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.

itunes 720p 1080p comparison
Comparison of 720p (left) and 1080p (right) video quality in iTunes Store content

In 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

iPhone 17 Pro Lower Logo Feature 1

iPhone 17 Pro Coming Soon With These 14 New Features

Monday June 30, 2025 1:08 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are less than three months away, and there are plenty of rumors about the devices. Apple is expected to launch the iPhone 17, iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max in September this year. Below, we recap key changes rumored for the iPhone 17 Pro models:Aluminum frame: iPhone 17 Pro models are rumored to have an...
A18 Pro Chip

New MacBook With A18 Pro Chip Spotted in Apple Code

Monday June 30, 2025 8:05 am PDT by
Apple is developing a MacBook with the A18 Pro chip, according to findings in backend code uncovered by MacRumors. Earlier today, Apple analyst Ming-Chi Kuo reported that Apple is planning to launch a low-cost MacBook powered by an iPhone chip. The machine is expected to feature a 13-inch display, the A18 Pro chip, and color options that include silver, blue, pink, and yellow. MacRumors...
iPhone 17 Pro Lower Logo Magsafe

iPhone 17 Pro's New MagSafe Design Revealed in Leaked Photo

Wednesday July 2, 2025 8:37 am PDT by
The upcoming iPhone 17 Pro and iPhone 17 Pro Max are rumored to have a slightly different MagSafe magnet layout compared to existing iPhone models, and a leaked photo has offered a closer look at the supposed new design. The leaker Majin Bu today shared a photo of alleged MagSafe magnet arrays for third-party iPhone 17 Pro cases. On existing iPhone models with MagSafe, the magnets form a...
Apple Watch Ultra Night Mode Screen

Apple Watch Ultra 3 Launching Later This Year With Two Key Upgrades

Wednesday July 2, 2025 1:13 pm PDT by
The long wait for an Apple Watch Ultra 3 appears to be nearly over, and it is rumored to feature both satellite connectivity and 5G support. Apple Watch Ultra's existing Night Mode In his latest Power On newsletter, Bloomberg's Mark Gurman said that the Apple Watch Ultra 3 is on track to launch this year with "significant" new features, including satellite connectivity, which would let you...
macbook air spacegray purple

Apple Planning to Launch Low-Cost MacBook Powered By iPhone Chip

Monday June 30, 2025 3:20 am PDT by
Apple is planning to launch a low-cost MacBook powered by an iPhone chip, according to Apple analyst Ming-Chi Kuo. In an article published on X, Kuo explained that the device will feature a 13-inch display and the A18 Pro chip, making it the first Mac powered by an iPhone chip. The A18 Pro chip debuted in the iPhone 16 Pro last year. To date, all Apple silicon Macs have contained M-series...
iOS 18

Apple Releases Second iOS 18.6 Public Beta

Tuesday July 1, 2025 10:19 am PDT by
Apple today seeded the second betas of upcoming iOS 18.6 and iPadOS 18.6 updates to public beta testers, with the betas coming just a day after Apple provided the betas to developers. Apple has also released a second beta of macOS Sequoia 15.6. Testers who have signed up for beta updates through Apple's beta site can download iOS 18.6 and iPadOS 18.6 from the Settings app on a compatible...
Wi Fi WiFi General Feature

iOS 26 Adds a Useful New Wi-Fi Feature to Your iPhone

Wednesday July 2, 2025 6:36 am PDT by
iOS 26 and iPadOS 26 add a smaller yet useful Wi-Fi feature to iPhones and iPads. As spotted by Creative Strategies analyst Max Weinbach, sign-in details for captive Wi-Fi networks are now synced across iPhones and iPads running iOS 26 and iPadOS 26. For example, while Weinbach was staying at a Hilton hotel, his iPhone prompted him to fill in Wi-Fi details from his iPad that was already...
maxresdefault

Five Features Coming to AirPods Pro 3

Friday June 27, 2025 10:52 am PDT by
Apple hasn't updated the AirPods Pro since 2022, and the earbuds are due for a refresh. We're counting on a new model this year, and we've seen several hints of new AirPods tucked away in Apple's code. Rumors suggest that Apple has some exciting new features planned that will make it worthwhile to upgrade to the latest model. Subscribe to the MacRumors YouTube channel for more videos. Heal...
replay all time playlist apple music

Apple Music Debuts All-New Personalized Playlist

Monday June 30, 2025 7:16 am PDT by
As part of its 10-year celebrations of Apple Music, Apple today released an all-new personalized playlist that collates your entire listening history. The playlist, called "Replay All Time," expands on Apple Music's existing Replay features. Previously, users could only see their top songs for each individual calendar year that they've been subscribed to Apple Music, but now, Replay All...

