Hardware acceleration with PGS subtitles hangs indefinitely

[mholt]

Describe the bug

I think there are 2 issues here, but I'll just post the info I know and let you decide! :)

Initiated from this reddit thread which has a little more background.

Hardware-accelerated encoding of a stream with PGS subtitles hangs indefinitely on Raspberry Pi 4. After disabling subtitles, stream works fine, but there's still an error in the logs either way (appears a couple times):

[matroska,webm @ 0x1b92af0] Stream #5: not enough frames to estimate rate; consider increasing probesize
[matroska,webm @ 0x1b92af0] Could not find codec parameters for stream 3 (Subtitle: hdmv_pgs_subtitle (pgssub)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options

• One issue is that the video doesn't play at all
• Another issue might be those errors

System (please complete the following information):

• OS: MacOS (server is running on Linux, Raspbian, Raspberry Pi 4)
• Virtualization: none
• Clients: Browser, Android
• Browser: Firefox 75
• Jellyfin Version: 10.5.5
• Playback: Transcode, I think?
• Installed Plugins: none
• Reverse Proxy: Caddy
• Base URL: /
• Networking: Host? Just a regular LAN
• Storage: local

To Reproduce

0. Enable the OMX hardware acceleration on Raspberry Pi
1. Get a mkv file with PGS subtitles that need to be burned in (I don't really know how this works -- MP4s with soft subs don't have this problem)
2. Enable a subtitle track before playing
3. Play the file

Expected behavior

The video should play, I suppose. And from that reddit thread, the other commenter helping me said that the "unspecified size" logs should not happen either, like a bug that was thought to have been fixed already. That might be a separate issue, not sure.

Logs

See logs from both a working stream (no subs) and non-working stream (with subs) here: https://gist.github.com/mholt/1511cf85f8ca983bdd6ddd93ba430e07

Screenshots

n/a

Additional context

When subs are enabled, it's just a black screen forever, and the web UI kinda freezes and I have to reload it to go back.

Let me know what other information you need!

[stale]

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[mholt]

Oh nooooo don't close it 😭

[stale]

This issue has gone 120 days without comment. To avoid abandoned issues, it will be closed in 21 days if there are no new comments.
If you're the original submitter of this issue, please comment confirming if this issue still affects you in the latest release or nightlies, or close the issue if it has been fixed. If you're another user also affected by this bug, please comment confirming so. Either action will remove the stale label.
This bot exists to prevent issues from becoming stale and forgotten. Jellyfin is always moving forward, and bugs are often fixed as side effects of other changes. We therefore ask that bug report authors remain vigilant about their issues to ensure they are closed if fixed, or re-confirmed - perhaps with fresh logs or reproduction examples - regularly. If you have any questions you can reach us on Matrix or Social Media.

[mholt]

I am not aware that this is fixed; please leave open.

[stale]

This issue has gone 120 days without comment. To avoid abandoned issues, it will be closed in 21 days if there are no new comments.
If you're the original submitter of this issue, please comment confirming if this issue still affects you in the latest release or nightlies, or close the issue if it has been fixed. If you're another user also affected by this bug, please comment confirming so. Either action will remove the stale label.
This bot exists to prevent issues from becoming stale and forgotten. Jellyfin is always moving forward, and bugs are often fixed as side effects of other changes. We therefore ask that bug report authors remain vigilant about their issues to ensure they are closed if fixed, or re-confirmed - perhaps with fresh logs or reproduction examples - regularly. If you have any questions you can reach us on Matrix or Social Media.

[mholt]

Not fixed yet.

[sparky002]

I get the same error although I'm not using a raspi. Using the latest Jellyfin docker on Unraid with gpu acceleration on.

[nyanmisaka]

Not an issue. The processor of RPI4 cannot handle subtitle burn-in.

[mholt]

Sorry, but what do you mean, it "cannot handle" it?

[nyanmisaka]

Software based subtitle burn-in is a cpu intensive task even for x86, the cpu of Pi4 is not fast enough to do it on the fly.

[mholt]

Can the GPU perform this?

[nyanmisaka]

GPU scaling filter hasn’t been implemented yet, not to mention the GPU overlay filter.
jc-kynesim/rpi-ffmpeg#42