Jellyfin Failing to transcode without error

[SpaceFlier]

I have a video encoded in mpeg4 and I'm getting very weird results upon playback. On a PC via the web interface the stream auto transcodes and it plays. On Andoird via the web interface it bring up the unsupported codec message and doesn't try to transcode. on Findroid the file plays but its just a black screen with the audio in the background. Looking in the ffmpeg logs I don't see any errors and it appears to end fine.

Code:

Metadata:
    encoder        : libebml v1.3.0 + libmatroska v1.4.1
    creation_time  : 2014-01-03T17:13:46.000000Z
  Duration: 00:57:34.85, start: 0.000000, bitrate: 842 kb/s
  Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 512x328 [SAR 1:1 DAR 64:41], 25 fps, 25 tbr, 1k tbn (default)
  Stream #0:1: Audio: mp3, 32000 Hz, stereo, fltp, 128 kb/s (default)
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg4 (native) -> hevc (hevc_nvenc))
  Stream #0:1 -> #0:1 (mp3 (mp3float) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[mpeg4 @ 0x55cbb71fe240] Video uses a non-standard and wasteful way to store B-frames ('packed B-frames'). Consider using the mpeg4_unpack_bframes bitstream filter without encoding but stream copy to fix it.
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b78-1.mp4' for writing
Output #0, hls, to '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b78.m3u8':
  Metadata:
    encoder        : Lavf59.27.100
  Stream #0:0: Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(bt709, progressive), 512x328 [SAR 1:1 DAR 64:41], q=2-31, 4214 kb/s, 25 fps, 12800 tbn (default)
    Metadata:
      encoder        : Lavc59.37.100 hevc_nvenc
    Side data:
      cpb: bitrate max/min/avg: 4214080/0/4214080 buffer size: 8428160 vbv_delay: N/A
  Stream #0:1: Audio: aac, 32000 Hz, stereo, s16, 256 kb/s (default)
    Metadata:
      encoder        : Lavc59.37.100 libfdk_aac
frame=    1 fps=0.0 q=0.0 size=N/A time=00:00:00.00 bitrate=N/A speed=  0x   
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b780.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b781.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b782.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b783.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b784.mp4' for writing
frame=  407 fps=0.0 q=15.0 size=N/A time=00:00:16.22 bitrate=N/A speed=30.5x   
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b785.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b786.mp4' for writing
[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b787.mp4' for writing


[q] command received. Exiting.

[hls @ 0x55cbb71f0640] Opening '/var/lib/jellyfin/transcodes/c9f9770f1fa688b1192a1a85431a8b788.mp4' for writing
frame=  636 fps=0.0 q=16.0 Lsize=N/A time=00:00:25.34 bitrate=N/A speed=31.4x   
video:7818kB audio:819kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

The only link I can think of is that I have hardware acceleration on nvenc with a 1660 super and this table doesn't show mpeg4 support, however, I have unselected mpeg4 from the decoding options. Jellyfin is running v10.9.6 in a proxmox VM with the GPU using pcie passthrough. The file in question is hosted on a network share with smb, and using cifs-utils to mount the share (all my other media is stored here and they all work fine). If anyone knows any command or other logs which may help find the cause please post them.

[TheDreadPirate]

For the Android device, you said "web interface". Did you access Jellyfin from a Chrome browser in Android? Or from the Jellyfin app with the web player selected? If you are using the web player in the Android app, switch to the integrated player.

Findroid does not request transcodes, AFAIK. And it defaults to exoplayer. Try switching to the MPV player in Findroid.

[SpaceFlier]

Chrome on android, and I had no idea findroid didn't request transcodes, thanks. Switching to the mpv player it just loads forever while I can see in the progress bar it's still catching forward and has downloaded the data, and I didn't see mpeg4 support on the GitHub page so I kind of expected that. The android jellyfin app does play the video but I'm still unsure why chrome doesn't on my phone but does on my pc

[TheDreadPirate]

What OS is the VM running and how is Jellyfin installed in the VM?

[SpaceFlier]

Ubuntu 22.04.4, via regular Linux install

[TheDreadPirate]

Your video works fine on my server. Transcodes correctly and the browser plays it without issue. But mine uses an Intel Arc GPU.

Can you share the full ffmpeg log when this video transcodes. I want to see the full ffmpeg command and all the parameters that were used.

Also, what Nvidia driver is your system running?