Why?

While very convenient, HTML5's <video> tag also has a few limits.

First, it does not handle transparent pixels. This limits video form to rectangular shapes, and is unsuitable for rendering in layers with other elements on the web page.

Also, there is a limit to "Inline and Auto Playback" on smartphones's browser.

In Android the "Inline Playback" feature is available but the "Auto Playback" is not available yet. Because of this limitation, user is required to touch the screen to turn on the video content at the website header for the first view. In iOS version 9 and old ones, both of these features are unavailable. The video contents play only in full screen mode. Both of these features are available for browsers in PC. But as making websites by Responsive Web Design for all devices (Android, iOS and PC), developers have to write separated source code for each of platform.

iPeg video format is a solution for these problems. With iPeg, the "Transparent Background" and "Inline Auto Playback" features can be enable by using only one source code for all platforms. With iPeg you can make impressive websites.