Choosing the Number of Renditions and Encoding Sets

I recently received an email inquiry that asked, “on average for multiple devices, how many different renditions/encoding sets do you recommend?” The answer was complex enough that I figured I would answer it in a blog post. 

There are multiple interlocking considerations, as you would suspect. Let’s start with Quality and Compatibility.

Quality and Compatibility 

1. The starting point for any multiple screen delivery inquiry is Apple Technote TN2224, which presents Apple’s vision as to how to create one set of files that plays on computers, iOS devices, and a Apple TV, an OTT box. Here’s the most important part, which you can click to see at full resolution in a separate browser window. 


Apple’s recommendations in TN2224. 

Essentially, Apple recommends encoding with the Baseline profile for compatibility with older iOS devices, Main for newer devices and High profile for the newest iOS devices. 

As you can read here, Google recommends encoding using the Baseline profile for all Android devices. That’s because, unlike Apple, Google doesn’t know the playback capabilities of all Android devices since most are made by third parties. In point of fact, most Android devices can play Main and High profile; Google is just presenting the most conservative view. 

To complete the picture, computers can play any profile, as can all other OTT boxes.

So the first big issue is whether you should encode multiple sets of files; one as shown in TN2224 for iOS, one using all Baseline for Android, and one using all High profile for the highest possible quality on computers and OTT devices. Or, should you create one set of files a la TN 2224 and distribute them to all targets. Beyond the potential Android compatibility issue, which I think is negligible, the issue comes down to the quality difference between files encoded using the Baseline and High profile. 

That’s an issue I explore in this video, which is from a course on Encoding for Multiple Screen Delivery on Udemy. Basically, I encoded files using the configurations shown in TN 2224, but the High profile, and compared the quality to the files encoded using the profiles suggested in the Tech Note.