libmad mp3 distortions

Ariff Abdullah ariff at FreeBSD.org
Fri Sep 18 13:24:23 UTC 2009


On Fri, 18 Sep 2009 14:10:37 +0300
Andriy Gapon <avg at icyb.net.ua> wrote:
> on 17/09/2009 17:14 Alexander Leidinger said the following:
> > Have you tried to play it with "madplay -v -a -6"? This will lower
> > the volume by 6dB. IIRC this is still with the sound before the
> > conversation to PCM. If this prevents the clipping, then it is
> > normal. The reason is that because of rounding (and other
> > operations) the value of a sample can be higher (or lower) than
> > originally. If it was at the max level before, it can now exceed
> > the max -> clipping. madplay is following the rules very strictly
> > (and IIRC working with higher precision and bitsize), while other
> > players have bigger mathematical errors. This would explain then,
> > why you see this with madplay but not with other players. The
> > problem I describe is not in the decoding step, the problem is at
> > the encoding level.
> 
> Alexander,
> 
> thanks a lot! madplay -a -6 does indeed produce correct sound.
> Bad news: despite the magnitude of configuratios options related to
> 'gain' and 'pre-amp' in audacious2 (all global, nothing specific to
> mad plugin), I couldn't get it work the same way as madplay. Sound
> gets quieter but the distortions are not fixed.
> 
> 

It is time for mp3gain/replaygain . You have to retrain your hearing
and listening comfort.

Search for "Loudness War".


--
Ariff Abdullah
FreeBSD

... Recording in stereo is obviously too advanced
    and confusing for us idiot ***** users :P ........

... Going with the standard and orthodox
    is the death of intellect ..............
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