iOS AVCaptureSession实现视频录制功能

本文实例为大家分享了AVCaptureSession实现视频录制功能的具体代码，供大家参考，具体内容如下

#import "RecordingVideoViewController.h"
#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>

@interface RecordingVideoViewController ()<AVCaptureFileOutputRecordingDelegate>

//会话 负责输入和输出设备之间的数据传递
@property (strong,nonatomic) AVCaptureSession  *captureSession;
//设备输入 负责从AVCaptureDevice获得输入数据
@property (strong,nonatomic) AVCaptureDeviceInput  *videoCaptureDeviceInput;
@property (strong,nonatomic) AVCaptureDeviceInput  *audioCaptureDeviceInput;
//视频输出流
@property (strong,nonatomic) AVCaptureMovieFileOutput  *captureMovieFileOutput;
//相机拍摄预览图层
@property (strong,nonatomic) AVCaptureVideoPreviewLayer  *captureVideoPreviewLayer;

//自定义UI控件容器
@property (strong,nonatomic) UIView  *viewContainer;
//聚焦图标
@property (strong,nonatomic) UIImageView  *focusCursor;
//录制时长
@property (strong,nonatomic) UILabel  *timeLabel;
//切换前后摄像头
@property (strong,nonatomic) UIButton  *switchCameraBtn;
//改变焦距
@property (strong,nonatomic) UIButton  *scaleBtn;
//计时器
@property (strong,nonatomic) NSTimer  *timer;


@end

@implementation RecordingVideoViewController {
 @private
  NSInteger _num;
  CGFloat _kCameraScale;
}


- (UIView *)viewContainer {
  if (!_viewContainer) {
    _viewContainer = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];

    UIButton *takeButton = [UIButton buttonWithType:UIButtonTypeCustom];
    takeButton.backgroundColor = [UIColor redColor];
    [takeButton setTitle:@"start" forState:UIControlStateNormal];
    [takeButton addTarget:self action:@selector(takeButtonClick:) forControlEvents:UIControlEventTouchUpInside];


    _timeLabel = [[UILabel alloc] init];
    _timeLabel.textColor = [UIColor redColor];
    _timeLabel.textAlignment = NSTextAlignmentCenter;
    _timeLabel.font = [UIFont boldSystemFontOfSize:20];
    _timeLabel.text = @"00:00";


    _switchCameraBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    [_switchCameraBtn setTitle:@"switch" forState:UIControlStateNormal];
    _switchCameraBtn.backgroundColor = [UIColor redColor];
    [_switchCameraBtn addTarget:self action:@selector(switchCameraBtnClick) forControlEvents:UIControlEventTouchUpInside];

    _scaleBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    [_scaleBtn setTitle:@"1X" forState:UIControlStateNormal];
    _scaleBtn.backgroundColor = [UIColor redColor];
    [_scaleBtn addTarget:self action:@selector(scaleBtnClick:) forControlEvents:UIControlEventTouchUpInside];

    [_viewContainer addSubview:takeButton];
    [_viewContainer addSubview:_timeLabel];
    [_viewContainer addSubview:_scaleBtn];
    [_viewContainer addSubview:_switchCameraBtn];
    [takeButton mas_makeConstraints:^(MASConstraintMaker *make) {
      make.size.mas_equalTo(CGSizeMake(60, 40));
      make.centerX.mas_equalTo(_viewContainer);
      make.bottom.mas_equalTo(_viewContainer).offset(-64);
    }];
    [_timeLabel mas_makeConstraints:^(MASConstraintMaker *make) {
      make.centerX.mas_equalTo(_viewContainer);
      make.height.mas_equalTo(@30);
      make.top.mas_equalTo(_viewContainer);
    }];
    [_scaleBtn mas_makeConstraints:^(MASConstraintMaker *make) {
      make.size.mas_equalTo(CGSizeMake(60, 40));
      make.left.mas_equalTo(_viewContainer).offset(10);
      make.top.mas_equalTo(_viewContainer);
    }];
    [_switchCameraBtn mas_makeConstraints:^(MASConstraintMaker *make) {
      make.size.mas_equalTo(CGSizeMake(60, 40));
      make.top.mas_equalTo(_viewContainer);
      make.right.mas_equalTo(_viewContainer).offset(-10);
    }];

