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Old 11th February 2019, 21:25   #1464  |  Link
benwaggoner
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Join Date: Jan 2006
Location: Portland, OR
Posts: 4,750
Quote:
Originally Posted by Nintendo Maniac 64 View Post
So um, as someone on the outside, I've got to ask - outside of DRM and satisfying "not invented here" syndrome, what benefit does xHE-AAC provide over something like Opus?
It supposedly offers somewhat better quality at very low bitrates. I've not seen a detailed double-blind listening test to validate that, though.

I think xHE-AAC is going to become more broadly supported on platforms, out of momentum. AAC licensees now get access to xHE-AAC for free so it's a trivial effort to roll in xHE-AAC support with platforms updates. And use of AAC in MPEG-4 streams is broadly understood and implemented. Opus does have a mapping, but I've not seem much use of it. MPEG-4 as a file format is more dominant than H.264 was; the Matroska based container formats aren't a significant player for commercially distributed content.

The biggest recent news is that Android Pie has xHE-AAC built in.

xHE-AAC also offers gapless switching between bitrates without having to do overlap decoding. Does Opus support that. I consider this a significant advantage of xHE-AAC over HE v1/v2 and LC, which can only do gapless switching within v1 or v2, but not between. xHE-AAC can switch from very low bitrates to very high quality, which wasn't feasible before.

And don't knock how critical DRM is for premium content. It's a Very Big Deal. And there are SoC reasons why mixing encrypted video and unencrypted audio can be problematic.
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