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

Generic iOS 18

iOS 18.1 With Apple Intelligence: New Features, Release Date, and More

Thursday October 10, 2024 8:26 am PDT by
iOS 18.1 will be released to the public in the coming weeks, and the software update introduces the first Apple Intelligence features for the iPhone. Below, we outline when to expect iOS 18.1 to be released. iOS 18.1: Apple Intelligence Features Here are some of the key Apple Intelligence features in the iOS 18.1 beta so far: A few Siri enhancements, including improved understanding...
top stories 12oct2024

Top Stories: iOS 18.1 Release Date, New Macs Incoming, and More

Saturday October 12, 2024 6:00 am PDT by
Things are firming up for a big Halloween week for Apple, with the company's next operating system updates reportedly coming early in the week and hardware launches coming a few days later. Ahead of those hardware launches, we've recently seen what appears to be one of the most significant physical product leaks in years, while some of the new features in Apple's recent software updates have ...
16 pro

iPhone 17 Pro Models Rumored to Introduce These 5 New Features

Friday October 11, 2024 8:55 am PDT by
While the iPhone 16 series was released just a few weeks ago, there are already many rumored features for the iPhone 17 models, and especially for the Pro models. Below, we recap five key new features rumored for the iPhone 17 Pro and Pro Max so far: 24MP front camera for all iPhone 17 models: All four iPhone 17 models will feature an upgraded 24-megapixel front-facing camera, according...
maxresdefault

The MacRumors Show: Apple's Shocking M4 MacBook Pro Leak

Friday October 11, 2024 8:27 am PDT by
On this week's episode of The MacRumors Show, we discuss the unprecedented leak of Apple's M4 MacBook Pro models and the company's rumored move to more staggered hardware and software releases. Subscribe to The MacRumors Show YouTube channel for more videos Multiple leaks surrounding Apple's unannounced 14-inch MacBook Pro with the M4 chip recently surfaced online. The leaks began with unboxin...
ios 18 1 make primary

iOS 18.1 Includes Option to Set 'Primary' Email Address and Change iCloud Email

Friday October 11, 2024 3:55 pm PDT by
In iOS 18.1, there is a new option to set a "Primary" email address in the Settings app, which means it is easier to change the main email address associated with your Apple Account. The Primary email address is the one that is visible to other people when collaborating on and sharing documents, sending calendar invites, and more. Apple did not previously make it easy to change an Apple...
Generic iOS 18 Feature Real Mock

Apple Stops Signing iOS 18.0

Thursday October 10, 2024 12:10 pm PDT by
Apple today stopped signing iOS 18.0, preventing iPhone users who have upgraded to iOS 18.0.1 from downgrading to iOS 18. Apple released iOS 18.0.1 a week ago on October 3. It is not unusual for Apple to stop signing older versions of iOS within a week or two after a new version of iOS is released. When Apple stops signing an update, it can no longer be installed on an iPhone due to a...
iPad mini review thumb

iPad Mini 7 Coming Next Month: What to Expect

Tuesday October 8, 2024 6:16 am PDT by
Rumors strongly suggest Apple will release the seventh-generation iPad mini in November, nearly three years after the last refresh. Here's a roundup of what we're expecting from the next version of Apple's small form factor tablet, based on the latest rumors and reports. Design and Display The new iPad mini is likely to retain its compact 8.3-inch display and overall design introduced with...
When Will Apple Launch More M4 Macs Feature

Will Apple Release M4 Macs Soon? Here's What the Latest Rumors Say

Thursday October 10, 2024 6:22 am PDT by
Apple often releases new Macs in the fall, but we are still waiting for official confirmation that the company has similar plans this year. We're approaching the middle of October now, and if Apple plans to announce new Macs before the holidays, recent history suggests it will happen this month. Here's what we know so far. As of writing this, it's been 220 days since Apple released a new...

Top Rated Comments

studentmac Avatar
165 months ago
Howaaaarrrd!!!
Score: 34 Votes (Like | Disagree)
theMaccer Avatar
165 months ago
Pic of Penny would be much better.
Score: 18 Votes (Like | Disagree)
SB27 Avatar
165 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
164 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
165 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
165 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)