Hi Narayanan,
When it comes to the audio files, there is an HTML5 <audio> tag which creates a player on your page without the need for a plugin. You don't need closed captioning for audio, just a transcript. Example:
<audio controls title="Ride of the Valkyries"> <source src="http://www.archive.org/download/RideOfTheValkyries/ride_of_the_valkyries_2.mp3" type="audio/mp3" /> <source src="http://www.archive.org/download/RideOfTheValkyries/ride_of_the_valkyries_2.ogg" type="audio/ogg" /></audio> <details> <summary>Looking for a Job - Transcript</summary> <p>Hi, my name is Eric, and I'm am here to help you learn how to find a job.</p> ... </details>
When it comes to videos, you can also do this right in HTML5:
<video poster="your-video-poster.jpg" controls tabindex="0" title="Your Video">
<source src="your-video.mp4" type='video/mp4' />
<source src="your-video.webm" type='video/webm' />
<track src="#inline-captions" label="English Captions" kind="subtitles" srclang="en-us" default />
</video>
<track src="#inline-captions" kind="captions" data-type="text/html" />
</video>
<details id="inline-captions">
<summary>Looking for a Job - HTML5 Transcript/Captions</summary>
<p><strong>(Animated pen draws a red line that leads into the text Looking for A Job)</strong></p>
<p><strong>(Cut to a medium shot of the Host. LINE DRAWING GRAPHIC: Stick person appears and waves.)</strong></p>
<p><span data-begin="2.50s" data-dur="3.84s">Hi, my name is Eric, and I'm will be teaching you this section of the course.</span></p>
...
</details>
You would normally need to upload your transcript as an TTML or WebVTT file and then insert the URL to the file in the <track> tag. This is a real pain in Moodle but it will work.
There is an alternative. As seen above, it is possible to embed your transcript right in your Moodle page... if you use Moodle WxT. As seen above, Moodle WxT supports embedding your transcript right in your Moodle page which is very convenient. Moodle WxT even automatically falls back to a Flash player for older browsers that don't support the HTML5 audio and video tags. Moodle WxT's theme is more WCAG 2.0 level AA compliant than most Moodle Themes that are available today. I only say "most" because I haven't tested them all. To learn more about Moodle WxT, contact Instrux Media.
Hope this helps.
Best regards,
Michael