[Athen] captions for ios devices

Sean J Keegan skeegan at stanford.edu
Thu Dec 20 14:10:37 PST 2012

> 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;
or, 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
you have to enable the closed caption decoder feature in the Videos menu
(Settings > Videos > Closed Captioning). The SCC file is the same file
type 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 the application iSubtitle (Mac only) to perform this process.
Subler, also Mac 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
option (I only tried this tool years ago, so your mileage may vary).

Handbrake may be an option now that there is improved subtitle support
for 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 hard subtitles (soft-subtitles can be enabled/disabled whereas
hard-subtitles are burned into the video itself). See
https://trac.handbrake.fr/wiki/Subtitles 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

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