# What the game emits over the boot intro, decomposed against the movie's own track.
#
# 2026-08-30. Capture: docs/re/structures/intro-audio-output-census.md
# Reference: ffmpeg -i /disc/dat/movie/ADV.wmv -map 0:a:0 -f f32le -ar 48000 -ac 6
#
# ADV.wmv carries ONE audio stream: wmapro, 48000 Hz, 5.1, 384 kb/s. Not XMA.
#
# ALIGNMENT (energy envelope, 100 Hz, summed over channels = permutation-invariant)
#   movie begins +6.63 s into the capture; envelope r = 0.7692
#   control: peak 0.7692, 99.9th pct 0.6241, median -0.0009
#   refined by sample-level correlation to +224 samples, r = 0.900
#
# CHANNEL MAP -- measured, not assumed. Every row's max is a distinct movie
# channel, i.e. a genuine permutation, and it is the IDENTITY:
#   cap ch0->FL +0.899   ch1->FR +0.935   ch2->FC +0.185
#   cap ch3->LFE +1.000  ch4->BL +0.960   ch5->BR +0.971
# 🔴 The ALSA order [0,1,4,5,2,3] documented in audio-capture-alsa-file-tee.md
# does NOT apply to this capture. See the doc for what that corrected.
#
# DECOMPOSITION  capture = 0.600 x movie + residual   (80 s from movie t=20 s)
#  ch    gain      r      cap rms    resid rms   resid/cap
#  FL   0.600  +0.905    -21.86      -29.28      -7.43 dB
#  FR   0.600  +0.935    -20.28      -29.29      -9.02 dB
#  FC   0.597  +0.146    -25.18      -25.27      -0.09 dB   <- movie explains NOTHING
#  LFE  0.600  +1.000    -43.66     -115.73     -72.06 dB   <- exact to precision
#  BL   0.600  +0.956    -24.89      -35.46     -10.58 dB
#  BR   0.600  +0.964    -24.02      -35.49     -11.47 dB
#
# RESIDUAL STRUCTURE -- residual vs residual correlation
#         FL      FR      FC     LFE      BL      BR
#  FL  +1.000  +0.918  +0.017  +0.001  +0.009  +0.004
#  FR  +0.918  +1.000  +0.034  +0.001  +0.015  +0.014
#  FC  +0.017  +0.034  +1.000  +0.000  +0.385  +0.378
#  LFE +0.001  +0.001  +0.000  +1.000  +0.000  -0.000
#  BL  +0.009  +0.015  +0.385  +0.000  +1.000  +0.929
#  BR  +0.004  +0.014  +0.378  -0.000  +0.929  +1.000
#
# Three coherent groups: a FRONT pair (0.918), a REAR pair (0.929), and a
# CENTRE whose partner LFE is empty. That is three stereo streams in 5.1.
#
# FC residual 100 ms frame levels: median -53.9 dB, p90 -19.9 dB,
# dynamic range 34.0 dB -- bursty, not steady noise.