/*

     File: StopNGoViewController.m

 Abstract: Document that captures stills to a QuickTime movie

  Version: 1.0

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#import "StopNGoViewController.h"

#include <mach/mach_time.h>

#import <AssetsLibrary/AssetsLibrary.h>

@implementation StopNGoViewController

@synthesize previewView, fpsSlider, startFinishButton, takePictureButton;

- (BOOL)setupAVCapture

{

    NSError *error = nil;

    // 5 fps - taking 5 pictures will equal 1 second of video

    frameDuration = CMTimeMakeWithSeconds(1./5., 90000); 

    AVCaptureSession *session = [AVCaptureSession new];

    [session setSessionPreset:AVCaptureSessionPresetHigh];

    // Select a video device, make an input

    AVCaptureDevice *backCamera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:backCamera error:&error];

    if (error)

        return NO;

    if ([session canAddInput:input])

        [session addInput:input];

    // Make a still image output

    stillImageOutput = [AVCaptureStillImageOutput new];

    if ([session canAddOutput:stillImageOutput])

        [session addOutput:stillImageOutput];

    // Make a preview layer so we can see the visual output of an AVCaptureSession

    AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

    [previewLayer setVideoGravity:AVLayerVideoGravityResizeAspect];

    [previewLayer setFrame:[previewView bounds]];

    // add the preview layer to the hierarchy

    CALayer *rootLayer = [previewView layer];

    [rootLayer setBackgroundColor:[[UIColor blackColor] CGColor]];

    [rootLayer addSublayer:previewLayer];

    // start the capture session running, note this is an async operation

    // status is provided via notifications such as AVCaptureSessionDidStartRunningNotification/AVCaptureSessionDidStopRunningNotification

    [session startRunning];

    return YES;

}

static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};

- (BOOL)setupAssetWriterForURL:(NSURL *)fileURL formatDescription:(CMFormatDescriptionRef)formatDescription

{

    // allocate the writer object with our output file URL

    NSError *error = nil;

    assetWriter = [[AVAssetWriter alloc] initWithURL:fileURL fileType:AVFileTypeQuickTimeMovie error:&error];

    if (error)

        return NO;

    // initialized a new input for video to receive sample buffers for writing

    // passing nil for outputSettings instructs the input to pass through appended samples, doing no processing before they are written

    assetWriterInput = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:nil];

    [assetWriterInput setExpectsMediaDataInRealTime:YES];

    if ([assetWriter canAddInput:assetWriterInput])

        [assetWriter addInput:assetWriterInput];

    // specify the prefered transform for the output file

    CGFloat rotationDegrees;

    switch ([[UIDevice currentDevice] orientation]) { 

        case UIDeviceOrientationPortraitUpsideDown:

            rotationDegrees = -90.;

            break;

        case UIDeviceOrientationLandscapeLeft: // no rotation

            rotationDegrees = 0.;

            break;

        case UIDeviceOrientationLandscapeRight:

            rotationDegrees = 180.;

            break;

        case UIDeviceOrientationPortrait:

        case UIDeviceOrientationUnknown:

        case UIDeviceOrientationFaceUp:

        case UIDeviceOrientationFaceDown:

        default:

            rotationDegrees = 90.;

            break;

    }

    CGFloat rotationRadians = DegreesToRadians(rotationDegrees);

    [assetWriterInput setTransform:CGAffineTransformMakeRotation(rotationRadians)];

    // initiates a sample-writing at time 0

    nextPTS = kCMTimeZero;

    [assetWriter startWriting];

    [assetWriter startSessionAtSourceTime:nextPTS];

    return YES;

}

- (IBAction)takePicture:(id)sender

{

    // initiate a still image capture, return immediately

    // the completionHandler is called when a sample buffer has been captured

    AVCaptureConnection *stillImageConnection = [stillImageOutput connectionWithMediaType:AVMediaTypeVideo];

    [stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection 

        completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *__strong error) {

          // set up the AVAssetWriter using the format description from the first sample buffer captured

          if ( !assetWriter ) {

              outputURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/%llu.mov", NSTemporaryDirectory(), mach_absolute_time()]];

              //NSLog(@"Writing movie to \"%@\"", outputURL);

              CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(imageDataSampleBuffer);

              if ( NO == [self setupAssetWriterForURL:outputURL formatDescription:formatDescription] )

                  return;

          }

          // re-time the sample buffer - in this sample frameDuration is set to 5 fps

          CMSampleTimingInfo timingInfo = kCMTimingInfoInvalid;

          timingInfo.duration = frameDuration;

          timingInfo.presentationTimeStamp = nextPTS;

          CMSampleBufferRef sbufWithNewTiming = NULL;

          OSStatus err = CMSampleBufferCreateCopyWithNewTiming(kCFAllocatorDefault, 

                                                               imageDataSampleBuffer, 

                                                               1, // numSampleTimingEntries

                                                               &timingInfo, 

                                                               &sbufWithNewTiming);

          if (err)

              return;

           // append the sample buffer if we can and increment presnetation time

          if ( [assetWriterInput isReadyForMoreMediaData] ) {

              if ([assetWriterInput appendSampleBuffer:sbufWithNewTiming]) {

                  nextPTS = CMTimeAdd(frameDuration, nextPTS);

              }

              else {

                  NSError *error = [assetWriter error];

                  NSLog(@"failed to append sbuf: %@", error);

              }

          }

          // release the copy of the sample buffer we made

          CFRelease(sbufWithNewTiming);

        }];

}

- (void)saveMovieToCameraRoll

{

    // save the movie to the camera roll

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

    //NSLog(@"writing \"%@\" to photos album", outputURL);

    [library writeVideoAtPathToSavedPhotosAlbum:outputURL

                                completionBlock:^(NSURL *assetURL, NSError *error) {

                                    if (error) {

                                        NSLog(@"assets library failed (%@)", error);

                                    }

                                    else {

                                        [[NSFileManager defaultManager] removeItemAtURL:outputURL error:&error];

                                        if (error)

                                            NSLog(@"Couldn't remove temporary movie file \"%@\"", outputURL);

                                    }

                                    outputURL = nil;

                                }];

}

- (IBAction)startStop:(id)sender

{

    if (started) {

        if (assetWriter) {

            [assetWriterInput markAsFinished];

            [assetWriter finishWriting];

            assetWriterInput = nil;

            assetWriter = nil;

            [self saveMovieToCameraRoll];

        }

        [sender setTitle:@"Start"];

        [takePictureButton setEnabled:NO];

    }

    else {

        [sender setTitle:@"Finish"];

        [takePictureButton setEnabled:YES];

    }

    started = !started;

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.

}

#pragma mark - View lifecycle

- (void)viewDidLoad

{

    [super viewDidLoad];

    [self setupAVCapture];

    // Do any additional setup after loading the view, typically from a nib.

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

    // Return YES for supported orientations

    return ( UIInterfaceOrientationPortrait == interfaceOrientation );

}

@end