Maybe this is an option; having the audio playback as the main time keeper, and then dropping frames in the view-port if they fail to render within time (within frame accuracy).
But one problem is for a heavy scene this could mean that no frames are ever rendered in time and all are dropped, a work around could be: measure the average delay it takes to render a frame and skip ahead to rendering the next frame by that delay. -brett --- On Sun, 7/17/11, Martin Poirier <the...@yahoo.com> wrote: > From: Martin Poirier <the...@yahoo.com> > Subject: Re: [Bf-committers] Help needed! Animation problems for 3D Audio GSoC > To: "bf-blender developers" <bf-committers@blender.org> > Date: Sunday, 17 July, 2011, 2:37 PM > Hi, > > I'd like to ask people with good knowledge of Blender's > animation and animation related structures to please > consider this problem, this is rather important for neXyon's > GSOC project. > > Thanks, > Martin > > --- On Sun, 7/17/11, neXyon <nex...@gmail.com> > wrote: > > > From: neXyon <nex...@gmail.com> > > Subject: [Bf-committers] Help needed! Animation > problems for 3D Audio GSoC > > To: bf-committers@blender.org > > Received: Sunday, July 17, 2011, 2:31 AM > > 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 > > > _______________________________________________ > Bf-committers mailing list > Bf-committers@blender.org > http://lists.blender.org/mailman/listinfo/bf-committers > _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers