AVAssetWriterInput参数sourceFormatHint有问题

Question

我正在使用AVAssetWriterInput，但sourceFormatHint参数提供了以下警告：

不兼容的整数到指针转换，将'int‘发送到'CMFormatDescriptionRef’类型的参数(又名'const *')

这是代码：

AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:settings sourceFormatHint:kCMMediaType_Video];
videoWriterInput.expectsMediaDataInRealTime = YES;
videoWriterInput.transform = videoTrack.preferredTransform;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:outputURL fileType:@"public.mpeg-4" error:nil];
[videoWriter addInput:videoWriterInput];

我应该在sourceFormatHint中传递哪些参数

Answer 1

你好，见下面的setUP，它为我工作.：)

-(BOOL) setUpWriter {
NSError* error = nil;
videoWriter = [[AVAssetWriter alloc] initWithURL:[self tempFileURL] fileType:AVFileTypeQuickTimeMovie error:&error];
NSParameterAssert(videoWriter);

//Configure video
NSDictionary* videoCompressionProps = [NSDictionary dictionaryWithObjectsAndKeys:
                                       [NSNumber numberWithDouble:1024*1024], AVVideoAverageBitRateKey,
                                       nil ];




NSDictionary* videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                               AVVideoCodecH264, AVVideoCodecKey,
                               [NSNumber numberWithInt:320.0], AVVideoWidthKey,
                               [NSNumber numberWithInt:568.0], AVVideoHeightKey,
                               videoCompressionProps, AVVideoCompressionPropertiesKey,
                               nil];
videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];
// videoWriterInput =[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings sourceFormatHint:kCMMediaType_Video];

NSParameterAssert(videoWriterInput);
videoWriterInput.expectsMediaDataInRealTime = YES;
NSDictionary* bufferAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                  [NSNumber numberWithInt:kCVPixelFormatType_32ARGB], kCVPixelBufferPixelFormatTypeKey, nil];

avAdaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput sourcePixelBufferAttributes:bufferAttributes] ;

//add input
[videoWriter addInput:videoWriterInput];
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:CMTimeMake(0, 1000)];

return YES;
}