I have a drum app that I've created basing it off of AVAudioPlayer instead of the common system sounds in order to have a bit of control.
The problem is that whenever two or more sounds are played at once, it lags and stops alls sounds, so your drum beat gets choppy and randomly stopped.
For example: boom boom chhhhh boom boom ch--- boom bo---- chhhhh
If you can tell at all from that onomatopoeia.
Here's the sound code, I have an array of preloaded AVAudioPlayer so that it loads faster.
- (void)triggerSound:(NSInteger)soundNumber {
NSInteger deltaNum = soundNumber*numberOfBuffers;
AVAudioPlayer *lowBuffer = [bufferBox objectAtIndex:deltaNum];
Boolean soundFired = FALSE;
// Find an unused buffer if possible, otherwise play sound from first buffer.
for (int i=0; i<numberOfBuffers; i++) {
NSLog(#"Buffer loop: %d", i);
NSLog(#"Buffer to load: %d", deltaNum);
AVAudioPlayer *tempBuffer = [bufferBox objectAtIndex:deltaNum+i];
if (!tempBuffer.playing) {
tempBuffer.currentTime = 0;
[tempBuffer play];
soundFired = TRUE;
break;
} else if (lowBuffer.currentTime>tempBuffer.currentTime) {
lowBuffer = tempBuffer;
}
}
if (!soundFired) {
lowBuffer.currentTime = 0;
[lowBuffer play];
soundFired = TRUE;
}
}
That method is called in the IBAction button press. ex: [drumObject triggerSound:3].
All help appreciated!
I've had much better experiences with the OpenAL API for some games. It is very different and more low level (you have to deal with sources and buffers) but it worked much better for me than AVAudioPlayer.
You could try using an iOS game engine for your audio needs.
For example: http://gamua.com/sparrow/
You don't actually have to use the graphics part of this engine. Just import and use the audio part of the framework (which provides a simple API on top of OpenAL).
Related
I'm making app using MPMoviePlayerController.
I want to make special function.
What I want to function is like this.
If I play movie, player will stop after few second (ex: 30sec).
If I click play button, player has to play from 30sec to next stop point.
For me to realize this function, I've used initialPlaybackTime and endPlaybackTime option of MPMoviePlayerContrller.
But, this function didn't work like my thought.
mplayer.initialPlaybackTime = 0;
mplayer.endPlaybackTime = 10;
[mplayer play];
....
[mplayer pause];
,,,
mplayer.initialPlaybackTime = 10;
mplayer.endPlaybackTime =30;
[mplayer play];
And, mplayer is played again from 0 to 10, not from 10 to 30.
This is a little late, but for anyone who comes upon this question, it appears that endplaybacktime and initialplayback time can only be set once for an initialized mpmovieplayercontroller. If you want to reset the values you'll have to destroy your mpmovieplayercontroller instance and create a new one.
This is very disappointing, could I be wrong? I would love it if I were.
Change your code to set the currentPlaybackTime before restarting the playback. Note, the order of initializing these properties does matter.
[...]
mplayer.initialPlaybackTime = 10.0;
mplayer.endPlaybackTime = 30.0;
mplayer.currentPlaybackTime = 10.0;
[mplayer play];
I have an app that streams music using AudioStreamer class by Matt Gallagher. This works fine as a background process except I want to be able to skip to the next song once the stream is finished. Unfortunately this part doesn't work.
Initially I had a timer that was monitoring the stream but realized that when the app backgrounds this timer no longer runs. So I tried adding a delegate callback in the packet read function:
void ASReadStreamCallBack(CFReadStreamRef aStream, CFStreamEventType eventType, void* inClientInfo)
{
AudioStreamer* streamer = (AudioStreamer *)inClientInfo;
double percent = [streamer progress]/[streamer duration];
if(percent>=0.98 || (percent>=0.95 && [streamer isIdle])){
if([streamer.delegate respondsToSelector:#selector(didFinishPlayingStream:)] ){
[streamer.delegate didFinishPlayingStream:streamer];
streamer.delegate = nil;
}
}
[streamer handleReadFromStream:aStream eventType:eventType];
}
This works fine when the app is in the foreground but no longer works when the app is backgrounding. The delegate method basically sends a request to get the stream URL for the next song, then once it has it creates a new AudioStreamer class
While the app is in background you can implemente the delegate to handle the different remote control states.
- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
switch (receivedEvent.subtype) {
case UIEventSubtypeRemoteControlTogglePlayPause:
if (player.isPlaying) {
[player pause];
} else {
[player start];
}
break;
case UIEventSubtypeRemoteControlPreviousTrack:
break;
case UIEventSubtypeRemoteControlNextTrack:
[self skipSong:nil];
break;
default:
break;
} }
Something like this works for me.
I've uploaded my AudioPlayer/streamer class inspired in part by Matt Gallagher's AudioStreamer to
https://code.google.com/p/audjustable.
One of the cooler features is its support for gapless playback. This means the AudioQueue is never closed between gaps; keeping iOS from suspending your app.
