Encoding with nvenc results in 'Codec not supported'

[alexjs]

Attempting to use hevc_nvenc codec results in 'No NVENC capable devices found'.

This is mentioned on ​https://trac.ffmpeg.org/wiki/HWAccelIntro as being resolvable by:

Note: If you get the No NVENC capable devices found error make sure you're encoding to a supported pixel format. See encoder info as shown above.

However the problem occurs with all pixel formats and all variants (h264_nvenc too, e.g.). The driver version hits the minimum requirement for nvenc mentioned in various documents on the Internet.

How to reproduce:

% ffmpeg -i in/Foreman_ProRes.mov -c:v hevc_nvenc -profile main -pixel_format yuv420p -preset default out/output.mp4 -v 56

[...]

[hevc_nvenc @ 0x23c2880] Loaded Nvenc version 7.0
[hevc_nvenc @ 0x23c2880] Nvenc initialized successfully
[hevc_nvenc @ 0x23c2880] 1 CUDA capable devices found
[hevc_nvenc @ 0x23c2880] [ GPU #0 - < GRID K520 > has Compute SM 3.0 ]
[hevc_nvenc @ 0x23c2880] Codec not supported
[hevc_nvenc @ 0x23c2880] No NVENC capable devices found
[hevc_nvenc @ 0x23c2880] Nvenc unloaded
Stream mapping:
  Stream #0:0 -> #0:0 (prores (native) -> hevc (hevc_nvenc))
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

Version:

ffmpeg version: N-82215-g3932ccc Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.2) 20160609
built on ...

Configuration [matches Standard Ubuntu, but with nvenc]:
--prefix=/home/ubuntu/ffmpeg_build --extra-cflags=-I/home/ubuntu/ffmpeg_build/include --extra-ldflags=-L/home/ubuntu/ffmpeg_build/lib --bindir=/home/ubuntu/bin --extra-libs=-ldl --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv --enable-gpl


Encoding on: Nvidia GRID K520 (AWS G2 instance)
Nvidia details:  NVIDIA-SMI 367.57                 Driver Version: 367.57
SDK Details: Video_Codec_SDK_7.0.1

[Hendrik]

GRID K520 is a Kepler GPU, those do not support HEVC.
Its also quite possible that the GRID GPUs do not have the encoder block at all.

[Carl Eugen Hoyos]

​https://developer.nvidia.com/nvidia-video-codec-sdk#SupportedGPUs

[alexjs]

Thanks both - apologies for the noise then.

Quick clarification, I see the same behaviour with h264_nvenc (as below) -- but it looks like h264 should be possible on Kepler? Could this be PEBKAC or is it a pure incompatibility? I'm assuming given the 'yuv444p not supported' message, it's because the older GPU doesn't have yuv444p support, and pixel_format doesn't (can't?) override it in this case?

$ ffmpeg -i in/Foreman_ProRes.mov -c:v h264_nvenc -profile main -preset default -pixel_format yuv420p out/output.mp4 -v 56
[...]
Splitting the commandline.
Reading option '-i' ... matched as input file with argument 'in/Foreman_ProRes.mov'.
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'h264_nvenc'.
Reading option '-profile' ... matched as option 'profile' (set profile) with argument 'main'.
Reading option '-preset' ... matched as AVOption 'preset' with argument 'default'.
Reading option '-pixel_format' ... matched as AVOption 'pixel_format' with argument 'yuv420p'.
Reading option 'out/output.mp4' ... matched as output file.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '56'.
Finished splitting the commandline.
[...]

[h264_nvenc @ 0x2dcb880] Loaded Nvenc version 7.0
[h264_nvenc @ 0x2dcb880] Nvenc initialized successfully
[h264_nvenc @ 0x2dcb880] 1 CUDA capable devices found
[h264_nvenc @ 0x2dcb880] [ GPU #0 - < GRID K520 > has Compute SM 3.0 ]
[h264_nvenc @ 0x2dcb880] YUV444P not supported
[h264_nvenc @ 0x2dcb880] No NVENC capable devices found
[h264_nvenc @ 0x2dcb880] Nvenc unloaded

[alexjs]

Incidentally I see the same behaviour with Nvidia Telsa K80 cards (below - same ffmpeg CLI) - which are a newer Compute SM. I am increasingly thinking PEBKAC, but I can't quite work it out...

[h264_nvenc @ 0x3d96880] Loaded Nvenc version 7.0
[h264_nvenc @ 0x3d96880] Nvenc initialized successfully
[h264_nvenc @ 0x3d96880] 1 CUDA capable devices found
[h264_nvenc @ 0x3d96880] [ GPU #0 - < Tesla K80 > has Compute SM 3.7 ]
[h264_nvenc @ 0x3d96880] YUV444P not supported
[h264_nvenc @ 0x3d96880] No NVENC capable devices found
[h264_nvenc @ 0x3d96880] Nvenc unloaded