尝试通过 AVAssetWriter 和 AVAssetWriterInput 方法将多个视频连接为一个时。在第三个视频之后,我收到来自 AVAssetWriter.error 的“无法编码”错误。
此外,我可以通过控制台看到成功读取缓冲区,但只有最后一次成功读取的视频才会在连接的 mov 中结束。任何对任何一个或两个问题的见解都值得赞赏,来源和日志如下。谢谢
+(void)doWriteWithVideoWriter:(AVAssetWriter *)videoWriter withIndex:(int)index withWriterInputArray:(NSMutableArray *)writersArray withInstance:(VideoCombinerManager *)theInstance{
if ([writersArray count] > 0)
{
int newIndex = index+1;
NSError *readerError;
NSDictionary *videoOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
AVAsset *sourceAsset = [theInstance.loadedAssetsForCompilationDictionary objectForKey:[theInstance.sortedKeysArray objectAtIndex:index]];
AVAssetTrack *videoTrack = [[sourceAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVAssetReaderTrackOutput *currentReaderTrackOutput = [[AVAssetReaderTrackOutput alloc] initWithTrack:videoTrack outputSettings:videoOptions];
AVAssetReader *currentReader = [[AVAssetReader alloc] initWithAsset:sourceAsset error:&readerError];
[currentReader addOutput:currentReaderTrackOutput];
[currentReader startReading];
AVAssetWriterInput *writerInput = [[writersArray objectAtIndex:0] retain];
dispatch_queue_t _processingQueue = dispatch_queue_create("asdf", NULL);
[writerInput requestMediaDataWhenReadyOnQueue:_processingQueue usingBlock:^{
if ([writerInput isReadyForMoreMediaData])
{
CMSampleBufferRef nextSampleBuffer;
if ([currentReader status] == AVAssetReaderStatusReading &&
(nextSampleBuffer = [currentReaderTrackOutput copyNextSampleBuffer])) {
if (nextSampleBuffer)
{
BOOL result = [writerInput appendSampleBuffer:nextSampleBuffer];
if (!result)
{
NSLog(@"videoWriter.error.userInfo: %@", videoWriter.error.userInfo);
}
CFRelease(nextSampleBuffer);
}
}
else
{
NSLog(@"writer done: %d", index);
dispatch_release(_processingQueue);
[writersArray removeObjectAtIndex:0];
[writerInput markAsFinished];
[writerInput release];
[currentReader release];
[currentReaderTrackOutput release];
[VideoCombinerManager doWriteWithVideoWriter:videoWriter withIndex:newIndex withWriterInputArray:writersArray withInstance:theInstance];
}
}
}];
}
else
[videoWriter finishWriting];
}
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videoWriter.error.userInfo: {
NSLocalizedDescription = "Cannot Encode";
NSLocalizedFailureReason = "The encoder required for this media is busy.";
NSLocalizedRecoverySuggestion = "Stop any other actions that encode media and try again.";
NSUnderlyingError = "Error Domain=NSOSStatusErrorDomain Code=-12915 \"The operation couldn\U2019t be completed. (OSStatus error -12915.)\"";
}
videoWriter.error.userInfo: {
NSLocalizedDescription = "Cannot Encode";
NSLocalizedFailureReason = "The encoder required for this media is busy.";
NSLocalizedRecoverySuggestion = "Stop any other actions that encode media and try again.";
NSUnderlyingError = "Error Domain=NSOSStatusErrorDomain Code=-12915 \"The operation couldn\U2019t be completed. (OSStatus error -12915.)\"";
}