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ffmpeg is really useful, but isn't doing some of these things on a CPU really inefficient? I know there are some offloads for Nvidia GPU’s for some video stuff,

ffmpeg is really useful, but isn't doing some of these things on a CPU really inefficient? I know there are some offloads for Nvidia GPU’s for some video stuff, but I was under the impression that they used Nvidia’s proprietary libraries that have limited codec support.

merb 6y ago
it's always a tradeoff between speed and quality. and most of the time cpu offers more quality while hardware encoders are faster, this is mostly because gpu encoders have a different use case than cpu encoders.
- astrange 6y ago
  The GPU encoders aren't GPGPU programs, but just hardware encoders that happen to be on the GPU. The reason they're worse is because the algorithms they use are worse than x264, which had much more development time and better developers. (who have since retired to become professional cosplayers.)
varenc 6y ago
ffmpeg supports various hardware decoders/encoders: https://trac.ffmpeg.org/wiki/HWAccelIntro https://trac.ffmpeg.org/wiki/HWAccelIntro I use the h264_videotoolbox hardware encoder on macOS all the time! But in my experience, CPU based encoding is always better and offers more fine tune control. It's just slow. And there's all sorts of filters and transformations that aren't possible in hardware. FFmpeg's Nvidia hardware support seems pretty good too. There's an official support doc on using ffmpeg: https://docs.nvidia.com/video-technologies/video-codec-sdk/ffmpeg-with-nvidia-gpu/ https://docs.nvidia.com/video-technologies/video-codec-sdk/f...
freeone3000 6y ago
NVENC is definitely limited -- it only supports H.264, H.265, and H.266. :P But it's absolutely the wrong thing to use for quality video encoding, since it introduces awful artifacting. GPGPU programs for H.264 is being limited, since CUVID is still seen as "good enough" so I've seen support for this in Blender, and nothing else.

merb 6y ago

it's always a tradeoff between speed and quality. and most of the time cpu offers more quality while hardware encoders are faster, this is mostly because gpu encoders have a different use case than cpu encoders.

astrange 6y ago
The GPU encoders aren't GPGPU programs, but just hardware encoders that happen to be on the GPU. The reason they're worse is because the algorithms they use are worse than x264, which had much more development time and better developers. (who have since retired to become professional cosplayers.)

varenc 6y ago

ffmpeg supports various hardware decoders/encoders: https://trac.ffmpeg.org/wiki/HWAccelIntro https://trac.ffmpeg.org/wiki/HWAccelIntro I use the h264_videotoolbox hardware encoder on macOS all the time! But in my experience, CPU based encoding is always better and offers more fine tune control. It's just slow. And there's all sorts of filters and transformations that aren't possible in hardware. FFmpeg's Nvidia hardware support seems pretty good too. There's an official support doc on using ffmpeg: https://docs.nvidia.com/video-technologies/video-codec-sdk/ffmpeg-with-nvidia-gpu/ https://docs.nvidia.com/video-technologies/video-codec-sdk/f...

freeone3000 6y ago

NVENC is definitely limited -- it only supports H.264, H.265, and H.266. :P But it's absolutely the wrong thing to use for quality video encoding, since it introduces awful artifacting. GPGPU programs for H.264 is being limited, since CUVID is still seen as "good enough" so I've seen support for this in Blender, and nothing else.