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Hydrogenaudio Forums > Lossy Audio Compression > AAC > AAC - General
SirGrey
Hi to All !
Hmmm.
Based on discussion occured on doom9 audio forum
(link, if interested: http://forum.doom9.org/showthread.php?s=&threadid=74415)
I get an impression, that abr mode using 2 pass encoding would be much effective, than one pass. Especially, when we are speaking about very low bitrates < 128Kbit.
Bit reservation can last through all the stream, DCT quantizers can be distributed much wiser and so on, I think.
So, the question to the Nero people and others interested - What do you think, would it really worth to try ?
May be 2 pass encoding will significally increase the quality of HE AAC encode at 64 Kbit ?
I think, if Ivan is not very busy this time, he can simply try it smile.gif
askoff
Why don't you use VBR? I't will be much more constant with quality than ABR or 2pass VBR would be. I don't think that using 2pass mode is verry smart, because I can't think of a reason to have specific bitrate to every song. There is two different modes for that all ready (CBR and ABR).
SirGrey
>>Why don't you use VBR?
Because you can't predict the size....

Edit: spelling correction
askoff
QUOTE(SirGrey @ Apr 22 2004, 01:42 AM)
>>Why don't you use VBR?
Because you can't predict the size....

Edit: spelling correction

Why do you need to predict it?
SirGrey
>>Why do you need to predict it?
When you create music files for archiving purposes and have no need to predict size - I would advice you to use flac biggrin.gif
But when you need to squize the music into some container (i.e portable, streaming and so on) you need to select bitrate, based on quality you expect to reach.
That's my position...
askoff, BTW:
Sorry, but I do not understand idea besides your posts.
>>>>Especially, when we are speaking about very low bitrates < 128Kbit.
>>Why don't you use VBR?
I was speaking about LOW bitrates. Personally, I use low bitrate, not because I need to achieve low quality (that stupid, yes ?), but because I need to get small size. So I KNEW the size I need BEFORE I begin coding...
Heh, may be I'm stupid today ? biggrin.gif
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