iOS合并多个视频(Obj-c&Swift)

0x00 写在前面

1. 需求是把两个或多个小视频合并成一个视频
2. 合并效果为首尾相接，不是视频重叠
3. 当前代码为示例代码，只展示了合并两个视频文件，要实现多个视频文件合并为一个，需要改动代码

0x01 代码展示(Obj-c&Swift)

//Obj-c
- (void)combVideos {
    NSBundle *mainBundle = [NSBundle mainBundle];
    NSString *firstVideo = [mainBundle pathForResource:@"1" ofType:@"mp4"];
    NSString *secondVideo = [mainBundle pathForResource:@"2" ofType:@"mp4"];
    
    NSDictionary *optDict = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:NO] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
    AVAsset *firstAsset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:firstVideo] options:optDict];
    AVAsset *secondAsset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:secondVideo] options:optDict];
    
    AVMutableComposition *composition = [AVMutableComposition composition];
    //为视频类型的的Track
    AVMutableCompositionTrack *compositionTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    //由于没有计算当前CMTime的起始位置，现在插入0的位置,所以合并出来的视频是后添加在前面，可以计算一下时间，插入到指定位置
    //CMTimeRangeMake 指定起去始位置
    CMTimeRange firstTimeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);
    CMTimeRange secondTimeRange = CMTimeRangeMake(kCMTimeZero, secondAsset.duration);
    [compositionTrack insertTimeRange:secondTimeRange ofTrack:[secondAsset tracksWithMediaType:AVMediaTypeVideo][0] atTime:kCMTimeZero error:nil];
    [compositionTrack insertTimeRange:firstTimeRange ofTrack:[firstAsset tracksWithMediaType:AVMediaTypeVideo][0] atTime:kCMTimeZero error:nil];
    
    //只合并视频，导出后声音会消失，所以需要把声音插入到混淆器中
    //添加音频,添加本地其他音乐也可以,与视频一致
    AVMutableCompositionTrack *audioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    [audioTrack insertTimeRange:secondTimeRange ofTrack:[firstAsset tracksWithMediaType:AVMediaTypeAudio][0] atTime:kCMTimeZero error:nil];
    [audioTrack insertTimeRange:firstTimeRange ofTrack:[firstAsset tracksWithMediaType:AVMediaTypeAudio][0] atTime:kCMTimeZero error:nil];
    
    NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
    NSString *filePath = [cachePath stringByAppendingPathComponent:@"comp.mp4"];
    AVAssetExportSession *exporterSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetHighestQuality];
    exporterSession.outputFileType = AVFileTypeMPEG4;
    exporterSession.outputURL = [NSURL fileURLWithPath:filePath]; //如果文件已存在，将造成导出失败
    exporterSession.shouldOptimizeForNetworkUse = YES; //用于互联网传输
    [exporterSession exportAsynchronouslyWithCompletionHandler:^{
        switch (exporterSession.status) {
            case AVAssetExportSessionStatusUnknown:
                NSLog(@"exporter Unknow");
                break;
            case AVAssetExportSessionStatusCancelled:
                NSLog(@"exporter Canceled");
                break;
            case AVAssetExportSessionStatusFailed:
                NSLog(@"exporter Failed");
                break;
            case AVAssetExportSessionStatusWaiting:
                NSLog(@"exporter Waiting");
                break;
            case AVAssetExportSessionStatusExporting:
                NSLog(@"exporter Exporting");
                break;
            case AVAssetExportSessionStatusCompleted:
                NSLog(@"exporter Completed");
                break;
        }
    }];
}

Swift代码:需要先导入 import AVFoundation
*Swift版本注释可参考Obj-c版本*

func combVideos() {
        let firstVideo = NSBundle.mainBundle().pathForResource("1", ofType: "mp4")
        let secondVideo = NSBundle.mainBundle().pathForResource("2", ofType: "mp4")

        let optDict = [AVURLAssetPreferPreciseDurationAndTimingKey : NSNumber(bool: false)]
        let firstAsset = AVURLAsset(URL: NSURL(fileURLWithPath: firstVideo!), options: optDict)
        let secondAsset = AVURLAsset(URL: NSURL(fileURLWithPath: secondVideo!), options: optDict)
        
        let composition = AVMutableComposition()
        do {
            let compositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)
            let firstTimeRange = CMTimeRange(start: kCMTimeZero, duration: firstAsset.duration)
            let secondTimeRange = CMTimeRange(start: kCMTimeZero, duration: secondAsset.duration)
            
            // 添加视频
            try compositionTrack.insertTimeRange(secondTimeRange, ofTrack: secondAsset.tracksWithMediaType(AVMediaTypeVideo).first!, atTime: kCMTimeZero)
            try compositionTrack.insertTimeRange(firstTimeRange, ofTrack: firstAsset.tracksWithMediaType(AVMediaTypeVideo).first!, atTime: kCMTimeZero)
            
            // 添加声音
            let audioTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid)
            try audioTrack.insertTimeRange(secondTimeRange, ofTrack: secondAsset.tracksWithMediaType(AVMediaTypeAudio).first!, atTime: kCMTimeZero)
            try audioTrack.insertTimeRange(firstTimeRange, ofTrack: firstAsset.tracksWithMediaType(AVMediaTypeAudio).first!, atTime: kCMTimeZero)
            
            let cache = NSSearchPathForDirectoriesInDomains(.CachesDirectory, .UserDomainMask, true).last
            let filePath = cache! + "/comp_sw.mp4"
            
            let exporterSession = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetHighestQuality)
            exporterSession?.outputFileType = AVFileTypeMPEG4
            exporterSession?.outputURL = NSURL(fileURLWithPath: filePath)
            exporterSession?.shouldOptimizeForNetworkUse = true
            exporterSession?.exportAsynchronouslyWithCompletionHandler({ () -> Void in
                switch exporterSession!.status {
                case .Unknown:
                    print("unknow")
                case .Cancelled:
                    print("cancelled")
                case .Failed:
                    print("failed")
                case .Waiting:
                    print("waiting")
                case .Exporting:
                    print("exporting")
                case .Completed:
                    print("completed")
                }
            })
        } catch {
            print("\(error)")
        }
    }

0x10 效果 (时间变化)

1.png

2.png

合并后.png

欢迎大家交流指正