    _focusCursor = [[UIImageView alloc] init];
    kBorder(_focusCursor, 1, [UIColor yellowColor]);
    _focusCursor.alpha = 0;
    [_viewContainer addSubview:self.focusCursor];
    [_focusCursor mas_makeConstraints:^(MASConstraintMaker *make) {
      make.size.mas_equalTo(CGSizeMake(40, 40));
      make.center.mas_equalTo(_viewContainer);
    }];

  }
  return _viewContainer;
}

- (void)viewDidLoad {
  [super viewDidLoad];

  self.title = @"视频录制";
  _kCameraScale = 1.0f;
  //初始化会话对象
  _captureSession = [[AVCaptureSession alloc] init];
  if ([_captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720]) {
    _captureSession.sessionPreset = AVCaptureSessionPreset1280x720;
  }


  NSError *error = nil;

  //获取视频输入对象
  AVCaptureDevice *videoCaptureDevice = [self cameraDeviceWithPosition:(AVCaptureDevicePositionBack)];
  if (!videoCaptureDevice) {
    NSLog(@"获取后置摄像头失败！");
    return;
  }
  _videoCaptureDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:videoCaptureDevice error:&error];
  if (error) {
    NSLog(@"取得视频设备输入对象时出错");
    return;
  }


  //获取音频输入对象
  AVCaptureDevice *audioCatureDevice = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject];
  _audioCaptureDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioCatureDevice error:&error];
  if (error) {
    NSLog(@"取得音频设备输入对象时出错");
    return;
  }

  //初始化设备输出对象
  _captureMovieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

  //将设备输入添加到会话中
  if ([_captureSession canAddInput:_videoCaptureDeviceInput]) {
    [_captureSession addInput:_videoCaptureDeviceInput];
    [_captureSession addInput:_audioCaptureDeviceInput];

    //防抖功能
    AVCaptureConnection *captureConnection = [_captureMovieFileOutput connectionWithMediaType:AVMediaTypeAudio];
    if ([captureConnection isVideoStabilizationSupported]) {
      captureConnection.preferredVideoStabilizationMode = AVCaptureVideoStabilizationModeAuto;
    }
  }

  //将设备输出添加到会话中
  if ([_captureSession canAddOutput:_captureMovieFileOutput]) {
    [_captureSession addOutput:_captureMovieFileOutput];
  }


  //创建视频预览图层
  _captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
  self.viewContainer.layer.masksToBounds = YES;
  _captureVideoPreviewLayer.frame = self.viewContainer.bounds;
  _captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
  [self.view.layer addSublayer:_captureVideoPreviewLayer];

  //显示自定义控件
  [self.view addSubview:self.viewContainer];

  //添加点按聚焦手势
  UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapScreen:)];
  [self.viewContainer addGestureRecognizer:tapGesture];

}

-(void)viewDidAppear:(BOOL)animated{
  [super viewDidAppear:animated];
  [self.captureSession startRunning];
}

-(void)viewDidDisappear:(BOOL)animated{
  [super viewDidDisappear:animated];
  [self.captureSession stopRunning];
  [self.timer invalidate];
  self.timer = nil;
}

- (void)viewWillDisappear:(BOOL)animated {
  [super viewWillDisappear:animated];
  [self.captureVideoPreviewLayer setAffineTransform:CGAffineTransformMakeScale(1, 1)];
}

- (void)didReceiveMemoryWarning {
  [super didReceiveMemoryWarning];
}

//开始 + 暂停录制
- (void)takeButtonClick:(UIButton *)sender {
  if ([self.captureMovieFileOutput isRecording]) {
    [self.captureMovieFileOutput stopRecording];

    [self.navigationController popViewControllerAnimated:YES];

  } else {
    AVCaptureConnection *captureConnection = [self.captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
    captureConnection.videoOrientation = [self.captureVideoPreviewLayer connection].videoOrientation;

    NSString *filePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"Movie.mov"];
    NSLog(@"%@",filePath);
    [self.captureMovieFileOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:filePath] recordingDelegate:self];


    self.switchCameraBtn.hidden = YES;

    sender.backgroundColor = [UIColor greenColor];
    [sender setTitle:@"stop" forState:UIControlStateNormal];

    self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timeAction) userInfo:nil repeats:YES];
    [self.timer setFireDate:[NSDate distantPast]];
  }
}

