Comments must not document the past or reference plan circumstances:
drop the stale pointer to a never-created audio_correlate_layout.hpp,
the "step b" plan labels, the "carved out of reserved space" history
note, and a README pointer; reword a past-tense seqlock comment to
describe the failure mode in the present.
Replace the strncpy in log_ring_push with a bounded memcpy: same
semantics (truncate + NUL), but without the C4996 deprecation warning
on every host build.
Extends the two-path correlation from rate-only to the full layout, removing the
"channels/bit-depth assumed = device" limitation. correlate_format tries each
candidate de-interleaving (float32 / int16; mono..7.1) of the hook capture, runs
the rate correlation per layout, and keeps whichever aligns with the loopback;
a wrong de-interleaving is noise and won't.
The catch: the hook can't know a guessed stream's real frame size, so its verify
tap pads each render buffer to the device block -- which over-reads stale staging
bytes for a stream with fewer channels/bits, scrambling the audio. So the tap is
now self-describing: it prefixes each buffer with its frame count
([count][count*device_block bytes]), and the host strips the padding per candidate
layout (take the real count*real_block of each chunk) before de-interleaving.
- audio_correlate.hpp: ChunkedCapture + chunk-aware correlate_format + candidate
layouts; absolute-margin confidence gate (the true layout scores ~1.0, a truly
ambiguous alternative within ~0.001 -- 2ch@R == 1ch@2R for identical channels --
is correctly left unconfident).
- audio_hook.cpp: chunked verify tap (free-space-checked so framing can't tear).
- audio_format_verifier: parse chunks; recover_layout path. AudioMirror now corrects
the full format.
- audio_correlation_test: layout recovery from padded chunks (stereo float, 16-bit
PCM, 5.1, mono). audio_verify_test gains scenario (b): 2ch on a multichannel
endpoint with distinct per-channel content (new env-gated ToneSource mode) ->
recovers ch=2/32-bit float end-to-end.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
When the host attaches to an already-running game it never saw the stream's
Initialize, so the render-hook assumes the device mix format and measures only
the sample rate from the render cadence -- which a jittery game can make wrong
(intermittent pitch shift). But during the measurement window the game is still
audible, so we have the same audio twice: the hook (pre-mix, unknown format) and
a process-loopback (post-mix, the known device format). Cross-correlating them
pins the true rate from ground truth.
- common/include/coop/audio_correlate.hpp: the pure correlator. Resample the hook
by each candidate standard rate up to the device rate and score how well it
aligns with the loopback across the window (drift-detecting). audio_correlation_test
recovers every rate (score ~1.0 vs ~0.01 for wrong ones), incl. 44100-vs-48000,
and rejects unrelated signals.
- Hook measurement tap: a host-set verify_capture ring flag makes the hook push a
still-being-measured (guessed) stream's raw pre-mix bytes WITHOUT silencing, so
the host can co-capture both signals (a silenced game's loopback is silent).
Inert by default -- the shipping no-echo path is untouched.
- host/src/audio/audio_format_verifier: co-captures hook + loopback and correlates,
feeding a correction into the existing override channel. Wired into AudioMirror's
measurement window (hidden in the gap loopback already covers, so exact streams
pay nothing). audio_verify_test drives it end-to-end against coop_mock_game.
Rate vs layout are coupled (correlating the waveform needs the right channel
de-interleaving), so this step assumes the hook layout matches the device (the
common stereo-on-stereo case); recovering a different channel count / bit depth
is step b.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
