I init AVCaptureVideoDataOutput with this method:
// Setup the video output
_videoOutput = [[AVCaptureVideoDataOutput alloc] init];
_videoOutput.alwaysDiscardsLateVideoFrames = YES;
_videoOutput.minFrameDuration = kCMTimeZero;
_videoOutput.videoSettings =
[NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA],(id)kCVPixelBufferPixelFormatTypeKey
,AVVideoCodecH264, AVVideoCodecKey, nil];
// Setup the audio output
_audioOutput = [[AVCaptureAudioDataOutput alloc] init];
NSLog(#"dispatch_queue_t");
// Setup the queue
dispatch_queue_t queue = dispatch_queue_create("MyQueue", NULL);
[_videoOutput setSampleBufferDelegate:self queue:queue];
[_audioOutput setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
And i have a problem that the delegate method:
(void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
is won't called.in IOS4 this method called, any idea why it happen?
Add input and output to the session.
Then call [session startRunning].
Related
I'm capturing audio using AVCaptureAudioDataOutputSampleBufferDelegate
_captureSession = [[AVCaptureSession alloc] init];
[self.captureSession setSessionPreset:AVCaptureSessionPresetLow];
// Setup Audio input
AVCaptureDevice *audioDevice = [AVCaptureDevice
defaultDeviceWithMediaType:AVMediaTypeAudio];
AVCaptureDeviceInput *captureAudioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];
if(error){
NSLog(#"Error Start capture Audio=%#", error);
}else{
if ([self.captureSession canAddInput:captureAudioInput]){
[self.captureSession addInput:captureAudioInput];
}
}
// Setup Audio output
AVCaptureAudioDataOutput *audioCaptureOutput = [[AVCaptureAudioDataOutput alloc] init];
if ([self.captureSession canAddOutput:audioCaptureOutput]){
[self.captureSession addOutput:audioCaptureOutput];
}
[audioCaptureOutput release];
//We create a serial queue
dispatch_queue_t audioQueue= dispatch_queue_create("audioQueue", NULL);
[audioCaptureOutput setSampleBufferDelegate:self queue:audioQueue];
dispatch_release(audioQueue);
/*We start the capture*/
[self.captureSession startRunning];
Delegate:
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
// do something with sampleBuffer
}
The question is how can i play audio from sampleBuffer?
You can create NSData from the CMSampleBufferRef using the following code and then play it with AVAudioPlayer.
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
AudioBufferList audioBufferList;
NSMutableData *data= [NSMutableData data];
CMBlockBufferRef blockBuffer;
CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, NULL, &audioBufferList, sizeof(audioBufferList), NULL, NULL, 0, &blockBuffer);
for( int y=0; y< audioBufferList.mNumberBuffers; y++ ){
AudioBuffer audioBuffer = audioBufferList.mBuffers[y];
Float32 *frame = (Float32*)audioBuffer.mData;
[data appendBytes:frame length:audioBuffer.mDataByteSize];
}
CFRelease(blockBuffer);
AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithData:data error:nil];
[player play];
}
I'm worried about how this will do performance wise though. There probably is a better way to do what you are trying to accomplish.
this is my code that freezes my app
AVCaptureConnection *videoConnection = [videoOutput connectionWithMediaType:AVMediaTypeVideo];
if ([videoConnection isVideoOrientationSupported] )
{
[videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
}
this is my videoOutput init
// Setup video capture
videoInput = [[AVCaptureDeviceInput deviceInputWithDevice: front? frontVideoDevice: rearVideoDevice error: &error] retain];
videoOutput = [[AVCaptureVideoDataOutput alloc] init];
[videoOutput setAlwaysDiscardsLateVideoFrames: YES];
// Set the video output to store frame in BGRA (It is supposed to be faster)
NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey;
NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA];
NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key];
[videoOutput setVideoSettings:videoSettings];
when I initialize the session in the second time my app stop responding
but if i remove the code of the avcaptureconnection everything is fine
?
...!
I called
[session startRunning]
before the
AVCaptureConnection *videoConnection = [videoOutput connectionWithMediaType:AVMediaTypeVideo];
if ([videoConnection isVideoOrientationSupported] )
{
[videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
}
my bad :)
I have a camera preview window which is working well 90% of the time. Sometimes however, when returning to my app if it's been in the background, the preview will not display. This is the code I call when the view loads:
- (void) startCamera {
session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetPhoto;
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = _cameraView.bounds;
[_cameraView.layer addSublayer:captureVideoPreviewLayer];
captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
captureVideoPreviewLayer.position=CGPointMake(CGRectGetMidX(_cameraView.bounds), 160);
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
NSLog(#"ERROR: %#", error);
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Important!"
message:#"Unable to find a camera."
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
[alert autorelease];
}
[session addInput:input];
stillImage = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG , AVVideoCodecKey, nil];
[stillImage setOutputSettings:outputSettings];
[session addOutput:stillImage];
[session startRunning];
}
If this happens, I can switch to my preferences view and back again and al is well,but it's an annoying bug I'd like to kill. The preview window is a UIView in my storyboard.
Do not start the capture session on view load, instead start it on viewWillAppear and stop it on viewWillDissapear.
Seems like your view controller is cleaning up some memory when the app is in the background. Make sure you are initializing your capture session with this in mind.
Allocate your session lazily in a private property getter method rather than in your start method you will avoid memory leaks this way.
