Magic.gif

本章介紹一下視頻采集的實現，主要有功能有
1.音、視頻文件錄制播放
2.焦距設置
3.防抖功能
4.攝像頭切換
5.手電筒功能
6.聚焦處理
7.二維碼掃描
8.視頻裁剪壓縮
9.流數據采集處理(暫未處理，后期會補上)
10.旋轉檢測(<CoreMotion/CoreMotion.h> 方位檢測)

實現思路如下

      由于小視頻、流媒體、二維碼掃描用的都是使用了AVFoundation的框架，只
是輸入AVCaptureInput、輸出AVCaptureoutput對象不同和對應的輸出內容處理不
一樣，所以想寫一個工具類來集中處理
 功能還是比較全的，代碼量也不小，目前大約六、七百行，通過.h文件大家可以自己
去找自己感興趣的地方去看
因為是個多功能集成類，為了不至于一上來所有的輸入輸出對象都加入進來，所以所有
輸入輸出對象以及設備管理對象均以懶加載的方式去按需加載

.h 文件

typedef NS_ENUM(NSInteger,ERecordResult) {
    ERecordSucess,
    ERecordLessThanMinTime,
    ERecordFaile
};

typedef NS_ENUM(NSUInteger,EAVCaptureOutputType) {
    EAVCaptureMovieFileOutput,      //文件輸出
    EAVCaptureVideoDataOutput,      //data輸出
    EAVCaptureMetadataOutput        //元數據輸出
};

#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>

@protocol ReCordPlayProtoCol <NSObject>
@optional
- (void)joyRecordTimeCurrentTime:(CGFloat)currentTime
                       totalTime:(CGFloat)totalTime;

- (void)joyCaptureOutput:(AVCaptureFileOutput *)captureOutput
didStartRecordingToOutputFileAtURL:(NSURL *)fileURL
         fromConnections:(NSArray *)connections;

-(void)joyCaptureOutput:(AVCaptureFileOutput *)captureOutput
didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
        fromConnections:(NSArray *)connections error:(NSError *)error
           recordResult:(ERecordResult)recordResult;

- (void)joyCaptureOutput:(AVCaptureOutput *)captureOutput
didOutputMetadataObjects:(NSArray *)metadataObjects
          fromConnection:(AVCaptureConnection *)connection;
@end

@interface JoyMediaRecordPlay : NSObject
@property (nonatomic,strong)AVCaptureSession            *captureSession;
@property (nonatomic,strong)AVCaptureVideoPreviewLayer  *preViewLayer;       //視圖層
//@property (nonatomic,assign)TIMERBLOCK recordProgressBlock;
//@property (nonatomic,copy)IDBLOCK recordFinishBlock;
@property (nonatomic,weak)id<ReCordPlayProtoCol>        delegate;
@property (nonatomic,assign)EAVCaptureOutputType        captureOutputType;

#pragma mark 初始化類型,默認錄制文件
-(instancetype)initWithCaptureType:(EAVCaptureOutputType)captureType;

#pragma mark 準備錄制
- (void)preareReCord;

#pragma mark 設置焦距
- (void)updateVideoScaleAndCropFactor:(CGFloat)scale;

#pragma mark 防抖功能
- (void)openStabilization;

#pragma mark 開始錄制
- (void)startRecordToFile:(NSURL *)outPutFile;

#pragma mark 停止錄制
- (void)stopCurrentVideoRecording;

#pragma mark 移除輸入
-(void)removeAVCaptureAudioDeviceInput;

#pragma mark 手電筒
- (void)switchTorch;

#pragma mark 切換攝像頭
- (void)switchCamera;

#pragma mark 設置聚焦點
- (void)setFoucusWithPoint:(CGPoint)point;
@end

@interface JoyMediaRecordPlay (JoyRecorderPrivary)

- (BOOL)isAvailableWithCamera;

- (BOOL)isAvailableWithMic;

- (void)getVideoAuth:(BOOLBLOCK)videoAuth;

- (void)showAlert;

#pragma mark 視頻裁剪壓縮
+ (void)mergeAndExportVideosAtFileURLs:(NSURL *)fileURL
                                newUrl:(NSString *)mergeFilePath
                      widthHeightScale:(CGFloat)whScalle
                            presetName:(NSString *)presetName
                           mergeSucess:(VOIDBLOCK)mergeSucess;

#pragma mark 視頻保存相冊
+ (void)saveToPhotoWithUrl:(NSURL *)url;

#pragma mark - 視頻地址

+ (NSString *)generateFilePathWithType:(NSString *)fileType;

#pragma mark 獲取文件大小
+ (CGFloat)getfileSize:(NSString *)filePath;

@end

.m文件

#import "JoyMediaRecordPlay.h"
#import <Photos/Photos.h>
#import <AssetsLibrary/AssetsLibrary.h>
#import <JoyAlert.h>

/*
這里簡單介紹一下三個協議，按需去實現就行了，下面會詳細講具體處理
AVCaptureFileOutputRecordingDelegate 文件錄制協議,小視頻用這個
AVCaptureVideoDataOutputSampleBufferDelegate 流數據協議，流媒體數據
AVCaptureMetadataOutputObjectsDelegate 元數據協議，二維碼掃描
*/
@interface JoyMediaRecordPlay ()<AVCaptureFileOutputRecordingDelegate,AVCaptureVideoDataOutputSampleBufferDelegate,AVCaptureMetadataOutputObjectsDelegate>
@property (nonatomic,strong)NSTimer *timer;    //定時器，用于計時和時間進度條管理
@property (nonatomic,assign)CGFloat recordTime;    //當前錄制時間
@property (nonatomic,assign)CGFloat totalTime;     //總錄制時間
@property (nonatomic,strong)AVCaptureDeviceInput        *mediaDeviceInput;          //視頻輸入
@property (nonatomic,strong)AVCaptureDeviceInput        *audioDeviceInput;          //音頻輸入
@property (nonatomic,strong)AVCaptureMovieFileOutput    *movieFileOutput;           //視頻文件輸出
@property (nonatomic,strong)AVCaptureStillImageOutput   *stillImageOutput;          //圖像輸出
@property (strong, nonatomic) AVCaptureVideoDataOutput  *videoDataOutput;           //視頻data輸出
@property (strong, nonatomic) AVCaptureAudioDataOutput  *audioDataOutput;           //視頻data輸出
@property (strong, nonatomic) AVCaptureMetadataOutput   *metadataOutput;            //元數據輸出
@property (strong, nonatomic) AVCaptureConnection       *captureConnection;
@property (assign,nonatomic) UIBackgroundTaskIdentifier backgroundTaskIdentifier;   //后臺任務標識

@end

static const CGFloat KTimerInterval = 0.05;
static const CGFloat KMaxRecordTime = 20;
static const CGFloat KMinRecordTime = 3;

@implementation JoyMediaRecordPlay

//初始化錄制類型以確定要進行何種數據采集
-(instancetype)initWithCaptureType:(EAVCaptureOutputType)captureType{
    if (self = [super init])
    {
        self.captureOutputType = captureType;
        __weak __typeof (&*self)weakSelf = self;
    //獲取授權，成功則預準備錄制，否則彈警告，警告框可自行去掉，因為本人用了
自己寫的一個pod庫,你直接使用會因為找到相應文件而crash，也可以去pod中配置 
JoyTool這庫并update下來
        [self getVideoAuth:^(BOOL boolValue) {boolValue?[weakSelf preareReCord]:[weakSelf showAlert];}];
    }
    return self;
}

-(instancetype)init{
    if (self = [super init])
    {
        __weak __typeof (&*self)weakSelf = self;
        [self getVideoAuth:^(BOOL boolValue) {boolValue?[weakSelf preareReCord]:[weakSelf showAlert];}];
    }
    return self;
}

//錄制時間，默認15s，否則按給定執行
-(CGFloat)totalTime{
    return _totalTime = _totalTime?:15;
}

//輸入輸出對象管理,以及數據采集的啟停管理
-(AVCaptureSession *)captureSession{
    return _captureSession = _captureSession?:[[AVCaptureSession alloc]init];
}

#pragma mark private method ??????????????????????????????????????????????????
#pragma mark 視頻輸入
-(AVCaptureDeviceInput *)mediaDeviceInput{
    if (!_mediaDeviceInput) {
        __block AVCaptureDevice *frontCamera = nil;
        __block AVCaptureDevice *backCamera  = nil;
        NSArray *cameras = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
        [cameras enumerateObjectsUsingBlock:^(AVCaptureDevice *camera, NSUInteger idx, BOOL * _Nonnull stop) {
            if(camera.position == AVCaptureDevicePositionFront) {frontCamera = camera;}
            if(camera.position == AVCaptureDevicePositionBack)  {backCamera = camera;}
        }];
        [self setExposureModeWithDevice:backCamera];
        _mediaDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:backCamera error:nil];
    }
    return _mediaDeviceInput;
}

#pragma mark 音頻輸入
-(AVCaptureDeviceInput *)audioDeviceInput{
    if (!_audioDeviceInput) {
        NSError *error;
        _audioDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio] error:&error];
    }
    return _audioDeviceInput;
}

#pragma mark 圖片輸出
-(AVCaptureStillImageOutput *)stillImageOutput{
    if (!_stillImageOutput) {
        _stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
        [_stillImageOutput setOutputSettings:[[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil]];  //設置參數AVVideoCodecJPEG參數表示以JPEG的圖片
    }
    return _stillImageOutput;
}

#pragma mark 文件輸出
-(AVCaptureMovieFileOutput *)movieFileOutput{
    return _movieFileOutput = _movieFileOutput?:[[AVCaptureMovieFileOutput alloc] init];
}

#pragma mark data輸出
-(AVCaptureVideoDataOutput *)videoDataOutput{
    if  (!_videoDataOutput){
        _videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
        _videoDataOutput.videoSettings = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
        dispatch_queue_t videoQueue = dispatch_queue_create("Video Capture Queue", DISPATCH_QUEUE_SERIAL);
        [_videoDataOutput setSampleBufferDelegate:self queue:videoQueue];
    }
    return _videoDataOutput;
}

#pragma mark 元數據輸出
-(AVCaptureMetadataOutput *)metadataOutput{
    if (!_metadataOutput){
        _metadataOutput = [[AVCaptureMetadataOutput alloc]init];
//        _metadataOutput.rectOfInterest = CGRectMake(0.2, 0.2, 0.6, 0.6);
//        //設置輸出數據代理
        [_metadataOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    }
    return _metadataOutput;
}

#pragma mark 輸入輸出對象連接
-(AVCaptureConnection *)captureConnection{
    return _captureConnection = _captureConnection?:[self.movieFileOutput connectionWithMediaType:AVMediaTypeVideo];
}

#pragma mark layer層
-(AVCaptureVideoPreviewLayer *)preViewLayer{
    if (!_preViewLayer) {
        _preViewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
        _preViewLayer.masksToBounds = YES;
        _preViewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    }
    return _preViewLayer;
}

//配置曝光模式
- (void)setExposureModeWithDevice:(AVCaptureDevice *)device{
    NSError *error = nil;
    //注意改變設備屬性前一定要首先調用lockForConfiguration:調用完之后使用unlockForConfiguration方法解鎖
    [device lockForConfiguration:&error];
    //設置持續曝光模式
    if ([device isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure])[device setExposureMode:AVCaptureExposureModeContinuousAutoExposure];
    [device unlockForConfiguration];
}

-(NSTimer *)timer{
    if (!_timer)
    {
        _timer = [NSTimer scheduledTimerWithTimeInterval:KTimerInterval target:self selector:@selector(startTime:) userInfo:nil repeats:YES];
//        [[NSRunLoop mainRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
    }
    return _timer;
}

#pragma mark計時器事件處理
- (void)startTime:(NSTimer *)timer{
//    self.recordProgressBlock?self.recordProgressBlock(self.recordTime,self.totalTime):nil;
    if ([self.delegate respondsToSelector:@selector(joyRecordTimeCurrentTime:totalTime:)]) {
        [self.delegate joyRecordTimeCurrentTime:self.recordTime totalTime:self.totalTime];
    }
    self.recordTime += KTimerInterval;
    if(_recordTime>=KMaxRecordTime){[self stopCurrentVideoRecording];}
}

//定時器開啟
- (void)startTimer{
    [self.timer invalidate];
    self.timer = nil;
    self.recordTime = 0;
    [self.timer fire];
}

//停止計時
- (void)stopTimer{
    [self.timer invalidate];
    self.timer = nil;
}

//文件視頻開始錄制代理，也就是小視頻的開始錄制
#pragma mark - AVCaptureFileOutputRecordignDelegate
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections{
    [self startTimer];
    if([self.delegate respondsToSelector:@selector(joyCaptureOutput:didStartRecordingToOutputFileAtURL:fromConnections:)]){
        [self.delegate joyCaptureOutput:captureOutput didStartRecordingToOutputFileAtURL:fileURL fromConnections:connections];
    }
}

#pragma mark 文件錄制結束代理 小視頻錄制結束
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error{
    [self endBackgroundTask];
    if ([self.delegate respondsToSelector:@selector(joyCaptureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: recordResult:) ])
    {
        ERecordResult result = error?ERecordFaile:(self.recordTime>KMinRecordTime?ERecordSucess:ERecordLessThanMinTime);
        [self.delegate joyCaptureOutput:captureOutput didFinishRecordingToOutputFileAtURL:outputFileURL fromConnections:connections error:error recordResult:result];
    }
}

#pragma mark 流數據丟包 流媒體
-(void)captureOutput:(AVCaptureOutput *)captureOutput didDropSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
    
}

#pragma mark 流數據輸出 流媒體
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
    
}

#pragma mark 掃描到數據 二維碼掃描成功
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{
    if ([self.delegate respondsToSelector:@selector(joyCaptureOutput:didOutputMetadataObjects:fromConnection:)]) {
        [self.delegate joyCaptureOutput:captureOutput didOutputMetadataObjects:metadataObjects fromConnection:connection];
    }
}

-(void)dealloc{
    [self.timer invalidate];
    self.timer = nil;
    self.recordTime = 0;
    [self stopCurrentVideoRecording];
    [self.captureSession stopRunning];
    [self.preViewLayer removeFromSuperlayer];
}

#pragma mark private method ??????????????????????????????????????????????????End

#pragma mark public method ?????????????????????????????????????????????????? Start
#pragma mark 準備錄制
- (void)preareReCord{
    [self.captureSession beginConfiguration];
    [self.captureSession canSetSessionPreset:AVCaptureSessionPresetMedium]?[self.captureSession setSessionPreset:AVCaptureSessionPresetHigh]:nil;
    [self.captureSession canAddInput:self.mediaDeviceInput]?[self.captureSession addInput:self.mediaDeviceInput]:nil;
    [self.captureSession canAddInput:self.audioDeviceInput]?[self.captureSession addInput:self.audioDeviceInput]:nil;
    [self.captureSession canAddOutput:self.stillImageOutput]?[self.captureSession addOutput:self.stillImageOutput]:nil;
    switch (self.captureOutputType)
    {
    case EAVCaptureVideoDataOutput:
        [self.captureSession canAddOutput:self.videoDataOutput]?[self.captureSession addOutput:self.videoDataOutput]:nil;
        break;
    case EAVCaptureMetadataOutput:
        [self.captureSession canAddOutput:self.metadataOutput]?[self.captureSession addOutput:self.metadataOutput]:nil;
        if ([_metadataOutput.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeQRCode])
        {_metadataOutput.metadataObjectTypes = [NSArray arrayWithObjects:AVMetadataObjectTypeQRCode,AVMetadataObjectTypeUPCECode,
                                                AVMetadataObjectTypeCode39Code,
                                                AVMetadataObjectTypeCode39Mod43Code,
                                                AVMetadataObjectTypeEAN13Code,
                                                AVMetadataObjectTypeEAN8Code,
                                                AVMetadataObjectTypeCode93Code,
                                                AVMetadataObjectTypeCode128Code,
                                                AVMetadataObjectTypePDF417Code,
                                                AVMetadataObjectTypeQRCode,
                                                AVMetadataObjectTypeAztecCode, nil];}
            
        break;
    default:
        [self.captureSession canAddOutput:self.movieFileOutput]?[self.captureSession addOutput:self.movieFileOutput]:nil;
        break;
    }
    //設置輸出數據代理
    [self.captureSession commitConfiguration];
    [self openStabilization];
    [self.captureSession startRunning];
}

//這個地方講一下，每次錄制結束都要移除輸入設備管理，否則下次錄制代理不會走的
#pragma mark 移除輸入
-(void)removeAVCaptureAudioDeviceInput
{
    self.mediaDeviceInput?[self.captureSession removeInput:self.mediaDeviceInput]:nil;
    self.audioDeviceInput?[self.captureSession removeInput:self.audioDeviceInput]:nil;
    self.stillImageOutput?[self.captureSession removeOutput:self.stillImageOutput]:nil;
    switch (self.captureOutputType)
    {
    case EAVCaptureVideoDataOutput:
        self.videoDataOutput? [self.captureSession removeOutput:self.videoDataOutput]:nil;
        break;
    case EAVCaptureMetadataOutput:
        self.metadataOutput? [self.captureSession removeOutput:self.metadataOutput]:nil;
        break;
    default:
        self.movieFileOutput? [self.captureSession removeOutput:self.movieFileOutput]:nil;
        break;
    }
}

