我想将CG
Image转换为CMSampleBufferRef,并使用appendSampleBuffer:方法将其附加到AVAssetWriterInput.我设法使用以下代码获取CMSampleBufferRef,但是appendSampleBuffer:在提供生成的CMSampleBufferRef时,只需返回NO.我究竟做错了什么?
- (void) appendCGImage: (CGImageRef) frame
{
const int width = CGImageGetWidth(frame);
const int height = CGImageGetHeight(frame);
// Create a dummy pixel buffer to try the encoding
// on something simple.
CVPixelBufferRef pixelBuffer = NULL;
CVReturn status = CVPixelBufferCreate(kcfAllocatorDefault,width,height,kCVPixelFormatType_32BGRA,NULL,&pixelBuffer);
NSParameterassert(status == kCVReturnSuccess && pixelBuffer != NULL);
// Sample timing info.
CMTime frameTime = CMTimeMake(1,30);
CMTime currentTime = CMTimeAdd(lastSampleTime,frameTime);
CMSampleTimingInfo timing = {frameTime,currentTime,kCMTimeInvalid};
Osstatus result = 0;
// Sample format.
CMVideoFormatDescriptionRef videoInfo = NULL;
result = CMVideoFormatDescriptionCreateForImageBuffer(NULL,pixelBuffer,&videoInfo);
NSParameterassert(result == 0 && videoInfo != NULL);
// Create sample buffer.
CMSampleBufferRef sampleBuffer = NULL;
result = CMSampleBufferCreateForImageBuffer(kcfAllocatorDefault,true,videoInfo,&timing,&sampleBuffer);
NSParameterassert(result == 0 && sampleBuffer != NULL);
// Ship out the frame.
NSParameterassert(CMSampleBufferDataIsReady(sampleBuffer));
NSParameterassert([writerInput isReadyForMoreMediaData]);
BOOL success = [writerInput appendSampleBuffer:frame];
NSParameterassert(success); // no go :(
}
附:我知道这段代码中有内存泄漏,为了简单起见,我省略了一些代码.
解决方法
阿哈,我完全错过了
AVAssetWriterInputPixelBufferAdaptor课程,特别是将像素缓冲区配置为写入器输入.现在的代码工作,即使没有凌乱的CMSampleBuffer的东西.