being served over http? Does it make any difference if
> you save a file wget for example first?
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