AVMutableComposition
在使用AVAssetExportSession
. 但是,当我尝试在第一个视频轨道之后立即添加另一个视频轨道时,我遇到了问题。1)播放第一个视频,并且在 mov 文件的持续时间内冻结其最后一帧(第二个视频永远不会播放)。2) 在第二个视频完全播放之前,会显示一个黑框。3)会话根本不会导出。
我通过调整视频资产各自的时间范围来获得这些不同的结果insertTimeRange:ofTrack:
.. 方法。
AVURLAsset *firstAsset = [AVURLAsset URLAssetWithURL:vidPathURL options:nil];
AVURLAsset *secondAsset = [AVURLAsset URLAssetWithURL:audPathURL options:nil];
AVURLAsset *thirdAsset = [AVURLAsset URLAssetWithURL:vidPathURL2 options:nil];
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
CMTime nextClipStartTime = CMTimeAdd(kCMTimeZero, firstAsset.duration);
CMTimeRange timeRange = CMTimeRangeMake(kCMTimeZero, thirdAsset.duration);
AVAssetTrack *secondVideoTrack = [[thirdAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
[firstTrack insertTimeRange:timeRange ofTrack:secondVideoTrack atTime:nextClipStartTime error:nil];
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
CGAffineTransform rotationTransform = CGAffineTransformMakeRotation(M_PI_2);
firstTrack.preferredTransform = rotationTransform;
// export session
有谁知道应该在这里调整什么?
谢谢。