Moodle 2.6 has a function of the $OUTPUT object called pix_url that takes the name of the image, however it would not work for the video, another option would be to use some variables and functions of Moodle to get the path to the theme folder where your video is probably something like
<?php echo $CFG->wwwroot.'/theme/'.current_theme() ?>
Doing this you will have a URL that directs to your theme folder, ai is add /camiodovideo/
Looking at the internal code of Moodle itself holds this variable for many of its libraries like the /lib/outputrenderers.php itself and the /lib/pagelib.php, so it’s pretty safe to use.