Hi Mauro, Geert, > That doesn't seem to be the right thing to do here. > > Assuming that sampling rate is 48 kHz, you'll > have duration = 1.875, which would be rounded to 1. > > In other words, the above is identical to: > > au->pts = count > > Now, I don't know from where that CLOCK_UNIT_90KHZ came from. > Mauro, here's my current understanding: The values for PTS have to be defined in terms of a 90khz clock. So for 30fps video, the values for PTS per frame would be: frame_num/30 * 90000 so 0, 3000, 6000, 9000...etc The same math is being used here for audio, but instead we have the total audio sample count and a 48000 samples/sec I did miss this rounding error though, I'm sorry.