Multiple id3v2 TXXX tags for ReplayGain when using TaggedFile

[Danacus]

I am trying to extract ReplayGain tags from files, as described on the ReplayGain Specification. For id3v2, All different types of ReplayGain information are stored in separate TXXX tags and the description serves as the key (e.g. REPLAYGAIN_TRACK_GAIN or REPLAYGAIN_ALBUM_GAIN). However, when using Tag in lofty, this description seems to get removed, making it impossible to distinguish between different ReplayGain tags, as illustrated below when using Tag::get_items;

    TagItem {
        item_key: Unknown(
            "TXXX",
        ),
        item_value: Text(
            "-10.43 dB\0",
        ),
    },
    TagItem {
        item_key: Unknown(
            "TXXX",
        ),
        item_value: Text(
            "-10.40 dB\0",
        ),
    },

I don't know which of those is album gain and which is track gain, because the description is not stored (from what I can tell).

The documentation of lofty mentions that those TXXX tags are identified by their descriptions, but I'm not sure how those descriptions can be used. Am I missing something, or is it currently not possible to get the descriptions of TXXX when using the generic Tag (or a Tag converted to a ID3v2Tag)?

[Serial-ATA]

That's an issue, TXXX/WXXX frames should be removed during the conversion to Tag, so thanks! The issue with those is there's no real way for a TagItem to store that extra description. What you'll have to do is read a concrete file type (e.g. MP3File) and obtain an ID3v2Tag.

[Serial-ATA]

In the next release, I'll add some ItemKeys for ReplayGain so you can use Tag, and the conversion isn't lossy.

[Danacus]

That would be great, thanks a lot! For now, I'll use a concrete file type, as you suggested.

I'm currently trying to add support for ReplayGain to amberol, a music player (see https://gitlab.gnome.org/World/amberol/-/issues/75). The maintainer of amberol will most likely prefer a solution using Tag, since that's what he's already using right now.

[Serial-ATA]

This was simpler to implement than I thought, could try out 97f081f? If all goes well I can publish 0.7.3 🙂.

[Danacus]

That was really fast! I'll try it tomorrow.

[Danacus]

This is working well for me. Thanks!

[Serial-ATA]

Great, thanks! 0.7.3 is out now 🙂.