Vulkan ffv1 hw decode broken at least for 1920x1080 test file

[Andrew-R]

Summary of the bug:
How to reproduce:

bash-5.1$ ~/bin/ffmpeg8-vk -hwaccel vulkan -hwaccel_output_format vulkan  -i ~/1-ffv1.avi -vf hwdownload,format=yuv420p -vframes 1 /dev/shm/vulkan-test3.png
ffmpeg version N-118190-g8bb682d454 Copyright (c) 2000-2025 the FFmpeg developers
  built with gcc 11.2.0 (GCC)
  configuration: --enable-opencl --disable-debug --enable-libx265 --enable-libx264 --enable-gpl --enable-libplacebo --enable-vulkan --enable-libshaderc --enable-libzimg --enable-libaom --enable-libdav1d --enable-libsoxr --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-gnutls --enable-libass --enable-libbluray --enable-libcdio --enable-frei0r --enable-libgsm --enable-openal --enable-libopus --enable-librtmp --enable-libsnappy --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp
  libavutil      60.  2.100 / 60.  2.100
  libavcodec     62.  0.101 / 62.  0.101
  libavformat    62.  0.100 / 62.  0.100
  libavdevice    62.  0.100 / 62.  0.100
  libavfilter    11.  0.100 / 11.  0.100
  libswscale      9.  0.100 /  9.  0.100
  libswresample   6.  0.100 /  6.  0.100
  libpostproc    59.  1.100 / 59.  1.100
[aist#0:1/pcm_s16le @ 0xb406540] Guessed Channel Layout: stereo
Input #0, avi, from '/home/guest/1-ffv1.avi':
  Metadata:
    software        : Lavf58.56.100
  Duration: 00:01:03.40, start: 0.000000, bitrate: 91562 kb/s
  Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv420p, 1920x1080, 90191 kb/s, 30 fps, 30 tbr, 30 tbn
  Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
File '/dev/shm/vulkan-test3.png' already exists. Overwrite? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (ffv1 (native) -> png (native))
Press [q] to stop, [?] for help
Output #0, image2, to '/dev/shm/vulkan-test3.png':
  Metadata:
    software        : Lavf58.56.100
    encoder         : Lavf62.0.100
  Stream #0:0: Video: png, rgb24(pc, gbr/unknown/unknown, progressive), 1920x1080, q=2-31, 200 kb/s, 30 fps, 30 tbn
    Metadata:
      encoder         : Lavc62.0.101 png
[image2 @ 0xb422ac0] The specified filename '/dev/shm/vulkan-test3.png' does not contain an image sequence pattern or a pattern is invalid.
[image2 @ 0xb422ac0] Use a pattern such as %03d for an image sequence or use the -update option (with -frames:v 1 if needed) to write a single image.
[out#0/image2 @ 0xb407a40] video:1318KiB audio:0KiB subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: unknown
frame=    1 fps=0.1 q=-0.0 Lsize=N/A time=00:00:00.03 bitrate=N/A speed=0.00217x

Resulted vulkan-test3.png jus plain broken

Doing similar decode but w/o Vulkan gives ok png

~/bin/ffmpeg8-vk -i ~/1-ffv1.avi -vframes 1 /dev/shm/vulkan-test3-novulkan.png

[Andrew-R]

Broken output

[Lynne]

I need a sample, not an output.

[Andrew-R]

1 frm sample made with ffmpeg -i ~/1-ffv1.avi -c:v copy -vframes 1 -an /dev/shm/sample-ffv1.mkv

[Lynne]

Fixed in 3cbe3418b2b7