Choose a media-type and file extension for Web Publications packaged in "OCF lite"

[llemeurfr]

The use of a simplified version of OCF is discussed by the Audio TF, as a way to be able to package audio based Web Publications without waiting for future W3C Web Packaging technologies. The upcoming BD-Comics-Manga CG will certainly also want to package contents using the same technique. This makes this simplified version of OCF more than a pure "OCF for Audio" format; rather a generic packaging mechanism for Web Publications, with know constraints (discussed elsewhere).

Such a Web Publication container will essentially be used:

• to exchange in-progress packaged Web Publications between different individuals and/or different organizations;
• to provide packaged Web Publications from a publisher or conversion house to the distribution or sales channel; and
• to deliver packaged Web Publications to Reading Systems or users.

What should be the mime-type for this file format?
What should be the preferred file extension for this file format?

Note: the first draft boldly uses the following values:

• mime-type: application/wpub+zip (= a zipped web publication)
• file extension: pwp (a packaged web publication)

[iherman]

My only (slight and purely 'diplomatic') reservation is with the extension. We have to be careful not to give the impression that we normatively define a our own packaging format for PWP; this may be considered to be a breach of our charter. I am not sure what extension we could use; what about, say, zwp for zipped web publication?

[GarthConboy]

Or, as this really for audiobooks at this stage... maybe ".zab" (zipped audio book) and "application/audiobook+zip"?

[iherman]

@GarthConboy I would prefer not. As @llemeurfr said, the same format may be useful for, e.g., manga at some point, and I do not think we would like to see proliferation of different media types and, even more importantly, different specifications for each of those categories (if we can avoid it, that is).

My 2 cents...

[GarthConboy]

That's a good point... but it's also not clear these specialized uses may ever drive what we do with Web Publications for packaging (if we do anything at all) -- so, for that reason, I'd tend to avoid "wp". But, just my 2-cents, and not something I feel too strongly about.

Happy New Year!

[iherman]

Happy new year to you, too, @GarthConboy!

but it's also not clear these specialized uses may ever drive what we do with Web Publications for packaging

I can see a bunch of use cases. Eg, as long as we do not have a clear solution for offlining, putting a Web Publication onto my iPad (which does not have a real file system) may only be doable by packaging the content for a possible wpub+zip aware reader; the same publication cannot really be deployed on the iPad as a Web Publication (ie, depending on the browser only).

Ie, let us not, from the start, close the door on these...

[llemeurfr]

I stand by the opinion that we should not tie this spec to the audio publication use case.

And I agree that we can find another extension. The pros of .pwp are that it's not already used, it's pretty generic, it blankly represents what we specify and the future web packaging spec will certainly not use this extension.

It's about a Container Format. I tried ".wcf" (too microsoftian), ".pcf" (weird in French)
... but I didn't propose "epub4" even if it would be my favorite.

.wpc (for Web Publication Container" has been used previously (Windows 95 Wordpad Converter and Corel Wordperfect character mapping) but they are old / unknown formats and we could reuse it.

nb: IMO we should not focus on the "WP -> packaged" use case, but rather focus on the "package -> WP use case" (a publisher releases a package, this package is put online by a "bookseller").

[iherman]

... ".pcf" (weird in French)

For the non-French: PCF is the common abbreviation for the French Communist Party:-)

[iherman]

@llemeurfr

• .wpc would work for me (I must admit I did not even hear about that Wordpad converter before...)
• .wpz which would fit with the wpub+zip media type
• .wpf for stand for "Web Publication File"

(We probably need some reserved time around our dinner at the F2F meeting for this type of bike shedding:-)

B.t.w., I would prefer to "reserve" .pwp to the case if and when Web Packaging is a reality, and we would decide to use it with a separate suffix.

[HadrienGardeur]

Or, as this really for audiobooks at this stage... maybe ".zab" (zipped audio book) and "application/audiobook+zip"?

