How to Encode for iOS Devices
At the recent Streaming Media Europe conference in London, encoding expert Jan Ozer gave a one-hour introduction to encoding for iOS devices. Ozer started out with the basics:
"What is H.264? H.264 is a compression technology," Ozer said. "If you're producing for iOS devices, you should use H.264, and that's the only codec you really need to know about."
Simple, right? But other things are more complicated, such as video encoding profiles and levels:
"What are profiles and levels?" Ozer asked. "There are literally dozens of H.264 encoding options, but most of them impact quality, and if you mess those up maybe you're quality's a little bit sub-optimal, maybe your data rate's too high. Not a big deal. If you mess up profile and level, the files that you produce won't play on the target devices. So really, when you're producing H.264 for iOS device delivery, the things you need to know when encoding your files are 'what is the profile?' and 'what is the level?'"
Ozer went on to the explain the essential profiles:
"What are the H.264 profiles? There's pretty much three that we worry about when we're producing for computer playback. There's Baseline, there's Main, and there's High. This is the definition from Wikipedia: it's says that a profile defines a set of coding tools or algorithms that can be used in generating a bitstream," Ozer said.
For a fuller look at encoding for iOS devices, watch the video below.
HOW TO: Encoding Video for iOS Devices
This seminar starts by detailing the playback specs for all iOS devices, old and new. Then, learn the strategies used by prominent iTunes publishers to serve the complete range of installed iOS devices. Next, the seminar switches to cellular wireless delivery, with a technical description of Apple's HTTP Live Streaming (HLS), including recommendations for the number of streams and Apple's encoding parameters. The seminar concludes with a review of encoding options for HLS and techniques for serving multiple target platforms such as Flash and iOS devices with a single set of encoded H.264 files.
Jan Ozer, Principal, Doceo Publishing