Recommended Video Encoding Specifications

At IRIS Education, we strive to simplify video encoding and streaming.  Through years of experimenting and observing best industry practices, our encoding experts have come up with a set of recommended specifications that will yield the most versatile file formats.

Given the variety of devices and platforms on the marketplace, our current recommendation is to encode using the H.264 video codec and AAC audio codec as MP4 files.  These MP4 files can be streamed using the RTMP protocol in a Flash-based player (such as Longtail's popular JW Player).  The same MP4 files can also be streamed to iOS devices (iPads, iPods, iPhones) using their native HTML5-based players even though they do not support Flash.  Gone are the days where you needed different files encoded in different formats to deliver to different operating systems (e.g., Windows Media for Windows users and QuickTime for Mac users), as 99% of desktop computers have Adobe's Flash plugin already installed.  We use Flash Media Servers and Wowza Media Servers to be able to securely stream to all of these devices and platforms simultaneously.

We also have found that not every Internet user has access to the same amount of bandwidth.  It's now best practice to encode media into multiple bit rates to accommodate users with low bandwidth capacity, as well as users with high capacity.  We also know that most users are not tech-savvy enough to be able to know which version of the video they should select.  Now there is a solution for all of this, allowing the best possible user experience.

The JW Player has support for referencing multiple files of the same video, and selects the best one to use based on the user's connection and viewing size, giving the optimal viewing experience.  This is known as Bitrate Switching, or sometimes referred to as Dynamic Streaming.  For instance, a viewer with a lot of bandwidth who only views at a small resolution does not need the highest resolution file (that would be a waste of bandwidth, since a video quality improvement would not be discernable to the human eye).  Similarly, when viewing in full-screen, if there is bandwidth to support using the high quality version, the player will use it, but if the user doesn't have the necessary bandwidth the player will automatically step down to the next file that the user's connection will support.  Be sure to check out our Video Comparison page and turn on the "Show Quality Info" checkbox to see this technology in action.  Also take a look at our Bitrate Switching Demo to see how it works on an Internet connection with fluctuations in available bandwidth.

We recommend encoding each video into at least three different bit rates at 400kbps, 800kbps, and 1500kbps.  Below are the recommended encoding specifications we use for our encoding in Sorenson Squeeze.  If you are going to encode your own content, you should try to adhere to these specifications: