[NSMutableArray objectAtIndex：]：索引0超出AVURLAsset的空数组范围

问题描述：

我试着用下面的代码合并音频。[NSMutableArray objectAtIndex：]：索引0超出AVURLAsset的空数组范围

AVMutableComposition* composition = [AVMutableComposition composition]; 
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:audioURL options:nil]; 
AVURLAsset* audioAsset1 = [[AVURLAsset alloc]initWithURL:audioURL1 options:nil]; 
AVURLAsset* audioAsset2 = [[AVURLAsset alloc]initWithURL:audioURL1 options:nil]; 
AVMutableCompositionTrack *compositionVideoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
NSError* error = NULL; 
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,videoAsset.duration) 
             ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo]objectAtIndex:0] 
             atTime:kCMTimeZero 
AVMutableCompositionTrack *compositionAudioTrack1 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
     [compositionAudioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero,audioAsset1.duration) 
             ofTrack:[[audioAsset1 tracksWithMediaType:AVMediaTypeAudio]objectAtIndex:0] 
             atTime:kCMTimeZero 
             error:&error]; 
AVMutableCompositionTrack *compositionAudioTrack2 = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid]; 
     [compositionAudioTrack2 insertTimeRange:CMTimeRangeMake(kCMTimeZero,audioAsset2.duration) 
             ofTrack:[[audioAsset2 tracksWithMediaType:AVMediaTypeAudio]objectAtIndex:0] 
             atTime:kCMTimeZero 
             error:&error];

当我尝试执行 “[[audioAsset1 tracksWithMediaType：AVMediaTypeAudio] objectAtIndex：0]” 这是给下面的错误

*** Terminating app due to uncaught exception 'NSRangeException', 
reason: '*** -[NSMutableArray objectAtIndex:]: index 0 beyond bounds for empty array'

但是，当我尝试打印audioAsset1控制台，它正在打印“< AVURLAsset：0x198920，URL ='路径'>”。我检查了路径，该文件在那里。

我的错误是什么？请帮我解决它。

请问我们能否看到`audioURL1`的值？ – 2010-12-09 14:17:12

我检查了调试模式。我从audioURL获取它。不在audioURL1中。 – jfalexvijay 2010-12-09 14:34:09

答

我解决了这个问题;

只是我已经更换了如下声明

NSURL *audioURL = [NSURL URLWithString:path]; 
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:audioURL options:nil]

与下面的语句

NSURL *audioURL = [NSURL fileURLWithPath:path] 
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:audioURL options:nil]

感谢。

[NSMutableArray objectAtIndex：]：索引0超出AVURLAsset的空数组范围

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