Creating Closed Captions with MAGpie

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If you're using a broadcast captioning system, you should first ask your vendor if the system can generate captions in your target format either QuickTime, Windows Media, or Real.

You can find a relatively complete list of captioning tools at www.captions.org/softlinks.cfm. MAGpie, developed by NCAM, is one of the most popular tools, and downloaded for free at http://ncam.wgbh.org/webaccess/magpie/.

On the download page, you'll see that installing MAGpie involves several elements, including the Java Virtual Machine, which actually runs the program. Print and follow these installation instructions carefully, otherwise the program won't run I know because I didn't, and it didn't. One uninstall and meticulous reinstall later, and everything was fine.

MAGpie works most efficiently when applying captions to the actual compressed file you'll be distributing, so if you haven't encoded your file, do so before starting. With this and your captions file properly formatted, you're ready to start.

MAGpie's interface has two windows, one to play the video and the other to format the captions and synchronize them to the video stream. Since all controls are on the synchronization screen, I'll mostly show shots of that screen, though if you jump ahead to Figure 11.10, you can see the Player.

Open MAGpie, then click File > New Project in MAGpie's file menu. MAGpie's Open New Project screen appears (Figure 11.4). You can return to this screen at any time by clicking File > Properties.

Figure 11.4. MAGpie's Project Properties screen.


Click the Browse button on the top right to load your media file. Then click the radio button if you're captioning a QuickTime file, or the Oratrix GRiNS Player if you're captioning a Windows Media or Real Video file. I'm working with a Windows Media file, so I'll choose the GRiNS player.

As you can see, MAGpie allows you to set separate text options for the Caption and Speaker identification styles. Interestingly, though the Media Access Group's default font is Roman, the default for this tool is Arial, with a white font against a black background. To save a trip back later, click each style and boost the font size to 18, which is what we'll use in our final captions. Accept all other font defaults.

The Segment Annotation style is an advanced feature that applies Karaoke-style labeling to the captions. Leave this at the default setting (Style segments manually). If your video file is not 320x240, adjust the video parameters to those of your file, and adjust caption width and height accordingly. For example, if your file is 640x480, enter that into the video width and height fields, and make the caption width 640, and the caption height 480. Then, click OK.

Next, MAGpie displays the Create New Project Track screen (Figure 11.5) where you choose the type and name of the track. Audio descriptions are audio files containing narrated descriptions of the video for those with impaired vision, which is an entirely different operation, which I'll cover later in this chapter. Make sure Captions are clicked, and either accept the track name (as I've done) or enter a new one, and click OK.

Figure 11.5. This screen chooses between captions and audio descriptions.


After you click this screen, the main MAGpie interface should appear with your video in a separate player. Now let's insert the text file containing the captions. Right click on Track One, and choose Insert Captions from File (Figure 11.6).

Figure 11.6. Right-click and choose Insert Captions from File.


MAGpie opens a standard File Open dialog, which you should use to select and load your file. Note that MAGpie loads your file starting on Row 2 of the captions. It's not necessary, but if you'd like to delete Row 1 so your captions start on Row 1, just click the blank line, right click, and choose Delete Selected Row. When you're done, MAGpie should look like it does in Figure 11.7.

Figure 11.7. Use MAGpie's player controls to search around the file.


As you can see, each caption row has a column for Start and End time. You don't have to insert an End time; if that column is blank, MAGpie simply replaces the caption with the subsequent caption at its designated start time. The only reason to insert an End time is if you'd like the closed-captioned screen area to go blank.

Note the player controls on the top of the MAGpie menu. Use these to play the file in the player, which should be located in a separate window on the left. Alternatively, you can press F6 to start and stop the video.

Synchronizing Captions and Audio

To start synchronizing captions to audio, click Row 1 and make sure you're at the absolute start of the video file. Click F9, and MAGpie will insert 0:00:00.00 to synchronize the video starting point with the first row.

MAGpie then automatically advances to the next caption row. Use the player controls to advance the video to where the next caption should appear and press F9 again. With a little practice, you should be able to play the video in real time, and press the F9 key to synchronize each row with the associated audio.

It forces you to concentrate, but I focus on the penultimate word in each caption. When I hear that word, I press F9, and read ahead and find the penultimate word of the next caption. Follow this procedure through to the end of the video file, making sure the final row is blank but contains a start time as shown in Figure 11.8. This helps ensure that the exported caption file will work with all formats.

Figure 11.8. Make sure the last row does not contain a caption but does have a start time.


Once the file is complete, you can use the player controls to test your file and make sure your synchronization is accurate. Any changes you can make directly into the timecode of each starting point; just touch it and enter the new start time. Or you can rewind the video until it's in front of that caption, start playback, and then press F9 when appropriate.

Now it's time to adjust the captions to the necessary justification (Figure 11.9). In this case, since I'm sitting on the left, I'll keep all my comments on the left, right-justify Ken's questions, and center-justify all other captions. If you didn't spell-check your captions in your word processor, you can access MAGpie's spell-check function by clicking Edit > Check Spelling in the main menu.

Figure 11.9. Enter any changes directly in the timecode, then left, center, and right-justify the captions as required.


Because Ken and I were sitting still on our respective sides of the screen, I didn't insert any speaker names during the interview. Note that MAGpie reflects the Media Access Group's policy of isolating the speaker name on the first row of a caption, as shown in Figure 11.1. If you adopt a different policy, you can place the speaker name within the first row of the caption, so long as it's clearly distinguished from the spoken word.

Figure 11.10 contains the preview video from a 320x240 video produced in MAGpie. At 18 points, the text is reasonably readable and proportionate to the video. If you find your font size inappropriate, click File > Properties to return to the MAGpie Project Properties screen.

Figure 11.10. MAGpie's preview screen.


In terms of workflow, you can certainly enter captions directly into MAGpie if you choose, though I find it less efficient than creating a separate narration file in Word and then formatting that document for MAGpie. If you decide to enter the text directly into MAGpie, simply click the caption box to make the field active, and type the desired text. Use one carriage return to create another line within the caption, and a double carriage return to switch from caption to caption.

One final note. Though MAGpie is a free download, it proved very stable in my tests, performed on a Windows XP Professional computer (I did not test the Mac version). I encountered only one problem I couldn't change justifications when working with 320x240 files, though this worked perfectly with 640x480 files.

Exporting the Captioned Stream

Exporting a file from MAGpie is simple; Click Export and choose the desired format (Figure 11.11). The only caveat is that MAGpie automatically overwrites any files in that directory without warning, so be careful to make sure there are no files in the path before exporting.

Figure 11.11. Exporting caption files from MAGpie.


The Plain Text export feature is useful if you need a transcript of the event. Now that we have our exported captions properly formatted, it's time to mate them with our compressed video files to produce captioned video playback.

There are efforts underway to standardize how QuickTime, Real, and Windows Media files synchronize with text (see www.w3.org/AudioVideo/timetext.html), but until these standards are set and adopted by each company, you'll have to create a separate text file for each technology.

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    DV 101. A Hands-On Guide for Business, Government & Educators
    DV 101: A Hands-On Guide for Business, Government and Educators
    ISBN: 0321348974
    EAN: 2147483647
    Year: 2005
    Pages: 110
    Authors: Jan Ozer

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