Apple TV 3 (2012) Short Review - 1080p and better WiFi

Apple's two goals with the Apple TV 3 refresh seem to be - improved wireless connectivity, and of course support for 1080p content. We've touched on the first one, and the second one we touched on with the single core A5. Going from the single core Cortex A8 A4 to a single core Cortex A9 in the A5R2 might not seem to make much sense superficially, 20% increase in IPC aside, until you realize there are other things inside an SoC than CPU and GPU. I'm talking about the video decode blocks, which no doubt the primary reason for the change in SoC. Both the A4 and A5 use Imagination's PowerVR VXD (D for Decode, VXE is E for encode) family of encoders and decoders. The A4 used a PowerVR VXD375, and the A5 uses a more powerful VXD decoder. 

That difference in SoC allows the Apple TV 3 to decode 1080p30 H.264 at a higher profile than the A4-based Apple TV 2. Apple outlines their H.264 decode capabilities as shown in the table below: 

Unsurprisingly these decode parameters are very close to the iPad 2 / iPhone 4S which carry A5R1 (H.264 High Profile up to Level 4.1), so we can know for sure that A5R2 inherits a similar decode block at least. Moving to a better decoder allows the device to decode video which has been encoded with more H.264 features as well, and thus achieve higher encoder efficiency.

I've touched on this before but bitrate and file size doesn't grow much between the 720p and 1080p encodes of the same media for iTunes content. I fired up MediaInfo and took a look at the 720p and 1080p copies of the same episode of Dexter freshly downloaded from iTunes. 

iTunes 720p30 - 4 Mbps H.264 High@L3.1 with 2 Reference frames

iTunes 1080p30 - 5 Mbps H.264 High@L4.0 with CABAC and 4 Reference frames

Unsurprisingly the 1080p30 iTunes video uses the maximum encode parameters for the A5 SoC with H.264 Level 4.0. They've also gone for CABAC and 4 reference frames, which makes these 1080p encodes much more efficient in terms of quality / bit than the 720p encodes. 5 Mbps is still a bit low even with these encode parameters for 1080p where the typical guidance is around 10 Mbps. No doubt the bitrate of your lowest common denominator cable ISP is the limitation here, and unfortunately Apple currently lacks the infrastructure to stream different 1080p bitrates and encodes. 

While the bump up to H.264 high profile and inclusion of CABAC and 5 reference frames makes iTunes' 1080p encodes eerily similar to Blu-ray in features, the lower bitrate results in quality which simply isn't close. Videophiles will definitely be able to tell the difference between Apple's 1080p content and Blu-ray.

Apparently the 25% larger file size isn't enough to warrant additional NAND either, as again the Apple TV 2 and 3 still include 8 GB for caching iCloud Photo Stream content and iTunes media locally.

Just like before, the only video output option is HDMI, where the Apple TV 3 lets you go up to 1080p at 50 or 60 Hz. Audio output continues to be over HDMI or a full size TOSLINK. Apple TV continues to also output Dolby Digital 5.1 if the source content offers it. 

I don't remember there being SXGA, XGA, and SVGA options in the previous builds of Apple TV, but as of the latest 5.0 (Build 4099) update these options are also now available for selection if you're interested in running the device with a non 16:9 aspect ratio display. 

It goes without saying that running the Apple TV 3 at its native resolution on a 1080p display results in much better looking everything (UI, navigation, and media) than it did with the 720p model. Obviously upscaling 720p on a 1080p display resulted in a less than satisfactory experience, but made Apple TV 2 very suited to smaller 720p displays. 

The Apple TV 3 doesn't seem strained drawing the UI at 1920x1080, in fact the 2.25x increase in pixel count doesn't seem to have slowed down the interface at all. There were a few areas that always seemed to drop frames on Apple TV 2 (namely the album art flip on the currently playing screen, one which continually nagged me every time it happened) which simply don't drop frames anymore, thank goodness. The only place I ever encounter lag is the related video YouTube picker which appears at the end of a video, where both the Apple TV 2 and 3 stutter, and a few edge cases. For example, trying to do much of anything the first time you enable iTunes Match seems to particularly strain the single core A9 in the A5R2. Outside that however, Apple TV 3 seems pretty performant, and doesn't disappoint when actually playing back media.