Caption Maker from Microsoft is an online tool for creating captions (as opposed to Camtasia 8, which you can work with offline). It is one of many alternatives available on the market.
It requires that you have your video uploaded to a http server (e.g. Dropbox) in any format your browser can play, e.g. mp4.
Consider whether it will be easier to distribute the script for translation or whether you want to send this guide to the translators and ask them to use the tool directly.
The advantage of the second solution will be that you will not have to spend time synchronizing the various versions of the subtitles afterwards.
If it's not possible, use the output file (see below) and distribute it to the translators. Ask them to keep to the structure & timings to ease synchronizing.
Paste in the URL to the video file and click 'Load':
Start creating the captions:
- play and pause the video and enter parts of the script underneath the screen
- click save and continue
Repeat until the end of the video:
You will immediately see the results on the right hand side in the 'Caption list' window.
Select the output format TTML. Copy the content displayed and paste it into a text editor (e.g. Notepad).
Save the file as .ttml:
- choose 'All files'
- enter file name followed by .ttml
- choose UTF-8 encoding
Upload the video to the OVP and add the subtitle files. Follow the 'Uploading subtitles' description.