A previous attempt swapped `-timeout` → `-stimeout` unconditionally to
fix EADDRINUSE on the reporter's transitional ffmpeg. That broke every
install on a modern ffmpeg (5+/6+/7+) — current Debian/Ubuntu/Homebrew
— where `-stimeout` was removed and `-timeout` is back to meaning
socket I/O. Verified locally: `ffmpeg -stimeout ...` errors
"Unrecognized option 'stimeout'" on ffmpeg 7.1.
install on a modern ffmpeg (5+/6+/7+) — current Debian/Ubuntu/Homebrew
— where `-stimeout` was removed and `-timeout` is back to meaning
socket I/O. Verified locally: `ffmpeg -stimeout ...` errors
"Unrecognized option 'stimeout'" on ffmpeg 7.1.
ffmpeg has shipped THREE arrangements of this option over time and
Bambuddy supports the full range:
- Pre-deprecation (early 4.x and earlier): `-timeout` is socket I/O.
- Transitional (~late-4.x, Jammy-era): `-timeout` is deprecated and
repurposed to RTSP listen-mode timeout; any non-zero value implies
`-listen`, which makes ffmpeg bind the TLS-proxy port and fail with
EADDRINUSE. `-stimeout` is the replacement socket I/O option.
- Modern (5.x / 6.x / 7.x): `-stimeout` REMOVED. `-timeout` is back to
socket I/O — the original meaning.
So no single literal is correct on all installs.
Fix: `rtsp_socket_timeout_flag()` in services/camera.py probes
`ffmpeg -h demuxer=rtsp` once and picks `-stimeout` when ffmpeg
advertises it (covers transitional + older builds that kept it as an
alias), else `-timeout` (modern + pre-deprecation). Cached at module
level for the process lifetime — ffmpeg doesn't swap mid-run.
The function returns the option name without a leading dash; callers
prepend it themselves so a formatting bug can't pass an empty flag.
Wired into both RTSP ffmpeg call sites in lockstep: routes/camera.py
(printer camera) and services/external_camera.py (external RTSP),
which use the same TLS-proxy + ffmpeg pattern and would hit the same
regression on either ffmpeg cohort.
Tests: 8 in test_ffmpeg_rtsp_timeout_flag.py — 6 probe unit tests
(prefers stimeout when advertised, falls back to timeout on modern,
defaults to timeout when ffmpeg missing or probe raises, caches across
calls, trailing-space substring guard against `-listen_timeout`
false-positives), 2 parametrised guards against either RTSP ffmpeg
argv re-hard-coding a literal instead of consuming the probe. 37
probe + existing external-camera tests green.
