I saw some similar questions with different solutions, but I want to know if there's a way using something similar to what I've already come up with.
Essentially, a uiview will take one color when the player starts playing, and go back to the starting color when it is finished playing
- (void)playSoundWithColor {
self.image = self.pressedImage;
[audioPlayer play];
while ([audioPlayer isPlaying]) {
if (audioPlayer.currentTime == audioPlayer.duration)
self.image = self.startingImage;
}
}
The best way to do what you're trying to do is to make your class an AVAudioPlayerDelegate and to use
audioPlayerDidFinishPlaying:successfully:
That method is called right when the player finishes and doesn't have any continuous loop and memory issues. It will give you the most reliable and efficient performance overall.
Related
i would like to play sound in a loop, with AVAudioPlayer, just like in metronome app, from ios examples. I have the following code:
BOOL continuePlaying = YES;
while(continuePlaying){
[_audioPlayer play];
...do some other stuff
}
The problem is, that sound plays only once- during the first iteration. In next iterations play method doesn't seem to do anything. I would be grateful for any suggestions on what could be wrong.
PS: I know that AVAudiopoayer has numberOfLoops property, but in this case i want to do some other stuff between each plays, so i have to use a loop (i would like to create a metronome app).
Instead of playing while loop, capture delegate when ur sound finish playing
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
You can start playing sound again and do other stuff you would like to do.
Looping in case of playing sound seems illogical since you are firing multiple play and that wont work,
Check with this code, It worked for me:
dispatch_async(dispatch_get_global_queue(0, 0), ^{
while (continuePlaying)
{
[player play];
//do your stuffs here
}
});
I am creating an application which displays a certain video based on an external event, which may require the playing video to change quickly - once per second or more. However, there must not be a gap or lag between the videos.
What is the best way to do this? There are only four videos, each about two megabytes.
I was considering creating four MPMoviePlayerControllers, and have their views added to the main view but hidden, and switching by pausing and hiding the current video, then unhiding and playing the next video. Is there a more elegant solution?
Edit
Here's some more information for my exact sitaution:
The different video frames share mostly common pixels- so it's OK for a frame to stick during switch, but NOT okay for black frames to appear.
Each video is only about ten seconds long, and there are only four videos. The general state transitions are 1<->2<->3<->4->1.
The video playback should compatible with simultaneous AVAudioRecorder recording. As far as I can tell, MPMoviePlayerController is not.
You'll need to set up and prebuffer all the video streams to avoid hiccups, so I don't think your multiple MPMoviePlayerController solution is too far off the mark.
However, that specific solution is potentially problematic because each movie player has its own UI. The UIs do not synchronize with each other, so one might be showing the control bar, another not; one might be in full screen mode, etc. Switching among them will cause visual discontinuities.
Since it sounds like your video switching is not necessarily user-initiated, I'm guessing you don't care too much about the standard video player UI.
I would suggest dropping down to the underlying layer, AV Foundation. In theory, you can just create an AVPlayerItem for each video. This is a stream-management object with no UI overhead, so it's perfect for what you're doing. You could then -- again, in theory -- create one AVPlayer and one AVPlayerLayer to handle the display. When you wanted to switch from one AVPlayerItem stream to another, you could call the AVPlayer's replaceCurrentItemWithPlayerItem: message to swap out the data stream.
I made a little test project (GitHub) to verify this, and unfortunately the straightforward solution isn't quite perfect. There is no video flow glitching, but in the transition from AVPlayer to AVPlayer, the presentation layer seems to briefly flash the previous movie's last-seen frame at the size appropriate to the next movie. It seems to help to allocate separate AVPlayer objects for each movie and switch among them to a constant player layer. There still seems to be an instantaneous flash of background, but at least it's a subtle defect. Here's the gist of the code:
#interface ViewController : UIViewController
{
NSMutableArray *players;
AVPlayerLayer *playerLayer;
}
#property (nonatomic) IBOutlet UIView *videoView;
- (IBAction) selectVideo:(id)sender;
#end
#implementation ViewController
#synthesize videoView;
- (void)viewDidLoad
{
[super viewDidLoad];
NSArray *videoTitles = [NSArray arrayWithObjects:#"Ultimate Dog Tease",
#"Backin Up", #"Herman Cain", nil];
players = [NSMutableArray array];
for (NSString *title in videoTitles) {
AVPlayerItem *player = [AVPlayer playerWithURL:[[NSBundle mainBundle]
URLForResource:title withExtension:#"mp4"]];
[player addObserver:self forKeyPath:#"status" options:0 context:nil];
[players addObject:player];
}
playerLayer = [AVPlayerLayer playerLayerWithPlayer:[players objectAtIndex:0]];
playerLayer.frame = self.videoView.layer.bounds;
playerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
[self.videoView.layer addSublayer:playerLayer];
}
- (void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
change:(NSDictionary *)change context:(void *)context
{
[object removeObserver:self forKeyPath:#"status"];
for (AVPlayer *player in players) {
if (player.status != AVPlayerStatusReadyToPlay) {
return;
}
}
// All videos are ready to go
[self playItemAtIndex:0];
}
- (void) playItemAtIndex:(NSUInteger)idx
{
AVPlayer *newPlayer = [players objectAtIndex:idx];
if (newPlayer != playerLayer.player) {
[playerLayer.player pause];
playerLayer.player = newPlayer;
}
[newPlayer play];
}
- (IBAction) selectVideo:(id)sender
{
[self playItemAtIndex:((UILabel *)sender).tag];
}
#end
Half the code is there just to observe the state of the players and make sure that playback doesn't start until all videos have been buffered.
