Improved H.264 Compression Holds Down File Sizes on 1080p iTunes Store Content

[croooow]

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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....

But they both look awful!

Chuck Lorre shows are painful to watch. I really wanted to like this show because of the subject matter, but it is a show that does not respect the intelligence of their audience. It is very successful so I understand why it is there, just do not understand why people who seem intelligent would like it.

Oh, and I am not a TV snob. I do not mind a "turn your brain off" show, just not something this dumb. Look up videos with the laugh track turned off and you will see what I mean.

Back on topic, like SB27 said. This is why Apple is successful. They put work into the experience of using their product. +1 for Apple (-∞ for Lorre)

 

[3282868]

I think that would be a good comparison.

1080P iTunes/Apple TV vs. a 1080P Blu-Ray.

Thanks, I spent a good amount of time comparing iTunes 1080P, 720P with my own copies and the original BD's as I was impressed that the 1080P file sizes were marginally larger or on par with the 720P versions. Interesting that Apple is making use of L4+ profile. Perhaps it's a bit unfair of a comparison as I handbrake the heck out of my BD rips (on my 12-Core Mac Pro is takes any where from 6-8 hours to encode), but is well worth it as the final result looks great on my 60" screen (not lossless of course but darn close).

How can you tell if something is in 1080p on the store or not? I haven't seen anything that differentiates between 720 and 1080.

Haven't checked the store to determine if Apple will differentiate 1080P/720P/SD encodes, however the files for 1080P versions have (1080P HD) in their name. I was able to use the new "purchased" section of iTunes and downloaded movies that weren't on my computer (according to iTunes), even though they were, and assumed this meant the 1080P versions. Sure enough, it did. So now I have 1080P, 720P and SD copies for each iTunes purchased movie.

 

[hirshnoc]

upconvert?

Is there a way to up-convert your existing 720p purchases to 1080p?

 

[khollister]

must go to the eye doctors - i can't really see any difference in clarity between the pictures. possibly the colour is better on the right one?

still, i guess at least i can feed good about sticking with my AppleTV2 for the time being then

Really? I think the difference is pretty large.

 

[AppleInLVX]

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.

And also delivering better Big Bang for the buck.

I could not agree more. This is part of the typically unquantifiable reason why Apple's stuff just feels better when you interact with it. This, more than anything, brought me into the fray all those years ago.

 

[11thIndian]

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.

There's no difference because you're using a G1 aTV. It's getting downscaled to 720p anyway.

The good news here is that the new aTV is capable of decoding a much higher data rate than what iTunes is providing. On average, the reports I've read have it at about 5.2-5.5 Mbps. The new A5X chip is capable of 25 Mbps. So original material, or ripped BR discs should be able to look substantial better.

 

[SAIRUS]

Hmm it's really a toss up. I'm glad we're finally getting 1080p, but the 720p wasn't all that amazing compared to blu-ray.

Yes, I know I get to benefit from both camps, some don't.

I guess I would of put more effort into improving the 720p videos. The only way ultimately VOD will win over physical media is for bandwidth pipelines to increase, and for the quality to overtake physical media.

 

[tdream]

The comparison shot selection is so dumb because we already know the difference between 720p and 1080p, yeah 1080p is a bit better. The article is about the compression techniques. Which btw have be used for a very long time on the scene, which have resulted in 720p entire full length movies comprised of 700mb data usually less.

Apple is just taking advantage of the available compression routines out there. It does make sense as in this case it's their prerogative not to push size but rather quality. Especially since iTunes is an online business and Steve Jobs wanted to move away from physical media especially Blu-Ray. It helps there business model and decreases costs, and is easier on the consumer's bandwidth.

Win win win all around.

 

[3282868]

Is there a way to up-convert your existing 720p purchases to 1080p?

Yup. In iTunes Store, select "Purchased", then "Movies." Any movies that are available in 1080P for the account you are currently signed into will be available for download (it doesn't state that they are 1080P versions, which is a bit confusing). To check, open the Finder window for your iTunes movies and look at the name of the file. It should have (1080P HD) in the name.

There's no difference because you're using a G1 aTV. It's getting downscaled to 720p anyway.

The good news here is that the new aTV is capable of decoding a much higher data rate than what iTunes is providing. On average, the reports I've read have it at about 5.2-5.5 Mbps. The new A5X chip is capable of 25 Mbps. So original material, or ripped BR discs should be able to look substantial better.

Not true. My first gen has a Crystal HD video card, I hacked it to run XBMC with the HD video card so it does play 1080P. Read up on it, it's a GREAT addition for ~$30-40. Been using it for a long time, more so than my 2nd gen Apple TV. I have everything connected to a media server with my encodes. Without the Crystal HD video card it simply crashes when trying to play my 1080P DTS mkv encodes.

25 Mbps is good, but 54 Mbps is the norm for Blu-Ray's. However, I couldn't imagine downloading such high encodes, would take the average consumer hours if not longer for very little difference in quality. Here's hoping the new Apple TV can handle my library as well as my hacked first gen.

 

[bsolar]

I wonder if they are using the Hi10P profile. 10bit encoding is very effective in giving higher compression without compromising quality, but requires higher computing power and player support is only recently becoming mainstream.

 

[11thIndian]

There could be any number of reasons why they chip is restricted to 4.0 vs 4.1. It maybe be that streaming material compressed at the 4.1 data rates just isn't possible across current local wifi networks.

What's the maximum data rate of 802.11n?

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My first gen has a Crystal HD video card, I hacked it to run XBMC with the HD video card so it does play 1080P. Read up on it, it's a GREAT addition for ~$30-40.[/B] Been using it for a long time, more so than my 2nd gen Apple TV. I have everything connected to a media server with my encodes. Without the Crystal HD video card it simply crashes when trying to play my 1080P DTS mkv encodes.

Gotcha. I re-read that after and realized I'd inopportunely slighted your intelligence. Apologies.

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25 Mbps is good, but 54 Mbps is the norm for Blu-Ray's. However, I couldn't imagine downloading such high encodes, would take the average consumer hours if not longer for very little difference in quality. Here's hoping the new Apple TV can handle my library as well as my hacked first gen.

Exactly. Apple has to play a very careful game here between quality and convenience. If they boost the data rates too high, the wait times for buffering will be too long, and people will get frustrated and give up.

OR they'll be peeved when they see how much bandwidth they've used on their next internet bill.

 

[3282868]

Gotcha. I re-read that after and realized I'd inopportunely slighted your intelligence. Apologies.

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Exactly. Apple has to play a very careful game here between quality and convenience. If they boost the data rates too high, the wait times for buffering will be too long, and people will get frustrated and give up.

OR they'll be peeved when they see how much bandwidth they've used on their next internet bill.

Spot on, and no offense taken

 

[Xtremehkr]

What an interesting choice of pictures to use.

 

[techwhiz]

High Profile Vs Main

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.​

This is a bunch of misinformed garbage.
This has everything to do with how the video was encoded.
The video was re-encoded with "high profile". The decoder must support high profile to decode the video. High profile gives better quality at the same resolution and allows you to increase resolution of the output without increasing file size dramatically.

The original content was probably 1080p or 1080i and was scaled down to 720p. Using high profile and no down-scaling allows better quality with only a marginal increase in file size.

The amount of computation required to decode high profile vs main profile is significant if done in software. They are probably using the additional two GPUs on the A5x to do the decode. iOS devices don't have dedicated chips for video decode. It's done either by the GPU or the CPU. Which is why, up until the release of the iPad(Generation 3), iOS devices have not been able to support high profile streams. They run out of CPU/GPU cycles.

Yea, they added software for decode on the devices but it's not just enabling it on the device and there are no tricks in the decoder. The tricks are done in the encoder to get the file size down.

 

[homeboy]

Hmm it's really a toss up. I'm glad we're finally getting 1080p, but the 720p wasn't all that amazing compared to blu-ray.

You're absolutley correct. Blu-Ray is utterly world class. The difference between a 1080p file on the web and a blu-ray movie is like night and day, but so is the size difference too 20-30GB versus 5-6GB for a 1080 Mkv file.

 

[Muramasa]

There's no difference because you're using a G1 aTV. It's getting downscaled to 720p anyway.

The good news here is that the new aTV is capable of decoding a much higher data rate than what iTunes is providing. On average, the reports I've read have it at about 5.2-5.5 Mbps. The new A5X chip is capable of 25 Mbps. So original material, or ripped BR discs should be able to look substantial better.

Just to clarify, the new TV is using the A5 chip, not the A5X. It's still better than the 2nd gen. TV with its A4 chip though.

http://www.apple.com/appletv/specs.html

My question is, who'd like to post up a HandBrake preset for me that better takes advantage of the new TV?

 

[scott911]

don't forget to factor in that you may be comparing these images on a crappy, work-supplied monitor, on work time. In a darkened room, with a quality property calibrated television, -that's were the difference matters and should be evaluated.

I personally see a significant difference between the sample images...

I've been waiting for apple to match what's long been a resolution standard, and am trilled to see they are working on improving encoding too.

 

[OwenDarko]

Im struggling to see a difference..i think it will be better in motion!

 

[samcraig]

The difference is easy to see.

It's $1

 

[GREEN4U]

Who actually read this article? I just lol'd at the pic of Wollowitz.

 

[commander.data]

The amount of computation required to decode high profile vs main profile is significant if done in software. They are probably using the additional two GPUs on the A5x to do the decode. iOS devices don't have dedicated chips for video decode. It's done either by the GPU or the CPU. Which is why, up until the release of the iPad(Generation 3), iOS devices have not been able to support high profile streams. They run out of CPU/GPU cycles.

Yea, they added software for decode on the devices but it's not just enabling it on the device and there are no tricks in the decoder. The tricks are done in the encoder to get the file size down.

As you say, video decoding is very compute intensive, but it is not done on the CPU or GPU. The concern isn't just using up compute cycle or performance, but power consumption. There are dedicated video decode units integrated in SoCs with PowerVR making a whole line of them. The 3rd generation iDevices were reported to use the PowerVR VXD 370 while the Apple A4 integrates a PowerVR VXD 375. I'm not sure what the Apple A5 uses, but it's certainly not using nothing. Even in computers, GPUs have dedicated video decode units because using regular GPU cores is not power efficient.

 

[JAT]

Now, map all this info into the following:

2GB monthly allowance.

Ouch.

 

[gnasher729]

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...

If you can't see the difference between 720p and 1080p, what makes you think you can see the difference between 1080p and 1080p with larger file size?

 

[Mr. Retrofire]

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

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

 

[11thIndian]

Just to clarify, the new TV is using the A5 chip, not the A5X. It's still better than the 2nd gen. TV with its A4 chip though.

Yes, and a single core at that. It seems clear that Apple is gearing this product exclusively towards the the job of media streaming, which should be self evident.

I think the larger ramifications of this are that Apple may not see the TV as a self contained platform for applications. We're seeing Apple bundle more "channels", and you may see the ability to customize that lineup with selection from a "channel store" that charges you a monthly subscription via iTunes like Netflix now does.

But I think the prospect of full iOS apps is constrained. The processor is stripped down, and what little internal storage exists is needed for media buffering.

I'd be willing to wager that we won't see a full on "appStore" on the TV. If you want to get those games/applications on your TV, do it running from your iPad/iPhone via AirPlay.