在这里，我正在使用 AVFoundation 框架来录制视频，并且我尝试一次使用前后摄像头，但是如果前摄像头正常工作，后摄像头在第一帧就会冻结，反之亦然。可以捕获会话一次有多个对象.这是任何人都可以帮助我的代码。
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.frame = CGRectMake(0, 0, 320, 568);
self.view.backgroundColor = [UIColor clearColor];
ActiveIndicatorView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 250)];
ActiveIndicatorView.backgroundColor = [UIColor clearColor];
[self.view addSubview:ActiveIndicatorView];
ActiveIndicatorViewBack = [[UIView alloc]initWithFrame:CGRectMake(0, 290, 320, 250)];
ActiveIndicatorViewBack.backgroundColor = [UIColor greenColor];
[self.view addSubview:ActiveIndicatorViewBack];
tracksArray = [[NSMutableArray alloc]
initWithCapacity:2];
[self startRecording];
}
-(void)startRecording{
[self StartCameraTwo];//front camera
[self StartCamera];//back camera
}
-(void)StartCamera{
// NSLog(@"Setting up capture session");
CaptureSessionBack = [[AVCaptureSession alloc] init];
//ADD VIDEO INPUT
AVCaptureDevice *VideoDeviceBack = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// VideoDeviceBack = [self frontCamera];
if (VideoDeviceBack)
{
NSError *error;
VideoInputDeviceBack = [AVCaptureDeviceInput deviceInputWithDevice:VideoDeviceBack error:&error];
if (!error)
{
if ([CaptureSessionBack canAddInput:VideoInputDeviceBack])
[CaptureSessionBack addInput:VideoInputDeviceBack];
else
NSLog(@"");
}
else
{
//NSLog(@"Couldn't create video input");
}
}
else
{
}
AVCaptureDevice *audioCaptureDeviceBack = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error = nil;
AVCaptureDeviceInput *audioInputBack = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDeviceBack error:&error];
if (audioInputBack)
{
[CaptureSessionBack addInput:audioInputBack];
}
previewBack = [self videoPreviewWithFrameBack :ActiveIndicatorViewBack.bounds];
previewBack.backgroundColor = [UIColor grayColor];
[ActiveIndicatorViewBack addSubview:previewBack];
// [preview addSubview:vie];
MovieFileOutputBack = [[AVCaptureMovieFileOutput alloc] init];
MovieFileOutputBack.minFreeDiskSpaceLimit = 1024 * 1024; //<<SET MIN FREE SPACE IN BYTES FOR RECORDING TO CONTINUE ON A VOLUME
if ([CaptureSessionBack canAddOutput:MovieFileOutputBack])
[CaptureSessionBack addOutput:MovieFileOutputBack];
//SET THE CONNECTION PROPERTIES (output properties)
[self CameraSetOutputPropertiesBack]; //(We call a method as it also has to be done after changing camera)
//NSLog(@"Setting image quality");
[CaptureSessionBack setSessionPreset:AVCaptureSessionPreset640x480];
if ([CaptureSessionBack canSetSessionPreset:AVCaptureSessionPreset640x480]) { //Check size based configs are supported before setting them
[CaptureSessionBack setSessionPreset:AVCaptureSessionPreset640x480];
}
if ([VideoDeviceBack isFocusModeSupported:AVCaptureFocusModeAutoFocus] && [VideoDeviceBack lockForConfiguration:&error]){
[VideoDeviceBack setFocusMode:AVCaptureFocusModeAutoFocus];
if ([VideoDeviceBack isFocusPointOfInterestSupported])
[VideoDeviceBack setFocusPointOfInterest:CGPointMake(0.5f,0.5f)];
[VideoDeviceBack unlockForConfiguration];
}
[CaptureSessionBack startRunning];
}
-(void)StartCameraTwo{
// NSLog(@"Setting up capture session");
CaptureSession = [[AVCaptureSession alloc] init];
//ADD VIDEO INPUT
AVCaptureDevice *VideoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
VideoDevice = [self frontCamera];
if (VideoDevice)
{
NSError *error;
VideoInputDevice = [AVCaptureDeviceInput deviceInputWithDevice:VideoDevice error:&error];
if (!error)
{
if ([CaptureSession canAddInput:VideoInputDevice])
[CaptureSession addInput:VideoInputDevice];
else
NSLog(@"");
}
else
{
//NSLog(@"Couldn't create video input");
}
}
else
{
}