#pragma mark 設置焦距
- (void)updateVideoScaleAndCropFactor:(CGFloat)scale{
    if (scale < self.mediaDeviceInput.device.activeFormat.videoMaxZoomFactor && scale>1)
    [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
        [captureDevice rampToVideoZoomFactor:scale withRate:10];
    }];
}

#pragma mark 防抖功能 并設置縮放比例最大以提高視頻質量
- (void)openStabilization{
    if ([self.captureConnection isVideoStabilizationSupported ] &&self.captureConnection.activeVideoStabilizationMode == AVCaptureVideoStabilizationModeOff)
    {
        self.captureConnection.preferredVideoStabilizationMode=AVCaptureVideoStabilizationModeAuto;//視頻防抖
    }
    self.captureConnection.videoScaleAndCropFactor = _captureConnection.videoMaxScaleAndCropFactor;//鏡頭縮放最大
}

#pragma mark 開始錄制
- (void)startRecordToFile:(NSURL *)outPutFile{
    if (![self.movieFileOutput isRecording]) {  // 如果此時沒有在錄屏
        if ([[UIDevice currentDevice] isMultitaskingSupported])//如果支持多任務則則開始多任務
        {
        __weak __typeof(&*self)weakSelf = self;
        self.backgroundTaskIdentifier=[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{[weakSelf endBackgroundTask];}];
        }
        
        if ([self.captureConnection isVideoOrientationSupported])
        self.captureConnection.videoOrientation =[self.preViewLayer connection].videoOrientation;
        self.recordTime = 0.0f;
        [_movieFileOutput startRecordingToOutputFileURL:outPutFile recordingDelegate:self];
    }
    else{[self.movieFileOutput stopRecording];//停止錄制
    }
}

#pragma mark - 視頻錄制
-(void)endBackgroundTask
{
    if (self.backgroundTaskIdentifier != UIBackgroundTaskInvalid) {
        [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTaskIdentifier];
    }
    self.backgroundTaskIdentifier = UIBackgroundTaskInvalid;
}

#pragma mark 暫停
- (void)stopCurrentVideoRecording
{
    if (self.movieFileOutput.isRecording) {
        [self stopTimer];
        [_movieFileOutput stopRecording];
    }
}

#pragma mark 手電筒
- (void)switchTorch{
    __weak __typeof (&*self)weakSelf = self;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        NSError *error = nil;
//設備參數修改時要鎖定配置，修改后unlock，攝像頭也一樣
        [device lockForConfiguration:&error];
        if (error) {NSLog(@"error:%@",error.description);}
//        AVCaptureTorchMode torchMode = device.torchMode == AVCaptureTorchModeOff?AVCaptureTorchModeOn:AVCaptureTorchModeOff;
        
        AVCaptureTorchMode torchMode = AVCaptureTorchModeAuto;
        AVCaptureDevice *currentDevice = [weakSelf.mediaDeviceInput device];
        if(currentDevice.position == AVCaptureDevicePositionFront) torchMode = AVCaptureTorchModeOff;
        [device setTorchMode:torchMode];
        [device unlockForConfiguration];
    });
}

#pragma mark 切換攝像頭 
- (void)switchCamera{
    [_captureSession beginConfiguration];
   //移除舊的輸入設備
    [_captureSession removeInput:_mediaDeviceInput];
    AVCaptureDevice *swithToDevice = [self getSwitchCameraDevice];
    [swithToDevice lockForConfiguration:nil];
    [self setExposureModeWithDevice:swithToDevice];
    self.mediaDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:swithToDevice error:nil];
 //替換更換攝像頭后的輸入對象
    [_captureSession addInput:_mediaDeviceInput];
    [_captureSession commitConfiguration];
}

- (void)cancleRecord{
    
}

#pragma mark 設置對焦
- (void)setFoucusWithPoint:(CGPoint)point{
    CGPoint cameraPoint= [self.preViewLayer captureDevicePointOfInterestForPoint:point];
    [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];
}