//切换摄像头
- (void)switchCameraBtnClick {
  AVCaptureDevicePosition currentPosition = self.videoCaptureDeviceInput.device.position;
  AVCaptureDevicePosition toPosition;
  if (currentPosition == AVCaptureDevicePositionUnspecified ||
    currentPosition == AVCaptureDevicePositionFront) {
    toPosition = AVCaptureDevicePositionBack;
  } else {
    toPosition = AVCaptureDevicePositionFront;
  }

  AVCaptureDevice *toCapturDevice = [self cameraDeviceWithPosition:toPosition];
  if (!toCapturDevice) {
    NSLog(@"获取要切换的设备失败");
    return;
  }

  NSError *error = nil;
  AVCaptureDeviceInput *toVideoDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:toCapturDevice error:&error];
  if (error) {
    NSLog(@"获取要切换的设备输入失败");
    return;
  }

  //改变会话配置
  [self.captureSession beginConfiguration];

  [self.captureSession removeInput:self.videoCaptureDeviceInput];
  if ([self.captureSession canAddInput:toVideoDeviceInput]) {
    [self.captureSession addInput:toVideoDeviceInput];

    self.videoCaptureDeviceInput = toVideoDeviceInput;
  }
  //提交会话配置
  [self.captureSession commitConfiguration];
}


//点按手势
- (void)tapScreen:(UITapGestureRecognizer *)tap {
  CGPoint point = [tap locationInView:self.viewContainer];

  //将界面point对应到摄像头point
  CGPoint cameraPoint = [self.captureVideoPreviewLayer captureDevicePointOfInterestForPoint:point];

  //设置聚光动画
  self.focusCursor.center = point;
  self.focusCursor.transform = CGAffineTransformMakeScale(1.5, 1.5);
  self.focusCursor.alpha = 1.0f;
  [UIView animateWithDuration:1 animations:^{
    self.focusCursor.transform = CGAffineTransformIdentity;
  } completion:^(BOOL finished) {
    self.focusCursor.alpha = 0.0f;

  }];

  //设置聚光点坐标
  [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];

}


/**设置聚焦点*/
-(void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point{

  AVCaptureDevice *captureDevice= [self.videoCaptureDeviceInput device];
  NSError *error = nil;
  //设置设备属性必须先解锁 然后加锁
  if ([captureDevice lockForConfiguration:&error]) {

    if ([captureDevice isFocusModeSupported:focusMode]) {
      [captureDevice setFocusMode:focusMode];
    }
    if ([captureDevice isFocusPointOfInterestSupported]) {
      [captureDevice setFocusPointOfInterest:point];
    }
    //    //曝光
    //    if ([captureDevice isExposureModeSupported:exposureMode]) {
    //      [captureDevice setExposureMode:exposureMode];
    //    }
    //    if ([captureDevice isExposurePointOfInterestSupported]) {
    //      [captureDevice setExposurePointOfInterest:point];
    //    }
    //    //闪光灯模式
    //    if ([captureDevice isFlashModeSupported:AVCaptureFlashModeAuto]) {
    //      [captureDevice setFlashMode:AVCaptureFlashModeAuto];
    //    }

    //加锁
    [captureDevice unlockForConfiguration];

  }else{
    NSLog(@"设置设备属性过程发生错误，错误信息：%@",error.localizedDescription);
  }
}



//调整焦距
-(void)scaleBtnClick:(UIButton *)sender
{
  _kCameraScale += 0.5;
  if(_kCameraScale > 3.0) {
    _kCameraScale = 1.0;
  }
  //改变焦距
  AVCaptureDevice *videoDevice = self.videoCaptureDeviceInput.device;
  NSError *error = nil;
  if ([videoDevice lockForConfiguration:&error]) {

    [videoDevice setVideoZoomFactor:_kCameraScale];

    [videoDevice unlockForConfiguration];

    [sender setTitle:[NSString stringWithFormat:@"%lgX",_kCameraScale] forState:UIControlStateNormal];

