Files
craft-libs/crates
alehelandClaude Opus 5.5 f68e4369eb craft-audio: decode the HE-AAC SBR high band
aac::Decoder::set_sbr(true) decodes HE-AAC at twice the core rate with the
SBR tool of ISO/IEC 14496-3 §4.6.18: QMF analysis and synthesis, frequency
band tables, patching with LPC inverse filtering, envelope adjustment with
limiter, boost, noise and sinusoids. TrackDecoder uses it in place of the
2x upsampler. Tables are transcribed from ETSI ES 201 980 Annex I.

Matches ffmpeg's decoder on AudioToolbox HE-AAC streams of 1-6 channels:
the same 962-sample delay, ~54 dB SNR, high band level within 0.01 dB.
Parametric stereo is still not decoded.

Refs #1121

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-13 07:34:10 +01:00
..
2026-11-12 06:26:09 -05:00
2026-11-12 10:37:55 -05:00