自定義相機碰到的問題，比如常見的拍照錄製影片方向，鏡像左右顛倒等問題
iOS開發了好幾年了，自定義相機都碰到過很多次，每次都是從網上copy程式碼使用，但是很多時候都會有方向等問題，從來沒有真正研究過，現在在這裡記錄一下自定義相機碰到的問題，以防忘記
問題一：橫向拍照/錄製影片，得到的影片也需要橫屏。
要實現這個功能，就需要獲取到設備的方向，這裡有兩種方法獲取方向
方法一：根據設備方向開關來獲取方向，[UIDevice currentDevice].orientation
方法二：根據重力感應獲取方向
DN_WEAK_SELF if([self.cmmotionManager isDeviceMotionAvailable]) { [self.cmmotionManager startAccelerometerUpdatesToQueue:[NSOperationQueue currentQueue] withHandler:^(CMAccelerometerData * _Nullable accelerometerData, NSError * _Nullable error) { DN_STRONG_SELF double x = accelerometerData.acceleration.x; double y = accelerometerData.acceleration.y; if (fabs(y) >= fabs(x)) { if (y >= 0) { //Down self.deviceOrientation = UIDeviceOrientationPortraitUpsideDown; } else { //Portrait self.deviceOrientation = UIDeviceOrientationPortrait; } } else { if (x >= 0) { //Righ self.deviceOrientation = UIDeviceOrientationLandscapeRight; } else { //Left self.deviceOrientation = UIDeviceOrientationLandscapeLeft; } } }]; }
獲取到方向後，在拍照前設置方向
AVCaptureConnection *myVideoConnection = [self.ImageOutPut connectionWithMediaType:AVMediaTypeVideo]; if ([myVideoConnection isVideoOrientationSupported]) { myVideoConnection.videoOrientation = [self getCaptureVideoOrientation:self.deviceOrientation]; }
在錄製影片前設置方向
AVCaptureConnection *connection = [self.captureMovieFileOutput connectionWithMediaType:AVMediaTypeVideo]; if ([connection isVideoOrientationSupported]) { connection.videoOrientation = [self getCaptureVideoOrientation:self.deviceOrientation]; }
問題二： 前置攝影機拍照時，照片和影片左右顛倒（類似微信）
這個問題其實很簡單，只要設置一下輸出對象的鏡像開關就可以了
AVCaptureSession *session = (AVCaptureSession *)self.session; for (AVCaptureVideoDataOutput* output in session.outputs) { for (AVCaptureConnection * av in output.connections) { //判斷是否是前置攝影機狀態 if ([self.input device].position == AVCaptureDevicePositionFront) { if (av.supportsVideoMirroring) { //鏡像設置 av.videoMirrored = YES; } } } }
錄製影片的話，解決左右顛倒 只能用以上的方法
而拍照的話，解決左右顛倒，還有一種方法，在拍完照片後，設置圖片方向
UIImageOrientation imgOrientation; //拍攝後獲取的的影像方向 if ([self.input device].position == AVCaptureDevicePositionFront && self.isFixLeftRightProblem) { NSLog(@"前置攝影機"); // 前置攝影機影像方向 UIImageOrientationLeftMirrored // IOS前置攝影機左右成像 imgOrientation = UIImageOrientationLeftMirrored; if (image.imageOrientation == UIImageOrientationRight) { imgOrientation = UIImageOrientationLeftMirrored; }else if (image.imageOrientation == UIImageOrientationLeft) { imgOrientation = UIImageOrientationRightMirrored; }else if (image.imageOrientation == UIImageOrientationDown) { imgOrientation = UIImageOrientationDownMirrored; }else if (image.imageOrientation == UIImageOrientationUp) { imgOrientation = UIImageOrientationUpMirrored; } image = [[UIImage alloc]initWithCGImage:image.CGImage scale:1.0f orientation:imgOrientation]; }
問題三：自定義相機拍照後，在其他端查看時，方向不正確
這時候就需要矯正方向了
/*! ** 矯正圖片方向 參考 //www.cocoachina.com/articles/12021 */ - (UIImage *)fixOrientation { // No-op if the orientation is already correct if (self.imageOrientation == UIImageOrientationUp) return self; // We need to calculate the proper transformation to make the image upright. // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored. CGAffineTransform transform = CGAffineTransformIdentity; switch (self.imageOrientation) { case UIImageOrientationDown: case UIImageOrientationDownMirrored: transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height); transform = CGAffineTransformRotate(transform, M_PI); break; case UIImageOrientationLeft: case UIImageOrientationLeftMirrored: transform = CGAffineTransformTranslate(transform, self.size.width, 0); transform = CGAffineTransformRotate(transform, M_PI_2); break; case UIImageOrientationRight: case UIImageOrientationRightMirrored: transform = CGAffineTransformTranslate(transform, 0, self.size.height); transform = CGAffineTransformRotate(transform, -M_PI_2); break; case UIImageOrientationUp: case UIImageOrientationUpMirrored: break; } switch (self.imageOrientation) { case UIImageOrientationUpMirrored: case UIImageOrientationDownMirrored: transform = CGAffineTransformTranslate(transform, self.size.width, 0); transform = CGAffineTransformScale(transform, -1, 1); break; case UIImageOrientationLeftMirrored: case UIImageOrientationRightMirrored: transform = CGAffineTransformTranslate(transform, self.size.height, 0); transform = CGAffineTransformScale(transform, -1, 1); break; case UIImageOrientationUp: case UIImageOrientationDown: case UIImageOrientationLeft: case UIImageOrientationRight: break; } // Now we draw the underlying CGImage into a new context, applying the transform // calculated above. CGContextRef ctx = CGBitmapContextCreate(NULL, self.size.width, self.size.height, CGImageGetBitsPerComponent(self.CGImage), 0, CGImageGetColorSpace(self.CGImage), CGImageGetBitmapInfo(self.CGImage)); CGContextConcatCTM(ctx, transform); switch (self.imageOrientation) { case UIImageOrientationLeft: case UIImageOrientationLeftMirrored: case UIImageOrientationRight: case UIImageOrientationRightMirrored: // Grr... CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage); break; default: CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage); break; } // And now we just create a new UIImage from the drawing context CGImageRef cgimg = CGBitmapContextCreateImage(ctx); UIImage *img = [UIImage imageWithCGImage:cgimg]; CGContextRelease(ctx); CGImageRelease(cgimg); return img; }
問題四：自定義相機打開後，這時候來電話了，再切回到相機不能拍照了。
這裡就需要監聽音頻中斷的通知AVCaptureSessionWasInterruptedNotification，中斷結束的通知AVCaptureSessionInterruptionEndedNotification
還要監聽系統電話來電 CTCallCenter callEventHandler，在中斷通知AVCaptureSessionWasInterruptedNotification中，將音頻輸入設備從session中移除，等中斷通知結束後，判斷是否時系統電話造成的，如果是則將音頻輸入設備加入session
監聽來電的程式碼 <CoreTelephony/CTCallCenter.h> <CoreTelephony/CTCall.h>
DN_WEAK_SELF self.callCenter = [[CTCallCenter alloc] init]; self.callCenter.callEventHandler = ^(CTCall * call) { DN_STRONG_SELF if([call.callState isEqualToString:CTCallStateDisconnected]) { NSLog(@"Call has been disconnected");//電話被掛斷(我們用的這個) self.isSystemCall = NO; } else if([call.callState isEqualToString:CTCallStateConnected]) { NSLog(@"Call has been connected");//電話被接聽 } else if([call.callState isEqualToString:CTCallStateIncoming]) { NSLog(@"Call is incoming");//來電話了 self.isSystemCall = YES; [self endCall]; } else if([call.callState isEqualToString:CTCallStateDialing]) { NSLog(@"Call is Dialing");//撥號 self.isSystemCall = YES; [self endCall]; } else { NSLog(@"Nothing is done"); } };
中斷音頻程式碼
- (void)initNotification { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(AVCaptureSessionWasInterruptedNotification:) name:AVCaptureSessionWasInterruptedNotification object:self.session]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(AVCaptureSessionInterruptionEndedNotification:) name:AVCaptureSessionInterruptionEndedNotification object:self.session]; } #pragma mark - 通知 - (void)AVCaptureSessionWasInterruptedNotification:(NSNotification *)notification { AVCaptureSessionInterruptionReason reason = [notification.userInfo[AVCaptureSessionInterruptionReasonKey] integerValue]; NSLog(@"fanshijian 中斷 : %d reason : %ld",self.session.interrupted,(long)reason); if (reason == AVCaptureSessionInterruptionReasonAudioDeviceInUseByAnotherClient) { [self removeAudioInput]; } } - (void)AVCaptureSessionInterruptionEndedNotification:(NSNotification *)notification { NSLog(@"fanshijian 中斷結束 : %d",self.session.interrupted); if (![DNVideoChatConfig sharedConfig].isSystemCall) { [self addAudioInput]; } } - (void)addAudioInput { if (!_audioCaptureDeviceInput) { //添加一個音頻輸入設備 AVCaptureDevice *audioCaptureDevice = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject]; //添加音頻 NSError *error = nil; AVCaptureDeviceInput *audioCaptureDeviceInput = [[AVCaptureDeviceInput alloc]initWithDevice:audioCaptureDevice error:&error]; if (error) { NSLog(@"取得設備輸入對象時出錯，錯誤原因：%@",error.localizedDescription); return; } self.audioCaptureDeviceInput = audioCaptureDeviceInput; } if ([self.session canAddInput:self.audioCaptureDeviceInput]) { [self.session addInput:self.audioCaptureDeviceInput]; } } - (void)removeAudioInput { [self.session removeInput:self.audioCaptureDeviceInput]; }
可以參考demo //github.com/smallMas/FSEditVideo.git 類FSLiveWindow