    [CATransaction begin];
    [CATransaction setAnimationDuration:0.25];
    [self.captureVideoPreviewLayer setAffineTransform:CGAffineTransformMakeScale(_kCameraScale, _kCameraScale)];
    [CATransaction commit];

  } else {
    NSLog(@"修改设备属性失败!")
  }
}



#pragma mark -------- AVCaptureFileOutputRecordingDelegate ----------
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections {
  NSLog(@"开始录制");
}

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error {
  NSLog(@"录制结束");
  ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];
  [assetsLibrary writeVideoAtPathToSavedPhotosAlbum:outputFileURL completionBlock:^(NSURL *assetURL, NSError *error) {
    if (error) {
      NSLog(@"保存视频到相簿过程中发生错误，错误信息：%@",error.localizedDescription);
    }
  }];
}

//录制计时
- (void)timeAction {
  self.timeLabel.text = [NSString stringWithFormat:@"%.2ld:%.2ld",_num/60,_num%60];
  _num ++;
}


/**取得指定位置的摄像头*/
- (AVCaptureDevice *)cameraDeviceWithPosition:(AVCaptureDevicePosition )position{
  NSArray *cameras = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
  for (AVCaptureDevice *camera in cameras) {
    if ([camera position] == position) {
      return camera;
    }
  }
  return nil;
}

@end

参考代码：

#import "VideoTestViewController.h"
#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>

typedef void(^PropertyChangeBlock)(AVCaptureDevice *captureDevice);

@interface VideoTestViewController ()<AVCaptureFileOutputRecordingDelegate>//视频文件输出代理

@property (strong,nonatomic) AVCaptureSession *captureSession;//负责输入和输出设备之间的数据传递
@property (strong,nonatomic) AVCaptureDeviceInput *captureDeviceInput;//负责从AVCaptureDevice获得输入数据
@property (strong,nonatomic) AVCaptureMovieFileOutput *captureMovieFileOutput;//视频输出流
@property (strong,nonatomic) AVCaptureVideoPreviewLayer *captureVideoPreviewLayer;//相机拍摄预览图层

@property (assign,nonatomic) BOOL enableRotation;//是否允许旋转（注意在视频录制过程中禁止屏幕旋转）
@property (assign,nonatomic) CGRect *lastBounds;//旋转的前大小
@property (assign,nonatomic) UIBackgroundTaskIdentifier backgroundTaskIdentifier;//后台任务标识
@property (strong,nonatomic) UIView *viewContainer;
@property (strong,nonatomic) UIButton *takeButton;//拍照按钮
@property (strong,nonatomic) UIImageView *focusCursor; //聚焦光标


@end

@implementation VideoTestViewController

#pragma mark - 控制器视图方法
- (void)viewDidLoad {
  [super viewDidLoad];
}

-(void)viewWillAppear:(BOOL)animated{
  [super viewWillAppear:animated];

  //初始化会话
  _captureSession=[[AVCaptureSession alloc]init];
  if ([_captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720]) {//设置分辨率
    _captureSession.sessionPreset=AVCaptureSessionPreset1280x720;
  }
  //获得输入设备
  AVCaptureDevice *captureDevice=[self getCameraDeviceWithPosition:AVCaptureDevicePositionBack];//取得后置摄像头
  if (!captureDevice) {
    NSLog(@"取得后置摄像头时出现问题.");
    return;
  }
  //添加一个音频输入设备
  AVCaptureDevice *audioCaptureDevice=[[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject];


  NSError *error=nil;
  //根据输入设备初始化设备输入对象，用于获得输入数据
  _captureDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:captureDevice error:&error];
  if (error) {
    NSLog(@"取得设备输入对象时出错，错误原因：%@",error.localizedDescription);
    return;
  }
  AVCaptureDeviceInput *audioCaptureDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:audioCaptureDevice error:&error];
  if (error) {
    NSLog(@"取得设备输入对象时出错，错误原因：%@",error.localizedDescription);
    return;
  }
  //初始化设备输出对象，用于获得输出数据
  _captureMovieFileOutput=[[AVCaptureMovieFileOutput alloc]init];

  //将设备输入添加到会话中
  if ([_captureSession canAddInput:_captureDeviceInput]) {
    [_captureSession addInput:_captureDeviceInput];
    [_captureSession addInput:audioCaptureDeviceInput];
    AVCaptureConnection *captureConnection=[_captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
    if ([captureConnection isVideoStabilizationSupported ]) {
      captureConnection.preferredVideoStabilizationMode=AVCaptureVideoStabilizationModeAuto;
    }
  }

  //将设备输出添加到会话中
  if ([_captureSession canAddOutput:_captureMovieFileOutput]) {
    [_captureSession addOutput:_captureMovieFileOutput];
  }

  //创建视频预览层，用于实时展示摄像头状态
  _captureVideoPreviewLayer=[[AVCaptureVideoPreviewLayer alloc]initWithSession:self.captureSession];

  CALayer *layer=self.viewContainer.layer;
  layer.masksToBounds=YES;

  _captureVideoPreviewLayer.frame=layer.bounds;
  _captureVideoPreviewLayer.videoGravity=AVLayerVideoGravityResizeAspectFill;//填充模式
  //将视频预览层添加到界面中
  //[layer addSublayer:_captureVideoPreviewLayer];
  [layer insertSublayer:_captureVideoPreviewLayer below:self.focusCursor.layer];

  _enableRotation=YES;
  [self addNotificationToCaptureDevice:captureDevice];
  [self addGenstureRecognizer];
}

-(void)viewDidAppear:(BOOL)animated{
  [super viewDidAppear:animated];
  [self.captureSession startRunning];
}

-(void)viewDidDisappear:(BOOL)animated{
  [super viewDidDisappear:animated];
  [self.captureSession stopRunning];
}

- (void)didReceiveMemoryWarning {
  [super didReceiveMemoryWarning];
}

-(BOOL)shouldAutorotate{
  return self.enableRotation;
}

////屏幕旋转时调整视频预览图层的方向
//-(void)willTransitionToTraitCollection:(UITraitCollection *)newCollection withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator{
//  [super willTransitionToTraitCollection:newCollection withTransitionCoordinator:coordinator];
////  NSLog(@"%i,%i",newCollection.verticalSizeClass,newCollection.horizontalSizeClass);
//  UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
//  NSLog(@"%i",orientation);
//  AVCaptureConnection *captureConnection=[self.captureVideoPreviewLayer connection];
//  captureConnection.videoOrientation=orientation;
//
//}
//屏幕旋转时调整视频预览图层的方向
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
  AVCaptureConnection *captureConnection=[self.captureVideoPreviewLayer connection];
  captureConnection.videoOrientation=(AVCaptureVideoOrientation)toInterfaceOrientation;
}
//旋转后重新设置大小
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
  _captureVideoPreviewLayer.frame=self.viewContainer.bounds;
}

-(void)dealloc{
  [self removeNotification];
}
#pragma mark - UI方法
#pragma mark 视频录制
- (void)takeButtonClick:(UIButton *)sender {
  //根据设备输出获得连接
  AVCaptureConnection *captureConnection=[self.captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
  //根据连接取得设备输出的数据
  if (![self.captureMovieFileOutput isRecording]) {
    self.enableRotation=NO;
    //如果支持多任务则则开始多任务
    if ([[UIDevice currentDevice] isMultitaskingSupported]) {
      self.backgroundTaskIdentifier=[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil];
    }
    //预览图层和视频方向保持一致
    captureConnection.videoOrientation=[self.captureVideoPreviewLayer connection].videoOrientation;
    NSString *outputFielPath=[NSTemporaryDirectory() stringByAppendingString:@"myMovie.mov"];
    NSLog(@"save path is :%@",outputFielPath);
    NSURL *fileUrl=[NSURL fileURLWithPath:outputFielPath];
    [self.captureMovieFileOutput startRecordingToOutputFileURL:fileUrl recordingDelegate:self];
  }
  else{
    [self.captureMovieFileOutput stopRecording];//停止录制
  }
}
#pragma mark 切换前后摄像头
- (void)toggleButtonClick:(UIButton *)sender {
  AVCaptureDevice *currentDevice=[self.captureDeviceInput device];
  AVCaptureDevicePosition currentPosition=[currentDevice position];
  [self removeNotificationFromCaptureDevice:currentDevice];
  AVCaptureDevice *toChangeDevice;
  AVCaptureDevicePosition toChangePosition=AVCaptureDevicePositionFront;
  if (currentPosition==AVCaptureDevicePositionUnspecified||currentPosition==AVCaptureDevicePositionFront) {
    toChangePosition=AVCaptureDevicePositionBack;
  }
  toChangeDevice=[self getCameraDeviceWithPosition:toChangePosition];
  [self addNotificationToCaptureDevice:toChangeDevice];
  //获得要调整的设备输入对象
  AVCaptureDeviceInput *toChangeDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:toChangeDevice error:nil];

