So, let’s start talking a little bit about the returns on investment (there has to be some, right?) from WWDC ’06. Specifically, for the people following Riven X, the issue where looping movies with sound have this extremely annoying gap in the sound output when they loop.

For anyone keeping scores, you know Cyan seemed to have used, how to say, deficient audio encoders in Riven. Well, after chatting with some QuickTime engineers on Friday morning, we determined that the sound tracks in those movies are in fact too short, thus causing the gap during playback.

I had never previously considered that possibility, focussing instead on potential problems in my rendering code. After all, it was far more likely that I had screwed up rather than Cyan…

I haven’t done the DSP / analysis to determine if the track discrepancy is constant, proportional or random, but I suspect it will either be constant or related to the movie’s timescale (remember that QuickTime is not sample based but time based). Hopefully I should be able to address this issue sometime in October.