iOS视频录制

#import "MovieViewController.h"

#import <AVFoundation/AVFoundation.h>

#import <AssetsLibrary/AssetsLibrary.h>

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

@interface MovieViewController ``()<AVCaptureFileOutputRecordingDelegate>

@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 (weak, nonatomic) IBOutlet UIView *viewContainer;

@property (weak, nonatomic) IBOutlet UIButton *takeButton;//拍照按钮

@property (weak, nonatomic) IBOutlet UIImageView *focusCursor; //聚焦光标

@end

@implementation MovieViewController

- (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. }

-(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]; }

-(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

- (IBAction)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

- (IBAction)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

文／Ashoka_APP（简书作者）
原文链接：http://www.jianshu.com/p/8c8357351090
著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。