SAURON's "coolant flush sound glitched and perma" is one instance of a systemic
defect. SetupPatch (L4AUDLVL.cpp) decided looping from the SAMPLE flag alone:
AL_LOOPING = (info.loop != ForceStatic)
That armed every non-ForceStatic sample -- 224 of the 603 authored zones,
including unmistakable one-shots -- as an OpenAL source that never ends on its
own. Any such sound whose note-off never arrives plays forever. Measured 1946
LoopAtWill x Transient arming events in one short session.
The sample flag expresses PERMISSION; the SOURCE decides. Three facts [T1]:
* the enum's own comments (L4AUDLVL.h:14-19) -- LoopAtWill = "will play once
OR LOOP AS DESIRED", ForceStatic = "plays only once EVEN IF LOOPED" (a
veto), LoopAlways = "ramp up and then down";
* LoopAtWill is enum value 0, i.e. the DEFAULT an unauthored sample receives
(WTPresets.cpp:37) -- it cannot mean "loop forever";
* LoopAlways, the real always-loop, is used by ZERO shipped samples.
"As desired" is the source's authored AudioRenderType (Transient=one-shot vs
Sustained=held), streamed from AUDIO*.RES (AUDLVL.cpp:28) and already consulted
by the renderer (L4AUDRND.cpp:567, AUDREND.cpp:184). SetupPatch now takes it,
threaded from all three L4AudioSource call sites (Direct/Dynamic3D/Static3D).
New rule: LoopAlways->1, ForceStatic->0, LoopAtWill->the source's render type.
MEASURED before changing behaviour (BT_LOOP_AUDIT=1, scratchpad/loopaudit.py):
LoopAtWill x Transient -> loop=0 (was 1) 1946 events
LoopAtWill x Sustained -> loop=1 unchanged 65 events
ForceStatic x Transient -> loop=0 unchanged 292 events
The engine loops (EngineAccel07_z0..z2, EngineMotor01, EnginePower01) are all
LoopAtWill/Sustained and PRESERVED -- no regression there. All 24 reclassified
samples are genuine one-shots: laser charge/fire/explosion/loaded, missile
loading, engine shift, coolant pressure inc/dec.
A/B PROOF (scratchpad/loopab.py, same session both arms, only BT_LOOP_LEGACY
differs), asking the engine's own BT_AUDIO_DUMP what is still playing with
loop=1 long after every release:
[legacy] EnginePower01, CoolantPresInc03_z2, CoolantPresDcr03_z2
[fixed] EnginePower01
The two stuck coolant sources are the reported symptom. They were eventually
reclaimed when a later trigger reused the source, which is why the bug was
intermittent -- the "perma" case is when nothing else retriggers it. The fix
removes the mechanism.
BT_LOOP_LEGACY=1 restores the old rule for a field A/B without a rebuild. The
layers to listen to are the beam sustains: LaserA/CSustain* are authored
LoopAtWill on a TRANSIENT source, so they now end with the sample instead of
looping until note-off. The render type is T1 authored data; the interpretation
that LoopAtWill defers to it is a strong reading of the enum + defaults rather
than a disassembled statement, and is flagged as such in the KB.
Plausibly bears on #32 (audio cutting in/out late in a match): a stuck looping
source holds its pool slot for the rest of the round.
Rigs: scratchpad/flushsnd.py (flush start/stop pairing), flushsnd2.py (stuck-
source hunt), loopaudit.py (the classification matrix), loopab.py (the A/B).
KB: context/wintesla-port.md audio section, context/decomp-reference.md env
table (BT_LOOP_AUDIT / BT_LOOP_LEGACY / BT_AUDIO_DUMP / BT_AUD_TAIL),
docs/AUDIO_FIDELITY.md F38. checkctx.py CLEAN.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
