Re: non-realtime sound simulation (simulating only N msec perframe)
Jason Daly <[email protected]>
| Newsgroups | gmane.comp.lib.openal |
|---|---|
| Message-ID | <[email protected]> |
[email protected] wrote: > Hi guys, this is my first work with OpenAL, I'm new here, and if this is a stupid question don't hesitate to let me know. :) Also, if you need more information in order to answer the question, I will do my best to answer. > > So here's the scenario: I am modifying a game I play (Alien Arena) which uses openAL for sound. I am adding a feature which allows you to export videos. The export feature lets you set a desired output framerate, then it changes the main loop so that exactly 1000/framerate milliseconds are simulated every frame. The idea is that you first record a demo normally, then play it back and have it export the video. > > Is there a way to do this with the audio in openAL as well? So if the export framerate is 25, can I have openAL simulate 40 Milliseconds and then just stop? Also, can I have it "render" the mixed PCM sound into a buffer instead of (or as well as) playing it on the soundcard? > > The reason I ask is that all the tutorials and documentation I have seen refer to alSourcePlay and alSourceStop, but nothing about setting an amount of time to simulate before stopping automatically. > Hi, Max, There is no provision for this kind of functionality in the OpenAL spec. I haven't heard of any of the implementations providing anything like this either. That said, I wouldn't think it would be all that hard to hack into an implementation, if you're so inclined. Since you're capturing video, I'm guessing you don't need to actually play the audio at the same time, so you wouldn't need to talk to hardware at all (this would likely be much more complicated if you did). If you start with OpenAL-Soft, you can look at the "wave" backend, which renders to a .wav file instead of to audio hardware. Then, you can play with the code (probably in the ALC area) to get it to execute the start/stop functionality you want. --"J" _______________________________________________ Openal mailing list [email protected] http://opensource.creative.com/mailman/listinfo/openal