You can implement AudioPlayerDelegate:didFinishBufferingSourceWithQueueItemId and AudioPlayerDelegate:didFinishPlayingQueueItemId to queue up the next track by calling AudioPlayer:queueDataSource.
Let me know if you need help using it.
I implemented OpenAL code to my iphone game. When I starts the game, it runs for 1 sec and stalls for 2 sec then resumes (hiccup effect). I believe its delayed due to the sound files loading. What is the solution? Can anyone recommend any book, site or sources code (not the iphone reference, please)? Is there a loading process and where should I initialize the loading process? Would that help?
Below, I have included the related components of the OpenAL code that I have implemented. The sound file will be played and invoked by a "if" statement in the gameloop. The OpenALController class is for the sound sources and buffers creation and the InitOpenAL method is invoked in OpenALController. MyView is a customized subclass of UIView and connected to the main view (I didn't use the default view).
// MyView.m
// A customized UIView as the main view.
#import "OpenALSoundController.h"
- (void)startPlaying{
...
[self initializeValuables];
...
[self initializeTimer];
}
- (void)initializeTimer {
if (theTimer == nil) {
theTimer = [CADisplayLink displayLinkWithTarget:self selector:#selector)gameLoop)];
theTimer.frameInterval = 2;
[theTimer addToRunLoop: [NSRunLoop currentRunLoop] forMode: NSDefaultRunLoopMode];
}
}
- (void)gameLoop {
...
If something = true
// Play the sound
[[OpenALSoundController sharedSoundController] playSound1];
...
}
...
#end
// OpenALSoundController.h
#interface OpenALSoundController : NSObject {
...}
...
+ (OpenALSoundController*) sharedSoundController
...
#end
// OpenALSoundController.m
// Singleton accessor
{
static OpenALSoundController* shared_sound_controller;
#synchronized(self)
{
if(nil == shared_sound_controller)
{
shared_sound_controller = [[OpenALSoundController alloc] init];
}
return shared_sound_controller;
}
return shared_sound_controller;
}
- (void) initOpenAL{
...
file_url = [[NSURL alloc] initFileURLWithPath:[[NSBundle mainBundle] pathForResource:#"fire" ofType:#"wav"]];
firePcmData = MyGetOpenALAudioDataAll((CFURLRef)file_url, &data_size, &al_format,&sample_rate);
alBufferData(fireOutputBuffer, al_format, firePcmData, data_size, sample_rate);
[file_url release];
...
alSourcei(outputSourceFire, AL_BUFFER, fireOutputBuffer);
...
}
You might be interested in Finch, an OpenAL sound engine for iOS. It’s very well suited to games. It’s usually better to reuse some already existing code than develop and maintain your own.
First its better to use mp3, as wav files are huge and loading from disk takes time. Mp3 files are smaller on disk, loaded into memory and decompressed there for playing. Try experimenting by reducing mp3 bitrate/encoding quality too.
Also you need to preload sounds to avoid hiccups, otherwise you will have a delay the first time a sound is played.
I'm using OpenAL sound framework on the iPhone, and I'm setting different volumes on individual sounds. I'm running into a problem where I'm hearing an initial popping/clicking noise when switching from one sound to the next.
It's really noticeable when I have one sound that's got a high volume (1.0) and a second
sound that has a low one (0.2). When I hit the loud sound, and then
hit the soft sound, I hear the pop/click. But when I go from the soft
sound to the loud, I don't notice anything. So the pop/click really
happens when switching from loud to soft sounds.
Here's the init sound method:
- (id) initWithSoundFile:(NSString *)file doesLoop:(BOOL)loops
{
self = [super init];
if (self != nil)
{
if(![self loadSoundFile:file doesLoop:loops])
{
debug(#"Failed to load the sound file: %#...", file);
[self release];
return nil;
}
self.sourceFileName = file;
//temporary sound queue
self.temporarySounds = [NSMutableArray array];
//default volume/pitch
self.volume = 1.0;
self.pitch = 1.0;
}
return self;
}
and here's the play function:
- (BOOL) play
{
if([self isPlaying]) //see if the base source is busy...
{
//if so, create a new source
NSUInteger tmpSourceID;
alGenSources(1, &tmpSourceID);
//attach the buffer to the source
alSourcei(tmpSourceID, AL_BUFFER, bufferID);
alSourcePlay(tmpSourceID);
//add the sound id to the play queue so we can dispose of it later
[temporarySounds addObject: [NSNumber numberWithUnsignedInteger:tmpSourceID]];
//a "callback" for when the sound is done playing +0.1 secs
[self performSelector:#selector(deleteTemporarySource)
withObject:nil
afterDelay:(duration * pitch) + 0.1];
return ((error = alGetError()) != AL_NO_ERROR);
}
//if the base source isn't busy, just use that one...
alSourcePlay(sourceID);
return ((error = alGetError()) != AL_NO_ERROR);
}
and here's the function where i set the volume for each sound immediately after playing (ive tried setting it before playing too):
- (void) setVolume:(ALfloat)newVolume
{
volume = MAX(MIN(newVolume, 1.0f), 0.0f); //cap to 0-1
alSourcef(sourceID, AL_GAIN, volume);
//now set the volume for any temporary sounds...
for(NSNumber *tmpSourceID in temporarySounds)
{
//tmpSourceID is the source ID for the temporary sound
alSourcef([tmpSourceID unsignedIntegerValue], AL_GAIN, volume);
}
}
Any help is greatly appreciated as I've tried everything I can think of. I would be so grateful.