/**
 *  設置聚焦點
 *
 *  @param point 聚焦點
 */
-(void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point{
    [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
        //聚焦
        if ([captureDevice isFocusModeSupported:focusMode]) {
            [captureDevice setFocusMode:focusMode];
        }
        //聚焦位置
        if ([captureDevice isFocusPointOfInterestSupported]) {
            [captureDevice setFocusPointOfInterest:point];
        }
        //曝光模式
        if ([captureDevice isExposureModeSupported:exposureMode]) {
            [captureDevice setExposureMode:exposureMode];
        }
        //曝光點位置
        if ([captureDevice isExposurePointOfInterestSupported]) {
            [captureDevice setExposurePointOfInterest:point];
        }
    }];
}

/**
 * 改變設備屬性的統一操作方法
 * @param propertyChange 屬性改變操作
 */
- (void)changeDeviceProperty:(IDBLOCK)propertyChange
{
    AVCaptureDevice *captureDevice = [self.mediaDeviceInput device];
    NSError *error;
    //注意改變設備屬性前一定要首先調用lockForConfiguration:調用完之后使用unlockForConfiguration方法解鎖
    if ([captureDevice lockForConfiguration:&error]) {
        propertyChange(captureDevice);
        [captureDevice unlockForConfiguration];
    }else{
        NSLog(@"設置設備屬性過程發生錯誤，錯誤信息：%@",error.localizedDescription);
    }
}

- (AVCaptureDevice *)getSwitchCameraDevice{
    AVCaptureDevice *currentDevice = [self.mediaDeviceInput device];
    AVCaptureDevicePosition currentPosition = [currentDevice position];
    BOOL isUnspecifiedOrFront = (currentPosition==AVCaptureDevicePositionUnspecified||currentPosition==AVCaptureDevicePositionFront);
    AVCaptureDevicePosition  swithToPosition = isUnspecifiedOrFront?AVCaptureDevicePositionBack:AVCaptureDevicePositionFront;
    NSArray *cameras= [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    __block AVCaptureDevice *swithCameraDevice = nil;
    [cameras enumerateObjectsUsingBlock:^(AVCaptureDevice *camera, NSUInteger idx, BOOL * _Nonnull stop) {
        if(camera.position == swithToPosition){swithCameraDevice = camera;*stop = YES;};
    }];
    return swithCameraDevice;
}

@end

##類別，權限處理、視頻裁剪壓縮、視頻存儲
#pragma mark  權限認證、緩存處理 類別???????????????????????????????????????????????????????????????????????????開始
@implementation JoyMediaRecordPlay(JoyRecorderPrivary)
- (BOOL)isAvailableWithCamera
{
    return [self isAvailableWithDeviveMediaType:AVMediaTypeVideo];
}

- (BOOL)isAvailableWithMic
{
    return [self isAvailableWithDeviveMediaType:AVMediaTypeAudio];
}

- (BOOL)isAvailableWithDeviveMediaType:(NSString *)mediaType
{
    AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    return !(status == ALAuthorizationStatusDenied||status == ALAuthorizationStatusRestricted);
}

- (void)getVideoAuth:(BOOLBLOCK)videoAuth{
    __weak typeof(self)weakSelf = self;
    AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (authStatus == AVAuthorizationStatusNotDetermined)
    {
        [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo
                                 completionHandler:^(BOOL granted) {
                                     granted?[weakSelf authAudio:videoAuth]:videoAuth(NO); }];
    }
    else if (authStatus == AVAuthorizationStatusAuthorized)
    { [self authAudio:videoAuth];}
    else
    {videoAuth(NO);}
}

- (void)authAudio:(BOOLBLOCK)audio {
    if ([[AVAudioSession sharedInstance] respondsToSelector:@selector(requestRecordPermission:)]) {
        [[AVAudioSession sharedInstance] requestRecordPermission:^(BOOL granted) {
            audio(granted);
        }];
    }
}

- (void)showAlert{
    [[JoyAlert shareAlert] showAlertViewWithTitle:@"請在iPhone的“設置-隱私”選項中，允許%@訪問你的攝像頭和麥克風。"
                                          message:nil
                                           cancle:@"好"
                                          confirm:nil
                                       alertBlock:nil];
}

#pragma mark 視頻保存相冊
+ (void)saveToPhotoWithUrl:(NSURL *)url{
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:url];
    } completionHandler:nil];
}

#pragma mark  視頻裁剪   ??????????????????????????????????????????????????????????????開始
/*
 fileURL :原視頻url
 mergeFilePath:新的fileurl
 whScalle:所需裁剪的寬高比
 presetName:壓縮視頻質量,不傳則 AVAssetExportPresetMediumQuality
 */
+ (void)mergeAndExportVideosAtFileURLs:(NSURL *)fileURL newUrl:(NSString *)mergeFilePath widthHeightScale:(CGFloat)whScalle presetName:(NSString *)presetName mergeSucess:(VOIDBLOCK)mergeSucess

{
    NSError *error = nil;
    
    CMTime totalDuration = kCMTimeZero;
    //轉換AVAsset
    AVAsset *asset = [AVAsset assetWithURL:fileURL];
    if (!asset) {
        return;
    }
    
    AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
    //提取音頻、視頻
    NSArray * assetArray = [asset tracksWithMediaType:AVMediaTypeVideo];
    
    AVAssetTrack *assetTrack;
    if (assetArray.count) {
        assetTrack = [assetArray objectAtIndex:0];
    }
    
    [JoyMediaRecordPlay audioTrackWith:mixComposition assetTrack:assetTrack asset:asset totalDuration:totalDuration error:error];
    
    AVMutableCompositionTrack *videoTrack = [JoyMediaRecordPlay videoTrackWith:mixComposition assetTrack:assetTrack asset:asset totalDuration:totalDuration error:error];
    
    CGFloat renderW = [JoyMediaRecordPlay videoTrackRenderSizeWithassetTrack:assetTrack];
    totalDuration = CMTimeAdd(totalDuration, asset.duration);
    
    NSMutableArray *layerInstructionArray = [JoyMediaRecordPlay assetArrayWith:videoTrack totalDuration:totalDuration assetTrack:assetTrack renderW:renderW widthHeightScale:whScalle];
    
    [JoyMediaRecordPlay mergingVideoWithmergeFilePath:mergeFilePath layerInstructionArray:layerInstructionArray mixComposition:mixComposition totalDuration:totalDuration renderW:renderW widthHeightScale:whScalle presetName:presetName mergeSucess:mergeSucess];
}

//壓縮視頻
+(void)mergingVideoWithmergeFilePath:(NSString *)mergeFilePath
               layerInstructionArray:(NSMutableArray*)layerInstructionArray
                      mixComposition:(AVMutableComposition *)mixComposition
                       totalDuration:(CMTime)totalDuration
                             renderW:(CGFloat)renderW
                    widthHeightScale:(CGFloat)whScalle
                          presetName:(NSString *)presetName
                         mergeSucess:(VOIDBLOCK)mergeSucess

{
    //get save path
    NSURL *mergeFileURL = [NSURL fileURLWithPath:mergeFilePath];
    
    //export
    AVMutableVideoCompositionInstruction *mainInstruciton = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
    mainInstruciton.timeRange = CMTimeRangeMake(kCMTimeZero, totalDuration);
    mainInstruciton.layerInstructions = layerInstructionArray;
    AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
    mainCompositionInst.instructions = @[mainInstruciton];
    mainCompositionInst.frameDuration = CMTimeMake(1, 30);
    mainCompositionInst.renderSize = CGSizeMake(renderW, renderW/whScalle);//renderW/4*3
    
    __block AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:presetName?:AVAssetExportPresetMediumQuality];
    exporter.videoComposition = mainCompositionInst;
    exporter.outputURL = mergeFileURL;
    exporter.outputFileType = AVFileTypeMPEG4;
    exporter.shouldOptimizeForNetworkUse = YES;
    [exporter exportAsynchronouslyWithCompletionHandler:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            switch (exporter.status) {
                case AVAssetExportSessionStatusCompleted:
                    mergeSucess?mergeSucess():nil;
                    break;
                default:
                    break;
            }
        });
    }];
    
}

//合成視頻
+ (NSMutableArray *)assetArrayWith:(AVMutableCompositionTrack *)videoTrack
                     totalDuration:(CMTime)totalDuration
                        assetTrack:(AVAssetTrack *)assetTrack
                           renderW:(CGFloat)renderW
                  widthHeightScale:(CGFloat)whScalle

{
    NSMutableArray *layerInstructionArray = [[NSMutableArray alloc] init];
    
