CMSampleBufferRef 转 image

CVImageBufferRef buffer;
buffer = CMSampleBufferGetImageBuffer(sampleBuffer);

CVPixelBufferLockBaseAddress(buffer, 0);
uint8_t *base;
size_t width, height, bytesPerRow;
base = (uint8_t *)CVPixelBufferGetBaseAddress(buffer);
width = CVPixelBufferGetWidth(buffer);
height = CVPixelBufferGetHeight(buffer);
bytesPerRow = CVPixelBufferGetBytesPerRow(buffer);

CGColorSpaceRef colorSpace;
CGContextRef cgContext;
colorSpace = CGColorSpaceCreateDeviceRGB();
cgContext = CGBitmapContextCreate(base, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGColorSpaceRelease(colorSpace);

CGImageRef cgImage;
UIImage *image;
cgImage = CGBitmapContextCreateImage(cgContext);
image = [UIImage imageWithCGImage:cgImage];
CGImageRelease(cgImage);
CGContextRelease(cgContext);

CVPixelBufferUnlockBaseAddress(buffer, 0);