I need to do surround panning for a couple of applications. The following is what I have so far. it's not principled or analytical --- I just made it up this morning off the cuff. I'm hoping some of you will have suggestions. Pointers to sample code for better versions would be nice.
/* * "pan" is midi pan, 0 (left) to 127 (right) * "speaker" is 0 (left surround), 32 (left front), * 64 (center), 95 (right front), 128 (right surround) * "separation" is 95 for 4-channel surround (left * front and right front taper down to 0 amplitude * at right pan=127 and left pan=0, respectively). * and is 64 for 6-channel surround (center tapers * down to 0 amplitude at left and right). * * Returns amplitude 0-127 for requested speaker. */ static int panf(int pan, int speaker, int separation) { int val; val = abs(pan - speaker); val = (val * 127) / separation; val = 127 - val; if (val < 0) return 0; if (val > 127) return 127; return val; }
Greg
