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ADA Compliance for Locally Hosted Streaming Videos
Brian BolingMedia Services LibrarianTemple University Libraries
What makes videos ADA compliant?
For hearing impairment and intellectual disabilities, closed captioning (CC).
For visual impairment, descriptive video service (DVS).
So are we going to record descriptions for our locally hosted streaming films….?
We’re not qualified. Video description requires the creation of a completely new script by specially trained writers. For example:
"Arthur's family members are aardvarks, too. His younger sister D.W. is about 4 years old and has small, round eyes and light brown hair down to her shoulders. She wears a pink dress with white tights.” *
* http://main.wgbh.org/wgbh/pages/mag/resources/the-abcs-of-dvs.html
So are we going to record descriptions for our locally hosted streaming films….?
Section 508 requirements for visual description currently apply only to multimedia content on the websites of Federal Government Agencies.
Though descriptive video is not mandatory, we should make sure that any information included in a locally produced video can be accessed in an alternative manner…for instance, as text or a transcript that can be accessed by screen reader technology.
Case study: World Society in Literature and Film general education class
In January 2013, a professor notified me that a student with visual and hearing impairment had enrolled in her course on Latin American film.
Of the two disabilities, the visual impairment was worse. None of the DVDs contained description for the visually impaired. We don’t have the expertise to describe videos in-house; the Media Access Group at WGBH does offer DVS services for a fee.
Working with the student and the Office of Disability Services, we determined that a “reasonable accommodation” would be:
• Purchasing additional DVDs of reserve films to allow extended loan.• Finding a volunteer from the course to view and describe the films
alongside the student. (This set-up allowed student to request real time clarification of the description.)
Subtitles vs. Closed Captions
Subtitles are helpful, but do not by themselves make a program accessible.
In addition to spoken dialogue, closed captions also need to convey important background noises and sound effects:
For example…
[ inaudible ]
[ horse galloping ]
[ ominous music ]
[ thunder rumbling ]
Subtitles vs. Closed Captions
Subtitles for the Deaf and Hard of Hearing (SDH)
SDH are closer to Closed Captions than traditional subtitles, because they contain information on sound effects, as well as identification of off screen speakers.
Despite comparable content, SDH and Closed Captions differ in appearance. Captions usually appear against a black background, making them more legible to persons with certain visual disabilities.
Frankly, my dear, I don’t
Subtitles and Closed Captions Encoded on DVDs
Two possibilities for encoding
1. The DVD has Closed Captions (stored as Text file)
2. DVD has English Subtitles or SDH (stored in the VOBSUB format)
VOBSUB format consists of two files
• the .sub file containing image data of the subtitles • the .idx file containing an index to caption timings
The best case scenario is that the DVD has closed captions; converting subtitles from VOBSUB requires OCR and additional clean-up.
The Initial Steps To Creating Caption Files
First, decrypt the DVD and save the decrypted files to your hard drive.
The free program DVDFab works on both MAC and PC platforms and allows you to decrypt DVDs.
Available at www.dvdfab.com
And now for a brief legal disclaimer…
The most recent DMCA rulemaking session allows circumventing Technological Protection Measures:
“when circumvention is accomplished solely to access the playhead and/or related time code information embedded in copies of such works and solely for the purpose of conducting research and development for the purpose of creating players capable of rendering visual representations of the audible portions of such works and/or audible representations or descriptions of the visual portions of such works to enable an individual who is blind, visually impaired, deaf, or hard of hearing, and who has lawfully obtained a copy of such a work, to perceive the work” (emphasis mine)
In other words, circumvention to convert subtitles/captions is not sanctioned.
*“Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control Technologies,” 77 Federal Register 208 (26 October 2012), pp. 65260-65279.
And now for a brief legal disclaimer…
The following Fair Use analysis would seem to favor proceeding with circumvention.
1. The circumvention is made for the purpose of teaching at a nonprofit educational institution. Additionally, the circumvention is made in order to comply with another federal law. (Favors Fair Use)
2. The copyrighted work is audiovisual, thus creative work (Against Fair Use)3. The entire subtitle track is being copied. (Against Fair Use)4. The use would have a minimal impact on the market. Filmmakers don’t
typically profit by selling subtitle files and, after all, you ARE licensing any work you post on a local server. (Favors Fair Use)
Contract language sometimes states that a film cannot be altered. It helps to clarify at the time of licensing that you will need to caption the film.
Steps For Using DVDFab HD Decrypter
1. Insert DVD into computer
2. Open DVDFab, pick HD Decrypter, and give it time to scan the source media
3. Select a local drive as your “Target”; you need several GBs of free space
4. Click on the button
5. You will receive the message:“The DVD Copy option is expired. You are going to use HD Decrypter.”Click on “OK”
6. Wait for the message “Process completed successfully!” and click
The Initial Steps To Creating Caption Files
Next, convert the decrypted content into .mp4 format.
