Quickchannel Online Video Platform sends HLS streams to all devices for optimum delivery and quality. The actual formats supported on your account can be checked in Settings → Upload → Formats.

HLS is supported on all modern browsers and devices, however for very old browsers like Internet Explorer on Windows 7 or devices like Android 2 the fallback MP4 format is used.
Here you can also check if your account is configured to store original format of the uploaded media.