* craft-audio: FilmCraft's FLAC encoder and MP1/MP2 decoder speed-ups
FLAC: per-order predictor kernels, merged Rice partition sums, the LPC
window kept per block length, and batches consumed by offset
(filmcraft 5eaff794, d9dad4a5). The output is unchanged: 64 golden cases
hash the same before and after.
MP1/MP2: the faster synthesis filterbank (filmcraft 51c755e5), with its
bit-exact test.
* craft-audio: FilmCraft's AAC and Opus decoder speed-ups and refactors
AAC: table-driven Huffman decoding, per-stage FFT twiddles and fused
stages, reused per-channel work buffers, and the encoder's memoised
per-band work (filmcraft f9627280, d587ceed, 6121635c, dc124ab7,
7a532eca).
Opus: radix-2/3/4 FFT kernels in the CELT IMDCT, the PVQ table built
once, one de-emphasis loop for both channels, the SILK resampler
without per-sample divisions and with eight partial sums, concealment
and FEC capped at 120 ms (filmcraft bf7ac420, 12e32026, c4dc64d1,
eb352ec8, 87b8e22d, 014b5e56, 78d77b72).
The per-frame mid-only flag this crate fixed in the SILK decoder is
kept in the refactored decode.
* craft-media: Ogg CRC-32 by slice-by-16
FilmCraft's 6763f9bf: sixteen independent lookups per 16 input bytes, so
opening a file is several times faster. Checked against a bit-at-a-time
reference on every short length and alignment, and across every split.
* craft-audio: SoundCraft's CAF cookie-size and FLAC vendor-length checks
A CAF magic cookie size above the signed range is refused instead of
passed to symphonia (soundcraft 3bd3965), and a Vorbis comment block
whose vendor string claims more than the block holds is refused
(soundcraft ddfe991). Each with its regression test.
* craft-audio: AC-3 reads bits through the shared BitReader
FilmCraft's 1c9c2e82: the AC-3 decoder's private bit-at-a-time reader is
replaced by craft-media's BitReader, with its two tests: the decoded
output of 2,000 synthetic and 12 real syncframes (and their damaged
variants) hashes the same as before, and the reader agrees with the old
one on random reads, skips and overruns. The three AC-3 features now
turn on craft-media's bitstream module.
* craft-audio: the quantiser rounds without a libm call
SoundCraft's d293336, the audio-io part: round-half-away by integer
arithmetic in the bounce's inner loop, with its test against f64::round
over the quantiser's range.
* craft-audio: AC-3 and E-AC-3 decoder
FilmCraft's AC-3 decoder as `craft_audio::ac3` behind `ac3-decode`:
every AC-3 channel mode and frame size, and E-AC-3 independent
substream 0 with spectral extension, in WAV order without downmix.
`TrackDecoder` and the native read path take AC-3 and E-AC-3 in MP4,
Matroska and raw streams.
Not bit-exact: zero-bit mantissas are filled with decoder-specific
dither (A/52 §7.3.4), so tests compare at 65-94 dB SNR on tones and
27-48 dB on white noise. 7.1 E-AC-3 decodes as its 5.1 core.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* craft-audio: review fixes, round 1 (#447)
An AC-3 / E-AC-3 packet is as long as all the primary syncframes in it.
Before the first decode, TrackDecoder::frames_per_packet gave 1536 for any
AC-3 track, and conceal used the first syncframe's header only. An E-AC-3
stream of one-, two- or three-block syncframes then got the wrong MP4 length
and seek positions and the wrong Matroska positions. A packet that groups
several such syncframes concealed at a fraction of its length.
Seeks in AC-3 and E-AC-3 now have to match the whole-file decode bit for bit,
as every other codec's do. The dither is seeded from each syncframe, so the
old 25 dB bound was looser than the decoder needs.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* craft-audio: review fixes, round 2 (#447)
- AC-3 / E-AC-3 packets that decode to different lengths (in the packets
read ahead, or any decoded since) have no frames_per_packet, so a
Matroska seek finds its packet by timestamp rather than by index times
the first packet's length.
- E-AC-3 syncframes of fewer than six blocks may reuse exponents from any
syncframe before them: once one is seen, a seek decodes from the start
of the stream instead of 1536 frames before the target.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* craft-audio: review fixes, round 3 (#447)
- Matroska E-AC-3: the first seek reads every packet's syncframe headers (only the headers,
header stripping undone) and places packets by the frames their primary syncframes hold.
Packets that started to differ in length after the eight read ahead were placed as the first
packet's length times their index.
- A packet whose later syncframe fails no longer sets the length lost packets are concealed at,
nor marks the packets' lengths as differing: it decoded only in part.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* Merge main; E-AC-3 in Matroska: read packet headers only up to the seek target, and count a packet of dependent syncframes as zero frames
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Dylan M. Taylor <dylan@dylanmtaylor.com>
Dylan M. Taylor
