hi, what is the range for left_samples and right_samples? since it's double i figured it should be -1.0 to 1.0, but that didn't produce any good results. next i tried int16 range -0x8000 to 0x7fff, but the result are still about .3 db off.
-0x8000 to 0x7fff is correct. That's the range of CD data, and the output of the mpg123 library I was using when I wrote MP3Gain.
Not sure why your results are off by a bit.