Re: Intensity Stereo for low bitrates

Hallo Patryk!

Thanks for your answer!

What I forgot to mention: I am trying to encode low-bitrate CBR files,
not VBR!
Of course I did not mean that IS should be enabled by default, I just
wanted to try it.
(maybe someone has still a working binary?)

I did not do any listening tests, but some people claim that intensity
stereo should be better for this special use case (also in lame/TODO in
the LAME CVS repository - see [1]).

Below are examples of 96kbps and 80kbps encoded stereo files with LAME
and Fraunhofer - see [2].

Is it possible to reduce the artifacts in these (and similar) examples?
The exact stereo information would not be that important (something like
Parametric Stereo in HE-AACv2 would be nice;) ), that's why I wanted to
try if intensity stereo would help.

Or does someone have any other hints how to improve encoding of
low-bitrate CBR MP3 files?

Thanks a lot,
LG
Georg


[1] from CVS/lame/TODO, line 127:
"Use intensity stereo. This is a must-have for low bitrates, but if the
algorythm is very good it could also be used in every case."


[2] low-bitrate CBR examples:

Original Source File (44.1kHz, stereo):
https://auphonic.com/media/audio-examples/tim.wav

Encoded in 96kbps CBR (lame3.99.5 and Fraunhofer/iTunes12.2.2.25):
https://auphonic.com/media/audio-examples/tim-lame-96k.mp3
https://auphonic.com/media/audio-examples/tim-itunes-96k.mp3

Encoded in 80kbps CBR:
https://auphonic.com/media/audio-examples/tim-lame-80k.mp3
https://auphonic.com/media/audio-examples/tim-itunes-80k.mp3

It is possible to hear artifacts especially from 18s to 28s.
The Fraunhofer encoded files contain a lot of musical noise.

I used LAME default settings to encode these files:
lame -h --cbr -b 96 tim.wav tim-lame-96k.mp3
lame -h --cbr -b 80 tim.wav tim-lame-80k.mp3



On 2015-10-21 20:54, FPatryk wrote:
> As far as i know, the intensity stereo has been abandoned here since now
> the algorithm of selecting between joint stereo MS and stereo is more
> advanced than in FHG.
> 
> 
> I see no need to re-enable it, (especially by default) because the
> coding technologies have evolved much from that time.
> Greetings, Patryk.
> 
> 
> 
> __________ Informacja programu ESET NOD32 Antivirus, wersja bazy
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