HDMI Mirroring

One of Tegra 2’s most interesting features is support for multiple displays—HDMI 1.3 at 1080p mirroring is supported. The implementation on the 2X is how other Android phones with HDMI ports should have worked, you plug the HDMI cable in, and everything on the phone is instantly mirrored on the connected display. Android isn’t suddenly rendered at higher resolution, it’s just scaled up to whatever resolution of HDMI device you connect to, but that looks surprisingly good.

In portrait mode, there are black bars at the left and right, but rotate to landscape and the WVGA Android screen fills 1080P displays. WVGA (800x480) isn’t exactly 16:9, but it’s close, so there’s a little stretching in landscape but nothing noticeable.

The result is that you can use the 2X to play angry birds on a 55” TV without waiting for the console version, browse the web, give a PDF or PPT presentation, or do anything you’d do on the phone on a different screen. I put together a reasonably comprehensive video showing off HDMI mirroring.

There’s a tiny bit of input lag. In the video I shot showing off HDMI mirroring, it’s entirely possible some of that is just the result of my Onkyo TX-SR608 A/V receiver which seems to add a consistent 100ms of lag to almost everything, even in game mode. The supplied microHDMI cable is just long enough to stretch from the receiver to my couch, I could use a few more feet to be comfortable however.

You can also play videos over the HDMI connection, while doing so the 2X shows a "showing on second display" message:

HDMI mirroring works shockingly well, and sends all audio over HDMI. It’s a bit difficult to look at the TV and interact with the phone’s touchscreen, but not impossible. WebOS and others have drawn circles on the screen to show where fingers are. The tradeoff there is that it’s one more element to clutter display.

Video Playback

The big question is how well the X2 (or any Tegra 2 smartphone) could work as a mini-HTPC. NVIDIA advertises a big long list of codecs that Tegra 2 can decode:

LG’s own spec list (what's below is actually for the Korean version, but the video codec support is the same) is much closer to the truth for the X2 because of Android’s player framework and other limitations.

You can play back H.264 1080p30 content, but it has to be Baseline profile—no B frames, two reference frames. I used handbrake and messed around with a variety of other encode profiles and eventually settled on a bitrate of around 10 Mbps. That puts a 2 hour movie at around 8 GB total, which is too big to fit on a FAT32 microSD card. If you’re going to fit 2 hours of video on that SD card and stay under 4 GB, bitrate should be around 4 Mbps. Tegra 2 can decode H.264 1080P baseline at a maximum of 20 Mbps.

Interestingly enough, I tried the iPhone 4 preset in handbrake which is H.264 960x400 High profile and noticed some stuttering and dropped frames. Media playback on Tegra 2 as it stands definitely works best with H.264 baseline, it’s just a matter of having gobs of storage to park video on.

The 2X didn’t do very well in our media streamer test suite. Some of that is because the software lacks the ability to open mkvs and a huge number of our files. The two that did open and playback successfully were test 3, an 8 Mbps 1080p WMV9 video with 5.1 WMA audio, and file 19, a simple m4v container test. Unfortunately we’re still not at the point where you can dump just about anything you’d stick on an HTPC on your mobile device without a transcode in-between, it’s no pirate phone.

Software Preload and Constant Crashing Battery Life and Final Thoughts
POST A COMMENT

75 Comments

View All Comments

  • rpmrush - Monday, February 7, 2011 - link

    Solid review, but please at least use spell check. I'm not a grammar or typo freak, but there were way too many simple typos that spell check wouldn't even let you get by with. At least have someone proof read it before you publish to the public. Reply
  • zowie - Tuesday, February 8, 2011 - link

    who can create a new type battery, who will be the richest man in the world Reply
  • uhuznaa - Tuesday, February 8, 2011 - link

    Yeah, and until then those who manage to come up with some decent power management will be the richest...

    Seriously, every improvement on the battery front almost always just leads to devices drawing more power. It's somewhat ironic that last year's iPhone still leads the pack when it comes to battery life. Power management (that is: don't draw more power than absolutely necessary by throttling or shutting down components that aren't needed or aren't fully needed in a given moment) is hard and boring design work nobody seems to care for. And with devices and software getting replaced with the next iteration every few months this is even understandable, it's just not worth the effort, especially when nobody seems to care and benchmarks are so much more important to the crowd.
    Reply
  • DanNeely - Tuesday, February 8, 2011 - link

    How is is typically played back: Cropped, or vertically resampled? Reply
  • Wilco1 - Tuesday, February 8, 2011 - link

    Tegra 3 has 4 1.5GHz Cortex-A9's according to a leaked slide.

    That was a great article! A few minor corrections: The ARM11 VFP is fully pipelined (so it can beat the A8 on FP performance). Like the A8, Scorpion is 2-way in-order, not limited out-of-order. In-order cores issue instructions in-order but may complete them out-of-order. On the other hand, OoO cores use register renaming to issue instructions out-of-order but complete them in-order.

    Note none of the micro benchmarks used emits Neon instructions. JIT compilers don't have enough time to generate high quality code, let alone autovectorize! For proper benchmarking you will need to run native code compiled with a quality compiler (not GCC - it is still far behind the state of the art on ARM, especially Thumb-2).
    Reply
  • metafor - Tuesday, February 8, 2011 - link

    I would argue with that definition of OoO. A design does not need register renaming in order to issue any arbitrary instruction OoO. It's simply a trade-off of whether to centralize hazard tracking on register accesses or on retirement. Reply
  • PWRuser - Tuesday, February 8, 2011 - link

    Excellent review. Please, in your future reviews don't stop including gems like this one:

    "Generally while browsing I can feel when Flash ads are really slowing a page down - the 2X almost never felt that way."

    That's what matters! Including hands on observations along with a full volley of synthetic benchmarks.

    This review comes as close as humanly possible to portraying a handset's ability to readers without the said readers trying it out.

    Your attention to detail puts other reviews to shame. Keep up the good work.
    Reply
  • sarge78 - Tuesday, February 8, 2011 - link

    Don't forget about ST-Ericsson's U8500 A9. They could be a major player in 2011/2012 with potential design wins from Nokia and Sony Ericsson. Reply
  • warisz00r - Tuesday, February 8, 2011 - link

    What equipments do you use to test the phone's audio quality with? Reply
  • phut- - Tuesday, February 8, 2011 - link

    "NVIDIA tells us that the Tegra 2 SoC is fully capable of a faster capture rate for stills and that LG simply chose 2MP as its burst mode resolution. For comparison, other phones with burst modes capture at either 1 MP or VGA. That said, unfortunately for NVIDIA, a significant technological advantage is almost meaningless if no one takes advantage of it. It'll be interesting to see if the other Tegra 2 phones coming will enable full resolution burst capture.  unfortunately for NVIDIA, a significant technological advantage is almost meaningless if no one takes advantage of it. It'll be interesting to see if the other Tegra 2 phones coming will enable full resolution burst capture.  meaningless if no one takes advantage of it. It'll be interesting to see if the other Tegra 2 phones coming will enable full resolution burst capture."

    LG have probably made this decision based on the sensitivity of the invariably minuscule sensor they will have used. Having 6 frames of 12mp is pointless if they are 12 incomprehensible megapixels due to the lacklustre sensitivity of the pixels in their chosen part.

    The kind of sensor you find delivering a meaningful burst in something like a 5D mk2 is enormous and power hungry, in comparison to an operating environment such as a phone.
    Reply

Log in

Don't have an account? Sign up now