I am learning objective c and doing a sample app to fetch video feed from iPhone camera. I was able to get the feeds from camera and display it on screen. Also I was trying to update some UILabel in screen for each frame from the video inside the delegate method. But the label value is not getting updated always. Here is the code I am using
This section will initialize the capture
- (void)initCapture
{
NSError *error = nil;
device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus] && [device lockForConfiguration:&error]) {
[device setFocusMode:AVCaptureFocusModeContinuousAutoFocus];
[device unlockForConfiguration];
}
AVCaptureDeviceInput *captureInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
//AVCaptureStillImageOutput *imageCaptureOutput = [[AVCaptureStillImageOutput alloc] init];
AVCaptureVideoDataOutput *captureOutput =[[AVCaptureVideoDataOutput alloc] init];
captureOutput.alwaysDiscardsLateVideoFrames = YES;
//captureOutput.minFrameDuration = CMTimeMake(1, 1);
captureOutput.alwaysDiscardsLateVideoFrames = YES;
dispatch_queue_t queue;
queue = dispatch_queue_create("cameraQueue", NULL);
[captureOutput setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
// Set the video output to store frame in BGRA (It is supposed to be faster)
NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey;
NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA];
NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key];
[captureOutput setVideoSettings:videoSettings];
self.captureSession = [[AVCaptureSession alloc] init];
[self.captureSession addInput:captureInput];
[self.captureSession addOutput:captureOutput];
self.prevLayer = [AVCaptureVideoPreviewLayer layerWithSession: self.captureSession];
self.prevLayer.frame = CGRectMake(0, 0, 320, 320);
self.prevLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
[self.videoPreview.layer addSublayer: self.prevLayer];
[self.captureSession startRunning];
}
This method is called for each video frame.
#pragma mark AVCaptureSession delegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
i++;
self.lblStatus.Text = [NSString stringWithFormat:#"%d",i];
}
I am trying to print UILabel inside this method but it is not printed always. THere is much delay for the label text to change.
Could someone help please?
Thanks.
Your sampleBufferDelegate's captureOutput is being called from a non-main thread - updating GUI objects from there can do no good. Try using performSelectorOnMainThread instead.
I have this app the records video and I need to fire a method every time a frame is grabbed. After banging my head on the wall, I decided to try the following: create a dispatch queue, as I would grab a video from the output, just to have a method called when the frame is recorded by the camera.
I am trying to understand a section of code created by Apple to record videos to figure out how I should add the dispatch queue. This is the apple code and the section marked between asterisks is what I have added, in order to create the queue. It compiles without errors, but captureOutput: didOutputSampleBuffer: fromConnection: is never called.
- (BOOL) setupSessionWithPreset:(NSString *)sessionPreset error:(NSError **)error
{
BOOL success = NO;
// Init the device inputs
AVCaptureDeviceInput *videoInput = [[[AVCaptureDeviceInput alloc] initWithDevice:[self backFacingCamera] error:error] autorelease];
[self setVideoInput:videoInput]; // stash this for later use if we need to switch cameras
AVCaptureDeviceInput *audioInput = [[[AVCaptureDeviceInput alloc] initWithDevice:[self audioDevice] error:error] autorelease];
[self setAudioInput:audioInput];
AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
[self setMovieFileOutput:movieFileOutput];
[movieFileOutput release];
// Setup and start the capture session
AVCaptureSession *session = [[AVCaptureSession alloc] init];
if ([session canAddInput:videoInput]) {
[session addInput:videoInput];
}
if ([session canAddInput:audioInput]) {
[session addInput:audioInput];
}
if ([session canAddOutput:movieFileOutput]) {
[session addOutput:movieFileOutput];
}
[session setSessionPreset:sessionPreset];
// I added this *****************
dispatch_queue_t queue = dispatch_queue_create("myqueue", NULL);
[[self videoDataOutput] setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
// ******************** end of my code
[session startRunning];
[self setSession:session];
[session release];
success = YES;
return success;
}
What I need is just a method where I can process every frame that is being recorded.
thanks
Having set yourself as the delegate, you'll receive a call to:
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
Every time a new frame is captured. You can put whatever code you want in there — just be careful because you won't be on the main thread. It's probably safest to do a quick [target performSelectorOnMainThread:#selector(methodYouActuallyWant)] in -captureOutput:didOutputSampleBuffer:fromConnection:.
Addition: I use the following as setup in my code, and that successfully leads to the delegate method being called. I'm unable to see any substantial difference between it and what you're using.
- (id)initWithSessionPreset:(NSString *)sessionPreset delegate:(id <AAVideoSourceDelegate>)aDelegate
{
#ifndef TARGET_OS_EMBEDDED
return nil;
#else
if(self = [super init])
{
delegate = aDelegate;
NSError *error = nil;
// create a low-quality capture session
session = [[AVCaptureSession alloc] init];
session.sessionPreset = sessionPreset;
// grab a suitable device...
device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// ...and a device input
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if(!input || error)
{
[self release];
return nil;
}
[session addInput:input];
// create a VideDataOutput to route output to us
AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
[session addOutput:[output autorelease]];
// create a suitable dispatch queue, GCD style, and hook self up as the delegate
dispatch_queue_t queue = dispatch_queue_create("aQueue", NULL);
[output setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
// set 32bpp BGRA pixel format, since I'll want to make sense of the frame
output.videoSettings =
[NSDictionary
dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
forKey:(id)kCVPixelBufferPixelFormatTypeKey];
}
return self;
#endif
}
- (void)start
{
[session startRunning];
}
- (void)stop
{
[session stopRunning];
}
// create a suitable dispatch queue, GCD style, and hook self up as the delegate
dispatch_queue_t queue = dispatch_queue_create("aQueue", NULL);
[output setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
Also very important into
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
be sure to put a
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; at the beginning and a [pool drain] at the end else will crash after too many processes.