Received memory warning in recording the video - iphone

Question

I made an app for ipad which contains image dragging and video recording.
It takes screenshots as recording starts and after that makes movie by appending them.
When i record video of 5 to 10 seconds , it works fine. But as i try to record video of 1 minute or more, it crashes and gives "Received memory warning" in log.
I have used the following code ;
- (IBAction)btnRecording_Pressed:(id)sender
{
if ([recordButton.titleLabel.text isEqualToString:#"Start Recording"]) {
backButton.enabled = NO;
[recordButton setTitle:#"Stop Recording" forState:UIControlStateNormal];
fileIndex = 0;
recTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/5.0 target:self selector:#selector(startFrameCapture) userInfo:nil repeats:YES];
[recTimer retain];
[self startRecording];
}else{
[recordButton setTitle:#"Start Recording" forState:UIControlStateNormal];
[recTimer invalidate];
[recTimer release];
[self stopRecording];
[self getFileName];
}
}
-(void)startFrameCapture
{
fileIndex++;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
documentsDirectory = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"Screenshot%d.jpg",fileIndex]];
[self performSelectorInBackground:#selector(newThread:) withObject:documentsDirectory];
}
-(void)newThread:(NSString *)frameName{
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
else
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imageData = UIImageJPEGRepresentation(viewImage, 1.0);
[imageData writeToFile:frameName atomically:YES];
}
- (void) startRecording{
if([recorder isRecording]){
NSLog(#"Stopped Recording");
[self stopRecording];
}else{
NSLog(#"Started Recording");
[self prepareRecorderNow];
[recorder record];
}
}
- (void) stopRecording{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
if([recorder isRecording]){
[recorder stop];
[recorder release];
recorder = nil;
}
[pool drain];
}
-(void)prepareRecorderNow{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
NSError *err = nil;
[audioSession setCategory :AVAudioSessionCategoryPlayAndRecord error:&err];
if(err){
NSLog(#"audioSession: %# %d %#", [err domain], [err code], [[err userInfo] description]);
return;
}
[audioSession setActive:YES error:&err];
err = nil;
if(err){
NSLog(#"audioSession: %# %d %#", [err domain], [err code], [[err userInfo] description]);
return;
}
recordSetting = [[NSMutableDictionary alloc] init];
[recordSetting setValue :[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];
[recordSetting setValue:[NSNumber numberWithFloat:44100] forKey:AVSampleRateKey];
[recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
[recordSetting setValue :[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];
// Create a new dated file
[recorderFilePath release];
recorderFilePath = [[NSString stringWithFormat:#"%#/deformed.caf", DOCUMENTS_FOLDER] retain];
NSURL *url = [NSURL fileURLWithPath:recorderFilePath];
err = nil;
recorder = [[ AVAudioRecorder alloc] initWithURL:url settings:recordSetting error:&err];
[recordSetting release];
if(!recorder){
NSLog(#"recorder: %# %d %#", [err domain], [err code], [[err userInfo] description]);
UIAlertView *alert =
[[UIAlertView alloc] initWithTitle: #"Warning"
message: [err localizedDescription]
delegate: nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
[alert release];
return;
}
//prepare to record
[recorder setDelegate:self];
[recorder prepareToRecord];
recorder.meteringEnabled = YES;
BOOL audioHWAvailable = audioSession.inputIsAvailable;
if (! audioHWAvailable) {
UIAlertView *cantRecordAlert =
[[UIAlertView alloc] initWithTitle: #"Warning"
message: #"Audio input hardware not available"
delegate: nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[cantRecordAlert show];
[cantRecordAlert release];
return;
}
NSLog(#"Not Over Man");
[pool drain];
}
What can be the issue ?
Thanks!!

Answer 1

You are creating a image context 5 times per second. That could be the problem.
Try reusing your UIGraphicsImageContext by saving it as an ivar or property.

Answer 2

I had a similar problem in case of Capturing Pictures, practically, I have seen the problem with the NOT RELEASED UIImage objects, which occupies most of the memory, here is a fix you can try
-(void)newThread:(NSString *)frameName
{
UIImage *viewImage=nil;
viewImage=[[UIImage alloc] init];
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
else
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imageData = UIImageJPEGRepresentation(viewImage, 1.0);
[imageData writeToFile:frameName atomically:YES];
[viewImage release];
}