AAC HE / LC --> when to choose one or another?

[LordIntruder]

Hi,


[ I've made a search on this one but found nothing. If what follows has already been discussed, thanks to forward me the link. ]

Here's my problem:

I encoded an AC3 file taken from a DVD (length = 1h 23min) into AAC and tried differents options:


- streaming HE : 56Mb
- streaming LC : 105Mb
- internet HE : 46Mb
- internet LC : 92Mb
- normal LC : 124Mb

What I wonder is why a so huge difference between LC and HE? I don't know what to choose. If the difference between say "streaming HE and LC" would be around 5Mb, it wouldn't hurt me but here I really don't know what option (LC or HE) to choose when I go in low format (I mean streaming, internet because normal and up tutorials say it is LC no choice) and I can't find an answer in the tutorial to help me so I ask you. :)

Quite franckly I can't even make the difference between one of the file encoded in Streaming HE which weigh 56Mb and the same encoded in Streaming LC 50Mb heavier!! (105Mb). Quickly I would maybe select the tiniest files but not sure it is a good choice.

What you people do in same case, what is the general and best theorical choice? I'm quite lost because if you only modify one option (LC or HE) the final size is 50Mb different.

Thanks for info. :)

[Kurtnoise]

Originally posted by LordIntruder
What you people do in same case, what is the general and best theorical choice? I'm quite lost because if you only modify one option (LC or HE) the final size is 50Mb different.
You are some filesize differences coz LC (Low Complexity) and HE (High Efficiency) haven't the same target bitrate....;)

If you want to optimize the video part (in the case of DivX creation by example), you can choose HE-AAC. This format is recommended for lower bitrates. But if you don't mind, take LC-AAC.

[bond]

first of all filesize alone means nothing, its the filesize/quality ratio that counts

choose lc-aac when you want to play your file on a hardware player or encode at high bitrates
choose he-aac when you dont want to play on hardware and aim at low bitrates or multichannel