Question

我已经查看了我可以找到的每个使用AVAssetExportSession设置元数据的示例，但即使音频导出工作正常（结果音频文件播放正常），仍然没有随文件导出的元数据。我正在使用Xcode 4.5，目标构建iOS 5，测试设备iOS 6.请看下面我正在使用的代码，请让我知道我做错了什么。

头

// for metadata export

NSArray *MyMetadata;
AVMutableMetadataItem *common1;
AVMutableMetadataItem *common2;
AVMutableMetadataItem *common3;
AVMutableMetadataItem *common4;

实施

AVAsset *asset = [AVAsset assetWithURL:audioFileInput];
AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:asset presetName:AVAssetExportPresetPassthrough];

if (!exportSession) {
    return;
}

CMTime startTime = CMTimeMake((int)(floor(fileStartMarker * 100)), 100);
CMTime stopTime = CMTimeMake((int)(ceil(fileEndMarker * 100)), 100);
CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime, stopTime);

exportSession.outputURL = audioFileOutput;
exportSession.outputFileType = @"com.apple.coreaudio-format";
exportSession.timeRange = exportTimeRange;

// define meta data for file
// Common metadata
common1 = [[AVMutableMetadataItem alloc] init];    // Title
common1.keySpace = AVMetadataKeySpaceCommon;
common1.key = AVMetadataCommonKeyTitle;
common1.value = @"Title Test Value";

common2 = [[AVMutableMetadataItem alloc] init];    // Description
common2.keySpace = AVMetadataKeySpaceCommon;
common2.key = AVMetadataCommonKeyDescription;
common2.value = @"Description Test Value";

common3 = [[AVMutableMetadataItem alloc] init];   // Creation Date
common3.keySpace = AVMetadataKeySpaceCommon;
common3.key = AVMetadataCommonKeyCreationDate;
common3.value = @"Creation Date Test Value";

common4 = [[AVMutableMetadataItem alloc] init];    // Software
common4.keySpace = AVMetadataKeySpaceCommon;
common4.key = AVMetadataCommonKeySoftware;
common4.value = @"My File Trimmer";

MyMetadata = [[NSArray alloc] initWithObjects:common1, common2, common3, common4, nil];
exportSession.metadata = MyMetadata;

[common1 release];
[common2 release];
[common3 release];
[common4 release];

[exportSession exportAsynchronouslyWithCompletionHandler:^{
    if (exportSession.status == AVAssetExportSessionStatusCompleted) {
        // export done
    }
    else if (exportSession.status == AVAssetExportSessionStatusFailed)     {
        // export failed
    }
}];

[MyMetadata release];

Answer 1

您是否尝试过设置标识符？

喜欢：

    let authorMeta = AVMutableMetadataItem()
    authorMeta.identifier = AVMetadataCommonIdentifierAuthor
    authorMeta.key = AVMetadataQuickTimeMetadataKeyAuthor
    authorMeta.keySpace = AVMetadataKeySpaceCommon
    authorMeta.value = "NFer"

如何正确使用AVAssetExportSession为音频资产设置元数据？

1 个答案: