Captioning with MAGpie 1.0
Translations of this article are available in:
- German - External Link - courtesy of Anatoli Bauer
Media Access Generator (MAGpie) - external link was developed by the CPB/WGBH National Center for Accessible Media (NCAM) - external link. This software tool is designed to make it easy for multimedia content developers to add captions to their audio and video content. MAGpie provides an environment for developers to listen to their content, add captions, and synchronize the captions to the content by adding a timecode to each event. MAGpie can then be used to export the captions to three multimedia formats:
- Microsoft's Synchronized Accessible Media Interchange (SAMI) format - external link,
- RealText - external link for use with RealPlayer,
- Apple's Quicktime format - external link.
It will also export the World Wide Web Consortium's (W3C) Synchronized Multimedia Integration Language (SMIL) format - external link, which is a display language used to display captions in Quicktime and RealPlayer.
Creating a Captioned Video Using MAGpie 1.0
You should already have MAGpie 1.0 installed on your computer. If you don't, visit NCAM's MAGpie download page - external link for information on how to get MAGpie.
If you want to follow along, download our sample sound clip - pig.wav (168KB, ). Save the file in a place where you can easily find it. Although captioning is usually done for videos, using the audio from the multimedia often allows captioning to be accomplished much easier because the audio file has a smaller file size and takes less room on the MAGpie screen than the full video file would. It is recommended that MAGpie be used with an audio version of the media file you wish to caption. Because the timing information is the same between the audio and video file, when you are done using MAGpie, the caption files can then be combined with your original video files.
Now that you've got all the files you need for this short captioning experience, let's begin!
- Open the MAGpie program. A
splash screen will appear for a couple of seconds. This screen
can be closed by clicking the Enter key on your keyboard, or you can wait for it
to close on its own. When the application opens, you should get
a screen that looks like this:
- Start a new project by selecting
- In the
- With the Media tab selected, use the pig.wav
file. The pig.wav file probably
won't show up until you select
from the drop-down menu. The wav
file should then appear and you can select it. Leave the Time
Units set to 100, and select the tab.
- The Stream tab is where you specify how the captions will look.
You should leave the initial paragraph alignment at center.
For now, don't change the default settings. If any of the settings
or information in these screens needs to be changed at a later
time, they can be accessed under
The first window contains the MAGpie captioning interface. This is where you will enter the captions and timecodes for your media. You may also add a title, copyright, and comments to the caption stream.
The second window contains the media player used to control the media file (pig.wav) you selected earlier as you add the captions.
Navigation between cells in the MAGpie program is a little different from what you would expect. Typical keys (Tab, Enter, or the arrow keys) that move the cursor from one cell to another in a spreadsheet program do not function the same way in MAGpie. The way to navigate from to cell to cell (or in MAGpie terminology, event to event) is to hold down Ctrl and then press an for the direction you want to move.
You can also control the media player using the keyboard. The following list of keyboard commands make navigating the media file much easier than having to use the Player selection in the menu bar, or clicking on the controls in the player itself:
When you are finished, Select the button
and two new windows should open.
- F5 - Pause
- F6 - Play
- F7 - Stop
- F11 - Move back a bit.
- Shift + Ctrl + F11 - Move back 5 seconds.
- F12 - Move forward a bit.
- Shift + Ctrl + F12 - Move forward 5 seconds.
- Make sure the pig.wav media file is at the beginning. The timecode in the media player should read 00:00:00.00. If not, press F7 to rewind to the beginning. Press the F6 key or the play arrow in the media player and listen to the first segment of the audio clip.
- Pause the clip using F5 and begin transcribing what was spoken in the far right-hand column of the table labeled Caption. Use Ctrl + ← to move to the Speaker column and type in the name of the speaker. (Ignore the Timecode column found in the left-hand side of the table. Timecodes are generally added after all the caption text and speakers have been completed.) You can usually only display one or two sentences per caption.
- Press the Enter key twice rapidly to add another line or event
to the table and begin listening to the media file again by clicking
F6. Your screen should now look like this:
- It is probably a good idea to save your work at this point. Press in the menu to save the caption stream. Give your stream a name you will recognize later. After you save the stream, you will be asked to save the project. The default directory for saving the project is the Magpie installation folder. You may want to navigate to the location where pig.wav is located and save the project there instead. This will eliminate some confusion when you export the files later. Remember, the project file stores the captions settings, such as color and font face, and information about which media file you're captioning. The stream file contains your individual captions with timing information.
- Using the same techniques outlined above, continue adding captions
until you have added captions for the entire clip.
- Now you need to add the timecode for each caption. Make sure
the media file is at the beginning again. Put your cursor somewhere
in the first caption row and press the F9 key.
This will add a timecode of 00:00:00.00 in the left column.
- Press the F6 key to begin playing the audio
clip. With the clip playing, press the F9 key
when the words at the beginning of each cell of caption text are
spoken. This will add a timecode for that individual caption and
move the cursor to the next cell. If you make a mistake, pause
the audio clip using F5 and move the cursor to
the caption you want to change. You can then use the F11
and F12 keys to adjust the position of the media
then press the F9 key again to overwrite the
previous timecode or change the timecode manually by typing it
in the left column of the caption row.
- Now when you preview your clip in the media player, it has captions.
Exporting the Caption Files
The next step in the process is exporting the stream you just created so it can be used in a Quicktime, RealPlayer, or Windows Media Player format. MAGpie allows you to output 3 different file types that correspond to these players. This selection can be made in the menu bar under. The three file output choices are shown below. The SAMI files are used by Windows Media Player and SMIL files by RealPlayer. Quicktime files are obviously used by Quicktime.
After one of these options is selected, a dialog box will appear that lists the file that was created and where that file has been saved. The location of this file will correspond to the location of the saved MAGpie stream or if you didn't save the stream, it will save them in the MAGpie folder.
Tips for Using MAGpie 1.0
If you're a MAGpie 1.0 user, you have made a decision that will save you lots of time and effort. Here are a few notes and words of advice if you use MAGpie 1.0 to create your caption files.
- Make sure you are using a media file that MAGpie can read. If you can open the media file with Windows Media Player, then MAGpie should be able to open it.
- Because video files can be so large, you should usually export a sound clip (mp3 or wav) and produce the captions using this smaller file. Make sure your media is completely edited before you begin the captioning process. If you change timing in your media later, your captions will not be synchronized.
- MAGpie puts the Speaker name on a line all by itself. Most of the time we need all the room we can get for the actual captions themselves, so we prefer to leave the speaker column blank and incorporate the speaker into the caption text. Example: "Homer: Are you saying you're never going to eat any animal again?" This will require a little bit of cleanup in the SAMI file after exporting, because MAGpie will always make the top line of the caption blank.
- There is an alternative to transcribing the audio in the MAGpie program.
You can create a .txt file containing a transcript of the audio or
video that can be imported into the program for timecode to be added
to it. The menu option to import text is found under
Homer: Are you saying you're never going to eat any animal again? What about bacon?
. If you choose to create captions this way, be aware that
MAGpie events (or cells) can only handle four lines of text. When there
are more than four lines of text in an event, and you try to do anything
in this event, even simply moving the cursor, the program will automatically
scroll you to the very top of the page. This can be prevented, however,
if you separate the lines of text in your txt file with one empty line between each caption display text and then import the text file, MAGpie will then place each separated block of text
in its own event.
- We have noticed some errors occur if the media file being captioned was generated on a Mac. These errors include actual messages that say the media file can't be opened, or the media player won't respond to key commands. When this happens, close MAGpie completely, and open the media file on its own to make sure that it does work on your PC. Then open MAGpie again and the media file should work properly.