如何从CMSampleBufferRef中将视频帧导出到NSData

// 导出视频帧到NSData
- (NSData *)exportVideoFrameFromSampleBuffer:(CMSampleBufferRef)sampleBuffer {
    // 将CMSampleBufferRef转换为CVPixelBufferRef
    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    
    // 获取像素缓冲区的基地址和行字节数
    void *baseAddress = CVPixelBufferGetBaseAddress(pixelBuffer);
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(pixelBuffer);
    
    // 计算数据的长度
    size_t bufferSize = CVPixelBufferGetHeight(pixelBuffer) * bytesPerRow;
    
    // 创建NSData对象并复制像素缓冲区的数据
    NSData *data = [NSData dataWithBytes:baseAddress length:bufferSize];
    
    // 解锁像素缓冲区的基地址
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
    
    return data;
}