我正在使用AVAssetWriter / AVAssetReader将PCM音频文件转码为AAC。我把它归结为一个在iOS6中工作但在iOS7中失败的简单项目。
一切顺利,直到我到[self.assetWriter finishWritingWithCompletionHandler:]然后,assetWriter进入失败状态,错误设置为-11800 AVFoundation未知错误,内部错误设置为-12733,显然对应于SampleBufferNotReady
dispatch_queue_t queue = dispatch_queue_create("audio.encode", DISPATCH_QUEUE_SERIAL);
success = [self.assetWriter startWriting];
if (!success)
{
[self showStatus:@"Export: writer failed to startWriting"];
return;
}
[self.assetWriter startSessionAtSourceTime:kCMTimeZero];
[assetWriterInput requestMediaDataWhenReadyOnQueue:queue
usingBlock:
^{
while([assetWriterInput isReadyForMoreMediaData])
{
NSAssert (self.assetWriter.status == AVAssetWriterStatusWriting, nil);
CMSampleBufferRef sampleBuffer = [assetReaderOutput copyNextSampleBuffer];
if (sampleBuffer)
{
NSAssert (CMSampleBufferIsValid(sampleBuffer), nil);
NSAssert (CMSampleBufferDataIsReady(sampleBuffer), nil);
BOOL success = [assetWriterInput appendSampleBuffer:sampleBuffer];
if (!success)
{
[self showError:self.assetWriter.error];
self.assetWriter = nil;
CFRelease(sampleBuffer);
return;
}
CFRelease(sampleBuffer);
}
else
{
if ([assetReader status] == AVAssetReaderStatusCompleted)
{
[assetWriterInput markAsFinished];
[self.assetWriter finishWritingWithCompletionHandler:^{
BOOL success = self.assetWriter.status == AVAssetWriterStatusCompleted;
if (success)
{
[self showStatus: @"Did it!"];
self.assetWriter = nil;
}
else
{
[self showError:self.assetWriter.error];
self.assetWriter = nil;
}
}];
}
else
{
[self showError:assetReader.error];
self.assetWriter = nil;
}
}
}
}
];
注意:我发布了Apple的一个错误,发布到开发论坛并使用了TSI。还没有得到任何答案。我的希望是你们中的一位天才会指出我的解决方法。
答案 0 :(得分:5)
我和你有同样的问题,但最后我解决了这个问题,我使用这种方法:
CMTime cmTime = CMTimeMake(longDuration, 1);
[assetWriter endSessionAtSourceTime:cmTime];
[assetWriter finishWritingWithCompletionHandler^(){
NSLog (@"finished writing");
];
如果我们调用finishWritingWithCompletionHandler,通常我们不需要调用它; 我希望这能解决你的问题。