I have set up an AVAudioPlayer object in viewDidLoad, as per the Apple guidelines, calling prepareToPlay as the last line in viewDidLoad (i have tried in awakeFromNib also).
When i press my play button, there is a pause, as it would appear to load the file, then it plays.
In audioPlayerDidFinishPlaying, i reload the player with a different sound, and when clicking play for a second time, the file plays instantly.
What would cause the player to lag on the first play?
Thanks.
The delay is due to AVAudioPlayer being initialised. Please see this answer.
The audio system runs on several asynchronous software processes (audio units, OS drivers, etc.) and hardware systems (DMA, DACs, audio amp power supplies, etc.) that never really all completely finish initialization until some sound is actually played all the way out the speakers or earphones.
Here's one method to do that: Create a sound file containing a half second of silence. On app start up, while your app and view controller are still loading, use AVAudioPlayer to play this file of silence. Now when your view finishes loading, AVAudioPlayer should be ready to play subsequent non-silent sounds much faster, since some audio (silence) has already already gone all the way out to the speakers.
What kind of sound are you playing? Alerts, something longer? If alerts, I did go this way and it's much better with lags ...
create system sound with AudioServicesCreateSystemSoundID
play system sound with AudioServicesPlaySystemSound
dispose system sound with AudioServicesDisposeSystemSoundID
... you only need to store SystemSoundID for each sound you would like to play.
Related
I am making a music game and when the user presses a note it will produce a sound. The sound naturally needs to play immediately when the user presses, so they can tell whether they are in time with the music. However, it feels as if the sound is lagging, especially when note presses become quicker.
My background .m4a music file is played with AVAudioPlayer. I chose to use this over Cocos Denshion as I have access to the currentTime property. I may be wrong, but I dont think I can access this with CocosDenshion.
I made a .wav file which is extremely short (less than a second). I preload my sound effect on init:
[[SimpleAudioEngine sharedEngine] preloadEffect:#"Assist.wav"];
Then to play the sound effect, in CCTouchesBegan I call:
[[SimpleAudioEngine sharedEngine] playEffect:#"Assist.wav"];
After that it calls my code to determine the users timing and awards points. Any idea why it might be lagging, or a better way to play sound effects in time with music?
EDIT: Ive tried a few things recently with no results. First I tried playing the sounds automatically as they came up to the appropriate time in the song. Still had the lag, so I dont think it is touch events being slow. I also tried 3 different sound libraries.
However, when I ran in the simulator, it seemed to not be laggy. Does anyone have an idea? Im clueless and its a major feature I cant really take out...
you should avoid this code:- [[SimpleAudioEngine sharedEngine] preloadEffect:#"Assist.wav"];
with the start of app you should load your framework SimpleAudioEngine by writing this code :-
//SimpleAudioEngine *palySound; made object in .h file.
palySound=[SimpleAudioEngine sharedEngine];
and whenever you want to play sound you can write: [palySound playEffect:#"Assist.wav"];
I am not sure what you're doing in your SoundEngine, but in my own experience, the best way to not get lag to play a sound is to assign an AVAudioPlayer for each sound file (unless you want to start messing around with AudioQueues).
Here it is an example:
Let's assume that you have an AVAudioPlayer *assistPlayer; in your current view controller.
In your viewDidLoad initialize it with your sound:
NSURL *wavURL = [[NSBundle mainBundle] URLForResource:#"Assist" withExtension:#"wav"];
assistPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:wavURL error:nil];
Then, in your IBAction where you want to play the file, just do:
[assistPlayer play];
You shouldn't get any lag.
Did you try Finch? It claims to play sounds with low latency, and it is also just a wrapper around OpenAL.
Other than that, I'm really not experienced with OpenAL, but can think of two possible reasons for your lag:
The main thread is too busy - Try to offload work from it to other
threads.
Perhaps OpenAL is defined with too large of a buffer, so the pipeline loads the entire sound into the buffer (or a big chunk of it), and only afterwards the playback starts.
I have an audio app that is having some problems with the way iOS 5 has changed audio behaviors. When my app's audio is playing (AVAudioSessionCategoryPlayback), and a Clock.app alarm or timer is fired from the OS, the UIAlertView notification pops up, but without the audio alert. My application sound ducks fine to get out of the way of the audio alert, but the alarm app's audio alert does not sound.
Naturally, tons of support requests poured in over the iOS 5 change. I have solved this temporarily by setting kAudioSessionProperty_OverrideCategoryMixWithOthers which lets the alarm audio come through, but there are a few very undesirable side-effects when doing this:
Other app's audio can play with/over mine.
The remote control events are not routed to my app, but to iPod.app.
None of the above drawbacks are acceptable for my app's requirements. I have been hacking away at this for some time now but haven't been able to crack it. How can I setup my audio such that:
My app's audio still uses the AVAudioSessionCategoryPlayback category for background audio.
The Clock.app alarms still have their audio alerts make sound
The app still responds to remote control notifications
After writing this question I went to file a bug report on this. I created a small sample project that I thought would replicate the issue, but I could not replicate it! This caused me to dig in deep once again and try to figure out what was up here…
I fired up an iOS alarm, then I placed a break point in audioPlayerBeginInterruption: and traced through my code line by line in the debugger. I noticed that before my code ran (while I was paused in the debugger), the iOS 5 alarm was sounding! Luckily it still sounded even as I was stepping through my app, so I was able to figure out which pieces of code specifically caused it to stop sounding.
Part of my interruptionHandler is to (obviously) stop the internal audio of my app to let the interruption come through. I never thought to inspect this method before, but turns out the problem existed in there. My stop method would call prepareToPlay immediately after stopping to make resuming faster the next time.
[self.player stop];
[self.player prepareToPlay]; // <- iOS 5 alarm sound stopped here.
The docs state the prepareToPlay method
preloads buffers and acquires the audio hardware needed for playback, which minimizes the lag between calling the play method and the start of sound output.
Sounds reasonable, and this worked for lesser iOS versions. My hypothesis is that must have made a change to the Clock.app alarm system such that the new alarm sounds use the hardware, whereas before it used the software. This is what I think is causing the iOS 5 alarms to be silent in some apps.
Removing the prepareToPlay lines caused the alarm to sound without using kAudioSessionProperty_OverrideCategoryMixWithOthers, thus solving all my issues laid out in this question.
TL;DR
Remove the prepareToPlay calls from your stop sound code logic. It will take a microsecond longer to start later, but will allow interruptions to sound.
I'd like to play multiple sound sequentially.
The sound data will be available via NSData.
(to be more precise, I'm going to play different sound whenever scrollViewDidEndScrolling is called, and stop previous sound if it is still playing)
Do I need to alloc/init AVAudioPlayer for every sequential sound?
If alloc/init/release AVAudioPlayer isn't a big deal, I could do that but I'm not sure
If using the higher-level AVAudioPlayer, then yes, you'd need to instantiate (alloc/init) an AVAudioPlayer for each.
Yet, the "expensive" part (time-wise) is prepareToPlay - which you could call in a separate thread, thus hopefully by the time you come to play any given sound, it will be fully ready to play.
I have a few single hit sounds(small sound effects) which I want to play when a button is pressed. Should I declare the player and then initialize the sound to the player in the IBAction of the button if I want to play different sounds on different buttons?
Or is there a method to call which you specify the sound as you play it?
the [audioPlayer play] statement plays what is already initialized or added to the player. How can I setup the play and call it at different places with some predefined sound?
Thanks
There's a bit of delay whenever you start playing a sound even if it's already loaded and all you have to do is hit [audioPlayer play]
If you need to initialize it before you play it i'd imagine the delay would be much more noticeable.
I think i'd make a separate audio player for each sound and populate an array with them. Keep an eye out for memory low messages and unload the objects if necessary but i don't think it will require much overhead.
So I have an app which plays many short sound clips. I need to know when the sounds are finished playing, and I need to use mp3s, so I'm using AVFoundation for the sound playback.
When a sound is actively playing, and the user uses the hardware volume buttons, the playback volume changes. Problem is, the app is NOT constantly playing sounds, and when it's not, and the hardware buttons are used, the RINGER volume gets adjusted instead.
How do I set it up so, as long as the app is running, the user can adjust the playback volume?
Thanks!
Turns out this can be accomplished by allocating an AVAudioPlayer with any valid sound file and calling the prepareToPlay method, without ever calling the play method.
Works perfectly.
Start an AudioSession and don't stop it when you're not playing sounds.
so you want to disable ringer playback volume as long as the app is running? therefore the hardware controls will only adjust the app playback sounds?
i dont think this is possible unless you are "always playing sound" for example, many games are always playing background music or what have you.
You might be able to accomplish this by constantly playing a 0 volume sound as long as your app is running. You could then play your sound clips over it.
How do I play multiple sounds simultaneously?