How get one channel of data from two-channel audio file?

Question

I need to either convert a 2-channel audio file to 1-channel or else get just one channel of data (does this lose some sound?) for a calculation. How would I do that?

Answer 1

In terms of a loop over byte[] data, double[] left, double[] right...
8-bit mono
for (int i = 0; i < data.length; i += 1) {
     left[i] = (double)data;
16-bit monofor (int i = 0; (i*2) < data.length; i++) {
left[i] = ((double)data[2*i] << 8) + (double)data[(2*i)+1]);
8-bit stereofor (int i = 0; (i*2) < data.length; i++) {
left[i] = (double)data[2*i];
right[i] = (double)data[(2*i)+1];
16-bit stereofor (int i = 0; (i*4) < data.length; i++) {
left[i] = ((double)data[2*i] << 8) + (double)data[(2*i)+1]);
right[i] = ((double)data[(2*i)+2] << 8) + (double)data[(2*i)+3]);