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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ArmedandDangerous - Tuesday, October 16, 2012 - link
What ever happened to the One X International review that was promised when you were reviewing the US version? Lots of promised articles and reviews that were never ever done...MrCake - Wednesday, October 17, 2012 - link
Yeah, already posted this comment for podcast 8, but it bears repeating. I'm less angry now, but still facepalming.It's not my expertise but I have designed a few hundred aluminum parts, so here's how it probably
works. The call-out is most likely equivalent to mil-std-171 7.2.2; this is a ~.0005" thickness coat,
decorative and scratch resistant. The coating itself is super hard, and can only be scratched by harder materials. The problem is the base metal yield strength is still fairly low. Chamfers (yes, we do pronounce the "h") have sharp edges, which make point contacts and therefore have theoretically infinite contact stresses till they're rounded off. To summarize; small contact areas, equal high pressures even at low forces; pressures over material yield cause deformations, and deformations over .0005" make you see silver. The chamfer finish is probably not a post anodization process,it's diamond ground and has a much finer surface finish. The rest of the phone is cnc milled, and is matte from either a sandblasting, or vibratory media process to remove machining marks. Anodize surfaces are as glossy/matte as their surface finish. And as to the "structural integrity" concern repeated, and repeated, and repeated; The iphone is thin, but the anodize coating is a couple orders of magnitude thinner and has negligible affect on structural integrity.
A possible fix would be mil-std-171 7.5.2 Anodize Type III which is an anodized hardcoat. It's a
similar process but coats to .002" thick, packs it's molecules much denser, and can pass a hardness test to rockwell C60. It's a reasonable response to the scratching issue, however it may not be appropriate for other reasons(prone to cracking instead of scratching, tolerance issues, more costly, less pretty.)
syxbit - Wednesday, October 17, 2012 - link
Great job guys. I'd appreciate it if you went into as much detail on the upcoming Nexus device(s).KPOM - Wednesday, October 17, 2012 - link
They will.WooDaddy - Wednesday, October 17, 2012 - link
I didn't RTFA (as if I need to question Anand consistently excellent analysis as it has been Anandtech's inception), but as soon as I saw the phrase 'murdered out' regarding the black/slate color, I was done. It was like Anand was at a poetry slam and he dropped the mic signifying that there is no one better.VivekGowri - Wednesday, October 17, 2012 - link
Hey, hey, I wrote that part :Pjuhatus - Wednesday, October 17, 2012 - link
iPhone review.. what about..Does it work as a phone??
SJD - Wednesday, October 17, 2012 - link
Don't know if I'm the first one to say this, but the HTC One S battery isn't removable. (At least it isn't over here in the UK - don't know if your version in the US is any different).Table - Physical Comparison - Page 1
Origin64 - Wednesday, October 17, 2012 - link
I do really want to point out that the iPhone 5 being 20% lighter than the 4 isn't really substantial, seeing as how a Galaxy S 1 weighs about half of that.Apple has excellent construction quality, but they build their phones from glass and aluminium and they are heavier than the competition. There's no advantage here, no breakthrough, the iPhone 5 is just a different design that has a thinner battery and less glass. It's not as interesting as you make it seem.
thunng8 - Wednesday, October 17, 2012 - link
What are you on about? The Galaxy S weighs 119g and the iphone 5 weighs 112g.