I'm reviewing all kinds of Android sound API and I'd like to know which one I should use. My goal is to get low latency audio or, at least, deterministic behavior regarding delay of playback.
We've had a lot of problems and it seems that Android sound API is crap, so I'm exploring possibilities.
The problem we have is that there is significant delay between sound_out.write(sound_samples); and actual sound played from the speakers. Usually it is around 300 ms. The problem is that on all devices it's different; some don't have that problem, but most are crippled (however, CS call has zero latency). The biggest issue with this ridiculous delay is that on some devices this delay appears to be some random value (i.e. it's not always 300ms).
I'm reading about OpenSL ES and I'd like to know if anybody had experience with it, or it's the same shit but wrapped in different package?
I prefer to have native access, but I don't mind Java layer indirection as long as I can get deterministic behavior: either the delay has to be constant (for a given device), or I'd like to get access to current playback position instead of guessing it with a error range of ±300 ms...
Source: Tips4all, CCNA FINAL EXAM
The lowest latency you can get is from SoundPool. There's a limit on how big of a sound you can play that way, but if you're under the limit (1Mb, IIRC) it's pretty low latency. Even that's probably not 40ms, though.
ReplyDeleteBut it is faster than what you can get by streaming, at least in my experience.
Caveat: You may see occasional crashes in SoundPool on Samsung devices. I'm have a theory that it only happens when you access the SoundPool from multiple threads, but I haven't verified this.