All I had to do was use calloc instead of malloc to allocate memory for the OpenAL buffer.
Or you could also zero set the memory with memset.
The wierd popping noise went off. It was due to junk memory in my case. That's why it was random too. Hope this helps.
This problem is caused by not calling alSourceStop.
The documentation doesn't really state this, but alSourceStop must be called on a sound source before it can be reused even if the sound had already finished and the AL_SOURCE_STATE parameter of the source is not AL_PLAYING.
I've randomly got to this unaswered question and, finding that the problem was not solved, I'll try to give my answer, even if a long time has passed.
I don't know OpenAL, but it sounds like this is a purely audio problem. It is normal to hear short clicks when you change suddenly the level of the audio, especially from a high value to a low value. For example, if you map directly the volume of the audio to a slider, which value is updated every few ms, you can easily hear clicks and pops when sliding fast the control. What audio software developers do is smoothing the parameter changes with a low pass filter.
In your case, I would suggest you to stop the clip after fading it out, and start a new clip by fading it in. The fade time can be as short as 2 ms: it's not audible, and the sound will play just finely.
I wonder if (some versions of) OpenAL can automatically deal with this issue.
Does anyone know or have good links that explain what iPhone's event loop does under the hood?
We are using a custom event loop in our OpenGL-based iPhone game framework. It calls our game rendering system, calls presentRenderbuffer and pumps events using CFRunLoopRunInMode. See the code below for details.
It works well when we are not using UIKit controls (as a proof, try Facetap, our first released game).
However, when using UIKit controls, everything almost works, but not quite. Specifically, scrolling of UIKit controls doesn't work properly.
For example, let's consider following scenario.
We show UIImagePickerController on top of our own view.
UIImagePickerController covers our custom view
We also pause our own rendering, but keep on using the custom event loop.
As said, everything works, except scrolling.
Picking photos works.
Drilling down to photo albums works and transition animations are smooth.
When trying to scroll photo album view, the view follows your finger.
Problem: when scrolling, scrolling stops immediately after you lift your finger. Normally, it continues smoothly based on the speed of your movement, but not when we are using the custom event loop. It seems that iPhone's event loop is doing some magic related to UIKit scrolling that we haven't implemented ourselves.
Now, we can get UIKit controls to work just fine and dandy together with our own system by using Apple's event loop and calling our own rendering via NSTimer callbacks. However, I'd still like to understand, what is possibly happening inside iPhone's event loop that is not implemented in our custom event loop.
- (void)customEventLoop { OBJC_METHOD;
float excess = 0.0f;
while(isRunning) {
animationInterval = 1.0f / openGLapp->ticks_per_second();
// Calculate the target time to be used in this run of loop
float wait = max(0.0, animationInterval - excess);
Systemtime target = Systemtime::now().after_seconds(wait);
Scope("event loop");
NSAutoreleasePool* pool = [[ NSAutoreleasePool alloc] init];
// Call our own render system and present render buffer
[self drawView];
// Pump system events
[self handleSystemEvents:target];
[pool release];
excess = target.seconds_to_now();
}
}
- (void)drawView { OBJC_METHOD;
// call our own custom rendering
bool bind = openGLapp->app_render();
// bind the buffer to be THE renderbuffer and present its contents
if (bind) {
opengl::bind_renderbuffer(renderbuffer);
[context presentRenderbuffer:GL_RENDERBUFFER_OES];
}
}
- (void) handleSystemEvents:(Systemtime)target { OBJC_METHOD;
SInt32 reason = 0;
double time_left = target.seconds_since_now();
if (time_left <= 0.0) {
while((reason = CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, TRUE)) == kCFRunLoopRunHandledSource) {}
} else {
float dt = time_left;
while((reason = CFRunLoopRunInMode(kCFRunLoopDefaultMode, dt, FALSE)) == kCFRunLoopRunHandledSource) {
double time_left = target.seconds_since_now();
if (time_left <= 0.0) break;
dt = (float) time_left;
}
}
}
If you NSLog [[NSRunLoop currentRunLoop] currentMode] from [UIScrollView setContentOffset:] when [UIScrollView isDecelerating] is true you will see UITrackingRunLoopMode.
In general, the system will use modes besides kCFRunLoopDefaultMode on the main UI thread run loop, only some of which are documented. The only way to get full system behavior is to cooperate with the system run loop on the main thread.
You could try using an NSTimer and letting the system call you instead of calling CFRunLoopRunInMode yourself. An NSTimer is free to run over time, and when no other UI is shown the system run loop would not be doing anything besides calling the timer.
The alternative would be to return from your customEventLoop function while system controls are being displayed, and call it again when resuming your custom UI.