Cuvid decoders do not work with CUDA hwaccel anymore

[bermond]

Cuvid decoders do not work with CUDA hwaccel anymore in FFmpeg git master. An error message says that Codec h264_cuvid is not supported with this chroma format.

How to reproduce:

$ ffmpeg -init_hw_device cuda=gpu:0 -hwaccel cuda -hwaccel_output_format cuda -hwaccel_device gpu -c:v h264_cuvid -i input.mp4 -y test-out.mp4
ffmpeg version N-118749-g0f7d77fc42 Copyright (c) 2000-2025 the FFmpeg developers
  built with gcc 14.2.1 (GCC) 20250207
  configuration: --prefix=/usr --enable-lto --disable-rpath --enable-gpl --enable-version3 --enable-nonfree --enable-shared --disable-static --disable-stripping --disable-htmlpages --enable-gray --enable-alsa --enable-avisynth --enable-bzlib --enable-chromaprint --enable-frei0r --enable-gcrypt --enable-gmp --enable-gnutls --enable-iconv --enable-ladspa --enable-lcms2 --enable-libaom --enable-libaribb24 --enable-libaribcaption --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcelt --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libdavs2 --enable-libdc1394 --enable-libdvdnav --enable-libdvdread --enable-libfdk-aac --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-libglslang --enable-libgme --enable-libgsm --enable-libiec61883 --enable-libilbc --enable-libjack --enable-libjxl --enable-libklvanc --enable-libkvazaar --enable-liblc3 --enable-liblcevc-dec --enable-liblensfun --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopencv --enable-libopenh264 --enable-libopenjpeg --enable-libopenmpt --enable-libopenvino --enable-libopus --enable-libplacebo --enable-libpulse --enable-libqrencode --enable-libquirc --enable-librabbitmq --enable-librav1e --enable-librist --enable-librsvg --enable-librubberband --enable-librtmp --disable-libshaderc --enable-libshine --enable-libsmbclient --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libsvthevc --enable-libsvtvp9 --disable-libtensorflow --enable-libtesseract --enable-libtheora --disable-libtls --disable-libtorch --enable-libtwolame --enable-libuavs3d --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libvvenc --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxevd --enable-libxeve --enable-libxavs --enable-libxavs2 --enable-libxcb --enable-libxcb-shm --enable-libxcb-xfixes --enable-libxcb-shape --enable-libxvid --enable-libxml2 --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-lzma --enable-decklink --disable-mbedtls --enable-libmysofa --enable-openal --enable-opencl --enable-opengl --disable-openssl --disable-pocketsphinx --enable-sndio --enable-sdl2 --enable-vapoursynth --enable-vulkan --enable-xlib --enable-zlib --enable-amf --enable-cuda-nvcc --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-libdrm --enable-libvpl --enable-libnpp --enable-nvdec --enable-nvenc --enable-omx --enable-rkmpp --enable-v4l2-m2m --enable-vaapi --enable-vdpau
  libavutil      59. 59.100 / 59. 59.100
  libavcodec     61. 33.102 / 61. 33.102
  libavformat    61.  9.107 / 61.  9.107
  libavdevice    61.  4.100 / 61.  4.100
  libavfilter    10.  9.100 / 10.  9.100
  libswscale      8. 13.101 /  8. 13.101
  libswresample   5.  4.100 /  5.  4.100
  libpostproc    58.  4.100 / 58.  4.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2023-02-17T22:54:31.000000Z
  Duration: 00:00:40.75, start: 0.000000, bitrate: 817 kb/s
  Stream #0:0[0x1](und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 576x1024 [SAR 1:1 DAR 9:16], 684 kb/s, 29.97 fps, 29.97 tbr, 30k tbn (default)
    Metadata:
      creation_time   : 2023-02-17T22:54:31.000000Z
      handler_name    : ISO Media file produced by Google Inc. Created on: 02/17/2023.
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      creation_time   : 2023-02-17T22:54:31.000000Z
      handler_name    : ISO Media file produced by Google Inc. Created on: 02/17/2023.
      vendor_id       : [0][0][0][0]
[h264_cuvid @ 0x5ea53363e140] Codec h264_cuvid is not supported with this chroma format.
[vist#0:0/h264 @ 0x5ea5335a5f40] [dec:h264_cuvid @ 0x5ea533683d00] Error while opening decoder: Invalid argument
Error opening output file test-out.mp4.
Error opening output files: Invalid argument

The command bellow, without hwaccel, works:

$ ffmpeg -c:v h264_cuvid -i input.mp4 -y test-out.mp4

A git bisect shows the offending commit as being: 7e9655800da385f8dc9d31f6ac831910f98c8c9e.

Operating System: Arch Linux
FFmpeg: git master

[Balling]

We need an input file. But that is not an offending commit, because 50 series Nvidia cards NVDEC silicon supports those formats in HW.

h264_cuvid is deprecated as decoder and encoder, use new h264_nvenc.

[Gyan]

They may but my quick check also triangulated to that commit:
​https://github.com/GyanD/codexffmpeg/issues/173

[Balling]

Hm, so I can see the input file is just normal h264 8 bit file, hm. Then it should be a bug.

[bermond]

Thank you for the replies.

We need an input file.

This can be used as an input file (download command, needs yt-dlp):

$ yt-dlp --format best https://www.youtube.com/shorts/n5jf9PpZzGY

It's an 8-bit YUV 4:2:0 video, which should work with h264_cuvid when using CUDA hwaccel. It was working right before the mentioned commit.

They may but my quick check also triangulated to that commit:
​​https://github.com/GyanD/codexffmpeg/issues/173

This seems to be exactly the same issue. Thanks for sharing.

Note: using RTX 3060 with proprietary NVIDIA drivers 570.124.04.

[Balling]

I still do not get it why are using it like this, that is kinda wrong... h264_nvenc should be used.

ffmpeg -init_hw_device cuda=gpu:0 -hwaccel cuda -hwaccel_output_format cuda -hwaccel_device gpu -hwaccel cuda -i input.mp4 -c:v h264_nvenc -y test-out.mp4

[bermond]

I still do not get it why are using it like this, that is kinda wrong... h264_nvenc should be used.

h264_nvenc is an encoder, and I guess you are confusing things here. This issue is not about the encoder.

But the issue is about the decoder. And more specifically, about Cuvid decoders (h264_cuvid, hevc_cuvid and so on).

ffmpeg -init_hw_device cuda=gpu:0 -hwaccel cuda -hwaccel_output_format cuda -hwaccel_device gpu -hwaccel cuda -i input.mp4 -c:v h264_nvenc -y test-out.mp4

Your example does not use Cuvid decoders, which are the subject of this issue.

[Aleksoid1978]

Replying to bermond:

ffmpeg -init_hw_device cuda=gpu:0 -hwaccel cuda -hwaccel_output_format cuda -hwaccel_device gpu -hwaccel cuda -i input.mp4 -c:v h264_nvenc -y test-out.mp4

Your example does not use Cuvid decoders, which are the subject of this issue.

It's use NVDEC decoder, better use it then CUDA.

[Timo Rothenpieler <timo@rothenpieler.org>]

In fed66124/ffmpeg:

avcodec/cuviddec: use pre-existing chroma format information

Fixes #11505

[bermond]

I can confirm this is now fixed by commit fed6612415c98fc1b0193bb5a92442fab550fd49.

Thank you for fixing this!

[Balling]

I still do not get it BTW, you either use -hwaccel and its format or cuvid as decoder, before -i.