How to play a WAV file?

[xaviershay]

I found AudioSpecWAV, but none of the audio initialisation methods seem to take it as a type, and it doesn't implement AudioCallback. I tried implementing this myself with my own callback looking something like:

struct MyWav {
    wav: AudioSpecWAV,
    volume: f32,
    pos: usize,
}

impl AudioCallback for MyWav {
    type Channel = f32;

    fn callback(&mut self, out: &mut [f32]) {
        for x in out.iter_mut() {
            *x = match self.wav.buffer().get(self.pos) {
                Some(v) => { self.pos += 1; v as f32 },
                None => { 0.0 }
            }
        }
    }
}

... but I don't know how to work around the following error I get:

the traitcore::marker::Syncis not implemented for the type*mut u8``

[xaviershay]

Moved to stackoverflow with a little more detail: http://stackoverflow.com/questions/33057198/how-to-play-a-wav-file-with-rust-sdl2

[nukep]

There's no interface for playing back a WAV file, or any buffer with an audio format determined at runtime. The issue is that AudioCallback defines a fixed type (compile-time), whereas a loaded WAV could be any audio format (run-time).

AudioSpecWAV doesn't currently implement Send or Sync, although it really should, as it's an immutable data type. Using the type in an AudioCallback won't work right now without an unsafe somewhere. :(

I may introduce a PR to allow dynamically specifying an audio format for playback, but for the meanwhile, you can convert the WAV to a target audio format using AudioCVT. I can provide an example when I have the time.

[xaviershay]

hrm ok, thanks for the pointers.