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View Full Version : Any advantage to using HE-AAC at higher bitrates?




devburke
Sep 10, 2009, 01:46 AM
So iTunes 9 introduced the ability to encode in HE-AAC (as well as AAC with bitrates up to 320 kbps), but everything I see on the internet about it basically says it allows better quality at lower bitrates. Does it help for higher bitrates too?



J the Ninja
Sep 10, 2009, 02:22 AM
"Better quality for the same bit rate" is a better way of putting it.

devburke
Sep 10, 2009, 02:29 AM
"Better quality for the same bit rate" is a better way of putting it.

So really, there’s reason not to use it?

InnocenceMyth
Sep 10, 2009, 03:18 PM
So really, there’s reason not to use it?

A) you *can't* use it in iTunes for bitrates higher than 80

B) its "efficiency" comes from replicating the higher frequencies. The higher the bitrate, the less need to replicate them because they are already there

Nermal
Sep 11, 2009, 04:24 AM
I'm a bit bored so I did some tests, AAC at the default bitrate (256 kb/s) vs HE-AAC at the default (64). It's not really a fair comparison and AAC at 256 definitely sounded better. I'm not an audiophile and even I could tell the difference :)

When compared with AAC at 128, things may be a bit closer (I didn't test this). HE didn't sound bad (just not as good as AAC at 256), and certainly looks like a good competitor when you have limited space.

broken-chaos
Sep 11, 2009, 05:41 AM
Sounds like it could be a pretty good codec to choose for combining with some (particularly streaming) movie or video encodes. You often don't need extremely high sound quality (particularly if it gets used for something like YouTube!), and bandwidth is still a very valuable resource to conserve.

I'll not be swapping any music over to it, but stuffing more quality in low bitrates is definitely a worthwhile endeavour.