如何在iphone SDK上添加音频到视频文件

I have a video file and an audio file. Is it possible to merge it to one video with with sound file. I think AVMutableComposition should help me, but I still dont understand how. any advices?

我有一个视频文件和一个音频文件。是否可以将其与声音文件合并为一个视频。我认为AVMutableComposition应该对我有所帮助，但我仍然不明白如何。任何建议？

3 个解决方案

#1

Thanks Daniel. I figured it out, its easy.

谢谢Daniel。我想通了，很简单。

AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:audioUrl options:nil];
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:videoUrl options:nil];

AVMutableComposition* mixComposition = [AVMutableComposition composition];

AVMutableCompositionTrack *compositionCommentaryTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio 
                                                                                    preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionCommentaryTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset.duration) 
                                    ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] 
                                     atTime:kCMTimeZero error:nil];

AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo 
                                                                                    preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) 
                               ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] 
                                atTime:kCMTimeZero error:nil];

AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition 
                                                                      presetName:AVAssetExportPresetPassthrough];   

NSString* videoName = @"export.mov";

NSString *exportPath = [NSTemporaryDirectory() stringByAppendingPathComponent:videoName];
NSURL    *exportUrl = [NSURL fileURLWithPath:exportPath];

if ([[NSFileManager defaultManager] fileExistsAtPath:exportPath]) 
{
    [[NSFileManager defaultManager] removeItemAtPath:exportPath error:nil];
}

_assetExport.outputFileType = @"com.apple.quicktime-movie";
DLog(@"file type %@",_assetExport.outputFileType);
_assetExport.outputURL = exportUrl;
_assetExport.shouldOptimizeForNetworkUse = YES;

[_assetExport exportAsynchronouslyWithCompletionHandler:
 ^(void ) {      
            // your completion code here
     }       
 }
 ];

#2

Yes it is possible, here is a snippet of code that is used to add audio to an existing composition, i grabbed this from apples sample code, you should probably view the whole project, youll find it very useful, the project is AVEditDemo and you can find it in the WWDC 2010 material that they posted here developer.apple.com/videos/wwdc/2010. Hope that helps

是的，这是可能的，这里是用于向现有合成添加音频的代码片段，我从苹果示例代码中抓取这个，你应该查看整个项目，你会发现它非常有用，项目是AVEditDemo而你可以在他们发布的WWDC 2010资料中找到它developer.apple.com/videos/wwdc/2010。希望有所帮助

 - (void)addCommentaryTrackToComposition:(AVMutableComposition *)composition withAudioMix:(AVMutableAudioMix *)audioMix

{

NSInteger i;

NSArray *tracksToDuck = [composition tracksWithMediaType:AVMediaTypeAudio]; // before we add the commentary



// Clip commentary duration to composition duration.

CMTimeRange commentaryTimeRange = CMTimeRangeMake(self.commentaryStartTime, self.commentary.duration);

if (CMTIME_COMPARE_INLINE(CMTimeRangeGetEnd(commentaryTimeRange), >, [composition duration]))

    commentaryTimeRange.duration = CMTimeSubtract([composition duration], commentaryTimeRange.start);



// Add the commentary track.

AVMutableCompositionTrack *compositionCommentaryTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

[compositionCommentaryTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, commentaryTimeRange.duration) ofTrack:[[self.commentary tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:commentaryTimeRange.start error:nil];





NSMutableArray *trackMixArray = [NSMutableArray array];

CMTime rampDuration = CMTimeMake(1, 2); // half-second ramps

for (i = 0; i < [tracksToDuck count]; i++) {

    AVMutableAudioMixInputParameters *trackMix = [AVMutableAudioMixInputParameters audioMixInputParametersWithTrack:[tracksToDuck objectAtIndex:i]];

    [trackMix setVolumeRampFromStartVolume:1.0 toEndVolume:0.2 timeRange:CMTimeRangeMake(CMTimeSubtract(commentaryTimeRange.start, rampDuration), rampDuration)];

    [trackMix setVolumeRampFromStartVolume:0.2 toEndVolume:1.0 timeRange:CMTimeRangeMake(CMTimeRangeGetEnd(commentaryTimeRange), rampDuration)];

    [trackMixArray addObject:trackMix];

}

audioMix.inputParameters = trackMixArray;

}

}

#3

Here is the swift version:

这是快速版本：

    func mixAudio(audioURL audioURL: NSURL, videoURL: NSURL) {
    let audioAsset = AVURLAsset(URL: audioURL)
    let videoAsset = AVURLAsset(URL: videoURL)

    let mixComposition = AVMutableComposition()

    let compositionCommentaryTrack = mixComposition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid)

    // add audio
    let timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration)
    let track = audioAsset.tracksWithMediaType(AVMediaTypeAudio)[0]
    do {
        try compositionCommentaryTrack.insertTimeRange(timeRange, ofTrack: track, atTime: kCMTimeZero)
    }
    catch {
        print("Error insertTimeRange for audio track \(error)")
    }

    // add video
    let compositionVideoTrack = mixComposition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)

    let timeRangeVideo = CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
    let trackVideo = videoAsset.tracksWithMediaType(AVMediaTypeVideo)[0]
    do {
        try compositionVideoTrack.insertTimeRange(timeRangeVideo, ofTrack: trackVideo, atTime: kCMTimeZero)
    }
    catch {
        print("Error insertTimeRange for video track \(error)")
    }

    // export
    let assetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetPassthrough)
    let videoName = "export.mov"
    exportPath = "\(NSTemporaryDirectory())/\(videoName)"
    let exportURL = NSURL(fileURLWithPath: exportPath!)

    if NSFileManager.defaultManager().fileExistsAtPath(exportPath!) {
        do {
            try NSFileManager.defaultManager().removeItemAtPath(exportPath!)
        }
        catch {
            print("Error deleting export.mov: \(error)")
        }
    }

    assetExportSession?.outputFileType = "com.apple.quicktime-movie"
    assetExportSession?.outputURL = exportURL
    assetExportSession?.shouldOptimizeForNetworkUse = true
    assetExportSession?.exportAsynchronouslyWithCompletionHandler({ 
        print("Mixed audio and video!")
        dispatch_async(dispatch_get_main_queue(), {
            print(self.exportPath!)

        })
    })

}