The iPhone 5 Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on October 16, 2012 11:33 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 5
Video: Finally High Profile H.264
Section by Brian Klug
There are a few things different with video capture on the iPhone 5 thanks to improvements to both the ISP inside Apple’s A6 SoC, and also software UI changes. First off, because the iPhone 5 display is now 16:9, there’s no cropped view by default or aspect-correct view with letterboxing for video capture. Instead the iPhone 5 video capture window takes an iPad-like approach with transparent UI elements for preview and shooting video.
What’s new is the ability to take still images at 1920x1080 while recording video by tapping a still image capture button that appears while recording. This is a feature we’ve seen onboard a ton of other smartphones and works the same way here. Note that you can’t magically get a wider field of view or the whole CMOS area while shooting video, it’s essentially dumping one frame from video capture as a JPEG instead of into an H.264 container.
In addition the iPhone 5’s tweaked Sony CMOS still uses a smaller center region for video capture. The difference in field of view is pretty big, but nothing that users haven’t already dealt with in the past.
The iPhone 5 brings two main things to video capture. The first is improved electronic image stabilization tweaks and improvements to ISP. The difference is visible but not too dramatic unless you know what you’re looking for. I would wager most users won’t notice a huge step forward from the 4S but if you’re using an iPhone 4 this will be a marked improvement.
The other improvement is video encoding. The iPhone 5 now shoots rear facing 1080p30 video at 17 Mbps H.264 high profile with CABAC. This is a huge step in encoding from the relatively absurd 22–24 Mbps baseline H.264 that the iPhone 4S would shoot at 1080p30. The result is vastly more quality per bit on the iPhone 5, for a big reduction in storage space per minute of video. I did some digging around and found that the A6 uses an Imagination Technologies PowerVR VXE380 for encoding and VXD390 for decoding, which is what I thought was in the previous SoC as well but perhaps wasn’t clocked high enough for encode at high profile. This brings the iPhone 5’s encoder on paper up to match what I see other smartphones running their 1080p video at as well (17 Mbps high profile).
On the front facing camera Apple is shooting 720p30 at 11 Mbps H.264 baseline, as opposed to the VGA at 3.5 Mbps that the 4S shot. Interestingly enough both front and rear shooting modes still are just mono audio, 64 kbps AAC. I would’ve liked to see stereo here since almost all the competition is shooting stereo, and it’d put those 3 microphones to use.
To get a feel for video quality, I stuck my iPhone 4S and iPhone 5 in my dual camera bracket with pistol grip and made a series of three videos. I then combined them and put them side by side for ease of comparison. I’ve uploaded the result to YouTube, but you can also grab the original videos (548 MB zip) if you’d like from the site directly without the transcode.
Overall the most dramatic improvement is the front facing camera, which is obviously night and day. Better image stabilization is noticeable while I’m walking around being intentionally shaky, but nothing hugely dramatic. The main rear facing video improvement seems to be an increase in sharpness (watch the power lines and wires in the native resolution version) and slightly wider field of view. That’s to say nothing of the fact that this quality comes at a bitrate that’s lower than the previous version but with better encode settings.
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Zink - Wednesday, October 17, 2012 - link
That's would be light enough to float.manders2600 - Wednesday, October 17, 2012 - link
It would be really nice to see some of these benchmarks next to an Android device running Jellybean.From my personal experience with the Galaxy Nexus, all of the benchmarks run in this article improve dramatically (many by more than 50%) with that OS version.
I'm really curious to see what a comparison between the performance of an S4 (Krait) and an A6 would be in that situation, since so much of the CPU tests are impacted by OS.
manders2600 - Wednesday, October 17, 2012 - link
But great read, though!. . . sorry, forgot to include that.
Tremendous research went into this, and it is well appreciated.
phillyry - Sunday, October 21, 2012 - link
I agree.I mean it's good that you have the devices on their native OSes but showing them on their upgraded OSes would bee good too 'cause it would add another realistic point of comparison.
cjl - Wednesday, October 17, 2012 - link
In the article, you state:"Which brings us to the next key detail with the anodization process: typically, the thickness of the anodization is half the thickness of the base aluminum. So if you had an aluminum plate that was 1mm thick, post-anodization, you would end up with a 1.5mm thick plate"
You also talk about the pore density in anodizing, and claim that apple has a pore density higher than most.
