Question

我录制了带声音的视频。将其添加到AVMutableComposition然后将其导出时，视频将在播放声音时冻结。我错过了什么？

我有两条曲目：

_compositionVideoTrack = [self.composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
_compositionAudioTrack = [self.composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

然后创建曲目：

AVAssetTrack *clipVideoTrack = [[sourceAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVAssetTrack *clipAudioTrack = [[sourceAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];

然后我插入曲目：

[_compositionVideoTrack insertTimeRange:editRange ofTrack:clipVideoTrack atTime:self.composition.duration error:&editError];
[_compositionAudioTrack insertTimeRange:editRange ofTrack:clipAudioTrack atTime:self.composition.duration error:&editError];

最后我将其导出：

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:urlAsset presetName:AVAssetExportPresetPassthrough];
exportSession.outputFileType = AVFileTypeQuickTimeMovie;

文件是.mp4。它可能是文件格式吗？

Answer 1

尝试使用以下

导出

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:self.inputAsset presetName:AVAssetExportPresetLowQuality];
    exportSession.outputFileType = AVFileTypeQuickTimeMovie;

Answer 2

我认为你应该添加AVMutableVideoCompositionInstruction

Answer 3

你可以尝试这样做：

AVMutableComposition *mutableComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *videoCompositionTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[videoCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration) ofTrack:clipVideoTrack atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *audioCompositionTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[audioCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration) ofTrack:[[asset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];

然后使用可变组合初始化AVAssetExportSession

AVAssetExportSession* exporter = [[AVAssetExportSession alloc] initWithAsset:mutableComposition presetName:AVAssetExportPresetHighestQuality];

希望这会对你有所帮助

AVFoundation AVMutableComposition - 带音频的视频 - 冻结视频

3 个答案: