[Athen] captions for ios devices
tft at uw.edu
Mon Jan 7 13:06:45 PST 2013
There are many audio description vendors to choose from. Here's a list
from the ACB:
We've used several different vendors over the years, most recently Audio Eyes.
Technology Accessibility Specialist
DO-IT, Accessible Technology
UW Information Technology
University of Washington
tft at uw.edu
On Mon, Jan 7, 2013 at 7:06 AM, N Dogbo <ndogbo at gmail.com> wrote:
> Hi Terrill,
> Could you share contacts of the vender to whom you outsource video audio
> description orders?
> ----- Think not with your EYES and you shall have a perfect VISION! ---
> -----Original Message-----
> From: athen-list-bounces at mailman1.u.washington.edu
> [mailto:athen-list-bounces at mailman1.u.washington.edu] On Behalf Of Terrill
> Sent: Friday, December 28, 2012 1:01 PM
> To: Access Technology Higher Education Network
> Subject: Re: [Athen] captions for ios devices
> Hi All,
> I'm a little late joining this conversation, but just wanted to share what
> we're doing at DO-IT:
> We've created a custom media player that uses HTML5 as its primary player,
> and JW Player as fallback for those who are using older browsers that don't
> support HTML5. We've created a highly accessible custom player that
> communicates with both the HTML5 media and JW Player API's so all users -
> even those with older browsers - get exactly the same experience and
> identical feature sets.
> For video files, we're using MP4, which is now supported by most browsers
> and will eventually be supported by Firefox (the last major holdout). Until
> then, we're also delivering all our videos using Ogg (older videos) or WebM
> (newer videos), since those are the formats preferred by Firefox (and Opera,
> which only recently began supporting MP4). JW Player also supports MP4, so
> that same file works in the fallback player.
> For captions, we start with an SRT caption file. The standard format for
> HTML5 captions is WebVTT, which at its core is very similar to SRT, so it's
> easy to convert the SRT file to WebVTT with just a couple of edits in a text
> editor (there are also free tools available that will do the conversion).
> Browsers are starting to build in support for WebVTT captions in HTML5, but
> from my experience their implementation is still a little buggy, so we
> decided to build caption support into our custom controller rather than rely
> on browsers to do it.
> We upload all our videos to YouTube in addition to showing them on our own
> site. For YouTube, we upload the original SRT caption file. And for iOS, we
> embed the SRT caption file into our MP4 video file using Handbrake. It's
> great that iOS supports that because we're already delivering an MP4 file,
> so we don't really have to do anything extra-special - we just use that same
> MP4 file for all purposes, including delivery of captions in iOS. I recently
> discovered that my iPhone reports that it "Can't play the caption file" on
> at least one of our videos, so the iOS caption parser is apparently a little
> fussy, but most of the time it seems to work. iOS also supports multiple SRT
> files within a single MP4, so that's an effective strategy for delivering
> foreign-language subtitles. We aren't supporting subtitles yet on our
> videos, but we do have a few of them translated so we're working on
> implementing subtitles soon.
> Since you mentioned audio description Ken, we're implementing that in a
> couple of different ways:
> First, we outsource audio description for all our videos. The deliverable
> from vendors is a new video, with description mixed into the program audio.
> They do a great job of placing description in the best places so it's
> minimally intrusive plus they adjust volumes so the description can easily
> be heard over background sounds. The media player we've created includes a
> Description button that if clicked, swaps the source media file so if the
> user is viewing the non-described version the described version is loaded,
> and vice versa.
> We also provide a text version of the description in a WebVTT file, the same
> file format that's used for captions. This form of description is supported
> by the HTML5 spec. No browsers support it natively yet, but we built support
> into our custom player. The description text is displayed at the appropriate
> times just like captions are, but they're displayed in a box that's marked
> with ARIA role="alert", which causes screen readers to read the description
> as soon as it appears. This is off by default on our player since users have
> the option of viewing a professionally described video, but there's a
> Preferences button that allows users to experiment with different ways of
> getting their description delivered.
> One advantage of having a WebVTT-based description, at least as a supplement
> to the professionally described alternative version, is that the WebVTT
> description file can be used in conjunction with the caption file to build a
> transcript. In our transcript we markup the caption and description in such
> a way that they're visually distinct, plus we've added the text
> "Description:" to the start of each block of description content, hidden to
> everyone except screen reader users.
> We're planning to make our custom media player available as an open source
> project sometime in early 2013. The best place to stay abreast of that is my
> blog: http://terrillthompson.com/blog
> Terrill Thompson
> Technology Accessibility Specialist
> DO-IT, Accessible Technology
> UW Information Technology
> University of Washington
> tft at uw.edu
> On Thu, Dec 20, 2012 at 2:39 PM, Ken Petri <petri.1 at osu.edu> wrote:
>> Hi Dean,
>> The Handbrake method works just fine. But if you have a Mac iSubtitle
>> you more options.
>> Here's the too-long URL on how to do this with Handbrake:
>> A short URL to the entire DIY Captioning Techniques page is:
>> Other good info in this page as well. The info about how to add an audio
>> description track is forth-coming. That technique does, however, require
>> QuickTime Pro....
>> Ken Petri
>> Program Director, OSU Web Accessibility Center
>> 102D Pomerene Hall, 1760 Neil Avenue, Columbus, Ohio 43210
>> Office: 614.292.1760 | Mobile: 614.218.1499 | Fax: 614.292.4190
>> http://wac.osu.edu | petri.1 at osu.edu
>> On Thu, Dec 20, 2012 at 5:10 PM, Sean J Keegan <skeegan at stanford.edu>
>>> > I want to learn how to add captions for iOS devices. I found a
>>> > vendor site that gives instructions, but it says it only works using
>>> > QuickTime Pro on a Mac. I have been unsuccessful in searches to
>>> > confirm this. Can someone please tell me whether this is accurate?
>>> Hi Dean,
>>> Generally speaking, there are two ways to add captions to iOS media:
>>> embedding a caption file so that it requires the closed caption decoder;
>>> embedding a caption file as a subtitle track.
>>> The first method is what I call the "closed caption decoder" solution.
>>> This requires that you create an SCC file and embed this file into the
>>> original media file. In order to view these captions on an iOS device
>>> have to enable the closed caption decoder feature in the Videos menu
>>> (Settings > Videos > Closed Captioning). The SCC file is the same file
>>> as is used for captioning VHS media content and is a bit of a pain. From
>>> what I have found, you need to have Compressor (Mac only) in order to
>>> integrate the SCC caption into the original media file.
>>> The second method is what I call the "subtitle track" solution. This
>>> involves using the subtitle track to embed caption information into the
>>> media file. I have had much greater success using this solution as it is
>>> far easier to deal with the SRT caption file and the application used to
>>> embed the captions (as subtitles) into the original media. I have used
>>> application iSubtitle (Mac only) to perform this process. Subler, also
>>> only, also works.
>>> For Windows, the options are varied. Wondershare Video Converter
>>> is one tool that you could try. Previous versions seemed to work with
>>> getting a subtitle track into an MP4 media file, so that may be one
>>> (I only tried this tool years ago, so your mileage may vary).
>>> Handbrake may be an option now that there is improved subtitle support
>>> MP4 media files. With a user created SRT caption file, you can run the
>>> media file and caption file together through Handbrake to get soft or
>>> subtitles (soft-subtitles can be enabled/disabled whereas hard-subtitles
>>> burned into the video itself). See
>>> for more information. I have not tried this method myself (yet!).
>>> Take care,
>>> Sean Keegan
>>> Associate Director, Assistive Technology
>>> Office of Accessible Education - Stanford University
>>> athen-list mailing list
>>> athen-list at mailman1.u.washington.edu
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