Apple iTunes recognizes and categorizes MP4 audio files (preferably with an
.m4b extension, not
.mp4) correctly as audiobooks if the tag field
stik MediaType is set to
Audiobook. I shall assume that its successors, i. e. Music, Podcasts and TV, do so as well.
Classic MP3 files, however, use a different tag format: ID3, which has no official, documented way to mark a file as an audiobook. (One can use any string for
TCON content type, usually labeled genre, but that does not seem to matter to iTunes.) The kind of audio can manually be set in the iTunes GUI, but this will apparently not add or change the ID3 tag in any way, instead just update the database entry and possibly file location. This has been documented many times on the web, as has converting the MP3 into an AAC MP4.
- Is there any way to tag an MP3 file in such a way that Apple audio players/managers will import it as an audiobook without manual correction?
As an alternative, Iʼm considering to put a remuxed MP3 audio stream (i.e. not reencoded with AAC) into an MP4 container (v2, i.e. MPEG-4 Part 14,
.m4b file extension), but I donʼt know yet whether Apple supports them correctly.
MP3s can also use different tag formats, e.g. APE from Monkey's Audio, but as far as I know none are recognized by iTunes.