Ffmpeg leaving behind zombie tasks

[pashdown]

Describe the bug

Ffmpeg is leaving behind zombie tasks that need to be cleared out on a weekly basis by restarting the Scrypted docker.

To Reproduce

No specific actions, just running Scrypted with 30+ cameras.

Expected behavior

No zombies.

Logs

psax.log

Server (please complete the following information):

• OS: Debian 13
• Installation Method: Docker

Hardware Model (please complete the following information):

• Device: Mix of Amcrest, Axis cameras with a Reolink Doorbell

Client (please complete the following information, if applicable):

• Software: Browser

Additional context

Using a Mac Mini M4 in cluster mode in addition to the above server.

[koush]

what is the parent ppid. need it mapped to a specific plugin.

[pashdown]

I'll have to wait a week for the zombies to come out again, but I'll get you a full tree.

[yozik04]

Investigated zombie processes. Found 173 defunct  python3  zombies, all parented by PID 4925 ( npm exec scrypted-serve , Node) inside the  scrypted  Docker container (image ghcr.io/koush/scrypted:lite, up 10 days). Cause: Scrypted's Node core spawns python3 plugin subprocesses and fails to reap them on exit. Zombies span Jul 10 (container start) through Jul 19, accumulating in small batches over uptime. Currently harmless (no CPU/mem, PID count well under limits) but an unbounded leak; clears only on parent reaping or container/process restart.

Two distinct recurring jobs, like clockwork:

1. A pair every 4 hours — two  python3  forks ~2–3 min apart, at ~03:23/03:26, 07:23/07:26, 11:24/11:27, 15:24/15:27, 19:24/19:27, 23:25/23:28. → 6 pairs/day = 12/day.
2. A batch of 5 once daily at ~15:11–15:12 (all 5 within the same second). → 5/day.

Total ≈ 17 zombies/day, matching the histogram (11 on partial day Jul 10 → ~17/day thereafter). The regular 4-hour/daily cadence means these are scheduled/periodic tasks (e.g., maintenance, model/version or dependency checks by the Python plugins), not event-driven camera activity.

[pashdown]

scrypted-task-ps.txt

Looks like the webrtc plugin is at fault. Let me know if you need anything else.

[koush]

scrypted-task-ps.txt

thanks, its webrtc. what camera plugins and models do you have? webrtc typically doesn't use ffmpeg unless there's a issue with codecs. seems to be transcoding something to opus:

1288524 1420845 root | | _ /usr/bin/ffmpeg -hide_banner -analyzeduration 0 -probesize 512 -i rtsp://127.0.0.1:42171 -acodec libopus -flags +global_header -ar 48000 -b:a 40k -bufsize 96k -ac 2 -application lowdelay -dn -sn -vn -f rtp rtp://127.0.0.1:50080? -sdp_file pipe:4

[pashdown]

Is webrtc necessary for viewing cameras from a web browser? Otherwise, I can't think of why I need it.

A mix of Axis, Amcrest, and Reolink.

[koush]

yes webrtc transcodes the audio into a web capable format.

[pashdown]

Can I provide anything else to find the source of this?