Crate simplemad

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

To begin, create a new Decoder from a byte-oriented source using Decoder::decode or Decoder::decode_interval. Fetch results using get_frame or the Iterator interface.

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

#![allow(unused_variables)]
use simplemad::{Decoder, 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 decoder = Decoder::decode(file).unwrap();

for decoding_result in decoder {
    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 partial_decoder = Decoder::decode_interval(file_b, 1_000_f64, 2_000_f64);
let frames: Vec<Frame> = partial_decoder.unwrap()
                                        .filter_map(|r| match r {
                                            Ok(f) => Some(f),
                                            Err(_) => None})
                                        .collect();

Structs

Decoder	An interface for the decoding operation
Frame	A decoded frame

Enums

SimplemadError

An error encountered during the decoding process