Question

我在iOS 7上使用OpenGL将前置摄像头视频捕捉渲染为UIView 在iPhone显示屏上（同样的iphone 5）。我正在使用AVCaptureSessionPreset640x480 并将其传递给AVCaptureSession方法

[captureSession setSessionPreset:AVCaptureSessionPreset640x480];

然而，渲染视频的分辨率似乎低于上面设置的分辨率，它似乎是AVCaptureSessionPreset352x288。事实上，无论我经过什么从这些没有区别，分辨率是相同的

NSString *const AVCaptureSessionPresetPhoto;
NSString *const AVCaptureSessionPresetHigh;
NSString *const AVCaptureSessionPresetMedium;
NSString *const AVCaptureSessionPresetLow;
NSString *const AVCaptureSessionPreset352x288;
NSString *const AVCaptureSessionPreset640x480;
NSString *const AVCaptureSessionPreset1280x720;
NSString *const AVCaptureSessionPreset1920x1080;
NSString *const AVCaptureSessionPresetiFrame960x540;
NSString *const AVCaptureSessionPresetiFrame1280x720;
NSString *const AVCaptureSessionPresetInputPriority;

如何查看相机实际拍摄的分辨率？

由于

Answer 1

读取正在捕获的缓冲区的尺寸，如下所示（对于AVCaptureSessionPresetPhoto，您需要捕获静止图像，当然，而不是阅读视频帧...）：

- (void) captureOutput:(AVCaptureOutput *)captureOutput
       didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
              fromConnection:(AVCaptureConnection *)connection
  {
    CVPixelBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(imageBuffer,0);
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);
    CVPixelBufferUnlockBaseAddress(imageBuffer,0);

    // "width" and "height" now hold your dimensions...

  }

检查相机的iOS捕获分辨率

1 个答案: