toggle

AAPL Stock: 101.79 ( + 0.21 )

Printed from http://www.macnn.com

iTunes 1080p keeps size low through better H.264 compression

updated 02:10 pm EST, Fri March 9, 2012

Newer hardware required for maximum resolution

The 1080p video now sold on the iTunes Store manages its resolution without filesizes being as large as expected, Ars Technica notes. A 1080p video contains 2.25 times as many pixels as a 720p clip, but Ars remarks that the higher-resolution files are generally no more than 1.5 times as big. One example is Hugo, which is 3.99GB in 720p but only 4.84GB in 1080p.

The answer is said to involve H.264 compression. Apple's official specifications show the new Apple TV as supporting "High" or "Main" profiles up to level 4.0, while the new iPad and the iPhone 4S can operate up to level 4.1. It's thought that the High profile is allowing for more efficient decompression than that used in Main or "Baseline" profiles, common among older Apple devices. The iPad 2, for instance can only function up to Main Profile level 3.1. On Macs and PCs, iTunes requires a v10.6 update to support 1080p.




by MacNN Staff

toggle

Comments

Login Here

Not a member of the MacNN forums? Register now for free.

toggle

Network Headlines

toggle

Most Popular

MacNN Sponsor

Recent Reviews

Autodesk Smoke 2015

Since May of this year, Autodesk has been shipping the highly anticipated update to its high-end post-production video editing suite, ...

Crucial MX100 256GB SATA-3 SSD

While the price-per-gigabyte ratio for magnetic platter-based hard drives can't be beat, the speed that a SSD brings to the table for ...

Narrative Clip

With the advent of social media technology, people have been searching for new ways to share the events of their daily lives -- be it ...

toggle

Most Commented