AVCaptureDevice *audioCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error = nil;
AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error];
if (audioInput)
{
[CaptureSession addInput:audioInput];
}
preview = [self videoPreviewWithFrame:ActiveIndicatorView.bounds];
ActiveIndicatorView.backgroundColor = [UIColor redColor];
[ActiveIndicatorView addSubview:preview];
MovieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
MovieFileOutput.minFreeDiskSpaceLimit = 1024 * 1024; //<<SET MIN FREE SPACE IN BYTES FOR RECORDING TO CONTINUE ON A VOLUME
if ([CaptureSession canAddOutput:MovieFileOutput])
[CaptureSession addOutput:MovieFileOutput];
//SET THE CONNECTION PROPERTIES (output properties)
[self CameraSetOutputProperties]; //(We call a method as it also has to be done after changing camera)
//NSLog(@"Setting image quality");
[CaptureSession setSessionPreset:AVCaptureSessionPreset640x480];
if ([CaptureSession canSetSessionPreset:AVCaptureSessionPreset640x480]) { //Check size based configs are supported before setting them
[CaptureSession setSessionPreset:AVCaptureSessionPreset640x480];
}
if ([VideoDevice isFocusModeSupported:AVCaptureFocusModeAutoFocus] && [VideoDevice lockForConfiguration:&error]){
[VideoDevice setFocusMode:AVCaptureFocusModeAutoFocus];
if ([VideoDevice isFocusPointOfInterestSupported])
[VideoDevice setFocusPointOfInterest:CGPointMake(0.5f,0.5f)];
[VideoDevice unlockForConfiguration];
}
[CaptureSession startRunning];
}
- (void) CameraSetOutputProperties
{
//SET THE CONNECTION PROPERTIES (output properties)
CaptureConnection = [MovieFileOutput connectionWithMediaType:AVMediaTypeVideo];
//Set landscape (if required)
if ([CaptureConnection isVideoOrientationSupported])
{
AVCaptureVideoOrientation orientation = AVCaptureVideoOrientationLandscapeLeft; //<<<<<SET VIDEO ORIENTATION IF LANDSCAPE
[CaptureConnection setVideoOrientation:orientation];
}
//Set frame rate (if requried)
CMTimeShow(CaptureConnection.videoMinFrameDuration);
CMTimeShow(CaptureConnection.videoMaxFrameDuration);
if (CaptureConnection.supportsVideoMinFrameDuration)
CaptureConnection.videoMinFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
if (CaptureConnection.supportsVideoMaxFrameDuration)
CaptureConnection.videoMaxFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
CMTimeShow(CaptureConnection.videoMinFrameDuration);
CMTimeShow(CaptureConnection.videoMaxFrameDuration);
}
- (void) CameraSetOutputPropertiesBack
{
//SET THE CONNECTION PROPERTIES (output properties)
CaptureConnectionBack = [MovieFileOutputBack connectionWithMediaType:AVMediaTypeVideo];
//Set landscape (if required)
if ([CaptureConnectionBack isVideoOrientationSupported])
{
AVCaptureVideoOrientation orientation = AVCaptureVideoOrientationLandscapeLeft; //<<<<<SET VIDEO ORIENTATION IF LANDSCAPE
[CaptureConnectionBack setVideoOrientation:orientation];
}
//Set frame rate (if requried)
CMTimeShow(CaptureConnectionBack.videoMinFrameDuration);
CMTimeShow(CaptureConnectionBack.videoMaxFrameDuration);
if (CaptureConnectionBack.supportsVideoMinFrameDuration)
CaptureConnectionBack.videoMinFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
if (CaptureConnectionBack.supportsVideoMaxFrameDuration)
CaptureConnectionBack.videoMaxFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
CMTimeShow(CaptureConnectionBack.videoMinFrameDuration);
CMTimeShow(CaptureConnectionBack.videoMaxFrameDuration);
}
- (AVCaptureDevice *)frontCamera {
NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
for (AVCaptureDevice *device in devices) {
if ([device position] == AVCaptureDevicePositionFront) {
return device;
}
}
return nil;
}