Video Capture Quality

The iPhone 4 shot excellent quality 720p30 video and remained arguably the best in that category for a considerable run. Recently though it has been outclassed by smartphones that are shooting 1080p30 with impressive quality which record 720p30 just as well. The 4S catches back up on paper and likewise can capture video at 1080p30. Like every prior iDevice, there are no toggles to change video capture size - it’s always at the device’s maximum quality - 1080p30. Apple also made note of their own gyro-augmented electronic stabilization which the 4S brings. Practically every other smartphone we’ve seen has likewise included some electronic stabilization which leverages the pixels around the target 1080p or 720p area.

We’ve captured videos from the 4S in the dual camera mount alongside the 4, an SGS2, and a reference Canon Vixia HF11 for comparison. I also shot a low light comparison between the 4 and 4S. Showing the differences in video between all of those is something of a challenge, so I’ve done a few different things. First, you can grab the native format 4S versus 4 videos here (442 MB) and the 4S versus SGS2 video here (289 MB).

It’s hard to compare those side by side unless you have multiple instances of VLC open and hit play at the same time, so I also combined and synchronized the comparison videos side by side. The frame is 4096x2048 so we can see actual 1080p frames side by side. Though I realize 4K displays are hard to come by, you at least can see full size images which I’ve synchronized.

It’s readily apparent just how much more dynamic range the 4S has over the 4 when you look at the highlights and dark regions. In addition, the 4S does indeed have better white balance, whereas the 4 changes its white balance a few times as we pan left and right through different levels of brightness and ends up looking blue at the very end of the first clip.

Then comes the SGS2 comparison, and I start out with some unintentional shake where you can really see the 4S’ anti shake kick in. I considered the SGS2’s electronic anti shake pretty good, however its narrower field of view in 1080p capture exacerbates the shaking. Subjectively the two are pretty closely matched in terms of video quality, but the SGS2 runs its continual auto focus a lot and has a few entirely unfocused moments. The 4S’ continual auto focus is much more conservative and often requires a tap to refocus.

The Vixia HF11 comparison gives you an idea how the 4S compares to a consumer level camcorder shooting in its own maximum quality mode. I’d say the 4S actually gives it a run for its money, surprisingly enough, though the 4S (like every smartphone) still has rolling shutter in movement. Finally I shot a low light side by side with the 4S and 4, again white balance is better, but the 4S video in this mode looks a bit noisier than the 4. In addition, the 4S exhibits more lens flaring (something I noticed while shooting stills as well) than the 4.

Subjectively video quality from the 4S is very good, but it falls short in other ways. The 4S shoots video at 1080p30 baseline with 1 reference frame at 24 Mbps, with single channel 64 Kbps AAC audio. If you’ve been following our smartphone reviews, you’ll know that although this is the highest bitrate of any smartphone thus far (Droid 3 we’ve seen at 15 Mbps, SGS2 at 17 Mbps), it’s just baseline and not high profile we’ve seen on Exynos 4210 or OMAP4. In addition, two channel audio is becoming a new norm.

Media Info from video shot on the iPhone 4S

The result is that Apple is compensating for lower encoder efficiency (quality per bit) by encoding their 1080p video at a higher bitrate. Other players are getting the same quality at lower bitrates by using better high profile encoders. We dug a little deeper with some stream analysis software, and it appears that Apple’s A5 SoC is using the same encoder as the A4, complete with the same CAVLC (as opposed to CABAC which the other encoders in OMAP4 or Exynos 4210) and efficiency per frame size. It’s just a bit unfortunate, since the result is that video shot on the 4S will use ~40% more space per minute compared with 1080p30 video shot on other platforms (180 MB for 1 minute on the 4S, 128 MB for 1 minute on the SGS2, and 113 MB for 1 minute on OMAP4).

iPhone 4S iPhone 4

One last thing to note is that Apple roughly keeps the same cropped field of view size as the 4 on the 4S when shooting video. You can see this behavior in the rollover above. The 4S field of view is just slightly narrower than the 4. Note that the actual area reported from the sensor when in video capture mode is almost always a crop (sometimes with a 2x2 binning) of the full sensor size with some pixels around the frame for image stabilization.

Still Image Capture Quality Battery Life
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  • dacramer - Tuesday, November 01, 2011 - link

    The browser benchmarks show the 4s as fastest, but this benchmark is FLAWED as a measurement of CPU performance.

    The benchmark compares Safari to the Android stock browser. The stock Android browser does not support 2 cores, only 1. So all Android dual cores phones would be nearly twice as fast with another browser such as Opera.

    I'm surprised Anand did not include this discussion in the review. He seams fixated on the idea that stock to stock browser is a valuable comparison when it totally misleads readers on CPU performance.
    Reply
  • Lucian Armasu - Wednesday, November 02, 2011 - link

    In case you missed it, the Droid RAZR scored 10% faster than iPhone 4S in the SunSpider test.

    But yes, this is still mostly a software issue, and I expect the Android 4.0 browser to be even faster on the same chip.
    Reply
  • thunng8 - Wednesday, November 02, 2011 - link

    FYI, Google says the Galaxy Nexus scores 1983ms in Sunspider running ICS Reply
  • doobydoo - Wednesday, November 02, 2011 - link

    "Where did it show faster CPU?"

    Where did it in my comment?
    Reply
  • Breit - Thursday, November 03, 2011 - link

    I just run SunSpider 0.9.1 on my Galaxy S2, international model (everything stock, with Android 2.3.5) and it came in at 1626.5ms with Opera Mobile browser and 3354.8ms with the stock Android browser. So saying the CPU on the Galaxy S2 is weaker than the CPU on the 4S is just not right (and that by a big margin!).
    At least make comparisons with the best software there is and not just 'some' browser you eventually found on your phone...
    I'll bet there is someone programming his own browser just for the kicks or as an exercise for his programming skills and that browser scores over 9000ms in SunSpider. Does that mean the CPU in that phone is slow? ;)
    Reply
  • doobydoo - Friday, December 02, 2011 - link

    You could achieve the same results on the iPhone too..

    The comparison is (rightly) comparing stock browser to stock browser, and the iPhone 4S is faster. It would be even faster again using say, Opera.

    As for some guy posting 9000ms - you can filter the results to 'best' times so this is a non issue.
    Reply
  • Tetracycloide - Tuesday, November 01, 2011 - link

    Isn't there more to displays than just white level in nits, black level in nits (on a chart were I can't seem to find the Galaxy S II or the Infuse), and contrast (again, don't see the Samsung Galaxy S II or the Infuse on the contrast chart either)? Don't get me wrong, I don't agree in the slightest with the summary "this is apple cheerleading" but honestly the display comparisons are pretty lacking IMO. Where are the rest of them? There's more to a screen than just nits. Reply
  • medi01 - Thursday, November 03, 2011 - link

    Last time iphone disappeared from comparison photo, from the one where it would pale in comparison, when asked, author "explained' that he simply "forgot" it in the pocket. (!!!). Now they didn't even bother. Round of but kissing on "retina" hype and phones disappearing from charts.

    Find contrast of Galaxy phones on the charts pretty please...
    Reply
  • steven75 - Friday, November 11, 2011 - link

    Could you be any more of an Fandroid? Seriously. Reply
  • Stuka87 - Tuesday, November 01, 2011 - link

    Wait what?

    Almost every single page has a comparison to Android phones. Several of them have graphs showing the differences!

    And your comment on the displays may be your opinion, but actual measurements show otherwise. but hey, if you like your over saturated display with a much lower pixel density, thats your decision.
    Reply

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