Nero encoder 1.5.4.0—lower quality makes larger file; how can this be?, Was: Nero encoder: unexpected size results (TOS #6) Options

[Pete7874]

Hello,

I'm using Nero 1.5.4.0 AAC codec in Foobar 1.1.10. I converted the same source file to AAC using two different settings: q0.38 and q0.40. Theoretically, the q0.38 should have resulted in smaller file/lower bitrate. However, the resulting files were just the opposite - the q0.38 file ended up being larger / higher bit rate than the q0.40 file. How can that be?

I realize this is rather academic as nobody could potentially tell the two apart in ABX listening. I just found it a bit abnormal.

Thanks!

[lvqcl]

according to my rather old tests:

CODE

0.38  => 121.9 kbps (on average, of course)
0.39  => 126.7 kbps
0.393 => 128.1 kbps
0.394 => 125.5 kbps
0.4   => 128.4 kbps
...etc

This post has been edited by lvqcl: Jan 6 2012, 00:20

[Pete7874]

I suppose it depends on the source material. I just tried it again with a bunch of additional files, and in majority of cases, -q0.38 again delivered higher bit rates and file sizes than -q0.40. There were a couple of exceptions though.

[greynol]

Where is the cutoff between LC and HE?

[lvqcl]

IIRC 0.309 - 0.31

[Shandra]

By coincidence I encountered the same problem just a few days ago :insane: but haven't checked in this Forum so far but over at Doom9 (this threat) so I missed it allready beeing a topic here. Though there you will only find my results on a few sources and no more "findings" for now.

This post has been edited by Shandra: Jan 11 2012, 01:01

[Shandra]

Btw. Where your sources where you find the problem 48kHz samples?
As I now experienced it happen on that sampling rate, but not when downsampled to 44.1kHz...

[Pete7874]

Btw. Where your sources where you find the problem 48kHz samples?

Nope. All my sources were 44.1kHz material.

[lvqcl]

Mine too.

[Shandra]

Sigh - So there must be another parameter causing this. As for me - I encountered the anomaly with DVD Sources (48kHz) but not for CD Sources (44.1 kHz), and it didn't showed up when I downsampled the 48kHz to 44.1 kHz - Besides from Source, are you both sure the resulting MP4 was still 48kHz (Though I assume so, otherwise you would have mentioned it)? Would have been to nice to find a cause that could have been used for a bug report or such :/

[lvqcl]

Not a bug: http://www.hydrogenaudio.org/forums/index....st&p=526757

[Shandra]

Thanks lvqcl!

As I was just fiddling around with Nero AAC and how low I may go with the quality setting with my VHS and Digital Media Backups without sacrificing audio transparency for visual bitrates that topic annoyed me pretty badly - as from 1st sight I was unsure whether the Nero Encodes may be faulty somehow or that I may be doing something wrong in my chain of decoders/encoders!