Issues when using av1_amf to encode a video

[j.zwayn]

Summary of the bug:

Video is fullHD (1920x1080). We want to encode the video using av1_amf.
the card used is: AMD Radeon RX 7900 XT, Driver: 31.0.14000.62003
AMF version: AMF 1.4.29
ffmpeg: 2d202985b79630cd5056c4e32f8f77f22bf1067c

The resulting file do not have the right format: 1920x1080 as input and it output 1920x1082

How to reproduce:

% ffmpeg.exe -y -i input.mkv -b:v 5M -c:v av1_amf output.mkv 
ffmpeg version N-109535-gfcd557a2c2
built with gcc 10-win32 (GCC) 20210110

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Balling]

The resulting file do not have the right format: 1920x1080 as input and it output 1920x1082

Why are sure AMD can encode 1080 pixels? Nvidia cannot.

[jdek]

Added sample for av1 amf.

VLC says 1152/1082, ffprobe says 1082, mediainfo specifies 1080/1082.

ffprobe:

$ ffprobe elden_ring_av1_5mb.mkv
ffprobe version 4.3.5-0+deb11u1 Copyright (c) 2007-2022 the FFmpeg developers
  built with gcc 10 (Debian 10.2.1-6)
  configuration: --prefix=/usr --extra-version=0+deb11u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-pocketsphinx --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
[libdav1d @ 0x55e7f78f1b00] libdav1d 0.7.1
Input #0, matroska,webm, from 'elden_ring_av1_5mb.mkv':
  Metadata:
    SOFTWARE        : Lavf57.56.101
    ENCODER         : Lavf59.36.100
  Duration: 00:00:20.00, start: 0.000000, bitrate: 5013 kb/s
    Stream #0:0: Video: av1 (Main), yuv420p(tv, bt709, progressive), 1920x1082, 60 fps, 60 tbr, 1k tbn, 1k tbc
    Metadata:
      ENCODER         : Lavc59.56.100 av1_amf
      DURATION        : 00:00:20.000000000
[libdav1d @ 0x55e7f78f5bc0] libdav1d 0.7.1

Mediainfo:

$ mediainfo elden_ring_av1_5mb.mkv
General
Unique ID                                : 261833798229551093745524176964670436669 (0xC4FB5AF16BCDED45DDDBE2DEA3C3B53D)
Complete name                            : elden_ring_av1_5mb.mkv
Format                                   : Matroska
Format version                           : Version 4
File size                                : 12.0 MiB
Duration                                 : 20 s 0 ms
Overall bit rate                         : 5 013 kb/s
Writing application                      : Lavf59.36.100
Writing library                          : Lavf59.36.100
ErrorDetectionType                       : Per level 1
SOFTWARE                                 : Lavf57.56.101

Video
ID                                       : 1
Format                                   : AV1
Format/Info                              : AOMedia Video 1
Format profile                           : Main@L5.2
Codec ID                                 : V_AV1
Duration                                 : 20 s 0 ms
Bit rate                                 : 4 914 kb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Original height                          : 1 082 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 60.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.039
Stream size                              : 11.7 MiB (98%)
Writing library                          : Lavc59.56.100 av1_amf
Default                                  : No
Forced                                   : No
Color range                              : Limited

[nyanmisaka]

​https://gitlab.freedesktop.org/mesa/mesa/-/issues/9185#note_1954937

There is the same issue on Linux with the in developing av1_vaapi encoder. Unfortunately AMD developers said this is a hardware limitation in VCN 4.0 and will be resolved in the next generation.