这里只列出视频合成的核心代码,具体的请参考附件。
- (IBAction)MergeAndSave:(id)sender { if(firstAsset != nil && secondAsset != nil){ [ActivityView startAnimating]; 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]; AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid]; [secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:firstAsset.duration error:nil]; if(audioAsset != nil){ AVMutableCompositionTrack *AudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; [AudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, CMTimeAdd(firstAsset.duration, secondAsset.duration)) ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil]; } AVMutableVideoCompositionInstruction *MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction]; MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeAdd(firstAsset.duration, secondAsset.duration)); AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack]; AVAssetTrack *FirstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; UIImageOrientation FirstAssetOrientation_ = UIImageOrientationUp; BOOL isFirstAssetPortrait_ = NO; CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform; if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0) {FirstAssetOrientation_= UIImageOrientationRight; isFirstAssetPortrait_ = YES;} if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0) {FirstAssetOrientation_ = UIImageOrientationLeft; isFirstAssetPortrait_ = YES;} if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0) {FirstAssetOrientation_ = UIImageOrientationUp;} if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) {FirstAssetOrientation_ = UIImageOrientationDown;} CGFloat FirstAssetScaleToFitRatio = 320.0 / FirstAssetTrack.naturalSize.width; if(isFirstAssetPortrait_) { FirstAssetScaleToFitRatio = 320.0 / FirstAssetTrack.naturalSize.height; CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero]; } else { CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); [FirstlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 160)) atTime:kCMTimeZero]; } [FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration]; AVMutableVideoCompositionLayerInstruction *SecondlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:secondTrack]; AVAssetTrack *SecondAssetTrack = [[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; UIImageOrientation SecondAssetOrientation_ = UIImageOrientationUp; BOOL isSecondAssetPortrait_ = NO; CGAffineTransform secondTransform = SecondAssetTrack.preferredTransform; if(secondTransform.a == 0 && secondTransform.b == 1.0 && secondTransform.c == -1.0 && secondTransform.d == 0) {SecondAssetOrientation_= UIImageOrientationRight; isSecondAssetPortrait_ = YES;} if(secondTransform.a == 0 && secondTransform.b == -1.0 && secondTransform.c == 1.0 && secondTransform.d == 0) {SecondAssetOrientation_ = UIImageOrientationLeft; isSecondAssetPortrait_ = YES;} if(secondTransform.a == 1.0 && secondTransform.b == 0 && secondTransform.c == 0 && secondTransform.d == 1.0) {SecondAssetOrientation_ = UIImageOrientationUp;} if(secondTransform.a == -1.0 && secondTransform.b == 0 && secondTransform.c == 0 && secondTransform.d == -1.0) {SecondAssetOrientation_ = UIImageOrientationDown;} CGFloat SecondAssetScaleToFitRatio = 320.0 / SecondAssetTrack.naturalSize.width; if(isSecondAssetPortrait_) { SecondAssetScaleToFitRatio = 320.0 / SecondAssetTrack.naturalSize.height; CGAffineTransform SecondAssetScaleFactor = CGAffineTransformMakeScale(SecondAssetScaleToFitRatio,SecondAssetScaleToFitRatio); [SecondlayerInstruction setTransform:CGAffineTransformConcat(SecondAssetTrack.preferredTransform, SecondAssetScaleFactor) atTime:firstAsset.duration]; } else { ; CGAffineTransform SecondAssetScaleFactor = CGAffineTransformMakeScale(SecondAssetScaleToFitRatio,SecondAssetScaleToFitRatio); [SecondlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(SecondAssetTrack.preferredTransform, SecondAssetScaleFactor),CGAffineTransformMakeTranslation(0, 160)) atTime:firstAsset.duration]; } MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,SecondlayerInstruction, nil];; AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition]; MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction]; MainCompositionInst.frameDuration = CMTimeMake(1, 30); MainCompositionInst.renderSize = CGSizeMake(320.0, 480.0); NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000]]; NSURL *url = [NSURL fileURLWithPath:myPathDocs]; AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality]; exporter.outputURL = url; exporter.outputFileType = AVFileTypeQuickTimeMovie; exporter.videoComposition = MainCompositionInst; exporter.shouldOptimizeForNetworkUse = YES; [exporter exportAsynchronouslyWithCompletionHandler:^ { dispatch_async(dispatch_get_main_queue(), ^{ [self exportDidFinish:exporter]; }); }]; } }