Improved H.264 Compression Holds Down File Sizes on 1080p iTunes Store Content
Ars Technica takes a look at the new 1080p content available on the iTunes Store, showing how a "High" compression profile for H.264-encoded content on the iPhone 4S and new iPad and Apple TV are minimizing the increase in file size needed to move from 720p to 1080p.
Comparison of 720p (left) and 1080p (right) video quality in iTunes Store contentIn a survey of several titles now available in 1080p on the iTunes Store, the report found that file sizes generally increased by 15-25% over their respective 720p versions, despite the number of pixels more than doubling to reach the higher standard.
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 1920x1080 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.
The report also offers a comparison of video quality between the 720p and 1080p formats on the iTunes Store, noting that the increase in image quality for 1080p content is minor in many cases, but more significant in brighter scenes.
Popular Stories
The iPhone 17 Pro and iPhone 17 Pro Max are three months away, and there are plenty of rumors about the devices.
Below, we recap key changes rumored for the iPhone 17 Pro models as of June 2025:Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone X through iPhone 14 Pro have a...
iPadOS 26 allows iPads to function much more like Macs, with a new app windowing system, a swipe-down menu bar at the top of the screen, and more. However, Apple has stopped short of allowing iPads to run macOS, and it has now explained why.
In an interview this week with Swiss tech journalist Rafael Zeier, Apple's software engineering chief Craig Federighi said that iPadOS 26's new Mac-like ...
Alongside WWDC this week, Logitech announced notable new accessories for the iPad and Apple Vision Pro.
The Logitech Muse is a spatially-tracked stylus developed for use with the Apple Vision Pro. Introduced during the WWDC 2025 keynote address, Muse is intended to support the next generation of spatial computing workflows enabled by visionOS 26. The device incorporates six degrees of...
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup.
If you skipped the iPhone...
Apple today provided developers with a revised version of the first iOS 26 beta for testing purposes. The update is only available for the iPhone 15 and iPhone 16 models, so if you're running iOS 26 on an iPhone 14 or earlier, you won't see the revised beta.
Registered developers can download the new beta software through the Settings app on each device.
The revised beta addresses an...
Apple today added Mac Studio models with M4 Max and M3 Ultra chips to its online certified refurbished store in the United States, Canada, Japan, Singapore, and many European countries, for the first time since they were released in March.
As usual for refurbished Macs, prices are discounted by approximately 15% compared to the equivalent new models on Apple's online store. Note that Apple's ...
Apple today added M4 MacBook Air models to its refurbished store in the United States, making the latest MacBook Air devices available at a discounted price for the first time since they launched earlier this year.
Both 13-inch and 15-inch MacBook Air models are available, with Apple offering multiple capacities and configurations. The refurbished devices are discounted by approximately 15...