fn create_stream_description()

in src/backend/mod.rs [246:286]

• 35 lines of code
• 1 McCabe index (conditional complexity)

fn create_stream_description(stream_params: &StreamParams) -> Result<AudioStreamBasicDescription> {
    assert!(stream_params.rate() > 0);
    assert!(stream_params.channels() > 0);

    let mut desc = AudioStreamBasicDescription::default();

    match stream_params.format() {
        SampleFormat::S16LE => {
            desc.mBitsPerChannel = 16;
            desc.mFormatFlags = kAudioFormatFlagIsSignedInteger;
        }
        SampleFormat::S16BE => {
            desc.mBitsPerChannel = 16;
            desc.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsBigEndian;
        }
        SampleFormat::Float32LE => {
            desc.mBitsPerChannel = 32;
            desc.mFormatFlags = kAudioFormatFlagIsFloat;
        }
        SampleFormat::Float32BE => {
            desc.mBitsPerChannel = 32;
            desc.mFormatFlags = kAudioFormatFlagIsFloat | kAudioFormatFlagIsBigEndian;
        }
        _ => {
            return Err(Error::invalid_format());
        }
    }

    desc.mFormatID = kAudioFormatLinearPCM;
    desc.mFormatFlags |= kLinearPCMFormatFlagIsPacked;
    desc.mSampleRate = f64::from(stream_params.rate());
    desc.mChannelsPerFrame = stream_params.channels();

    desc.mBytesPerFrame = (desc.mBitsPerChannel / 8) * desc.mChannelsPerFrame;
    desc.mFramesPerPacket = 1;
    desc.mBytesPerPacket = desc.mBytesPerFrame * desc.mFramesPerPacket;

    desc.mReserved = 0;

    Ok(desc)
}