Comments on: restarting openAL after application interruption on the iPhone

By: Ben

Ben — Sat, 17 Sep 2011 11:55:27 +0000

Hey Sinji,

lots has changed since I originally wrote this. The way that interrupts are handled now in iOS is quite a bit different and really much easier. I dont have the code in front of me, but if I remember correctly you dont have to do much at all during an interrupt. If you are streaming and have a background thread running, you might want to do soething with that, but in terms of the OpenAL context I dont think you need to do much with it anymore.

I must apologize since I cant remember the specifics, check the docs.

Cheers!
-B

By: sinji

sinji — Sat, 17 Sep 2011 11:05:44 +0000

Help?
everything works except that if the interruption comes while setting up audio session in the initial function. which cause the ‘AudioSessionSetActive(true)’
fails.
i try to use a while loop to make sure the audio session initialized correctly.
but it doesn’t work.

By: jeffmo77

jeffmo77 — Tue, 17 May 2011 00:06:11 +0000

Hmm, this looks awesome, and exactly what I need! But after implementing, it seems that interruptionListenerCallback never gets called. I’m doing this in a cocos2D project within a CCLayer class.

Any ideas?

Jeffmo77

By: Oceansoul

Oceansoul — Wed, 12 Jan 2011 07:10:40 +0000

Even if it means spamming your thread, I have to post one more thing.
I just tried out your code and well .. since you´re about to go home please take this as a big ‘end-of-your-workday’-HUG :). You just saved me such a huge amount of nerves and time and … hell, years of my life which I would have spent brooding :).
Your piece of code works like charm.

Thanks a lot. I´ll recommend you ;).

Oceansoul

By: Ben

Ben — Wed, 12 Jan 2011 07:00:08 +0000

Hey Oceansoul,

No worries, glad you got it all figured out :-)

My explanations can sometimes be a bit obtuse. I don’t like to just give big blocks of code right out, otherwise people generally just cut and paste it and don’t try to understand what is actually going on. And sometimes, my explanations are just way _too_ obtuse, and nobody understands what the hell I am on about :-) So your confusion is probably warranted :-)

Also, this is a good time of day since it is the end of the day and I am just looking for excuses to not be working anymore :-)

Cheers!
-B

By: Oceansoul

Oceansoul — Wed, 12 Jan 2011 06:56:15 +0000

Whoa, that was a fast answer. Thanks for that. I just found it out, as well. And yes, it helped :).

Cheers

By: Oceansoul

Oceansoul — Wed, 12 Jan 2011 06:54:09 +0000

Nevermind. I think I got it :).

By: Ben

Ben — Wed, 12 Jan 2011 06:53:43 +0000

Hey Oceansoul,

When you call AudioSessionInitialize() the last parameter is: self. This gets passed back into the callback function as the inUserData. self being whatever class you are calling the initialize from within.

So when I put ‘yourControlObject’ i mean to say that you need to cast that void* to the right class so you can then call methods on it effectively. In my case my sound engine class is called BBSoundController, so I would cast that void* as a BBSoundController, then call _haltOpenALSession or whatever. Your class will obviously be whatever you have created.

Similarly, all this code generally lives in that sound controller class. So if you built a small sound engine using OpenAL, the class that you initialize the session with will be “your sound control object”.

Hope that helps!

CHeers!
-B

By: Oceansoul

Oceansoul — Wed, 12 Jan 2011 06:46:06 +0000

Brief question.
This seems extremely helpful, but where do I have to put the several code pieces?
And what is YourSoundControlObject ??

Otherwise this article seems like a godsend. I built a small sound engine using OpenAL and the session problem was driving me crazy.
So I´d be very glad for some more details on how to use your code snippets.

Oceansoul

By: ejoy2u

ejoy2u — Thu, 28 Oct 2010 03:36:48 +0000

I guess you got AUIOClient_StartIO failed.
I got the same issue yesterday, but if I debug and set breakpoint in resumeOpenALSession, I can hear sound everytime back to game.
So I put sleep after every line in resumeOpenALSession.
Yes, it works. you don’t need to put the resume code to appwillresign, just sleep it a bit.
Actually, I fixed 5 of 10 bugs by sleep when I was using OpenAL on iPhone.