Macos: Recording pipeline repeatedly stalls for 5–22 s (whole process), causing ~10% video loss and multi-second audio gaps#2366
Description
38.5-minute recording (14:01:52 → 14:40:24 UTC). During it, the pipeline froze 16 times:
- Video: 16
Wall-clock-confirmed forward jumpevents,total_forward_skew_secs="222.033"(~10% of the recording missing) - Mic: 6 silence insertions,
total_silence_ms=64429 - System audio: 172 silence insertions,
total_silence_ms=69615, plusdropping frames due to full channel
Evidence that the whole process stalls, not just capture The periodic memory snapshot normally fires at :25 every minute. During the stalls it fires late:
- 14:06:32 (+6.4 s), 14:19:37 (+12 s), 14:21:42 (+16.5 s), 14:28:32 (+6.5 s)
There are also windows with no log lines at all from any thread:
- 14:13:57.7 → 14:14:22.2 (24.5 s)
- 14:15:57.4 → 14:16:20.1 (22.6 s)
- 14:19:15.3 → 14:19:37.9 (22.6 s)
- 14:21:17.9 → 14:21:42.4 (24.5 s)
- 14:28:07.8 → 14:28:32.4 (24.6 s)
Mic and system-audio drops happen exactly in these windows: the sources keep producing data, but consumers are not draining the channels.
Suspicious pattern The longest video gaps are almost identical: 21.33, 21.35, 21.47, 21.23, 21.44, 21.77 s. This looks like a fixed timeout somewhere rather than random I/O latency.