shifathosn
/
effectcraft
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

M13.4: opus extreme-input tests, SILK doc 

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Brandon Thomas 2026-10-03 09:23:03 -04:00
parent 1906d9d639
commit 374d21e6a5
2 changed files with 36 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
crates/opusenc/src/silk/mod.rs
View File

@ -4,9 +4,10 @@
//! search), its NLSFs are quantised, and the excitation is chosen sample by sample by running
//! the decoder's exact fixed-point reconstruction (LTP and LPC synthesis with the dequantised
//! Q12/Q14 coefficients, quantisation offsets and the pseudo-random sign sequence), so the
//! encoder always holds the decoder's state and there is no drift. A per-frame search over a
//! gain offset hits the bit budget. Stereo input is coded as mid/side with the decoder's
//! stereo prediction (§4.2.8). No LBRR, no NLSF interpolation, no noise shaping.
//! encoder always holds the decoder's state and there is no drift. A noise-feedback loop
//! shapes the coding noise with a bandwidth-expanded LPC envelope, and a per-frame search over
//! a gain offset hits the bit budget. Stereo input is coded as mid/side with the decoder's
//! stereo prediction (§4.2.8). No LBRR, no NLSF interpolation.
pub(crate) mod analysis;
pub(crate) mod lpc;

32
crates/opusenc/tests/modes.rs
View File

@ -223,6 +223,38 @@ fn invalid_mode_bandwidth_panics() {
let _ = OpusEncoder::with_mode(1, 16_000, Mode::Silk, Bandwidth::Fullband);
}
#[test]
fn extreme_inputs_stay_decodable() {
let len = 24_000;
let mut s = 1u32;
let noise: Vec<f32> = (0..len)
.map(|_| {
s = s.wrapping_mul(1_664_525).wrapping_add(1_013_904_223);
(s >> 8) as f32 / (1u32 << 23) as f32 - 1.0
})
.collect();
let square: Vec<f32> = (0..len).map(|i| if (i / 60) % 2 == 0 { 0.999 } else { -0.999 }).collect();
let clicks: Vec<f32> = (0..len).map(|i| if i % 4_801 == 0 { 1.0 } else { 0.0 }).collect();
let dc = vec![0.7f32; len];
let nan: Vec<f32> = (0..len).map(|i| if i % 1000 == 0 { f32::NAN } else { 0.1 * (i as f32 * 0.01).sin() }).collect();
for (name, x) in [("noise", &noise), ("square", &square), ("clicks", &clicks), ("dc", &dc), ("nan", &nan)] {
for (mode, bw, rate) in
[(Mode::Silk, Bandwidth::Narrowband, 6_000u32), (Mode::Silk, Bandwidth::Wideband, 40_000), (Mode::Hybrid, Bandwidth::Fullband, 24_000)]
{
for c in [1usize, 2] {
let planar: Vec<Vec<f32>> = if c == 1 { vec![x.clone()] } else { vec![x.clone(), x.iter().map(|v| -0.5 * v).collect()] };
let (enc, packets) = encode(OpusEncoder::with_mode(c as u8, rate * c as u32, mode, bw), &planar);
assert!(packets.iter().all(|p| p.len() >= 3 && p.len() <= 1276), "{name} {mode:?}: packet sizes");
let dec = decode(&enc.opus_head(), &packets);
let peak = dec.iter().flatten().fold(0f32, |m, v| m.max(v.abs()));
let snr = if name == "nan" { f64::NAN } else { snr_search(&planar[0], &dec[0], 2).0 };
eprintln!("{name} {mode:?}/{bw:?} {c} ch: peak {peak:.2}, SNR {snr:.1} dB, {:.1} kb/s", bitrate(&packets) / 1000.0);
assert!(dec.iter().all(|ch| ch.iter().all(|v| v.is_finite() && v.abs() <= 4.0)), "{name} {mode:?}/{bw:?} {c} ch: bad output");
}
}
}
}
#[test]
fn silk_and_hybrid_silence() {
for (mode, bw, rate) in [(Mode::Silk, Bandwidth::Wideband, 16_000u32), (Mode::Hybrid, Bandwidth::Fullband, 32_000)] {