    AVMutableVideoCompositionLayerInstruction *layerInstruciton = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
    CGFloat rate = renderW / MIN(assetTrack.naturalSize.width, assetTrack.naturalSize.height);
    CGAffineTransform layerTransform = CGAffineTransformMake(assetTrack.preferredTransform.a, assetTrack.preferredTransform.b, assetTrack.preferredTransform.c, assetTrack.preferredTransform.d, assetTrack.preferredTransform.tx * rate, assetTrack.preferredTransform.ty * rate);
    layerTransform = CGAffineTransformConcat(layerTransform, CGAffineTransformMake(1, 0, 0, 1, 0, -(assetTrack.naturalSize.width - assetTrack.naturalSize.height/whScalle) / 2.0));//向上移動取中部影響
    layerTransform = CGAffineTransformScale(layerTransform, rate, rate);//放縮，解決前后攝像結果大小不對稱
    [layerInstruciton setTransform:layerTransform atTime:kCMTimeZero];
    [layerInstruciton setOpacity:0.0 atTime:totalDuration];
    //data
    [layerInstructionArray addObject:layerInstruciton];
    
    return layerInstructionArray;
}

//視頻大小
+(CGFloat)videoTrackRenderSizeWithassetTrack:(AVAssetTrack *)assetTrack{
    
    CGSize renderSize = CGSizeMake(0, 0);
    renderSize.width = MAX(renderSize.width, assetTrack.naturalSize.height);
    renderSize.height = MAX(renderSize.height, assetTrack.naturalSize.width);
    return MIN(renderSize.width, renderSize.height);
}

//videoTrack
+(AVMutableCompositionTrack*)videoTrackWith:(AVMutableComposition *)mixComposition
                                 assetTrack:(AVAssetTrack *)assetTrack
                                      asset:(AVAsset *)asset
                              totalDuration:(CMTime)totalDuration
                                      error:(NSError *)error{
    
    AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    
    [videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
                        ofTrack:assetTrack
                         atTime:totalDuration
                          error:&error];
    
    
    return videoTrack;
    
}

//audioTrack
+(void)audioTrackWith:(AVMutableComposition *)mixComposition
           assetTrack:(AVAssetTrack *)assetTrack
                asset:(AVAsset *)asset
        totalDuration:(CMTime)totalDuration
                error:(NSError *)error{
    AVMutableCompositionTrack *audioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    
    NSArray *array =  [asset tracksWithMediaType:AVMediaTypeAudio];
    if (array.count > 0) {
        AVAssetTrack *audiok =[array objectAtIndex:0];
        [audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
                            ofTrack:audiok
                             atTime:totalDuration
                              error:nil];
    }
}
#pragma mark  視頻裁剪   ??????????????????????????????????????????????????????????結束

#pragma mark - 視頻地址
+ (NSString *)generateFilePathWithType:(NSString *)fileType{
   return  [[[self class] getVideoPathCache] stringByAppendingString:[[self class] getVideoNameWithType:fileType]];
}

+ (NSString *)getVideoPathCache
{
    NSString *videoCache = [NSTemporaryDirectory() stringByAppendingPathComponent:@"videos"] ;
    BOOL isDir = NO;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL existed = [fileManager fileExistsAtPath:videoCache isDirectory:&isDir];
    if ( !(isDir == YES && existed == YES) ) {
        [fileManager createDirectoryAtPath:videoCache withIntermediateDirectories:YES attributes:nil error:nil];
    };
    return videoCache;
}

+ (NSString *)getVideoNameWithType:(NSString *)fileType
{
    NSTimeInterval now = [[NSDate date] timeIntervalSince1970];
    NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"HHmmss"];
    NSDate * NowDate = [NSDate dateWithTimeIntervalSince1970:now];
    ;
    NSString * timeStr = [formatter stringFromDate:NowDate];
    NSString *fileName = [NSString stringWithFormat:@"/video_%@.%@",timeStr,fileType];
    return fileName;
}

#pragma mark 獲取文件大小
+ (CGFloat)getfileSize:(NSString *)filePath
{
    NSFileManager *fm = [NSFileManager defaultManager];
    filePath = [filePath stringByReplacingOccurrencesOfString:@"file://" withString:@""];
    CGFloat fileSize = 0;
    if ([fm fileExistsAtPath:filePath]) {
        fileSize = [[fm attributesOfItemAtPath:filePath error:nil] fileSize];
        NSLog(@"視頻 - - - - - %fM,--------- %fKB",fileSize / (1024.0 * 1024.0),fileSize / 1024.0);
    }
    return fileSize/1024/1024;
}

@end
#pragma mark  權限認證、緩存處理 類別???????????????????????????????????????????????????????????????????????????結束

主文件git地址??這兒
簡單寫了個demo，主要還是看player的實現，view是臨時寫了一個，你可以把回調拿到vc里去處理。joytool masony框架可以用自己的