Losing some Metadata from Audio Files created with Audacity

Question

I have many short voice clips which I created with Audacity (windows) and exported using Audacity (Apple) in m4a format. The project was for Android originally which is why I created the clips before testing if I could get the data back . When I read the metadata with AVFoundation I lose some of my fields. specifically

1. Artist Name
2. Track Number

I have tried

AVAsset *asset;
asset = [AVURLAsset URLAssetWithURL:url options:nil];
for (NSString *format in [asset availableMetadataFormats]) {
    for (AVMetadataItem *item in [asset metadataForFormat:format]) {
        NSLog(@"Item %@ Value: %@",[item commonKey],[item value]);

With this I get values

1. title maps to Audacity: Track Title
2. albumnName maps to Audacity:Album Title
3. software value Lavf52.6
4. (null) maps to Audacity: Comments
5. (null) maps to Audacity: Genre
6. Another couple of null which I could not identify the data

I also tried but that gave me the non null values above

NSArray *metaDataList = [asset commonMetadata];
for (AVMetadateItem *item in metadataList)

Is there an alternate Metadata reader / or an alternative to Audacity which I could use to retrieve this data easily.

I am new to IOS and to the Apple world.

Thanks

Answer 1

It seems the problem was with Audacity for the Mac, it was losing my metadata. I exported it on Windows Audacity to m4a can copied the file across and can now find my Artist