I am new to Objective-C and iOS technology.I want to record the video through code and during run time, I have to get each frame as raw data for some processing.How can I achieve this? Please any one help me. Thanks in Advance. Here is my code so far:
- (void)viewDidLoad
{
[super viewDidLoad];
[self setupCaptureSession];
}
The viewDidAppear function
-(void)viewDidAppear:(BOOL)animated
{
if (!_bpickeropen)
{
_bpickeropen = true;
_picker = [[UIImagePickerController alloc] init];
_picker.delegate = self;
NSArray *sourceTypes = [UIImagePickerController availableMediaTypesForSourceType:picker.sourceType];
if (![sourceTypes containsObject:(NSString *)kUTTypeMovie ])
{
NSLog(@"device not supported");
return;
}
_picker.sourceType = UIImagePickerControllerSourceTypeCamera;
_picker.mediaTypes = [NSArray arrayWithObjects:(NSString *)kUTTypeMovie,nil];//,(NSString *) kUTTypeImage
_picker.videoQuality = UIImagePickerControllerQualityTypeHigh;
[self presentModalViewController:_picker animated:YES];
}
}
// Delegate routine that is called when a sample buffer was written
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
CVImageBufferRef cameraFrame = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(cameraFrame, 0);
GLubyte *rawImageBytes = CVPixelBufferGetBaseAddress(cameraFrame);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(cameraFrame);
**NSData *dataForRawBytes = [NSData dataWithBytes:rawImageBytes length:bytesPerRow * CVPixelBufferGetHeight(cameraFrame)];
**
PROBLEMS
1.(Here i am getting the raw bytes only once)
2.(After that i want to store this raw bytes as binary file in app path).
// Do whatever with your bytes
NSLog(@"bytes per row %zd",bytesPerRow);
[dataForRawBytes writeToFile:[self datafilepath]atomically:YES];
NSLog(@"Sample Buffer Data is %@\n",dataForRawBytes);
CVPixelBufferUnlockBaseAddress(cameraFrame, 0);
}
here i am setting the delegate of output// Create and configure a capture session and start it running
- (void)setupCaptureSession
{
NSError *error = nil;
// Create the session
AVCaptureSession *session = [[AVCaptureSession alloc] init];
// Configure the session to produce lower resolution video frames, if your
// processing algorithm can cope. We'll specify medium quality for the
// chosen device.
session.sessionPreset = AVCaptureSessionPresetMedium;
// Find a suitable AVCaptureDevice
AVCaptureDevice *device = [AVCaptureDevice
defaultDeviceWithMediaType:AVMediaTypeVideo];
// Create a device input with the device and add it to the session.
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device
error:&error];
if (!input)
{
// Handling the error appropriately.
}
[session addInput:input];
// Create a VideoDataOutput and add it to the session
AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
[session addOutput:output];
// Configure your output.
dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);
[output setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
// Specify the pixel format
output.videoSettings =
[NSDictionary dictionaryWithObject:
[NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
forKey:(id)kCVPixelBufferPixelFormatTypeKey]; //kCVPixelBufferPixelFormatTypeKey
// If you wish to cap the frame rate to a known value, such as 15 fps, set
// minFrameDuration.
// output.minFrameDuration = CMTimeMake(1, 15);
// Start the session running to start the flow of data
[session startRunning];
// Assign session to an ivar.
//[self setSession:session];
}
I appreciate any help.Thanks in advance.