the container is supported but it only supports the AAC codec which isn't exactly common.
or so i'm told.
<rant on>
The fascination with AC3 borders on absurd. We already murder video by cutting the bitrate (and often the resolution) by a significant degree, but heaven help us if we touch the audio!
If the audio nuts hadn't gotten a foot in the door, we could have just used MP4 containers with H.264 video and AAC audio, skipped MKV entirely, and everyone would have been happier. Multichannel AAC is just fine, and in fact is better than AC3 and DTS at any given bitrate. A 1.5Mbps DTS stream could easy be replaced with a sub-500Kbps AAC stream, saving a good megabit to either allocate to video or cut the file size entirely.
Instead we have to resort to convoluted solutions to play back video on everything from consoles to tablets. How many people downloaded VLC for the iPad because it handles MKV containers (i.e. AC3 audio), when had their material had been MP4/AAC in the first place they could have just used the built-in audio player?
Content providers need to stop shipping stuff in H.264 + AC3 and stick to H.264 + AAC. H.264 and AAC were meant to go together from day one; they're like peanut butter and jelly, the perfect complements to each other.
</rant off>
On a side note, I want to kick Google in the butt with a size 15 boot. They're going to use HE-AAC for
multichannel audio in Google Play store movies. HE-AAC (unlike LC-AAC) was engineered as a replacement for radio and other low-to-medium quality audio scenarios. It is not designed to scale up to CD quality audio, spectral band replication has a very clear quality tradeoff that improves audio at low bitrates when you're desperate for bits, but irreparably harms the audio quality once you're no longer bit starved. This is a format optimized around 64Kbps stereo for the love of Mike.