如何附加两个音频文件？

Question

我想在iPhone中附加两个音频文件。请帮助我做到这一点。

Answer 1

我得到了解决方案;以下是执行此操作的示例代码。

AVMutableComposition* composition = [AVMutableComposition composition]; 
AVURLAsset* audioAsset1 = [[AVURLAsset alloc]initWithURL:[NSURL fileURLWithPath:filePath1] options:nil]; 
AVURLAsset* audioAsset2 = [[AVURLAsset alloc]initWithURL:[NSURL fileURLWithPath:filePath2] options:nil]; 

AVMutableCompositionTrack *audioTrack1 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio 
                     preferredTrackID:kCMPersistentTrackID_Invalid]; 

[audioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset1.duration) 
         ofTrack:[[audioAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] 
          atTime:kCMTimeZero 
          error:&error]; 
[audioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset2.duration) 
         ofTrack:[[audioAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] 
          atTime:audioAsset1.duration 
          error:&error];

最后，我们必须使用AVAssetExportSession将它作为单个文件导出。

注：这只会工作，为的.m4a文件

Answer 2

- (BOOL) combineVoices1 
{ 
    NSError *error = nil; 
    BOOL ok = NO; 


    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0]; 


    CMTime nextClipStartTime = kCMTimeZero; 
    //Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack. 
    AVMutableComposition *composition = [[AVMutableComposition alloc] init]; 

    AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
    [compositionAudioTrack setPreferredVolume:0.8]; 
    NSString *soundOne =[[NSBundle mainBundle]pathForResource:@"test1" ofType:@"caf"]; 
    NSURL *url = [NSURL fileURLWithPath:soundOne]; 
    AVAsset *avAsset = [AVURLAsset URLAssetWithURL:url options:nil]; 
    NSArray *tracks = [avAsset tracksWithMediaType:AVMediaTypeAudio]; 
    AVAssetTrack *clipAudioTrack = [[avAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]; 
    [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset.duration) ofTrack:clipAudioTrack atTime:kCMTimeZero error:nil]; 

    AVMutableCompositionTrack *compositionAudioTrack1 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
    [compositionAudioTrack setPreferredVolume:0.3]; 
    NSString *soundOne1 =[[NSBundle mainBundle]pathForResource:@"test" ofType:@"caf"]; 
    NSURL *url1 = [NSURL fileURLWithPath:soundOne1]; 
    AVAsset *avAsset1 = [AVURLAsset URLAssetWithURL:url1 options:nil]; 
    NSArray *tracks1 = [avAsset1 tracksWithMediaType:AVMediaTypeAudio]; 
    AVAssetTrack *clipAudioTrack1 = [[avAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]; 
    [compositionAudioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset.duration) ofTrack:clipAudioTrack1 atTime:kCMTimeZero error:nil]; 


    AVMutableCompositionTrack *compositionAudioTrack2 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
    [compositionAudioTrack2 setPreferredVolume:1.0]; 
    NSString *soundOne2 =[[NSBundle mainBundle]pathForResource:@"song" ofType:@"caf"]; 
    NSURL *url2 = [NSURL fileURLWithPath:soundOne2]; 
    AVAsset *avAsset2 = [AVURLAsset URLAssetWithURL:url2 options:nil]; 
    NSArray *tracks2 = [avAsset2 tracksWithMediaType:AVMediaTypeAudio]; 
    AVAssetTrack *clipAudioTrack2 = [[avAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]; 
    [compositionAudioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset2.duration) ofTrack:clipAudioTrack2 atTime:kCMTimeZero error:nil]; 



    AVAssetExportSession *exportSession = [AVAssetExportSession 
              exportSessionWithAsset:composition 
              presetName:AVAssetExportPresetAppleM4A]; 
    if (nil == exportSession) return NO; 

    NSString *soundOneNew = [documentsDirectory stringByAppendingPathComponent:@"combined10.m4a"]; 
    //NSLog(@"Output file path - %@",soundOneNew); 

    // configure export session output with all our parameters 
    exportSession.outputURL = [NSURL fileURLWithPath:soundOneNew]; // output path 
    exportSession.outputFileType = AVFileTypeAppleM4A; // output file type 

    // perform the export 
    [exportSession exportAsynchronouslyWithCompletionHandler:^{ 

     if (AVAssetExportSessionStatusCompleted == exportSession.status) { 
      NSLog(@"AVAssetExportSessionStatusCompleted"); 
     } else if (AVAssetExportSessionStatusFailed == exportSession.status) { 
      // a failure may happen because of an event out of your control 
      // for example, an interruption like a phone call comming in 
      // make sure and handle this case appropriately 
      NSLog(@"AVAssetExportSessionStatusFailed"); 
     } else { 
      NSLog(@"Export Session Status: %d", exportSession.status); 
     } 
    }]; 


    return YES; 


}