Allocating three separate AVPlayerLayers (in addition to three AVPlayers) prevents any sort of flash. Unfortunately, an AVPlayer connected to an undisplayed AVPlayerLayer seems to assume that it doesn't need to maintain a video buffer. Every switch among layers then produces a transient video stutter. So that's no good.
A couple of things to note when using AV Foundation are:
1) The AVPlayer object doesn't have built-in support for looped playback. You'll have to observe for the end of the current video and manually seek to time zero.
2) There's no UI at all other than the video frame, but again, I'm guessing that this might actually be an advantage for you.
The MPMoviePlayerController is a singleton. Four instances will share the same pointer, the same view, etc. With the native player, I think you have only two alternatives: one is to change the contentURL property when you want a transition. If the latency this way unacceptable, the other alternative is to produce a longer video with the shorter clips concatenated. You can create very quick jumps within the single, longer clip by setting currentPlaybackTime.
I am using AVAudioPlayer in my program, but having touble in something
I have 10 sounds, and as I click one to play or then others don't stop, I tried to solve by
[myPlayer stop];
myPlayer = nil;
it works, but takes time, so what should I do to stop when it click 2nd row on tableview for playing another sound?
If any query regarding question, you may ask in comments,
I think You hae added some observer before calling, [myPlayer play];... So you have to remove those observer
I want to use AVAudioPlayer to play short sounds... because I have more control than System Sound.
I have several buttons which are hooked up to play several different short sounds.
Each sound file is about 1.5 - 2.0 seconds.
Everything works fine ...except ...I have to wait for the sound to stop before I can press the button and the sound will play again.
Currently the individual AVAudioPlayers are created on viewDidLoad ... and the sounds are called to play when the buttons are pressed
I tried creating the players when the button is pressed... this solves the above problem... but after a while the app crashes... all sound stops working.
Any ideas?
Thanks
Jonathan
If AVAudioPlayer stops playing sounds, it is usually because there are too many player instances created, usually leaked. You should make sure you release some after you are done.
You need to set the currentTime of the player to 0 before playing. Calling [player play] when it is already playing has no effect.
player.currentTime = 0;
[player play];
Creating new ones is fine, but make sure your header declares and does this:
- (void) audioPlayerDidFinishPlaying: (AVAudioPlayer *) player successfully: (BOOL) completed {
[player release];
}
if your app is simple, that will release the memory of anything done that's no longer necessary, as per mahboudz' suggestion.
This might not totally prevent crashing, depending on your sound file sizes, and if you dealloc the scene. You might want to add
if (self.view.superview) { //release }
or something.
This is all memory handling. You may want to brush up on pointers to know how to handle your player objects, literally within any function, and still feel comfortable placing release in dealloc OR the didFinish: delegate function, and know why it doesn't belong in the other one.
The iPhone can be interrupted, stopped, and messed with at any time, so you have to know how to handle the memory and how to deal with it when it happens. I just had a crash of a similar nature, and everything above applied to it. NSXML delegates would be a nightmare without knowing pointers... same for AVAudioPlayer
If you plan to use a lof of short sounds, you might want to think about switching to OpenAL.
It's not a lot more complicated and you will save yourselve some trouble in more complicated audio settings later on.
There's a tutorial and some useful code available here (archived here).
this is MAYBE because you have created the AVAudioPlayers inside the viewDidLoad(). I remember I had the same problem. Just initialize them inside the class but not there. hope it works!
EDIT:
ok i saw the date... 2009...
