Media types on 0434-choice-av recipe

[ksclarke]

Recipe info:

• Name: 0434-choice-av
• link: https://github.com/IIIF/cookbook-recipes/blob/master/recipe/0434-choice-av/manifest.json

Correction request

On line 46 there is a media type for a MP3. The media type in the manifest is audio/mp3 but it looks like IANA defines the MP3 media type as audio/mpeg (Cf. https://www.iana.org/assignments/media-types/audio/mpeg where it lists that media type for File extension(s): .mp1, .mp2, .mp3)

I'd like to raise a question about the audio/alac media type, too (for which there is no officially defined IANA media type). In the recipe, I would assume the ALAC codec is wrapped in an MPEG-4 container because the extension on the file is .m4a. I'm wondering in this case whether the audio/mpeg media type wouldn't be more appropriate(?)

I understand there is some use of audio/alac out in the wild but, as a point of comparison, would point to Wikipedia's entry for ALAC vs their entry for WAV (for which there also isn't a formal IANA media type defined). On the WAV page, there is a reference to possible media types (some under the vnd designation, which is supported by RFC-2361, and some just in popular use (e.g., audio/wav), but there are not any on the Wikipedia page for ALAC -- it just contains a statement that ALAC is often wrapped in an MPEG-4 container.

I realize there is less substantial backing for this argument (when compared to MP3 request above), but I'm wondering whether this media type shouldn't also be audio/mpeg because of its container(?)

Thanks for your consideration.

[glenrobson]

Cookbook agree with changing mp3 media type.

We would like to keep the Alac mime-type as long as its not clearly wrong as the intention of the recipe is that the first alac resource is unlikely to be supported so we can see if the viewers pick an alternative. If we pick a more supported mime-type then the viewer might try and player it.