Eating the Captioning Dog Food

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I'm prepping for an accessibility presentation and realized it was finally time for me to bite the bullet and caption a video. I even set aside an entire afternoon for it. Surprisingly though it only took me about 2 hours (for a 2 min video) to input text, do the final adjustments and export the final product. And it was much more relaxing than I thought it would be.

Captioning Content and Tools

The video is from the Internet Archive, specifically a 1948 Pedestrian Crossing public service video from the U.K. government (midcentury educational videos are often entertaining). I downloaded the 512K MPEG/.

The tool I'm using is Parity (developed by colleague Pat Besong). It's free to Penn State users (and installed in our lab) and hopefully will have a more public release in the future. It works mostly with Quicktime files and right now is Mac only (which is a common platform for many video shops, although not necessarily for the average instructor).

Here's what a section looks like (warning you not to get distracted while crossing or "you'll soon find yourself in trouble").

Man eating at table while car speeds by
This is a still image, not a video. Go to Export section to see video


Parity has an option to either import a text transcript or let you start from scratch (as in this case). To start from scratch, you open Parity, create a New Project then load a movie into the view screen. You can play portions of the video within Parity as needed.

Once you load a movie, just start to play it and type in the black caption box. The great thing about Parity is that it will continuously loop a 4-second segment until you are able to complete a caption. This looping is actually huge time saver - a surprising amount of video time is actually wasted on pressing rewind, getting back to the right section then starting over. The looping really kept me in the captioning grove.

After you write a caption for the 1st 4 seconds, you can hit return to go to the next 4 seconds (which also loops). You can keep going until the end. The big gotcha here is NOT to hit the Return button to start a new line in the caption (because it kicks you into the next section).

Below is a view of the Parity screen with a series of captions and automatically generated time codes. Click image to view close up.

Set of caption lines at right. Frowning man in video on left

Editing Captions

For what it's worth, I recommend going straight through a video to get the bare captions, then worrying about spell checking and shifting words around later. If you have to go back and listen to a segment, move your cursor to the appropriate caption line, then click the Start button to start the looping process.

You can also shuffle text between lines as needed. One thing to look out for is duplicate captions (if you re do a section). Just delete a caption if you need to remove a line. You can also insert and split captions.

To make final adjustments, I used the "Preview in QuickTime" option to view the captioned video. I could decide to move text around then click the preview again until I was happy. Parity also lets you adjust font formatting and color, although the default is probably fine.

Export for the Web

What Parity exports is a caption text file which can be played in other files. For Quicktime (the default), it exports a .txt file (with the transcript & formatting) and a .smi (SMIL) file which is an XML file which calls the movie and captions and puts them together. As you can imagine the movie, SMIL file and .txt must be in the same directory.

There are other caption export options including Flash, Adobe Encore and others, but you have to manually convert a Quicktime video to Flash. I recommend an external track whenever posssible. That way you (or someone else) can edit typos or adjust formatting even if you don't have access to Parity at the moment.

A main exception is streaming Quicktime video in which captions must be burned or embeded as part of the video (ah well).

Final Product

The simplest result is probably Quicktime, so here is it is. I used the embed tag to link to a SMIL file. Click the play button to start the video.


PATRICK JOSEPH BESONG Author Profile Page said:

Nice work on the captioning, Elizabeth. Just wanted to let you know that I'm working on a new version that has quite a few new features (I'm not even sure what your version has). I'm trying to get it to do SCC closed captions, since iPods support that format, but it's pretty cryptic and has been quite a challenge to figure out. I have had some good success lately, however. I want to get this new version done before I put it on the PSU Downloads page and update it on the lab machines. I only work on it at home, so progress has been a bit slow as of late. I'll let you know as soon as I have something usable for the short term.

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