I have the next code in my index for a video:
Are the paths valid?
https://root/folder/video/v1.ogvhttps://root/folder/video/v1.webmFirefox doesn't support .mp4 files which explains the Specified "type" attribute of "video/mp4" is not supported. error.
If you are using Apache, you can force it to use the correct MIME type. Add the following to your .htaccess file.
# MIME types for Video
AddType video/mp4 mp4 m4v f4v f4p
AddType video/ogg ogv
AddType video/webm webm
AddType video/x-flv flv