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AVFoundation-自定义拍照

AVFoundation-自定义拍照

作者: 一誠 | 来源:发表于2017-11-13 19:25 被阅读289次

    AVCaptureSession是AVFoundation的核心类,用于捕捉视频和音频,协调视频和音频的输入和输出流.

    • 输入源
      设备AVCaptureDevice
      [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]
    • 输出源
      添加AVCaptureOutput,即AVCaptureSession的输出源.一般输出源分成:音视频源,图片源,文件源等.
      音视频输出AVCaptureAudioDataOutput,AVCaptureVideoDataOutput.
      静态图片输出AVCaptureStillImageOutput(iOS10中被AVCapturePhotoOutput取代了)
      AVCaptureMovieFileOutput表示文件源.

    创建会话AVCaptureSession

    -(AVCaptureSession *)captureSession{
        if (!_captureSession) {
            _captureSession = [[AVCaptureSession alloc]init];
            if ([[UIDevice currentDevice]userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
                customLog(@"当前使用的是手机");
            }
        }
        return _captureSession;
    }
    

    创建输入源

    1、创建AVCaptureDevice

    -(AVCaptureDevice *)getCaptureDevice{
        // 每次获取都要重新创建
        NSArray * devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
        for (AVCaptureDevice * device in devices) {
            if (device.position == self.captureDevicePosition) {
                NSError * error = nil;
                if ([device lockForConfiguration:&error]) {
                    // 焦点 曝光 黑白色 -> 自动
                    if ([device isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus]) {
                        device.focusMode = AVCaptureFocusModeContinuousAutoFocus;
                    }
                    if ([device isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure]) {
                        device.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
                    }
                    if ([device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance]) {
                        device.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
                    }
                    
                    [device unlockForConfiguration];
                }
                
                _captureDevice = device;
                return _captureDevice;
            }
        }
        return nil;
    }
    

    2、创建AVCaptureDeviceInput

    -(AVCaptureDeviceInput *)getCaptureDeviceInput{
        NSError * error = nil;
        AVCaptureDevice * device = [self getCaptureDevice];
        _captureDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
        if (error || device == nil) {
            NSLog(@"创建失败: %@",error.description);
        }
        return _captureDeviceInput;
    }
    

    3、添加输入源到会话中

    AVCaptureSession * session = self.captureSession;
        // 添加输入对象到会话
        if ([session.inputs containsObject:self.captureDeviceInput]) {
            [session removeInput:self.captureDeviceInput];
        }
        AVCaptureDeviceInput * input = [self getCaptureDeviceInput];
        if ([session canAddInput:input]) {
            [session addInput:input];
        }
    

    创建输出源并添加到会话中

     // 添加照片输出
        if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.0")) {
            AVCapturePhotoOutput * photoOutput = [[AVCapturePhotoOutput alloc]init];
            
            // 先移除
            if ([session.outputs containsObject:self.captureOutput]) {
                [session removeOutput:self.captureOutput];
            }
            // 添加
            if ([session canAddOutput:photoOutput]) {
                [session addOutput:photoOutput];
            }
            
            self.captureOutput = photoOutput;
        }else{
            AVCaptureStillImageOutput * stillImageOutput = [[AVCaptureStillImageOutput alloc]init];
            NSDictionary *myOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
            [stillImageOutput setOutputSettings:myOutputSettings];
            
            // 先移除
            if ([session.outputs containsObject:self.captureOutput]) {
                [session removeOutput:self.captureOutput];
            }
            // 添加
            if ([session canAddOutput:stillImageOutput]){
                [session addOutput:stillImageOutput];
            }
            
            self.captureOutput = stillImageOutput;
        }   
    

    输出对象-视频流对象作为输出适合及时获取输出数据(直播)

        AVCaptureVideoDataOutput *videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
        [videoDataOutput setAlwaysDiscardsLateVideoFrames:YES];// 默认为YES
        // 设置代理,捕获视频样品数据
        // 注意:队列必须是串行队列,才能获取到数据,而且不能为空
        dispatch_queue_t photoCaptureQueue = dispatch_queue_create(MDPhotoCaptureQueue, DISPATCH_QUEUE_SERIAL);
        [videoDataOutput setSampleBufferDelegate:self queue:photoCaptureQueue];
        if ([session canAddOutput:videoDataOutput]) {
            [session addOutput:videoDataOutput];
        }
        #pragma mark AVCaptureVideoDataOutputSampleBufferDelegate
    - (void)captureOutput:(AVCaptureOutput *)output didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
    - // 及时获取视频输出数据
        customLog(@"采集到数据");
    }
    

    添加预览图层

    -(void)addPreviewLayer{
        // 视频预览图层
        AVCaptureVideoPreviewLayer *previedLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
        previedLayer.frame = [UIScreen mainScreen].bounds;
        _previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
        [self.view.layer insertSublayer:previedLayer atIndex:0];
        _previewLayer = previedLayer;
    }
    

    切换前后置摄像头-切换输入源

    - (void)changeInput{
        // 移除输入对象
        if (self.captureDeviceInput && [self.captureSession.inputs containsObject:self.captureDeviceInput]) {
            [self.captureSession removeInput:self.captureDeviceInput];
        }
        // 添加输入对象到会话
        AVCaptureDeviceInput * input = [self getCaptureDeviceInput];
        if ([self.captureSession canAddInput:input]) {
            [self.captureSession addInput:input];
        }
        self.isChangeCaptureDevicePostion = NO;
        // 给摄像头的切换添加翻转动画
        CATransition *animation = [CATransition animation];
        animation.duration = .5f;
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
        animation.type = @"oglFlip";
        if (self.captureDevicePosition == AVCaptureDevicePositionFront) {
            animation.subtype = kCATransitionFromLeft;
        }else{
            animation.subtype = kCATransitionFromRight;
        }
        [self.previewLayer addAnimation:animation forKey:nil];
    }
    

    拍照按钮点击-获取图片

    -(void)commitButtonAction{
        // 拍照
        if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.0")) {
            
            AVCapturePhotoOutput * output = (AVCapturePhotoOutput *)self.captureOutput;
            
            //从 AVCaptureStillImageOutput 中取得 AVCaptureConnection
            self.captureConnection = [output connectionWithMediaType:AVMediaTypeVideo];
            AVCapturePhotoSettings * settings = [AVCapturePhotoSettings photoSettings];
            
            [output capturePhotoWithSettings:settings delegate:self];
        }else{
            AVCaptureStillImageOutput * stillImageOutput = (AVCaptureStillImageOutput *)self.captureOutput;
            //从 AVCaptureStillImageOutput 中取得 AVCaptureConnection
            self.captureConnection = [stillImageOutput connectionWithMediaType:AVMediaTypeVideo];
            [stillImageOutput captureStillImageAsynchronouslyFromConnection:self.captureConnection completionHandler:^(CMSampleBufferRef  _Nullable imageDataSampleBuffer, NSError * _Nullable error) {
                if (imageDataSampleBuffer != nil) {
                    NSData * data = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
                    // 取得静态影像 两种获取方式
                    //UIImage * image = [[UIImage alloc]initWithData:data];
                    
                    CFDataRef cfData = CFBridgingRetain(data);
                    CGDataProviderRef dataProvider = CGDataProviderCreateWithCFData(cfData);
                    CGImageRef cgImage = CGImageCreateWithJPEGDataProvider(dataProvider, nil, YES, kCGRenderingIntentDefault);
                    CFBridgingRelease(cfData);
                    
                    // 裁剪图片
                    [self cropWithImage:[UIImage imageWithCGImage:cgImage]];
    
                    // 取得影像数据(需要ImageIO.framework 与 CoreMedia.framework)
                    CFDictionaryRef attachments = CMGetAttachment(imageDataSampleBuffer, kCGImagePropertyExifDictionary, NULL);
                    customLog(@"影像属性: %@", attachments);
                }
            }];
        }
    }
    

    代理获取图片AVCapturePhotoOutput

    #pragma mark AVCapturePhotoCaptureDelegate
    // IOS - 11
    - (void)captureOutput:(AVCapturePhotoOutput *)output didFinishProcessingPhoto:(AVCapturePhoto *)photo error:(NSError *)error{
        if (error) {
            customLog(@"获取图片错误 --- %@",error.localizedDescription);
        }
        if (photo) {
            if (@available(iOS 11.0, *)) {
                CGImageRef cgImage = [photo CGImageRepresentation];
                UIImage * image = [UIImage imageWithCGImage:cgImage];
                customLog(@"获取图片成功 --- %@",image);
            } else {
                customLog(@"不是走这个代理方法");
            }
        }
    }
    
    - (void)captureOutput:(AVCapturePhotoOutput *)output didFinishProcessingPhotoSampleBuffer:(nullable CMSampleBufferRef)photoSampleBuffer previewPhotoSampleBuffer:(nullable CMSampleBufferRef)previewPhotoSampleBuffer resolvedSettings:(AVCaptureResolvedPhotoSettings *)resolvedSettings bracketSettings:(nullable AVCaptureBracketedStillImageSettings *)bracketSettings error:(nullable NSError *)error{
        if (error) {
            customLog(@"获取图片错误 --- %@",error.localizedDescription);
        }
        if (photoSampleBuffer) {
            NSData *data = [AVCapturePhotoOutput JPEGPhotoDataRepresentationForJPEGSampleBuffer:photoSampleBuffer previewPhotoSampleBuffer:previewPhotoSampleBuffer];
            UIImage *image = [UIImage imageWithData:data];
            customLog(@"获取图片成功 --- %@",image);
        }
    }
    

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