I'm using the AVAudioPlayer to play sound FX on a separate thread in my app. Right now my app is fairly simple, I have a UIScrollView for a scrolling background, and a couple of CALayers that represent a player and an enemy in a simple side-scroller type game (think Mario or Kung Fu or whatnot)...I can move the player left and right, with the view scrolling appropriately with no problems. I have an "attack" button that's playing a sound effect...and many times when I play the sound effect, I get a little bit of a hitch, graphically. Is this just par for the course on the iPhone using Quartz? Is there some way to have this perform a little more smoothly without starting to investigate OpenGL?
Use NSData dataWithContentsOfMappedFile instead of dataWithContentsOfFile.
Also AVAudioPlayer handles it's own threading, you don't need to create one. [AVAudioPlayer play] returns after it started playing, not after it is done playing.
And don't forget to release your AVAudioPlayer when you no longer need it, for example if you only want to play a sound onces, implemement the audioPlayerDidFinishPlaying:successfully: delegate and release it in there.
How are you playing the sound? If I was to make a guess it would be that each time the sound is played the OS is actually loading it from disk as well as playing it.
Update:
Ok, you really don't need to be creating a new thread to play a sound. This alone could cause a stutter in a game and is also redundant - The AVAudioPlayer play method is asynchronous - it returns immediately and not when the sound ends.
I had the same problem with slowdown. To solve it, I first play and pause the sound when it first loads at volume 0 - this works better than prepareToPlay which still seems to result in slowdown:
player.volume = 0.0;
[player play];
[player pause];
player.volume = 1.0;
When it comes time to play a sound I just [player play];. Then every update cycle I loop through all my active sounds and catch ones that are about to end and rewind them instead of letting them expire - this avoids the overhead and slowdown of starting up the sound from scratch. The example here stops the sounds 1/15th of a second from the end of the sound:
for ({each player in active sounds})
{
if ((player.duration - player.currentTime) <= (1.0/15.0))
{
[player pause];
player.currentTime = 0.0;
}
}
Now it's ready to go for the next play. Seems to work fine!
Update: Turns out I was still getting some pauses the very first time the sound was played. I think playing it at zero volume wasn't actually doing anything, but I changed it to play at 0.0001 volume and then pause - it's inaudible but seems to do the job of prepping the sound.
Had the same problem at first. Per documentation you need to call "prepareToPlay" every time a sound has finished playing. Adopting the AVAudioPlayerDelegate protocol and adding the following method will do this.
-(void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag{
[player prepareToPlay];
}
(Using an answer rather than a comment for length and so I can show code):
My sound playing method is as follows:
- (void)playSoundThreaded:(id)soundPlayer
{
if(soundPlayer == nil)
return;
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
[(AVAudioPlayer*)soundPlayer play];
[pool release];
}
- (void)playSound:(AVAudioPlayer*)player
{
if(player == nil)
return;
[NSThread detachNewThreadSelector:#selector(playSoundThreaded:)
toTarget:self withObject:(id)player];
}
And the sound is loaded up as follows:
fxPlayer = [[AVAudioPlayer alloc] initWithData:
[NSData dataWithContentsOfFile:
[[NSBundle mainBundle] pathForResource:#"voicehiya" ofType:#"caf"]] error:NULL];
We've had some inkling that the sound is being reloaded from disk every time...but have no idea as to why that is or how to prevent it.
I think the thread is over complicating your player. Try this for a go:
/* setup the sound player */
AVAudioPlayer *player1=[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:audioFilePath] error:NULL];
player1.numberOfLoops = 0;
player1.volume=1.0f;
[player1 prepareToPlay];
and then playSound becomes
[player play];
And don't forget to have the AudioSession category set correctly too.
Why not just use AudioServicesPlaySystemSound? This is well suited to sound effects.
I use it in my game (vConqr) which is also based on a UIScrollView, with numerous other views (so all having their own CALayer), and it doesn't significantly impact performance.
I've been investigating this for a few days now thanks to a project I'm on at work. I added some home-rolled profiling to my code and found that the calls to play sounds were causing frame rate issues in my OpenGL game. I've got a few recommendations for you based on what I've found:
Use an AVAudioPlayer playing an mp3 for your background music.
Use OpenAL for your sound effects.
For sound effects, use the audio converter command line tool from apple to get your sounds to .caf format. This is an uncompressed format that doesn't require the CPU to decompress your sound to memory before sending it to the sound card. It can go directly, saving you time. Instructions on using the tool can be found HERE. (scroll to the very bottom of the page)
Use the lowest bit depths that still sound good. You don't really need 128 kbps - you can probably get away with 20 for a lot of things. Lower bit rate = less processing = faster sound.
I'll let you know if I find anything else that's useful! Good luck!