AVAudioPlayer is providing a very convenient way to play iPhone supported audio file. Especially, if you want to implement fast forward and rewind, AVAudioPlayer is the best choice.

But I just found an odd problem. If I use [AVAudioPlayer pause] method, next time if I invoke [AVAudioPlayer play], it had no responde. But after I changed pause to stop, it worked fine. The problem looks like it somewhere inside AVAudioPlayer to control the AudioQueue Object to resume playing. Whatever, by using [AVAudioPlayer stop], you can archive the same goal as [AVAudioPlayer pause] do, I mean FFW and RWD.

BTW, the document said, pause will return YES/NO, but clearly, it is a no return value instance method. The guy who is responsible for this method might copied the same comment from play!

What a joke. This line was there since iPhone 2.2, and is still there in 3.0b5. Didn’t there anybody reported this problem? Should I fire a bug?

Problem

I’ve been fighting for AVAudioPlayer and AudioQueue object for 2 days,

Here is my Dev environment:
iPhone: 3.0Beta 5
OSX 10.5.7

Here is my scenario:
1. I need to use AVAudioPlayer to play a CAF with IMA4 data format. Including fast forward and rewind.
2. I need to use AudioQueue Object to record audio, because 3.0 has not go public yet.
3. A common scenario is record an audio A, then play the original audio A’(Not the one recorded) or vice versa.

The problem is I could NOT play the A’ file  after I record file A.
[theAVAudioPlayer play] always return NO, but [theAVAudioPlayer prepareToPlay] return YES.
This situation only happened after I used the AudioQueue Object for recording. If I did not record, it always worked fine.

About the clean up.
1. I released the theAVAudioPlayer object and set to nil each time after I finished playing.
2. I closed the audio file and deposed the AudioQueue Object each time after I finished recording.

Solution

Thanks to Vitali Molodtsov[Open the original post Needs login], the solution is reset the AudioSessionCategory to kAudioSessionCategory_MediaPlayback just after finish recording. Then every thing goes fine.

Conclusion

I think this is a bug for AVAudioPlayer. Each time, when we initialize an AVAudioPlayer object, it should set the correct AudioSessionCategory for us silently, but it doesn’t. So I’ve fired a bug for Apple.