Captioning Web Video

 

 

 

The process of  creating web video has become so easy and cheap that it is no longer beyond the ability or resources of any faculty member.  Making that video accessible and compliant with federal guidelines for accessibility is becoming one of  the greatest challenges to would-be instructional video authors.  The difficulty in meeting this legally and morally essential goal has the potential to exert a chilling effect upon the production of instructional multimedia.  Individual video authors are especially challenged by the process of captioning, the provision of a synchronized text equivalent for audio tracks.  Obviously, the easiest way to solve this issue is to have a professional provider do the captioning for you!  Indeed, California Community College faculty have access to the DECT captioning grant funds (http://www.canyons.edu/Offices/Distance_Learning/Captioning/) for this purpose.  In the event, however, that you do not qualify for these funds (not a California Community College faculty member),  funds run short, or you simply desire the quick response, convenience and flexibility of captioning your own videos, you can do this yourself.

 

Fortunately, a combination of relatively inexpensive software tools including:  Camtasia Studio from Techsmith (http://www.techsmith.com), Express Scribe from NCH Software (http://www.nch.com.au/scribe/), and/or Dragon Naturally Speaking from Nuance (http://www.nuance.com) can be used to effect captioning without prohibitive time or cost requirements. 

 

The process of captioning consists of two stages:  the first, transcription of the soundtrack into a text file, is by far the most time-consuming.  Once this is accomplished, insertion of the text captions into the video in sync with the video action is relatively quick and simple.  We’ll address these two tasks in turn:

 

Transcription

 

Typically, the first task in captioning a web video is to extract the soundtrack into a stand-alone sound (mp3) file that can be used for transcription.  One way to accomplish this is to import the video into Camtasia and export the soundtrack as an mp3 digital audio file:

 

http://online2.sdccd.edu/tutorials/stextract/stextract.html

 

Once the audio file is created it can be used in a manual transcription process wherein a text transcript is created by typing while listening intermittently to the audio file.  This process can be greatly facilitated by use of a transcription-optimized audio player such as Express Scribe, available, gratis, from NCH software at:

 

http://www.nch.com.au/scribe/

 

We have prepared a tutorial on the use of Express Scribe which can be accessed via the link below:

 

http://online2.sdccd.edu/tutorials/express_scribe/express_scribe.html

 

It is also possible to use a voice-recognition package such as the Microsoft Windows voice-recognition engine now integrated into Camtasia 7.1+ or the commercially available Dragon Naturally Speaking (see links above) to convert the audio file into a rough text transcript.  This transcript must then be edited to produce a usable document.  The efficiency of this approach vs. the manual method described above is variable, but the tight integration between Camtasia Studio 7.1+ and the Windows voice-recognition technology has made this our method of choice for videos involving a single speaker for whom we have a voice recognition profile created. This method is generally ineffective for multi-speaker videos or those in which we cannot create a speaker voice profile.  A tutorial on the use of Windows VR and Camtasia Studio is available at:

 

http://online2.sdccd.edu/dgiberson/vr_test/vr_test.html

 

 A tutorial on this application of Dragon Naturally Speaking is available at:

 

http://online2.sdccd.edu/tutorials/captioning_transcription/captioning_transcription(2).html

 

 

Captioning

 

Once an accurate transcript of the video soundtrack has been created, the remainder of the captioning process is relatively simple and quick.  Breaking the transcript into easily readable chunks and inserting these captions into the video so that they display in sync with the soundtrack requires a software component called a captionator.  A number of free (Magpie - http://ncam.wgbh.org/webaccess/magpie/, World Caption - http://lss.wisc.edu/node/276) and commercial (Mac Caption - http://www.cpcweb.com/products/product_summary.htm, Hi-Caption - http://www.hisoftware.com/products/hicaptionstudio.html) captionators are available.  We prefer to use the built-in captionator in Camtasia Studio (http://www.techsmith.com).  This is not only an efficient, inexpensive option, but also allows output of the captioned video in highly compatible, web-friendly Adobe Flash format.  The tutorial linked below will show you how to caption using Camtasia

http://online2.sdccd.edu/tutorials/captioning_captioning_7.1/captioning_captioning_7.1.html

Here’s a sample video upon which you can practice:  http://online2.sdccd.edu/dgiberson/mouse_slow_captioning.zip

 

While Camtasia provides an ideal tool for captioning instructor-produced video, captioning of video found in publically accessible video repositories such as YouTube, Vimeo, Google Video, etc. is best done using another approach.  While we could download, caption, and re-post YouTube videos, this is arguably a violation of copyright.  A much safer alternative is to use the free web tool Overstream (http://www.overstream.net) which allows you to produce a caption stream that plays in sync with the online video without altering the original.  A tutorial showing you how to use Overstream for this purpose can be accessed at:

 

http://online2.sdccd.edu/tutorials/overstream/overstream.html

 

We’re also very excited about the new Google/YouTube automatic captioning service!  While the voice-recognition captions are not yet accurate enough for general use, you can download the machine-generated captions, edit them, and upload them back to YouTube (for your own videos).  This tutorial will show you how:

 

http://online2.sdccd.edu/tutorials/auto-captions/auto-captions.html

 

Questions about the captioning activities at SDCCD Online Learning Pathways are welcome and may be directed to Dave Giberson (dgiberso@sdccd.edu)