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.
Facebook
Twitter
RSS
276 Comments
View All Comments
rarson - Wednesday, October 17, 2012 - link
Car bumpers are not made of aluminum.Aluminum oxidizes. So if you scratch it, then you've removed that oxidation layer to allow it to further oxidize at that spot. Rust is just iron oxidation.
Spunjji - Friday, October 19, 2012 - link
It is not normal for them to scratch so damn easily. Furthermore, you might notice that other manufacturers (say, HTC?) take steps to harden the surfaces of their devices to avoid this kind of problem.name99 - Wednesday, October 17, 2012 - link
So you're basically(a) upset that Apple fans buy products based on how they look
(b) upset that Apple fans's don't care enough about how products look to care about this
???
The true sign of the demented mind --- that it can happily hold two contradictory opinions at once.
steven75 - Wednesday, October 17, 2012 - link
Would you buy a car that gets nicks and scratches from normal usage?Um yes, everyone does. I guess all cars should be recalled!
Spunjji - Friday, October 19, 2012 - link
Would you buy a car that gets nicks and scratches from simply driving down the street? No, you wouldn't. Stop distorting the argument for an easy victory, it makes for extremely aggravating reading.doobydoo - Saturday, October 20, 2012 - link
And what evidence do you have that the equivalent of 'driving down the street' with an iPhone causes scratching?ltcommanderdata - Tuesday, October 16, 2012 - link
Any final MHz rating on the GPU? Given Apple tends to use a 4:1 clock speed ratio between the CPU and GPU, the SGX543MP3 being up to 325MHz would make sense. The SGX543MP2 seemed to be clocked at 200MHz in the iPhone 4S and 250MHz in the iPad 2 and Apple said the iPad 2012 has a 2x faster GPU, so the SGX543MP4 in the A5X likely is also at 250MHz. A SGX543MP3 at 325MHz vs a SGX543MP4 at 250MHz would seem to explain the results seen in the benchmarks.A few corrections, on page 11 the GLBenchmark 2.5 - Triangle Texture Test - Fragment Lit (Offscreen 180p) is missing the iPad 2012 result.
In iPhone 5 Device Conclusions on page 22, you write "Going back to the old 4:3 aspect ratio iPhones feels extremely claustrophobic now", but it should be 3:2.
daar - Tuesday, October 16, 2012 - link
The in-depth tech info was nice, but would have preferred it in a second post. As an engineer, while I can appreciate the advances made with the new SoC and the depth of the effort went into researching all the aspects of the phone, I also think for most purposes, the length is counterproductive when the majority of readers are looking for indicators of whether the phone is worth an upgrade. Even without the tech explanation though, the review unnaturally lacked the concise detail I'm used to at AT.In some ways, it sort of came across that the tech explanation was a long worded way of making excuses for the iPhone 5's faults and direct comparisons to superior implementations were ignored. Simple example would be the camera, where praise was given about how they cut the size, that it looked good, explanation of the purple tint and so forth. If say, Samsung had released a phone with such issues, I'd expect the review to mention the sloppiness of it, esp with rivals such as the One X having a 2.0f lens (I quite enjoyed the One X/SG3 review comparison from AT). The excuse that the lack of innovation in the new iOS being that the aim of the phone is like that of an appliance whereas Android phones aiming to be PC's is baffling; the concept of a smartphone was a versatile device to aid in our daily lives not reach a point of some ambiguity called an appliance.
darwinosx - Tuesday, October 16, 2012 - link
That was a lot of words to say nothing besides bragging that you are an engineer. Nobody cares.kyuu - Tuesday, October 16, 2012 - link
What nobody cares about are your rabid attacks on any comment that has even the slightest critique of an Apple product.