Method read

lib-src/libscorealign/audiofilereader.cpp:33–53

long Audio_file_reader::read(float *data, long n)
{
    // note that "samples_per_frame" is really "frames_per_window" in this
    // context, so we're computing bytes per window
    float *input_data = (float *) alloca(bytes_per_frame * samples_per_frame);
    assert(input_data != NULL) ;
	
    long frames_read = (long) sf_readf_float(sf, input_data, n);
    long chans = sf_info.channels;
    // now convert to mono and move to data
    for (int frame = 0; frame < frames_read; frame++) {
        float sum = 0;
        for (int chan = 0; chan < sf_info.channels; chan++) {
            // sum over channels within a frame
            sum += input_data[frame * chans + chan];
        }
        // write the frame sum to result array
        data[frame] = sum;
    }
    return frames_read;
}


bool Audio_file_reader::open(const char *filename, Scorealign &sa, bool verbose)