  //改变会话的配置前一定要先开启配置，配置完成后提交配置改变
  [self.captureSession beginConfiguration];
  //移除原有输入对象
  [self.captureSession removeInput:self.captureDeviceInput];
  //添加新的输入对象
  if ([self.captureSession canAddInput:toChangeDeviceInput]) {
    [self.captureSession addInput:toChangeDeviceInput];
    self.captureDeviceInput=toChangeDeviceInput;
  }
  //提交会话配置
  [self.captureSession commitConfiguration];

}

#pragma mark - 视频输出代理
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections{
  NSLog(@"开始录制...");
}
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error{
  NSLog(@"视频录制完成.");
  //视频录入完成之后在后台将视频存储到相簿
  self.enableRotation=YES;
  UIBackgroundTaskIdentifier lastBackgroundTaskIdentifier=self.backgroundTaskIdentifier;
  self.backgroundTaskIdentifier=UIBackgroundTaskInvalid;
  ALAssetsLibrary *assetsLibrary=[[ALAssetsLibrary alloc]init];
  [assetsLibrary writeVideoAtPathToSavedPhotosAlbum:outputFileURL completionBlock:^(NSURL *assetURL, NSError *error) {
    if (error) {
      NSLog(@"保存视频到相簿过程中发生错误，错误信息：%@",error.localizedDescription);
    }
    if (lastBackgroundTaskIdentifier!=UIBackgroundTaskInvalid) {
      [[UIApplication sharedApplication] endBackgroundTask:lastBackgroundTaskIdentifier];
    }
    NSLog(@"成功保存视频到相簿.");
  }];

}

#pragma mark - 通知
/**
 * 给输入设备添加通知
 */
-(void)addNotificationToCaptureDevice:(AVCaptureDevice *)captureDevice{
  //注意添加区域改变捕获通知必须首先设置设备允许捕获
  [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
    captureDevice.subjectAreaChangeMonitoringEnabled=YES;
  }];
  NSNotificationCenter *notificationCenter= [NSNotificationCenter defaultCenter];
  //捕获区域发生改变
  [notificationCenter addObserver:self selector:@selector(areaChange:) name:AVCaptureDeviceSubjectAreaDidChangeNotification object:captureDevice];
}
-(void)removeNotificationFromCaptureDevice:(AVCaptureDevice *)captureDevice{
  NSNotificationCenter *notificationCenter= [NSNotificationCenter defaultCenter];
  [notificationCenter removeObserver:self name:AVCaptureDeviceSubjectAreaDidChangeNotification object:captureDevice];
}
/**
 * 移除所有通知
 */
-(void)removeNotification{
  NSNotificationCenter *notificationCenter= [NSNotificationCenter defaultCenter];
  [notificationCenter removeObserver:self];
}

-(void)addNotificationToCaptureSession:(AVCaptureSession *)captureSession{
  NSNotificationCenter *notificationCenter= [NSNotificationCenter defaultCenter];
  //会话出错
  [notificationCenter addObserver:self selector:@selector(sessionRuntimeError:) name:AVCaptureSessionRuntimeErrorNotification object:captureSession];
}

/**
 * 设备连接成功
 *
 * @param notification 通知对象
 */
-(void)deviceConnected:(NSNotification *)notification{
  NSLog(@"设备已连接...");
}
/**
 * 设备连接断开
 *
 * @param notification 通知对象
 */
-(void)deviceDisconnected:(NSNotification *)notification{
  NSLog(@"设备已断开.");
}
/**
 * 捕获区域改变
 *
 * @param notification 通知对象
 */
-(void)areaChange:(NSNotification *)notification{
  NSLog(@"捕获区域改变...");
}