Top Rated Comments

studentmac Avatar
174 months ago
Howaaaarrrd!!!
Score: 34 Votes (Like | Disagree)
theMaccer Avatar
174 months ago
Pic of Penny would be much better.
Score: 18 Votes (Like | Disagree)
SB27 Avatar
174 months ago
The Hidden Side of Apple Value

The press mainly focuses on the hardware, sales figures, etc. What people miss about the value that Apple is delivering to customers can be found in this story. At every turn and in every nook and cranny of the Apple ecosytem, their engineers are finding ways to deliver better bang for the buck. Video compression is just one of thousands of ways that Apple thinks completely differently about the user experience than anyone else. This is why they are a $500B company.

I was also struck while watching the keynote for the iPad by the amount of energy and focus put into iLife and iWork. That stuff is simply amazing for only $4.99 a copy (and with mostly free upgrades).

Yes, we are trapped in a closed Apple ecosytem. I like to think of myself as "happily trapped" given the sheer amount of energy, dollars, focus and excellence being delivered in every aspect of their ecosystem.

I will put the pom-poms down now, but this story prompted a visceral reaction and I felt it was worth noting.
Score: 17 Votes (Like | Disagree)
Mr. Retrofire Avatar
174 months ago
At every turn and in every nook and cranny of the Apple ecosytem, their engineers are finding ways to deliver better bang for the buck. Video compression is just one of thousands of ways that Apple thinks completely differently about the user experience than anyone else.
Not really. Apple use(d) their own H.264-encoder, which produces larger files with worse quality, compared to the open source x264-encoder (the command line version). The picture below shows how efficient the x264-encoder is (just an example):



They should work together with the x264-developers (http://www.videolan.org/developers/x264.html). They know the best settings and encoding strategies [1]. x264 is the H.264-encoder with the best visual quality. Warner Brothers use the x264-encoder to encode commercial BDs.

More info:
Seventh MPEG-4 AVC/H.264 Video Codecs Comparison (http://compression.ru/video/codec_comparison/h264_2011/)

Btw:
Apples uses still BZIP2 and ZLIB, which use 10-20 year old compression algorithms (BWT & deflate), to compress the file system, disk images, installer packages, software downloads (Mac App Store), software updates and so on. The newer LZMA and LZMA2 algorithms are not only faster (decompression), the resulting files require also 30 percent less disk space (faster file transfers (downloads)). Apple does not like & use good compression algorithms.


[1]
http://doom9.org/
http://doom10.org/
http://mewiki.project357.com/wiki/X264_Settings
Score: 9 Votes (Like | Disagree)
Deadman64 Avatar
174 months ago
I downloaded 1080P versions of my movies from iTunes and played them on my system (have a 1st gen aTV with a Crystal HD card for 1080P/DTS content on my 60" Pioneer Elite). Truthfully, I saw little difference between the 1080P and 720P iTunes versions, yet a major difference between my 1080P handbraked encodes and direct Blu-Ray movies.

I think that would be a good comparison.

1080P iTunes/Apple TV vs. a 1080P Blu-Ray.
Score: 9 Votes (Like | Disagree)
luke.mac1 Avatar
174 months ago
noting that the increase in image quality for 1080p content is minor in many cases, but more significant in brighter scenes.

So what they're saying is that the difference between 720p and 1080p in the iTunes store is almost negligible? I mean you can see the difference there on the scaled up image, but I imagine you can't really see it on a small screen. Maybe it will be better on a 27" imac or 50" HDTV.
I still think they should offer a larger, higher quality file size for people who wish to download it... maybe something to select in the preferences section of iTunes...
Score: 8 Votes (Like | Disagree)