AVF 11 - 混合音频 AudioMix

AVF 11 - 混合音频

---

一、简要说明

相关类

• AVAudioMix
  • AVMutableAudioMix
• AVAudioMixInputParameters
  • AVMutableAudioMixInputParameters

---

二、使用

- (void)testCom3{
    
        //创建一个音视频组合轨道
    AVMutableComposition *mainComposition = [[AVMutableComposition alloc]init];
    
        //可变音视频轨道添加一个 视频通道
    AVMutableCompositionTrack *compositionVideoTrack = [mainComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    
        //可变音视频轨道添加一个 音频通道
    AVMutableCompositionTrack *compositionAudioTrack = [mainComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    
#pragma mark - 获取音视频 track
    
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:self.movieFile1 options:nil];  // URLHookmark
   //    AVURLAsset *videoAsset2 = [[AVURLAsset alloc] initWithURL:self.movieFile2 options:nil];  // FurShader 无声
    
        //视频通道数组
    NSArray<AVAssetTrack *> *videoTrackers = [asset tracksWithMediaType:AVMediaTypeVideo];
    if (0 >= videoTrackers.count) {
        NSLog(@"数据获取失败");
        return ;
    }
    
        //获取第一个视频通道
    AVAssetTrack *video_track = [videoTrackers objectAtIndex:0];
    
        //获取音频轨道数组
    NSArray<AVAssetTrack *> *audioTrackers = [asset tracksWithMediaType:AVMediaTypeAudio];
    if (0 >= audioTrackers.count) {
        NSLog(@"获取音频数据失败");
        return;
    }
        //获取第一个音频轨道
    AVAssetTrack *audio_track = [audioTrackers objectAtIndex:0];
    
    
#pragma mark - 将获取的视轨倒入杯子
    
        //视频时间
    float video_times = (float)asset.duration.value / (float)asset.duration.timescale;
    
    compositionVideoTrack.preferredTransform = video_track.preferredTransform;
    NSError *error = nil;
    
        //把视频轨道数据加入到可变轨道之中
    [compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
                                   ofTrack:video_track
                                    atTime:kCMTimeZero
                                     error:&error];
    if (error) {
        NSLog(@"error;%@",error);
        return;
    }
        //*****************************************************
    
    int audio_time_scale = audio_track.naturalTimeScale;
    
    
        //获取音频的时间
    CMTime audio_duration = CMTimeMake(video_times * audio_time_scale, audio_time_scale);
    
        //将音频轨道加入到可变轨道中
    [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audio_duration)
                                   ofTrack:audio_track
                                    atTime:kCMTimeZero
                                     error:&error];
    if (error) {
        NSLog(@"音轨error:%@",error);
        return;
    }
    
#pragma mark - 再加入一个音轨
    
    NSURL *mixAssetUrl = self.musicFile1;
    
        //增加音轨
        //采集资源
    AVURLAsset *mixAsset = [[AVURLAsset alloc]initWithURL:mixAssetUrl options:nil];
    NSArray<AVAssetTrack *> *audioTrackers_mix = [mixAsset tracksWithMediaType:AVMediaTypeAudio];
    if (0 >= audioTrackers_mix.count) {
        NSLog(@"获取第二音轨资源失败");
        return;
    }
    
        //可变音视轨道再添加一个 音轨
    AVMutableCompositionTrack *mixAudioTrack = [mainComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];//第二音轨
    
        //将采集到数据加入到第二音轨
    [mixAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audio_duration)
                           ofTrack:[audioTrackers_mix objectAtIndex:0]
                            atTime:kCMTimeZero
                             error:&error];
    
    NSLog(@"tracks : %@",mainComposition.tracks);
    /* (
         "",
         "",
         ""
     ) */
    
//    [self saveComposition:mainComposition];
    
#pragma mark - 视频操作指令集合
    //视频操作指令集合
    AVMutableVideoComposition *select_videoComposition = [AVMutableVideoComposition videoCompositionWithPropertiesOfAsset:mainComposition];
    