/**
 * 会话出错
 *
 * @param notification 通知对象
 */
-(void)sessionRuntimeError:(NSNotification *)notification{
  NSLog(@"会话发生错误.");
}

#pragma mark - 私有方法

/**
 * 取得指定位置的摄像头
 *
 * @param position 摄像头位置
 *
 * @return 摄像头设备
 */
-(AVCaptureDevice *)getCameraDeviceWithPosition:(AVCaptureDevicePosition )position{
  NSArray *cameras= [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
  for (AVCaptureDevice *camera in cameras) {
    if ([camera position]==position) {
      return camera;
    }
  }
  return nil;
}

/**
 * 改变设备属性的统一操作方法
 *
 * @param propertyChange 属性改变操作
 */
-(void)changeDeviceProperty:(PropertyChangeBlock)propertyChange{
  AVCaptureDevice *captureDevice= [self.captureDeviceInput device];
  NSError *error;
  //注意改变设备属性前一定要首先调用lockForConfiguration:调用完之后使用unlockForConfiguration方法解锁
  if ([captureDevice lockForConfiguration:&error]) {
    propertyChange(captureDevice);
    [captureDevice unlockForConfiguration];
  }else{
    NSLog(@"设置设备属性过程发生错误，错误信息：%@",error.localizedDescription);
  }
}

/**
 * 设置闪光灯模式
 *
 * @param flashMode 闪光灯模式
 */
-(void)setFlashMode:(AVCaptureFlashMode )flashMode{
  [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
    if ([captureDevice isFlashModeSupported:flashMode]) {
      [captureDevice setFlashMode:flashMode];
    }
  }];
}
/**
 * 设置聚焦模式
 *
 * @param focusMode 聚焦模式
 */
-(void)setFocusMode:(AVCaptureFocusMode )focusMode{
  [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
    if ([captureDevice isFocusModeSupported:focusMode]) {
      [captureDevice setFocusMode:focusMode];
    }
  }];
}
/**
 * 设置曝光模式
 *
 * @param exposureMode 曝光模式
 */
-(void)setExposureMode:(AVCaptureExposureMode)exposureMode{
  [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
    if ([captureDevice isExposureModeSupported:exposureMode]) {
      [captureDevice setExposureMode:exposureMode];
    }
  }];
}
/**
 * 设置聚焦点
 *
 * @param point 聚焦点
 */
-(void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point{
  [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
    if ([captureDevice isFocusModeSupported:focusMode]) {
      [captureDevice setFocusMode:AVCaptureFocusModeAutoFocus];
    }
    if ([captureDevice isFocusPointOfInterestSupported]) {
      [captureDevice setFocusPointOfInterest:point];
    }
    if ([captureDevice isExposureModeSupported:exposureMode]) {
      [captureDevice setExposureMode:AVCaptureExposureModeAutoExpose];
    }
    if ([captureDevice isExposurePointOfInterestSupported]) {
      [captureDevice setExposurePointOfInterest:point];
    }
  }];
}

/**
 * 添加点按手势，点按时聚焦
 */
-(void)addGenstureRecognizer{
  UITapGestureRecognizer *tapGesture=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapScreen:)];
  [self.viewContainer addGestureRecognizer:tapGesture];
}
-(void)tapScreen:(UITapGestureRecognizer *)tapGesture{
  CGPoint point= [tapGesture locationInView:self.viewContainer];
  //将UI坐标转化为摄像头坐标
  CGPoint cameraPoint= [self.captureVideoPreviewLayer captureDevicePointOfInterestForPoint:point];
  [self setFocusCursorWithPoint:point];
  [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];
}

/**
 * 设置聚焦光标位置
 *
 * @param point 光标位置
 */
-(void)setFocusCursorWithPoint:(CGPoint)point{
  self.focusCursor.center=point;
  self.focusCursor.transform=CGAffineTransformMakeScale(1.5, 1.5);
  self.focusCursor.alpha=1.0;
  [UIView animateWithDuration:1.0 animations:^{
    self.focusCursor.transform=CGAffineTransformIdentity;
  } completion:^(BOOL finished) {
    self.focusCursor.alpha=0;
  }];
}
@end

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。

原文链接：https://blog.csdn.net/nb_token/article/details/73291935