To put it quite simply, all of this is wrong.
Anodizing creates a layer that is on the order of micrometers thick. How thick the coating is depends on the details of the anodizing process, not on the thickness of the base metal. Most decorative anodized coatings are a few micrometers thick, and as you discussed, it's really not that hard to scratch them. Thicker anodizing, sometimes known as hard anodizing, is possible, and it can be done to thicknesses of 25 micrometers (0.001") or greater - from what I can find, over 100 micrometers is possible. These thicker coatings provide pretty substantial scratch resistance, and significant increases in durability, but they require substantially more process control, and it is more difficult to get a consistent coating. Note that even the thickest of these coatings is around 0.006 inches (150 micrometers) or so, which is far, far less than a 2:1 ratio on the aluminum on which it is applied. Interestingly, this thickest possible coating is about what you speculate is the thickness on the iPhone 5, but given its propensity for scratching, I sincerely doubt this to be the case.
Now for pores. The pore size on anodized aluminum is a few tens of nanometers. There is absolutely no way that you could visibly see this, or any improvement in this from one product to the next. This is 20 times smaller than the smallest wavelength of visible light. Quite simply, you can't possibly see this, and this won't be any different between Apple and any other manufacturer.
That having been said, there are some slight differences in pore structure between coatings. They won't make a significant visible difference (if any at all), but they can make a difference in durability. Specifically, hard anodized coatings (as mentioned above) tend to have thicker walled pores relative to the pore diameter. This again helps increase the wear resistance of hard anodized parts.
TL,DR: The iPhone probably has a really thin anodizing coat (<10 um). The pores are never visible on anodizing. Anodizing can be done, even on very thin aluminum, such that it would be incredibly scratch resistant.
Jaguar36 - Wednesday, October 17, 2012 - link
+1 on this.Not sure where the Vivek got the 2:1 ratio for an anodization thickness, but its nonsense. If you have a 0.25" thick part you're not going to be getting a 0.125" thick anodization. Anodization is usually less than 0.001" thick, and has no relation to the base part thickness.
Cibafsa - Wednesday, October 17, 2012 - link
Whilst Android based device manufacturers do not have to bear the majority of the SOC design/manufacture costs or the OS development costs, they do not share in the iAds/App Store type revenue Apple does.Surely it is Apple that can afford to cut prices to cost or even lower. Perhaps it is the Android manufacturers that have to worry about cheap high end phones.
Will be interesting to see what price point the iPad mini comes in at.
steven75 - Wednesday, October 17, 2012 - link
Most people following this industry are well aware by now that the App Store is run near break-even and iAds were not very successful.Calista - Wednesday, October 17, 2012 - link
A good and through review but I found it a bit too long-winded. An example would be the following example straight from the first page:'All previous iPhones have maintained the same 3.5-inch, 3:2 aspect ratio display. With the rest of the world quickly moving to much larger displays, and with 16:9 the clear aspect ratio of choice, when faced with the decision of modernizing the iPhone platform the choice was obvious.'
It could have been shortened to:
'iPhone 5 moves from the previously used 3.5", 3:2 aspect ration to a 4", 16:9 aspect ratio as common among smartphones of today. They kept roughly the same width while increasing the hight with xx mm. The resolution went from 960x640 to 1136x640."
More information is contained in the rewritten part while at the same time being shorter. Don't forget that this is Anandtech and I assume every single one of your readers are familiar with both the size and resolution of previous iPhones as well as common aspect ratios used on phones.
The same could be said about the design. I'm sure every single one of your readers have held and played with an iPhone 4/4s, and so when comparing to those two you guys could have kept a lot shorter.
phillyry - Sunday, October 21, 2012 - link
Read better as originally posted than as you rewrote it.