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Re: detecting caption files?

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From: Jonathan Avila
Date: Jan 12, 2018 8:45AM

> >I can double check with Deque's engineers if aXe is programmed to examine 'inside' of MP4 files looking for a caption file, and if so, how, but I >also recall that YouTube also uses a proprietary time-stamp format for their captions, so if aXe is only looking for WebVTT or TTML >markup/time-stamp formats, it *might* be missing the proprietary format.
>(Just a guess at this time).

In my experience aXe core fails youtube videos for missing track elements even when the videos have captions. This is a situation where flagging a missing caption track is a potential violation that must be reviewed by a human or better automation is needed to inspect the encapsulated file or other new techniques need to be researched.

Jonathan

-----Original Message-----
From: WebAIM-Forum [mailto: <EMAIL REMOVED> ] On Behalf Of Tomlins Diane
Sent: Thursday, January 11, 2018 12:27 PM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] detecting caption files?

Thanks John :)
It would be nice if there was something that could detect the presence of caption files, but I understand that could be really difficult with the different formats. I can pretty much tell if the caption I see is YT's version, or an actual added caption file. It's especially obvious when you've got medical terminology or doctors with heavy accents, what comes out of YT's auto-captioning is hilarious (almost).

>I can double check with Deque's engineers if aXe is programmed to examine 'inside' of MP4 files looking for a caption file, and if so, how, but I >also recall that YouTube also uses a proprietary time-stamp format for their captions, so if aXe is only looking for WebVTT or TTML >markup/time-stamp formats, it *might* be missing the proprietary format.
>(Just a guess at this time).


JF