    AVMutableVideoComposition *first_vcn = [AVMutableVideoComposition videoCompositionWithPropertiesOfAsset:asset];
    
    select_videoComposition.renderSize = first_vcn.renderSize;  // (width = 1280, height = 720)
    
#pragma mark - AudioMix 操作
    //获取第一个音频轨道
    AVMutableAudioMixInputParameters *firstAudioParam = [AVMutableAudioMixInputParameters audioMixInputParametersWithTrack:compositionAudioTrack];
    
    float firstStartVolume = 0 ;
    float firstEndVolume = 0.1;
    
    //设置第一个音轨音量
    [firstAudioParam setVolumeRampFromStartVolume:firstStartVolume toEndVolume:firstEndVolume timeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)];
    
    
    //第二个音频轨道
    AVMutableAudioMixInputParameters *secondAudioParam = [AVMutableAudioMixInputParameters audioMixInputParametersWithTrack:mixAudioTrack];
    
    float secondStartVolume = 0.3;
    float secondEndVolume = 1;
    
    [secondAudioParam setVolumeRampFromStartVolume:secondStartVolume toEndVolume:secondEndVolume timeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)];
    
    //
    AVMutableAudioMix *videoAudioMixTools = [AVMutableAudioMix audioMix];
    videoAudioMixTools.inputParameters = @[firstAudioParam,secondAudioParam];
    
    
//    [self saveComposition:mainComposition];
    
    
#pragma mark - 保存
    NSURL *composedMovieUrl = [self getSaveURLWithExtension:@"m4a"];
    
    AVAssetExportSession *assetExportSession = [[AVAssetExportSession alloc] initWithAsset:mainComposition
                                                                                presetName:AVAssetExportPreset1280x720];
    
    
    assetExportSession.outputFileType              = AVFileTypeQuickTimeMovie;
    assetExportSession.outputURL                   = composedMovieUrl;
    assetExportSession.shouldOptimizeForNetworkUse = YES;
    
    assetExportSession.audioMix = videoAudioMixTools;
    
    [self startExport:assetExportSession];
    
    return;
    
#pragma mark - 播放
    
    AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:mainComposition];
    [item setAudioMix:videoAudioMixTools];
    
    AVPlayer *tmpPlayer = [AVPlayer playerWithPlayerItem:item];
    self.player = tmpPlayer;
    
    AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
    playerLayer.frame = NSMakeRect(0, 0, 300, 300);
    playerLayer.videoGravity = AVLayerVideoGravityResize;
    
    
    self.window.contentView.wantsLayer = YES;
    [self.window.contentView.layer addSublayer:playerLayer ];
 
    [self.player play];
}



- (NSURL *)getSaveURLWithExtension:(NSString *)extension{
    
    NSTimeInterval timestamp = [NSDate timeIntervalSinceReferenceDate];
    NSString *filename = [NSString stringWithFormat:@"%f.%@", timestamp,extension];
    NSString *docsDir = NSSearchPathForDirectoriesInDomains(NSDesktopDirectory, NSUserDomainMask, YES).firstObject;
    NSString *composedMoviePath = [docsDir stringByAppendingPathComponent:filename];
    
    // 保存設定
    NSURL *composedMovieUrl = [NSURL fileURLWithPath:composedMoviePath];
    
    NSLog(@"composedMovieUrl : %@",composedMovieUrl);
    
    return composedMovieUrl;
}

- (void)saveComposition:(AVMutableComposition *)composition{
    
    NSURL *composedMovieUrl = [self getSaveURLWithExtension:@"m4a"];
    
    AVAssetExportSession *assetExportSession = [[AVAssetExportSession alloc] initWithAsset:composition
                                                                                presetName:AVAssetExportPreset1280x720];
    
   
    assetExportSession.outputFileType              = AVFileTypeQuickTimeMovie;
    assetExportSession.outputURL                   = composedMovieUrl;
    assetExportSession.shouldOptimizeForNetworkUse = YES;
    
    [self startExport:assetExportSession];
    
}