Files
Sylpheed/docs
sylph-decoder ef4ea8fe86 re: the boot intro's audio output -- five live channels, not a stereo mix
Groundwork for the port's ask #4; it does not settle #4.

Captured the game's own output over the boot intro following the ALSA file-tee
recipe exactly -- paced pulse slave, --gpu=null, both mutes off. 148.02 s, 6ch
float32 48 kHz, 0.15-0.16 % silence against the 0.31 % the recipe page records
for its own clean run.

Provenance is the XMA probe rather than a screenshot, which is the right evidence
for an audio question: ADV's three contexts appear byte-exact (1294336 /
1118208 / 1171456), then the documented BGM_102 pair.

Five of the six channels carry distinct content; BR is 82 % silent and 11-15 dB
down. No channel is a copy of another -- the largest pairwise correlation is 0.70
between FL and FR.

That rules out a stereo mix, so 'ship one stream' cannot be right and the port's
held-wrong value stays wrong. It does NOT establish that summing is right, and
the 6-channel count is Xenia's hardcoded kFrameChannelsDefault -- what is
evidence is that five of them differ, which a stereo guest cannot produce.

NOT settled and named as such: the stream-to-channel mapping. The
cross-correlation of each captured channel against each decoded ADV stream has
not been run. One boot, one movie, and --gpu=null means no video cross-check.

Raw is 170 MB and is not committed; sent over share to the port.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v
2026-08-30 08:13:50 +00:00
..