[英]Change camera capture device while recording a video
我正在開發一個 iPhone 應用程序。 其中,有暫停和恢復相機的要求。 所以我使用AVFoundation
而不是使用UIImagePickerController
。
我的代碼是:
- (void) startup :(BOOL)isFrontCamera
{
if (_session == nil)
{
NSLog(@"Starting up server");
self.isCapturing = NO;
self.isPaused = NO;
_currentFile = 0;
_discont = NO;
// create capture device with video input
_session = [[AVCaptureSession alloc] init];
AVCaptureDevice *cameraDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if(isFrontCamera)
{
NSArray *videoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *captureDevice = nil;
for (AVCaptureDevice *device in videoDevices)
{
if (device.position == AVCaptureDevicePositionFront)
{
captureDevice = device;
break;
}
}
cameraDevice = captureDevice;
}
cameraDevice=[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:cameraDevice error:nil];
[_session addInput:input];
// audio input from default mic
AVCaptureDevice* mic = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
AVCaptureDeviceInput* micinput = [AVCaptureDeviceInput deviceInputWithDevice:mic error:nil];
[_session addInput:micinput];
// create an output for YUV output with self as delegate
_captureQueue = dispatch_queue_create("uk.co.gdcl.cameraengine.capture", DISPATCH_QUEUE_SERIAL);
AVCaptureVideoDataOutput* videoout = [[AVCaptureVideoDataOutput alloc] init];
[videoout setSampleBufferDelegate:self queue:_captureQueue];
NSDictionary* setcapSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange], kCVPixelBufferPixelFormatTypeKey,
nil];
videoout.videoSettings = setcapSettings;
[_session addOutput:videoout];
_videoConnection = [videoout connectionWithMediaType:AVMediaTypeVideo];
[_videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
NSDictionary* actual = videoout.videoSettings;
_cy = [[actual objectForKey:@"Width"] integerValue];
_cx = [[actual objectForKey:@"Height"] integerValue];
AVCaptureAudioDataOutput* audioout = [[AVCaptureAudioDataOutput alloc] init];
[audioout setSampleBufferDelegate:self queue:_captureQueue];
[_session addOutput:audioout];
_audioConnection = [audioout connectionWithMediaType:AVMediaTypeAudio];
[_session startRunning];
_preview = [AVCaptureVideoPreviewLayer layerWithSession:_session];
_preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
}
}
在這里,當我將相機更改為 Front 時,我遇到了問題。 當我通過將相機更改為前置來調用上述方法時,預覽層卡住了,並且沒有預覽。 我的疑問是“我們可以在捕獲會話的中間更換捕獲設備嗎?”。 請指導我哪里出錯(或)向我建議有關如何在錄制時在前后攝像頭之間導航的解決方案。
提前致謝。
是的你可以。 您只需要滿足幾件事。
我現在正在使用這兩個函數,它在會話運行時工作。
- (void)configureVideoWithDevice:(AVCaptureDevice *)camera {
[_session beginConfiguration];
[_session removeInput:_videoInputDevice];
_videoInputDevice = nil;
_videoInputDevice = [AVCaptureDeviceInput deviceInputWithDevice:camera error:nil];
if ([_session canAddInput:_videoInputDevice]) {
[_session addInput:_videoInputDevice];
}
[_session removeOutput:_videoDataOutput];
_videoDataOutput = nil;
_videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
[_videoDataOutput setSampleBufferDelegate:self queue:_outputQueueVideo];
NSDictionary* setcapSettings = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange], kCVPixelBufferPixelFormatTypeKey, nil];
_videoDataOutput.videoSettings = setcapSettings;
[_session addOutput:_videoDataOutput];
_videoConnection = [_videoDataOutput connectionWithMediaType:AVMediaTypeVideo];
if([_videoConnection isVideoOrientationSupported]) {
[_videoConnection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
}
[_session commitConfiguration];
}
- (void)configureAudioWithDevice:(AVCaptureDevice *)microphone {
[_session beginConfiguration];
_audioInputDevice = [AVCaptureDeviceInput deviceInputWithDevice:microphone error:nil];
if ([_session canAddInput:_audioInputDevice]) {
[_session addInput:_audioInputDevice];
}
[_session removeOutput:_audioDataOutput];
_audioDataOutput = nil;
_audioDataOutput = [[AVCaptureAudioDataOutput alloc] init];
[_audioDataOutput setSampleBufferDelegate:self queue:_outputQueueAudio];
[_session addOutput:_audioDataOutput];
_audioConnection = [_audioDataOutput connectionWithMediaType:AVMediaTypeAudio];
[_session commitConfiguration];
}
您不能在會話期間更改 captureDevice。 並且您一次只能運行一個捕獲會話。 您可以結束當前會話並創建一個新會話。 會有一點延遲(可能一兩秒取決於你的 CPU 負載)。
我希望 Apple 允許多個會話或每個會話至少允許多個設備......但他們還沒有......
您是否考慮過進行多個會話,然后再處理視頻文件以將它們合並為一個?
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.