maolan_widgets/
audio.rs

1use std::io;
2use std::path::Path;
3
4use symphonia::core::audio::SampleBuffer;
5use symphonia::core::codecs::{CODEC_TYPE_NULL, DecoderOptions};
6use symphonia::core::errors::Error as SymphoniaError;
7use symphonia::core::formats::FormatOptions;
8use symphonia::core::io::MediaSourceStream;
9use symphonia::core::meta::MetadataOptions;
10use symphonia::core::probe::Hint;
11
12/// Decode a WAV file to interleaved `f32` samples.
13///
14/// Returns `(samples, channels, sample_rate)`. Samples are normalised to the
15/// `[-1.0, 1.0]` range and are stored interleaved (`ch0, ch1, ...`).
16pub fn read_wav_f32(path: &Path) -> io::Result<(Vec<f32>, usize, u32)> {
17    let file = std::fs::File::open(path)
18        .map_err(|e| io::Error::other(format!("Failed to open '{}': {e}", path.display())))?;
19    let mss = MediaSourceStream::new(Box::new(file), Default::default());
20
21    let mut hint = Hint::new();
22    if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
23        hint.with_extension(ext);
24    }
25
26    let format_opts = FormatOptions::default();
27    let metadata_opts = MetadataOptions::default();
28    let decoder_opts = DecoderOptions::default();
29
30    let probed = symphonia::default::get_probe()
31        .format(&hint, mss, &format_opts, &metadata_opts)
32        .map_err(|e| {
33            io::Error::other(format!(
34                "Symphonia failed to probe format for '{}': {e}",
35                path.display()
36            ))
37        })?;
38    let mut format = probed.format;
39
40    let track = format
41        .tracks()
42        .iter()
43        .find(|t| t.codec_params.codec != CODEC_TYPE_NULL)
44        .or_else(|| format.tracks().first())
45        .ok_or_else(|| {
46            io::Error::other(format!("No usable audio track in '{}'", path.display()))
47        })?;
48
49    let channels = track.codec_params.channels.map(|c| c.count()).unwrap_or(1);
50    let sample_rate = track.codec_params.sample_rate.unwrap_or(48_000);
51    let track_id = track.id;
52
53    let mut decoder = symphonia::default::get_codecs()
54        .make(&track.codec_params, &decoder_opts)
55        .map_err(|e| {
56            io::Error::other(format!(
57                "Symphonia failed to create decoder for '{}': {e}",
58                path.display()
59            ))
60        })?;
61
62    let mut sample_buf = None;
63    let mut samples = Vec::new();
64
65    loop {
66        let packet = match format.next_packet() {
67            Ok(packet) => packet,
68            Err(SymphoniaError::IoError(e)) if e.kind() == std::io::ErrorKind::UnexpectedEof => {
69                break;
70            }
71            Err(e) => {
72                return Err(io::Error::other(format!(
73                    "Symphonia read error for '{}': {e}",
74                    path.display()
75                )));
76            }
77        };
78
79        if packet.track_id() != track_id {
80            continue;
81        }
82
83        let decoded = decoder.decode(&packet).map_err(|e| {
84            io::Error::other(format!(
85                "Symphonia decode error for '{}': {e}",
86                path.display()
87            ))
88        })?;
89
90        if sample_buf.is_none() {
91            let spec = *decoded.spec();
92            sample_buf = Some(SampleBuffer::<f32>::new(decoded.capacity() as u64, spec));
93        }
94        let buf = sample_buf.as_mut().unwrap();
95        buf.copy_interleaved_ref(decoded);
96        samples.extend_from_slice(buf.samples());
97    }
98
99    if samples.is_empty() {
100        return Err(io::Error::other(format!(
101            "No samples decoded from '{}'",
102            path.display()
103        )));
104    }
105
106    Ok((samples, channels, sample_rate))
107}
maolan_widgets/audio.rs

maolan_widgets/
audio.rs
