Hi guys! There's a serious problem with the way how animation works in regard to audio. The main problem is, that the animation system pushes the output, so it sets the data, renders a frame, advances to next frame (setting the data there) and renders again and so on, this works pretty good for video. But it doesn't work with audio, especially as audio has a very high temporal resolution (48000 eg. samples per second) compared to video (eg 25 frames per second) and moreover for audio the output device pulls the data, instead of the animation system pushing it, so the other way round.
I talked to Martin (Poirier) and Joshua (Leung) and even we three together cannot think up a nice solution for the problem, maybe some genious mind here on the list who is more into the animation code than I am has a really nice idea. Here are specific problems in detail: * Subsample Accuracy: To avoid stair steps as we currently have in volume animation. * Multi Threading: Audio runs in a separate thread. * Speed: The access mechanism has to be realtime capable! * Asynchronous access: Audio playback is ahead of video playback normally (buffering the samples, feeding them to the output device). The first point can be solved easily with a proper interpolation if you have two nearby samples, one in the past, one in the future, so this basically requires the animation data to be cached/buffered somehow or at least asynchronous accessible. As the cached data also solves points 3 and 4 it's pretty obvious that we need the data cached, we had that conclusion already. Questionable is now how to get the cache? One obvious solution is to require the user to "bake" it, but this heavily impacts how easy the system can be used and as we also already concluded this is a really ugly solution. Better is the automatic caching which leads us to the problem point 2 multi threading. I don't know if it's possible to cache in the main thread? I bet not. And as long as blenders (animation) data isn't accessible multithreaded we still have no solution for the problem. So now your help is needed. Any ideas? If not I'll have to do the baking solution to finish the project. Regards _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers