Well, the riveting coding work continues. So I think it is time to pop out a work in progress so that things make more sense. The diptych here is not how things will be in the final work. I do want to speed up and slow down the video, but what I was doing was constraining this so that after, say, slowing or speeding it up by a factor of 5 (so 5 x faster or 1/5 of normal) I’d flip the track back to normal playback speed. After building it and experimenting and playing with it it just doesn’t make sense. As you’re clicking the thing slows, then all of a sudden after another click, Hey Presto!” we’re back to normal speed. Nah. So this work in progress is just to see this in action. What hasn’t been done yet, well, both soundtracks remain, these will be removed and one soundtrack will be added as a separate child movie so that it plays normally independent of the image track speeds. This means the effect you get when mousing into either video so that the volume for that track changes will be removed (though in this demo it does create some pretty weird aleatory outcomes). So that also means I’d better let you mute, or perhaps pause?, the soundtrack.
For the final version clicking the slow and fast buttons (‘-‘ and ‘+’) will just keep speeding up or slowing down the video. QuickTime from memory doesn’t like to drop below 1/10 of normal speed (normal is whatever the video frame rate is) while I think acceleration probably depends on your CPU. Mousing into the other button (eg if you’ve sped the thing up, then mousing into the ‘-‘ button) will restore the current video to normal speed. Then add a pause button for the soundtrack, and perhaps see about making the buttons semi-transparent so they’re not quite so there. That should do it. I think.