相关疑难解决方法(0)

我正在使用AVFoundation并从中获取样本缓冲区AVCaptureVideoDataOutput,我可以使用以下命令将其直接写入videoWriter:

- (void)writeBufferFrame:(CMSampleBufferRef)sampleBuffer {
    CMTime lastSampleTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);    
    if(self.videoWriter.status != AVAssetWriterStatusWriting)
    {
        [self.videoWriter startWriting];
        [self.videoWriter startSessionAtSourceTime:lastSampleTime];
    }

    [self.videoWriterInput appendSampleBuffer:sampleBuffer];

}

我现在要做的是在CMSampleBufferRef中裁剪和缩放图像,而不将其转换为UIImage或CGImageRef,因为这会降低性能.