Crate simplemad [−] [src]

This crate provides an interface to libmad, the MPEG audio decoding library.

simplemad::decode takes a byte-oriented source and returns a channel that yields Result<Frame, MadError>. If you only need to decode part of a file, you can also use simplemad::decode_interval.

Frame and MadError correspond to libmad's struct types mad_pcm and mad_error, respectively. Samples are signed 32 bit integers and are organized into channels. For stereo, the left channel is channel 0.

MP3 files often begin with metadata, which will cause libmad to produce errors. It is safe to ignore these errors until libmad reaches audio data and starts producing frames.

Examples

use simplemad::{decode, decode_interval, Frame};
use std::fs::File;
use std::path::Path;

let path = Path::new("sample_mp3s/constant_stereo_128.mp3");
let file = File::open(&path).unwrap();
let file_b = File::open(&path).unwrap();
let mut decoder = decode(file);

for decoding_result in decoder.iter() {
    match decoding_result {
        Err(e) => println!("Error: {:?}", e),
        Ok(frame) => {
          println!("Frame sample rate: {}", frame.sample_rate);
          println!("First audio sample (left channel): {}", frame.samples[0][0]);
          println!("First audio sample (right channel): {}", frame.samples[1][0]);
        }
    }
}

// Decode the interval from 1s to 2s (to the nearest frame)
let mut partial_decoder = decode_interval(file_b, 1_000_f64, 2_000_f64);
let frames: Vec<Frame> = partial_decoder.iter()
                                        .filter_map(|r| match r {
                                            Ok(f) => Some(f),
                                            Err(_) => None})
                                        .collect();

decode	Decode a file in full
decode_interval	Decode part of a file from `start_time` to `end_time`, measured in milliseconds

Crate simplemad [−] [src]

Examples

Structs

Enums

Functions