[Standards-JIG] UPDATED: JEP-0158 (Robot Challenges)

Ian Paterson ian.paterson at clientside.co.uk
Wed Sep 28 19:08:17 UTC 2005

> > Why MP3 for the audio CAPTCHAs instead of Ogg Vorbis or Speex?
> Lowest common denominator? Vorbis would be nice, though, since it's 
> patent-free.

Yes, lowest common denominator.

You can use Ogg, Vorbis or Speex, but the only one that you can be sure
a JEP-0158 client will support is MP3:

"Clients that support the CAPTCHA type MUST be able to play or render
the specified MIME-types (see table below). They MAY also support other

IMHO, to encourage client implementations, the JEP should only *require*
one format for each type of media (at least at this stage of the
protocol development).

I'm completely open to specifying other required formats where that
makes sense. Here are my priorities:

1. They MUST be available in constrained runtime environments (PDAs,
Phones, Web browsers etc).
2. Relatively patent free
3. Existance of both open source and inexpensive commercial
4. Efficient compression

- Ian

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