@GarthConboy application/audiobook+zip is already used by Readium, although it hasn't been officially registered at IANA at this point.
It's probably best to avoid using the same media type and file extension between WP/PWP and RWPM.

[llemeurfr]

If we go down the route of choosing different extensions and media types for the container, depending the "class" of content (audio publication, digital visual narrative, text first, synchronized media), we should have a clear & extensible model, e.g. application/wp+audio+zip, with extension .wpa etc.

[iherman]

@llemeurfr that does not work, alas! The media type allows for a single '+'.

I would more be in favour of using one single media type for zipped web publications, and possibly use a profile mechanism of some sort in, say, HTTP, to talk about an audio (if necessary, ie, if it is not enough to use the data in the manifest).

[iherman]

@llemeurfr @wareid @TzviyaSiegman @GarthConboy

The #30 includes now a media type specification. Shouldn't this issue be closed?

[llemeurfr]

As of 11 March 2019, the draft contains:
media-type: application/wpub+zip
extension: lpf (for lightweight packaging format).

We can still set the mime-type to application/lpf+zip

[llemeurfr]

After reading https://en.wikipedia.org/wiki/Media_type, it seems to me that the mime-type application/lpf+zip makes more sense, lpf (lightweight packaging format) being also the recommended file extension and ziprepresenting the underlying structure of the media type application/lpf.

[iherman]

This issue was discussed in a meeting.

• RESOLVED: media-type: application/lpf+zip, extension: .lpf

View the transcript

media type
Ivan Herman: link: #29
Laurent Le Meur: I invite you to open reference #6 - the lpf light document. The first issue is issue #29 - we need to decide on the media type of the format. We want to use application-lpf+zip since lpf is lightweight packaging format, the +zip is that the underlying format is zip
… It was discussed - but are there any comments on this proposal?
Proposed resolution: media-type: application/lpf+zip, extension: .lpf (Ivan Herman)
Geoff Jukes: +1
Laurent Le Meur: +1
Nick Ruffilo: +1
Jun Gamou: +1
Ivan Herman: +1
Ric Wright: +1
George Kerscher: I’m assuming there are no conflicts with this extension on the various operating systems where they are registered?
Dave Cramer: https://filext.com/file-extension/LPF
Laurent Le Meur: I looked at the list, and it was only used in a very obscure way, and it wasn’t registered. Do you know of an open list of media types that we can check?
Rachel Comerford: 0 - I don’t understand the impact clearly enough to vote
George Kerscher: I don’t know, but I just recall how long it took to get epub recognized by the various browsers so that it would download. As long as there are no conflicts.
Dave Cramer: I had a similar question to George - the only LPF I find is unrelated and not widely used, so i think we’re pretty safe
Garth Conboy: +1
Geoff Jukes: FYI https://www.iana.org/assignments/media-types/media-types.xhtml
Laurent Le Meur: also found the obscure https://assiste.com/Types_de_fichiers/Extension_LPF.html
Wendy Reid: Any additional votes for the media-type application/lpf+zip and extension: .lpf ?
Ben Schroeter: +1
Gregorio Pellegrino: +1
George Kerscher: +1
Dave Cramer: 0
Brady Duga: 0
Deborah Kaplan: 0
Charles LaPierre: 0
Matt Garrish: 0
Marisa DeMeglio: 0
Resolution #2: media-type: application/lpf+zip, extension: .lpf

[iherman]

This issue was discussed in a meeting.

• No actions or resolutions

View the transcript

Choose a media-type and file extension for Web Publications packaged in “OCF lite”
Laurent Le Meur: #29
Laurent Le Meur: In the discussion about mimetypes, #29 what will we choose for file extension and media-type
Laurent Le Meur: application/lpf+zip
Laurent Le Meur: in the draft the extension is .lpf (lightweight package format) mimetype is application/lfp+zip
Nick Ruffilo: #29 on the 29th RESOLVED!