Withdraws my conclusion that the monitor-sink capture route cannot be fixed by
configuration, and with it the claim that only an in-emulator tap would work.
The container has no audio hardware -- no /proc/asound/cards, no /dev/snd, no
asound.conf -- so PulseAudio s stock default.pa module-always-sink supplies a
null sink, whose whole purpose is to exist when there is no device. A null sink
has no hardware clock: it is timer-driven, and anything the client fails to write
in time becomes silence in the monitor. That much was right.
What was wrong was inferring from it that the holes mean the guest runs below
real time. The alternative was never tested: xenia asks SDL for channel_samples_
= 256, which is 5.33 ms at 6 channels, and daemon.conf here is stock with no
fragment tuning. PULSE_LATENCY_MSEC overrides what SDL s PulseAudio backend
requests.
Measured, same title and sink and parec invocation:
xenia default (~5.3 ms) 347.5 s 39.3 percent silence 30.5 gaps/s
PULSE_LATENCY_MSEC=200 88.0 s 15.6 percent silence 3.5 gaps/s
An 8.7x reduction from one environment variable. Against the port s controls --
starved 32.9 gaps/s, genuine music bed 3.3, voice track 0.03, bar at 20 -- the
default is squarely starved and 200 ms lands at the level of real content.
Not yet a clean bill of health: the runs are not like-for-like at 88 s against
347 s, and the short one covers the splash logos where silence is real. What is
established is direction and scale. The consequence that matters is that the
capture route should be retried at raised latency before anyone spends a session
on a Canary rebuild.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
76d19f8551