NeroAac Megui Encoding

[Slabrdix]

I've come over a rather strange issue

I'm using the MeGui with NeroEncoder 1.3.3.0 to encode audio files to aac with different encoding types i get different sampling rates.

LC - 48 KHZ
HE - 24 KHZ
HE+PS - 24 Khz

regardless of what bitrate or q-rate I choose.

Why is everything but LC downsampling ... i can hear the quality difference.

[tebasuna51]

:search:

The difference between LC and HE is how the high frequency is compressed and stored in the aac stream.

HE uses the SBR (Spectral Band Replication) method, then there are a standard (LC) 24000 Hz encode, plus the SBR part with the high frequency. Your HE stream can be decoded to 48000 Hz with the appropriate decoder.

PS is something like Parametric Stereo, then your HE+PS can be read like mono 24 KHz by a decoder without support for PS and SBR parts.

[Slabrdix]

Hi ...

I used the PS3 to play them, and it say's that it's 24khz
I used mplayer to play them, and I can easyly tell that
the HE sounds muffled at the same Bitrate / q-Level

PS is not possible on multichannel sound .. but on the 2channel source mp4box tells me that it's only a 1 channel sound.

So possibly mplayer and the PS3 are not able to repoduce the SBR ??

Which application is ??? just to test my Ears ;)

[nurbs]

Yeah, the PS3 unfortunately doesn't do HE-AAC and only decodes the LC part.

[b66pak]

just as a curiosity it worth mentioning that PSP (build by sony too!!!) has HE-AAC and HE+PS-AAC support...
_

[smok3]

Hi ... Which application is ??? just to test my Ears ;)

try http://www.foobar2000.org/