I'm using the SimpleAudioEngine for cocos2d and when one track finished I would like to play another.
It only allows one background music to be preloaded at a time though. Would it be ridiculous to 'join' 2 .mp3s using audacity and then just convert to .caf and preload the whole thing?
Certainly not ridiculous, but be wary about how much memory your sounds require.
Also, why the conversion to .caf? You can play .mp3s. Is this just for compression?
Related
I need to play sounds (~5 seconds each) throughout my iphone application. When they're triggered, they need to play immediately.
For the moment I'm using AudioServices and (as you probably know) the first time you play a sound it lags, then every time there after it's perfect. Is there some code available that's clever enough to preload an AudioServices sound (by playing it silently maybe?). I've read adjusting the system volume programmatically will get your app rejected, so that's not an option. Seems AudioServices isn't made for volume correction from what I can see.
I've looked into OpenAL and while feasible seems a little over kill. AVAudioPlayer seems like a little bit of a better option, I'm using that for background music at present. Extending my music player to handle a 'sound board' might be my last resort.
On the topic of OpenAL, does anyone know of a place with a decent (app store friendly) OpenAL wrapper for the iPhone?
Thanks in advance
Finch could be perfect for you. It’s a tiny wrapper around OpenAL with very low latency and simple API. See also all SO questions tagged ‘Finch’.
If you use an AVAudioPlayer, you can call prepareToPlay when you initialize the object to reduce the delay between calling play and having the audio start.
I built an iPhone app using AudioServices to play short sounds. The first time a sound is played, there's a delay of half a second or so while the sound loads before it plays. This definitely makes for an awkward user experience.
Is there a way to preload sounds for AudioServices to play, or do I need to switch to audioQueues or some other method of playing sounds?
Thanks,
Maha
This is a well known problem. Everything in AudioServices is initialized lazily.
I think that your best choice is between Core Audio or OpenAL. OpenAL might be overkill, but it has a simple API. The oalTouch example is a good place to start.
Core Audio is a bit more raw, but it's well documented. The iPhone's OpenAL SDK is built on top of it.
I have a performance-intensive iPhone game I would like to add sounds to. There seem to be about three main choices: (1) AVAudioPlayer, (2) Audio Queues and (3) OpenAL. I’d hate to write pages of low-level code just to play a sample, so that I would like to use AVAudioPlayer. The problem is that it seems to kill the performace – I’ve done a simple measuring using CFAbsoluteTimeGetCurrent and the play message seems to take somewhere from 9 to 30 ms to finish. That’s quite miserable, considering that 25 ms == 40 fps.
Of course there is the prepareToPlay method that should speed things up. That’s why I wrote a simple class that keeps several AVAudioPlayers at its disposal, prepares them beforehand and then plays the sample using the prepared player. No cigar, still it takes the ~20 ms I mentioned above.
Such performance is unusable for games, so what do you use to play sounds with a decent performance on iPhone? Am I doing something wrong with the AVAudioPlayer? Do you play sounds with Audio Queues? (I’ve written something akin to AVAudioPlayer before 2.2 came out and I would love to spare that experience.) Do you use OpenAL? If yes, is there a simple way to play sounds with OpenAL, or do you have to write pages of code?
Update: Yes, playing sounds with OpenAL is fairly simple.
AVAudioPlayer is very marginal for game audio. Tackling AudioQueue or OpenAL by adapting one of the examples is definitely the way to go. latency is much more controllable that way.
If you're calling play on the main thread, try running it on a separate thread. What I ended up doing is:
#include <dispatch/dispatch.h>
dispatch_queue_t playQueue = dispatch_queue_create("com.example.playqueue", NULL);
AVAudioPlayer* player = ...
dispatch_async(playQueue, ^{
[player play];
});
which fixed the worst of the framerate stuttering I was experiencing.
I use OpenAL and the classes that came with the CrashLanding sample code. It's worked fine so far to play samples and play looped music all at the same time. I'm currently learning how to release the memory I've allocated for a sound (.wav file) when, for example, I want to play some intro music just once.
Use CocosDenshion – it’s free, easy, and works. It wraps AVAudioPlayer for background tracks and OpenAL for sounds.
Do you want to check the buffering with the implementation you're using? It might be somehow related to the 20ms delay you're experiencing. i.e., try to play around with the buffer size.
If yes, what movie format has best performance? And how would a simple setup look like? I have some views, and I want to play a short movie inside a view (not fullscreen). The movie is about 5 seconds long.
Looks like the system frameworks only support playing video full screen with the MPMoviePlayerController. Supported formats are basically flavors of H.264 and MPEG-4; more in the documentation.
Theoretically, you might be able to roll your own decoding and playback code, but I doubt you'd get acceptable performance. (And most of the Open Source media player examples I can think of are GPL. Not that I imagine they'd fare much better.)
If it's only 5 seconds long, you can fake it by playing the audio file in the background, and an animated UIImageView at the same time. Lots of apps do this like the ~50 or so baby sign language ones.
I am trying to develop a simple iPhone app. I need to play sound within a loop.
How can Play Audio file in loop without any interruption ?
Take a look at the new AVAudioPlayer class in the 2.2 release:
http://developer.apple.com/iphone/library/documentation/AVFoundation/Reference/AVAudioPlayerClassReference/Reference/Reference.html
It has functionality for looping sounds.
I really don't know the iPhone SDK at all, but this should be quick: try making the sound itself looping. That way, you should be able to play it with just a single call, and won't need to worry about timing the repeat properly to restart it at the exact right moment.
For instance, WAV files have very flexible support for looping, and any decent audio editor should let you set looping points.
The AVAudioPlayer has numberOfLoops property where you can specify the number of times you want the audio to loop.