Error getting snapshop from AVI file

[mikevbaker]

I have a really simple project that's supposed to create an image snapshot from each of the AVI files found in a folder.

private async void BtnProcess_Click(object sender, EventArgs e)
{
    if (Directory.Exists(TbFolderName.Text))
    {
        string[] files = Directory.GetFiles(TbFolderName.Text, "*.avi");

        foreach (string file in files)
        {
            await ProcessFile(file);
        }
    }
}

private async Task ProcessFile(string file)
{
    Debug.WriteLine(file);

    var mediaInfo = await FFProbe.AnalyseAsync(file);
    try
    {
        bool result = await FFMpeg.SnapshotAsync(file, file.Replace("avi", "png"));
        Debug.WriteLine($"{file.Replace("avi", "png")} {result}");
    }
    catch (Exception ex)
    {
        Debug.WriteLine(ex);
    }
}

I'm getting a really long error - the important part (I believe) is this
[swscaler @ 0000019edefcdf40] deprecated pixel format used, make sure you did set range correctly

With the Snapshot[Async] functions I don't see the option to set the pixel format. Can anyone tell me how I can deal with these files?

More info from the error output...

ffmpeg exited with non-zero exit-code (69 - ffmpeg version 4.4.1-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 11.2.0 (Rev1, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      56. 70.100 / 56. 70.100
  libavcodec     58.134.100 / 58.134.100
  libavformat    58. 76.100 / 58. 76.100
  libavdevice    58. 13.100 / 58. 13.100
  libavfilter     7.110.100 /  7.110.100
  libswscale      5.  9.100 /  5.  9.100
  libswresample   3.  9.100 /  3.  9.100
  libpostproc    55.  9.100 / 55.  9.100
[avi @ 0000019edeafc880] non-interleaved AVI
[h264 @ 0000019edeafe880] missing picture in access unit with size 20
[h264 @ 0000019edeafe880] no frame!
[h264 @ 0000019edeafe880] missing picture in access unit with size 8
[h264 @ 0000019edeafe880] no frame!
[h264 @ 0000019edeafe880] missing picture in access unit with size 10
[h264 @ 0000019edeafe880] no frame!
[h264 @ 0000019edeafe880] missing picture in access unit with size 20
[h264 @ 0000019edeafe880] no frame!
[h264 @ 0000019edeafe880] missing picture in access unit with size 8
[h264 @ 0000019edeafe880] no frame!
[h264 @ 0000019edeafe880] missing picture in access unit with size 10
[h264 @ 0000019edeafe880] no frame!
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, avi, from 'D:\PathToVideo\VideoFileSample.avi':
  Duration: 00:00:12.52, start: 0.000000, bitrate: 1496 kb/s
  Stream #0:0: Video: h264 (Baseline) (h264 / 0x34363268), yuvj420p(pc, bt470bg/bt470bg/bt709, progressive), 1280x720, 1461 kb/s, 29 fps, 29 tbr, 29 tbn, 58 tbc
  Stream #0:1: Audio: adpcm_ima_wav ([17][0][0][0] / 0x0011), 8000 Hz, mono, s16p, 32 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> png (native))
Press [q] to stop, [?] for help
[NULL @ 0000019edeafe880] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0000019edeb2b3c0] non-existing PPS 0 referenced
[h264 @ 0000019edeb2b3c0] decode_slice_header error
[h264 @ 0000019edeb2b3c0] no frame!
[NULL @ 0000019edeafe880] non-existing PPS 0 referenced
[h264 @ 0000019edeb25d40] non-existing PPS 0 referenced

that last part repeats for about 1500 lines.