带音频的CVPixelBuffer

Question

我使用AVFoundation从摄像头捕获CMSampleBufferRef，然后将其转换为CVPixelBufferRef以写入视频。我想做的是修改视频帧内的一些像素。这就是为什么我需要从我的CMSampleBuffer中取出CVPixelBufferRef。我的问题是我不能在我的新CVPixelBufferRef中包含原始CMSampleBuffer的音频数据

我还尝试用CVPixelBufferRef重新创建CMSampleBuffer，但返回错误：

- (CMSampleBufferRef)newModifyImage:(CMSampleBufferRef)sampleBuffer {
    CVImageBufferRef cvimgRef = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(cvimgRef,0);

    uint8_t *buf=(uint8_t *)CVPixelBufferGetBaseAddress(cvimgRef);

    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(cvimgRef); 
    size_t width = CVPixelBufferGetWidth(cvimgRef); 
    size_t height = CVPixelBufferGetHeight(cvimgRef); 


    CVPixelBufferRef pixelBufRef = NULL;
    CMSampleBufferRef newSampleBuffer = NULL;
    CMSampleTimingInfo timimgInfo = kCMTimingInfoInvalid;
    CMSampleBufferGetSampleTimingInfo(sampleBuffer, 0, &timimgInfo);

    OSStatus result = 0;

    OSType pixFmt = CVPixelBufferGetPixelFormatType(cvimgRef);

    CVPixelBufferCreateWithBytes(kCFAllocatorDefault, width, height, pixFmt, buf, bytesPerRow, NULL, NULL, NULL, &pixelBufRef);

    CMVideoFormatDescriptionRef videoInfo = NULL;

    result = CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixelBufRef, &videoInfo);

    CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixelBufRef, true, NULL, NULL, videoInfo, &timimgInfo, &newSampleBuffer);
    return newSampleBuffer;
}

Answer 1

检查RosyWriter示例代码http://developer.apple.com/library/ios/#samplecode/RosyWriter/Introduction/Intro.html%23//apple_ref/doc/uid/DTS40011110

它从样本缓冲区中写入视频和音频