About MP4 Quality

[anirban]

At what bit rate of NERO AAC ENCODER can I get same quality as 320kbps in LAME MP3? Any further changes to configuration in NERO ENCODER NEEDED?

[fibbingbear]

This question is probably more appropriate for the hydrogenaudio forums.

First, there is a problem with your statement:

1.) The chance that you can tell the difference between a 320 CBR KBPS MP3 and a 192 VBR MP3 is probably less than 0.1%, unless you're an audiophile. But if you were an audiophile, you wouldn't need to ask this question since you'd already know about all the different formats :-p

So the real question is: do you care about *transparency*, or *transcoding*?

The difference is:

For transparency, you're asking "at what bitrate does the encoded AAC/MP3 become indistinguishable from the original?" For MP3, it's probably around 192 VBR kbps with LAME (-V2 --vbr-new). For ND AAC, it's probably around -q 0.5, or ~170bkps VBR. Note that transparency is going to vary a lot with the type of audio you're encoding.

For transcoding, you're asking, "what format is best for storage, since I may re-encode this file in a different format multiple times." A lossless format is best, like FLAC, and if you have to go with lossy, go with the biggest (320KBPS for MP3 and -q 1.0 for AAC, which is about ~450kbps). However, I doubt this is what you're asking.

Note that if you don't care about 100% transparency, you can go a lot lower with the audio sounding good --- 96 kbps HE-AAC sounds quite good.

So, in conclusion... if you care about transparency, go with -q 0.5 as the command line option. If you care about transcoding with AAC, go with -q 1.0.