Brandon Thomas c2872fbd8d M6.2: filmcraft-aac — clean-room AAC-LC encoder and decoder ...

Encoder: transient-driven window switching (long/start/short/stop, grouping),
sine/KBD MDCT, MDCT-domain psychoacoustic model (Bark spreading, SFM tonality,
ATH, PE), TNS, per-band M/S, lambda rate-distortion loop with measured-error
scalefactor search and DP sectioning over all codebooks, bit reservoir with
fill elements (exact CBR), VBR quality scale, 1-8 channels (configs 1-7 + PCE
for 7ch), ASC + optional ADTS, 1024-sample priming reported.

Decoder: full AAC-LC syntax incl. PNS (correlated M/S noise), intensity stereo,
TNS, M/S, pulse data, both window shapes, PCE/DSE/FIL, ADTS helpers; never
panics on malformed input.

Tests use ffmpeg only as an oracle: our streams decode cleanly in ffmpeg
(CBR within 0.1%), our decoder matches ffmpeg to ~1e-7 on ffmpeg-encoded
streams (8-96 kHz, mono..7.1, IS/MS/TNS), plus fuzzing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-09-30 07:30:13 -04:00

..

derive.py

M6.2: filmcraft-aac — clean-room AAC-LC encoder and decoder

2026-09-30 07:30:13 -04:00

gen.py

M6.2: filmcraft-aac — clean-room AAC-LC encoder and decoder

2026-09-30 07:30:13 -04:00

probe.py

M6.2: filmcraft-aac — clean-room AAC-LC encoder and decoder

2026-09-30 07:30:13 -04:00