New Apple TV, iTunes Support Faster H.264 Compression

One of the downsides to the new 1080p content available from the iTunes Store is the larger file sizes associated with these TV shows and movies. But, as discovered by Ars Technica, Apple has added a new “high” compression profile for H.264 video on the iPhone 4S and new iPad and Apple TV that makes it possible for a smaller increase in file size when converting content from 720p to 1080p. As noted by MacRumors, the file sizes of 720p movies and TV shows only increase by roughly 15% to 25%, despite the fact that 1080p content has more than double the amount of pixels…

The report credits the new H.264 encoding algorithm, but it’s certainly not layman’s terms:

The reason that the 1080p versions of the iTunes Store videos can be a good deal better without doubling the file size—or worse—can be found in the tech specs of the new AppleTV and the new iPad. The AppleTV now supports H.264 compression for 1920×1080 resolution video at 30 frames per second using High or Main Profile up to level 4.0, the iPad and the iPhone 4S the same up to level 4.1. The profile indicates what kind of decompression algorithms the H.264 decoder has on board—the “High” profile obviously has some tricks up its sleeve that the “Main” or “Baseline” profiles known to previous devices don’t support. The level value indicates how many blocks or bits per second a device can handle.

[Ars Technica via MacRumors]

Post a response / What do you think?