視頻錄制
其實有了前面的拍照應(yīng)用之后要在此基礎(chǔ)上做視頻錄制功能并不復(fù)雜，程序只需要做如下修改：
- 添加一個音頻輸入到會話（使用[[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject]獲得輸入設(shè)備，然后根據(jù)此輸入設(shè)備創(chuàng)建一個設(shè)備輸入對象），在拍照程序中已經(jīng)添加了視頻輸入所以此時不需要添加視頻輸入。
- 創(chuàng)建一個音樂播放文件輸出對象AVCaptureMovieFileOutput取代原來的照片輸出對象。
- 將捕獲到的視頻數(shù)據(jù)寫入到臨時文件并在停止錄制之后保存到相簿（通過AVCaptureMovieFileOutput的代理方法）。
相比拍照程序，程序的修改主要就是以上三點。當然為了讓程序更加完善在下面的視頻錄制程序中加入了屏幕旋轉(zhuǎn)視頻、自動布局和后臺保存任務(wù)等細節(jié)。下面是修改后的程序：
//
// ViewController.m
// AVFoundationCamera
//
// Created by Kenshin Cui on 14/04/05.
// Copyright (c) 2014年 cmjstudio. All rights reserved.
// 視頻錄制
#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>
typedef void(^PropertyChangeBlock)(AVCaptureDevice *captureDevice);
@interface ViewController ()<AVCaptureFileOutputRecordingDelegate>//視頻文件輸出代理
@property (strong,nonatomic) AVCaptureSession *captureSession;//負責(zé)輸入和輸出設(shè)備之間的數(shù)據(jù)傳遞
@property (strong,nonatomic) AVCaptureDeviceInput *captureDeviceInput;//負責(zé)從AVCaptureDevice獲得輸入數(shù)據(jù)
@property (strong,nonatomic) AVCaptureMovieFileOutput *captureMovieFileOutput;//視頻輸出流
@property (strong,nonatomic) AVCaptureVideoPreviewLayer *captureVideoPreviewLayer;//相機拍攝預(yù)覽圖層
@property (assign,nonatomic) BOOL enableRotation;//是否允許旋轉(zhuǎn)（注意在視頻錄制過程中禁止屏幕旋轉(zhuǎn)）
@property (assign,nonatomic) CGRect *lastBounds;//旋轉(zhuǎn)的前大小
@property (assign,nonatomic) UIBackgroundTaskIdentifier backgroundTaskIdentifier;//后臺任務(wù)標識
@property (weak, nonatomic) IBOutlet UIView *viewContainer;
@property (weak, nonatomic) IBOutlet UIButton *takeButton;//拍照按鈕
@property (weak, nonatomic) IBOutlet UIImageView *focusCursor; //聚焦光標
@end
@implementation ViewController
#pragma mark - 控制器視圖方法
- (void)viewDidLoad {
[super viewDidLoad];
}
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
//初始化會話
_captureSession=[[AVCaptureSession alloc]init];
if ([_captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720]) {//設(shè)置分辨率
_captureSession.sessionPreset=AVCaptureSessionPreset1280x720;
}
//獲得輸入設(shè)備
AVCaptureDevice *captureDevice=[self getCameraDeviceWithPosition:AVCaptureDevicePositionBack];//取得后置攝像頭
if (!captureDevice) {
NSLog(@"取得后置攝像頭時出現(xiàn)問題.");
return;
}
//添加一個音頻輸入設(shè)備
AVCaptureDevice *audioCaptureDevice=[[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject];
NSError *error=nil;
//根據(jù)輸入設(shè)備初始化設(shè)備輸入對象，用于獲得輸入數(shù)據(jù)
_captureDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:captureDevice error:&error];
if (error) {
NSLog(@"取得設(shè)備輸入對象時出錯，錯誤原因：%@",error.localizedDescription);
return;
}
AVCaptureDeviceInput *audioCaptureDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:audioCaptureDevice error:&error];
if (error) {
NSLog(@"取得設(shè)備輸入對象時出錯，錯誤原因：%@",error.localizedDescription);
return;
}
//初始化設(shè)備輸出對象，用于獲得輸出數(shù)據(jù)
_captureMovieFileOutput=[[AVCaptureMovieFileOutput alloc]init];
//將設(shè)備輸入添加到會話中
if ([_captureSession canAddInput:_captureDeviceInput]) {
[_captureSession addInput:_captureDeviceInput];
[_captureSession addInput:audioCaptureDeviceInput];
AVCaptureConnection *captureConnection=[_captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
if ([captureConnection isVideoStabilizationSupported ]) {
captureConnection.preferredVideoStabilizationMode=AVCaptureVideoStabilizationModeAuto;
}
}
//將設(shè)備輸出添加到會話中
if ([_captureSession canAddOutput:_captureMovieFileOutput]) {
[_captureSession addOutput:_captureMovieFileOutput];
}
//創(chuàng)建視頻預(yù)覽層，用于實時展示攝像頭狀態(tài)
_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
//將視頻預(yù)覽層添加到界面中
//[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;
}
////屏幕旋轉(zhuǎn)時調(diào)整視頻預(yù)覽圖層的方向
//-(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;
//
//}
//屏幕旋轉(zhuǎn)時調(diào)整視頻預(yù)覽圖層的方向
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
AVCaptureConnection *captureConnection=[self.captureVideoPreviewLayer connection];
captureConnection.videoOrientation=(AVCaptureVideoOrientation)toInterfaceOrientation;
}
//旋轉(zhuǎn)后重新設(shè)置大小
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
_captureVideoPreviewLayer.frame=self.viewContainer.bounds;
}
-(void)dealloc{
[self removeNotification];
}
#pragma mark - UI方法
#pragma mark 視頻錄制
- (IBAction)takeButtonClick:(UIButton *)sender {
//根據(jù)設(shè)備輸出獲得連接
AVCaptureConnection *captureConnection=[self.captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
//根據(jù)連接取得設(shè)備輸出的數(shù)據(jù)
if (![self.captureMovieFileOutput isRecording]) {
self.enableRotation=NO;
//如果支持多任務(wù)則則開始多任務(wù)
if ([[UIDevice currentDevice] isMultitaskingSupported]) {
self.backgroundTaskIdentifier=[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil];
}
//預(yù)覽圖層和視頻方向保持一致
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];//停止錄制
}
}
#pragma mark 切換前后攝像頭
- (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];
//獲得要調(diào)整的設(shè)備輸入對象
AVCaptureDeviceInput *toChangeDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:toChangeDevice error:nil];
//改變會話的配置前一定要先開啟配置，配置完成后提交配置改變
[self.captureSession beginConfiguration];
//移除原有輸入對象
[self.captureSession removeInput:self.captureDeviceInput];
//添加新的輸入對象
if ([self.captureSession canAddInput:toChangeDeviceInput]) {
[self.captureSession addInput:toChangeDeviceInput];
self.captureDeviceInput=toChangeDeviceInput;
}
//提交會話配置
[self.captureSession commitConfiguration];
}
#pragma mark - 視頻輸出代理
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections{
NSLog(@"開始錄制...");
}
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error{
NSLog(@"視頻錄制完成.");
//視頻錄入完成之后在后臺將視頻存儲到相簿
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(@"保存視頻到相簿過程中發(fā)生錯誤，錯誤信息：%@",error.localizedDescription);
}
if (lastBackgroundTaskIdentifier!=UIBackgroundTaskInvalid) {
[[UIApplication sharedApplication] endBackgroundTask:lastBackgroundTaskIdentifier];
}
NSLog(@"成功保存視頻到相簿.");
}];
}
#pragma mark - 通知
/**
* 給輸入設(shè)備添加通知
*/
-(void)addNotificationToCaptureDevice:(AVCaptureDevice *)captureDevice{
//注意添加區(qū)域改變捕獲通知必須首先設(shè)置設(shè)備允許捕獲
[self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
captureDevice.subjectAreaChangeMonitoringEnabled=YES;
}];
NSNotificationCenter *notificationCenter= [NSNotificationCenter defaultCenter];
//捕獲區(qū)域發(fā)生改變
[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];
//會話出錯
[notificationCenter addObserver:self selector:@selector(sessionRuntimeError:) name:AVCaptureSessionRuntimeErrorNotification object:captureSession];
}
/**
* 設(shè)備連接成功
*
* @param notification 通知對象
*/
-(void)deviceConnected:(NSNotification *)notification{
NSLog(@"設(shè)備已連接...");
}
/**
* 設(shè)備連接斷開
*
* @param notification 通知對象
*/
-(void)deviceDisconnected:(NSNotification *)notification{
NSLog(@"設(shè)備已斷開.");
}
/**
* 捕獲區(qū)域改變
*
* @param notification 通知對象
*/
-(void)areaChange:(NSNotification *)notification{
NSLog(@"捕獲區(qū)域改變...");
}
/**
* 會話出錯
*
* @param notification 通知對象
*/
-(void)sessionRuntimeError:(NSNotification *)notification{
NSLog(@"會話發(fā)生錯誤.");
}
#pragma mark - 私有方法
/**
* 取得指定位置的攝像頭
*
* @param position 攝像頭位置
*
* @return 攝像頭設(shè)備
*/
-(AVCaptureDevice *)getCameraDeviceWithPosition:(AVCaptureDevicePosition )position{
NSArray *cameras= [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
for (AVCaptureDevice *camera in cameras) {
if ([camera position]==position) {
return camera;
}
}
return nil;
}
/**
* 改變設(shè)備屬性的統(tǒng)一操作方法
*
* @param propertyChange 屬性改變操作
*/
-(void)changeDeviceProperty:(PropertyChangeBlock)propertyChange{
AVCaptureDevice *captureDevice= [self.captureDeviceInput device];
NSError *error;
//注意改變設(shè)備屬性前一定要首先調(diào)用lockForConfiguration:調(diào)用完之后使用unlockForConfiguration方法解鎖
if ([captureDevice lockForConfiguration:&error]) {
propertyChange(captureDevice);
[captureDevice unlockForConfiguration];
}else{
NSLog(@"設(shè)置設(shè)備屬性過程發(fā)生錯誤，錯誤信息：%@",error.localizedDescription);
}
}
/**
* 設(shè)置閃光燈模式
*
* @param flashMode 閃光燈模式
*/
//-(void)setFlashMode:(AVCaptureFlashMode )flashMode{
// [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
// if ([captureDevice isFlashModeSupported:flashMode]) {
// [captureDevice setFlashMode:flashMode];
// }
// }];
//}
/**
* 設(shè)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];
}
}];
}
/**
* 設(shè)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];
}
}];
}
/**
* 設(shè)置聚焦點
*
* @param point 聚焦點
*/
-(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];
}
}];
}
/**
* 添加點按手勢，點按時聚焦
*/
-(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];
//將UI坐標轉(zhuǎn)化為攝像頭坐標
CGPoint cameraPoint= [self.captureVideoPreviewLayer captureDevicePointOfInterestForPoint:point];
[self setFocusCursorWithPoint:point];
[self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];
}
/**
* 設(shè)置聚焦光標位置
*
* @param point 光標位置
*/
-(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
