IOS Toggle AVFoundation相机 [英] IOS Toggle AVFoundation Camera
本文介绍了IOS Toggle AVFoundation相机的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
在我的应用程序中,我正在使用AVFoundation捕获图像
In my App I'm capturing images using AVFoundation
我按下了一个按钮,可以在前后摄像头之间切换,但是它不起作用.
I made a button to switch between front and back cameras but it won't work.
这是我使用的代码:
if (captureDevice.position == AVCaptureDevicePositionFront) {
for ( AVCaptureDevice *device in [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] ) {
if ( device.position == AVCaptureDevicePositionBack) {
NSError * error;
AVCaptureDeviceInput * newDeviceInput = [[AVCaptureDeviceInput alloc]initWithDevice:device error:&error];
[captureSesion beginConfiguration];
for (AVCaptureDeviceInput *oldInput in [captureSesion inputs]) {
[captureSesion removeInput:oldInput];
}
if ([captureSesion canAddInput:newDeviceInput]) {
[captureSesion addInput:newDeviceInput];
}
[captureSesion commitConfiguration];
break;
}
}
}
THX.
推荐答案
如果您的captureSession的sessionPreset
与要切换到的相机不兼容,则将无法通过canAddInput
测试.在切换相机之前,我总是重置为AVCaptureSessionPresetHigh
,然后尝试将其切换为我喜欢的任何预设.这是我使用的代码:
If your captureSession's sessionPreset
is not compatible with the camera you're switching to it will fail the canAddInput
test. I always reset to AVCaptureSessionPresetHigh
before toggling cameras then try to switch it to whatever preset I have preferred. Here's the code I use:
- (void)toggleCamera {
AVCaptureDevicePosition newPosition = self.currentCameraPossition == AVCaptureDevicePositionBack ? AVCaptureDevicePositionFront : AVCaptureDevicePositionBack;
AVCaptureDevice *device = [self videoDeviceWithPosition:newPosition];
AVCaptureDeviceInput *deviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:device error:nil];
[_captureSession beginConfiguration];
[_captureSession removeInput:self.deviceInput];
[_captureSession setSessionPreset:AVCaptureSessionPresetHigh]; //Always reset preset before testing canAddInput because preset will cause it to return NO
if ([_captureSession canAddInput:deviceInput]) {
[_captureSession addInput:deviceInput];
self.deviceInput = deviceInput;
self.currentCameraPossition = newPosition;
} else {
[_captureSession addInput:self.deviceInput];
}
if ([device supportsAVCaptureSessionPreset:self.sessionPreset]) {
[_captureSession setSessionPreset:self.sessionPreset];
}
if ([device lockForConfiguration:nil]) {
[device setSubjectAreaChangeMonitoringEnabled:YES];
[device unlockForConfiguration];
}
[_captureSession commitConfiguration];
}
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