How do I use TagLib-Sharp to write custom (PRIV) ID3 frames?

Question

Specifically, I'd like to write the Windows Media Player frames, such as theWM/MediaClassPrimaryID, WM/MediaClassSecondaryID and WM/WMCollectionGroupID frames.

I'm using PowerShell, but C# would be good too.

Answer 1

I'm a bit rusty, but the following should be mostly correct. I remember these tags being UTF-16 but you'll probably want to get an existing tag and try decoding its value with the Unicode encoder to be sure.

// Get or create the ID3v2 tag.
TagLib.Id3v2.Tag id3v2_tag = file.GetTag(TagLib.TagTypes.Id3v2, true);

if(id3v2_tag != null) {
    // Get the private frame, create if necessary.
    PrivateFrame frame = PrivateFrame.Get(id3v2_tag, "WM/MediaClassPrimaryID", true);

    // Set the frame data to your value.  I am 90% sure that these are encoded with UTF-16.
    frame.PrivateData = System.Text.Encoding.Unicode.GetBytes(value);
}