The free program HandBrake works on both MAC and PC platforms and allows conversion from VIDEO_TS and AUDIO_TS to mp4.
Available at http://handbrake.fr/downloads.php
Steps For Using Handbrake
1. Click on and select the folder with both the AUDIO_TS and VIDEO_TS folder. Click Open.
2. I typically leave Video and Advanced options on default. For our purposes, the key tabs are Audio and Subtitles.
3. For Audio, you will want to find the English track (usually the default).
4. For Subtitles, select Closed Captions or the English VOBSub option if CC are not available. If there is an option for “Foreign Audio Search”, select this track and make sure that “Forced Only” and “Burned In” are selected.
5. On the Chapters tab, unclick “Create chapter markers” to ensure file is standard mp4, rather than an m4v file. Click on
15 Minutes (more or less) Later
If your .mp4 contains Closed Captions…
If your .mp4 file contains Closed Captions, you will need to export that track from the file.
1. Open the file in Subler.2. Select the track with Closed Captions
(usually track 3). It will show the format as Tx3g.
3. Select “Export” from the File menu.4. Click “Save”.
Available at http://code.google.com/p/subler/
Final steps to convert [CC] to desired format
You now have a text file containing the Closed Captions and timing information.
1. Open the file in Jubler.2. Select “Save As” from the File menu.3. Choose the desired format.
For the streaming server used by my institution, caption files need to be in Timed Text Markup Language.
Your institution’s requirements may vary.
Available at www.jubler.org
If your .mp4 contains a VOBSub track…
If your .mp4 file contains a VOBSub track, you need to use OCR to extract the captions.
1. In Subler, select “New” in the File menu.2. Select “Import” a “File” in the File menu.3. Choose the .mp4 file.4. The “Action” field will show the VOBSub
track as “passthru”. Change this option to “Tx3g”.
5. Save the file with a different name to avoid overwriting your .mp4 file.
6. Reopen the file and export track 3 as above.
Available at http://code.google.com/p/subler/
Review and edit the OCR for errors
You now have a text file containing the Subtitles and timing information.
1. Open the file in Jubler.2. Check for OCR errors. 3. If OCR errors are few, you can correct
them within the Jubler interface.4. Otherwise, you may want to use a
text editing program to correct errors. Find and replace can be helpful.
5. If the film contains music or background sounds, look for gaps in time codes to add in these details.
Available at www.jubler.org
An OCR option for PC users
Subtitle Edit gives users more granular control over the OCR process.
It incorporates spell-check functionality to spot check captions as OCR runs.
It also has Find and Replace functions for editing after-the-fact.
Available at http://www.nikse.dk/subtitleedit/
What to do if your film does not have a subtitle or caption file
It depends…
If the film is short (especially if you have a transcript), you might be better off doing the captioning in-house.
If the film is lengthy, it is probably more cost effective to outsource captioning of the file.
The Described and Captioned Media Program website has an extensive list of captioning services:
http://www.dcmp.org/ai/10/
Tools needed for in-house captioning
To create Timed Text Markup Language files in-house, you need:
1. A spreadsheet program such as Microsoft Excel2. A media player with a time code display of at least a hundredth
of a second3. Enough time to do it yourself or a capable employee with time
As mentioned, having a transcript file saves time, but is not a necessity
Excel screenshot of Textbook video file
<tt xmlns=http://www.w3.org/2006/10/ttaf1> <body> <div xml:id="captions">
</div> </body></tt>
Duplication of effort?
Unfortunately, yes.
However, any type of caption clearinghouse would be of questionable legality…essentially indistinguishable from the “pirated subtitle” sites currently found on the Internet.
The Register of Copyright’s comments on proposed DMCA rulemaking makes it clear that not all captioning for accessibility will be considered as Fair Use. Rather, a case-by-case determination must be made.
One proposal to avoid duplication would be for video distributors themselves to include Closed Caption tracks or files when licensing video for educational streaming.
How video distributors can help librarians achieve ADA compliance
If you already have Closed Captions for your film:
Encode it into the .mp4 file you provideorConvert the text file to the library’s required format using
Subler
If your film has an entire subtitle track:
Convert it to a standard format like TTML, add sound
effect/musical information, and supply it to the library
If you do not currently caption your films, start. More and more universities will have internal ADA mandates in the near future.
Questions?
My contact information:[email protected]
Additional resources:
Described and Captioned Media Program Captioning Key:http://www.dcmp.org/captioningkey/Described and Captioned Media Program list of vendors:http://www.dcmp.org/ai/10/