Vorbis - Oct 2004 - Question about volume level recording in Ogg Vorbis

Hi 
 
I recorded many hundred of CDs in Ogg Vorbis with exactly the same
parameters.
I can see very big difference of volume level from one CD to another
when I play it onto my computer or my portable device (iRiver HP120).
So, I have two questions :

*	Is the reason of this fact is that it's depends on the volume
level at burning time of the original CD ? If not, what is the reason ?
*	Is there any way to increase volume level at Vorbis encoding
time ? If yes with which tools ?

Thanks for your help.
 
Franck, a Ogg vorbis addict ;o)

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"Franck Charlemagne" <fcharlemagne@workit.fr> writes:
> Is the reason of this fact is that it's depends on the volume level at
> burning time of the original CD ? If not, what is the reason ?
That's correct. There isn't (and shouldn't be) any standards for
recording volume of CD:s.
> Is there any way to increase volume level at Vorbis encoding time ? If
> yes with which tools?
There are loads of normalisation tools, for all platforms, that you
preferably use on the WAV files (or whatever input format you use)
before encoding them.

A better solution might be to make a tool that sets a tag on the OGG
file, according to which your player then can adjust it's volume. That
way, you don't need to risk damaging the "original" sample. There
is
some sort of semi-standard for that, for MP3:s.

On Fri, Oct 01, 2004 at 03:55:53PM +0200, Bj?rn Lindstr?m
wrote:
> "Franck Charlemagne" <fcharlemagne@workit.fr> writes:
> 
> > Is the reason of this fact is that it's depends on the volume
level at
> > burning time of the original CD ? If not, what is the reason ?
> 
> That's correct. There isn't (and shouldn't be) any standards
for
> recording volume of CD:s.
you mean 'percieved loudness' not 'recording volume'.  Pretty
much all
CDs use the full amplitude range.

If you want to play with the effect of changing how loud music is
without affecting the actual linear amplitude, play with 'multiband
companding' in Postfish (as a start ;-)
> > Is there any way to increase volume level at Vorbis encoding time ? If
> > yes with which tools?
You will clip.  Don't do it.  

If you absolutely must do this all at encode time, reduce the volume
level, don't increase it.  However, all pop music will end up being
reduced *alot* and the only thing that will stay ~ the same is
classical (the pop music is purposely highly dynamically compressed)

The best way to handle gain issues is during playback where you can
just alter the volume on the fly without modifying the music itself.
Some handheld players will do this; Google for ReplayGain.

Monty