使用 CVPixelBufferCreate 复制/复制 CVPixelBufferRef

Question

我需要创建 a 的副本，CVPixelBufferRef以便能够使用副本中的值以按位方式操作原始像素缓冲区。我似乎无法通过CVPixelBufferCreate, 或CVPixelBufferCreateWithBytes.

根据这个问题，它也可以用 memcpy() 来完成。但是，没有解释如何实现这一点，并且无论如何都需要调用哪些核心视频库。

Answer 1

这似乎有效：

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {

    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

    // Get pixel buffer info
    const int kBytesPerPixel = 4;
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    int bufferWidth = (int)CVPixelBufferGetWidth(pixelBuffer);
    int bufferHeight = (int)CVPixelBufferGetHeight(pixelBuffer);
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(pixelBuffer); 
    uint8_t *baseAddress = CVPixelBufferGetBaseAddress(pixelBuffer);

    // Copy the pixel buffer
    CVPixelBufferRef pixelBufferCopy = NULL;
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, bufferWidth, bufferHeight, kCVPixelFormatType_32BGRA, NULL, &pixelBufferCopy);
    CVPixelBufferLockBaseAddress(pixelBufferCopy, 0);
    uint8_t *copyBaseAddress = CVPixelBufferGetBaseAddress(pixelBufferCopy);
    memcpy(copyBaseAddress, baseAddress, bufferHeight * bytesPerRow);

    // Do what needs to be done with the 2 pixel buffers

}