Paul Taylor
2007-Aug-05 02:02 UTC
[Vorbis] Questions on embedding images and extending the list of known fields in Vorbis Comments
Having spent some time developing a tag library for mp3/id3 I am now trying to extend it to OggVorbis/Vorbis Comments. The format is much simpler which makes it much easier( thanks) but I have two issues, (Im new to Ogg so sorry if ive missed the answers elsewhere) : There is no official way to embed images, for music files the requirement to store the album art is a must these days. Somebody suggested base64 encoding the binary data and storing it within a field, or implementing it as seperate muxed stream, both of these are possible (although option one is much easier) but unless one there are Music players that use this method its a waste of time me doing it because only applications using my library will be able to read them. Does anybody know of applications that do this already. Is Xiph going to release some kind of recommendation on this because until they do ogg is never going to be able to compete with mp3 and mp4, this is even more of an issue with hardware players now showing album art (e,g ipod). I did notice the metadata container draft document and I expect images will be able to go in here, but this does not solve the current problem, a solution is needed that will work with Vorbis Comments , not some new technology that may takes years to gain widespread use. Secondly the list of official fields listed by Xiph is relatively small (http://lists.xiph.org/vorbis/doc/v-comment.html). Technically it is very easy to add additional fields, but once again what is the point if no other applications understand them. With audio files the application that creates/edit the metadata (CD Ripper,Tag Editor) is normally different to the one that plays the audio (Hardware/Software Player) so there is limited advantage in adding extra fields unless supported by both applications. As a starting point Vorbis Comment should at least support some of the straightforward fields that are implemented by ID3 such as BPM or Label. Xiph could also list extension lists to encourage cross compatability. For example here are two other unofficial lists, the first is very generic, the second contains generic fields , and fields related to the MusicBrainz database http://reactor-core.org/ogg-tagging.html http://wiki.musicbrainz.org/PicardQt/TagMapping thanks Paul