pub fn speech_level(pcm: &[f32], sample_rate: u32) -> f32Expand description
The loudest 10 ms window in pcm, the reference “speech level” the tail rule compares against.
Examples found in repository?
examples/tail_writer_probe.rs (line 19)
6fn main() {
7 let path = std::env::args()
8 .nth(1)
9 .expect("usage: tail_writer_probe <wav>");
10 let bytes = std::fs::read(&path).expect("readable wav");
11 let pcm: Vec<f32> = bytes[44..]
12 .as_chunks::<2>()
13 .0
14 .iter()
15 .map(|pair| f32::from(i16::from_le_bytes(*pair)) / 32_767.0)
16 .collect();
17
18 let offline = ftts_core::audio::trailing_noise_samples(&pcm, 24_000);
19 let level = ftts_core::audio::speech_level(&pcm, 24_000);
20 println!("input samples : {}", pcm.len());
21 println!("offline detector : {offline} samples");
22 println!("utterance level : {level:.5}");
23
24 // Exactly the CLI's packetization.
25 let mut writer =
26 ftts_core::audio::WavWriter::new_trimming_tail(Cursor::new(Vec::new()), 24_000)
27 .expect("header");
28 for packet in pcm.chunks(1_920) {
29 writer.write_samples(packet).expect("write");
30 }
31 let out = writer.finish().expect("finish").into_inner();
32 let written = (out.len() - 44) / 2;
33 println!(
34 "writer wrote : {written} samples (trimmed {})",
35 pcm.len() - written
36 );
37
38 // What the detector sees when handed only the tail, which is the writer's situation.
39 let hold = 24_000 * 250 / 1000;
40 let tail = &pcm[pcm.len().saturating_sub(hold)..];
41 println!(
42 "tail-only relative : {} samples (tail len {})",
43 ftts_core::audio::trailing_noise_samples_relative_to(tail, 24_000, level),
44 tail.len()
45 );
46}