Question

我使用follow代码将caf格式转换为m4a格式并保存到Iphone的另一个目录，它在IOS6中使用Xcode 4.6.3工作，但是当我更新到Xcode 5时，它不再工作了。如果在Xcode 5中使用IOS6模拟器，它会再次运行。

-(void)saveFile {
    NSString *docDirPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    outputFile = [NSURL fileURLWithPath:[docDirPath stringByAppendingPathComponent: [NSString stringWithFormat: @"%i.m4a", currentCueIndex + 1000]]];
}

所以我想知道这是IOS 7的错误还是Apple改变了一些事情？

由于

更新

AVURLAsset *audioAsset = [[AVURLAsset alloc]initWithURL:recordedTmpFile options:nil];
AVMutableComposition *mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionTrackA = [mixComposition     addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVAssetTrack *clipAudioTrack = [[audioAsset tracksWithMediaType:AVMediaTypeAudio] lastObject];

[compositionTrackA insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset.duration)  ofTrack:clipAudioTrack atTime:kCMTimeZero error:nil];

AVAssetExportSession *exporter =[[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetAppleM4A];

[self saveFile];


NSParameterAssert(exporter!=nil);
exporter.outputFileType=AVFileTypeAppleM4A;
exporter.outputURL=outputFile;
// Subtract a fraction of a second so the first word isn't chopped off
clipStartTime = clipStartTime - kSilenceBeforeFirstAudio;

CMTime start=CMTimeMake(clipStartTime * 100, 100);
CMTime duration=CMTimeMake(clipDuration * 100, 100);
CMTimeRange range=CMTimeRangeMake(start, duration);
exporter.timeRange=range;
[exporter exportAsynchronouslyWithCompletionHandler:nil];

Answer 1

好的，我发现了问题。应该替换这一行

[exporter exportAsynchronouslyWithCompletionHandler:nil];

到

   [exporter exportAsynchronouslyWithCompletionHandler:^{
        int exportStatus = exporter.status;
        switch (exportStatus) {

            case AVAssetExportSessionStatusFailed: {

                NSError *exportError = exporter.error;
                NSLog (@"AVAssetExportSessionStatusFailed: %@", exportError);
                break;
            }
            case AVAssetExportSessionStatusCompleted: {
                NSLog (@"AVAssetExportSessionStatusCompleted--");
                break;
            }
            case AVAssetExportSessionStatusUnknown: {
                NSLog (@"AVAssetExportSessionStatusUnknown");
                break;
            }
            case AVAssetExportSessionStatusExporting: {
                NSLog (@"AVAssetExportSessionStatusExporting");
                break;
            }
            case AVAssetExportSessionStatusCancelled: {
                NSLog (@"AVAssetExportSessionStatusCancelled");
                break;
            }
            case AVAssetExportSessionStatusWaiting: {
                NSLog (@"AVAssetExportSessionStatusWaiting");
                break;
            }
            default: { NSLog (@"didn't get export status"); break;}
        }

    }];

无法将cad格式转换为m4a格式

1 个答案: