9 Oct
2012
9 Oct
'12
2:49 p.m.
On 10/09/2012 06:25 PM, Atte André Jensen wrote:
On 10/09/2012 03:27 AM, Roger wrote:
Thanks for that explanation, Atte. Seems like mp3gain should do what you
want.
I use replay gain applied by SoundKonverter (and previously
foobar2000) and it seems to give good results across a mixture of mp3,
vorbis, flac and m4a files played with Amarok, DeadBeef, Qmmp and
Clementine all of which have Replay Gain support.
On 10/09/2012 05:01 AM, Atte André Jensen wrote:
Mind that replaygain and mp3gain are two different things.
Replaygain is "a proposed standard ... to measure the perceived
loudness of audio".
mp3gain "automatically adjusts mp3s so that they all have the same
volume" and it "uses David Robinson's Replay Gain algorithm to
calculate how loud the file actually sounds to a human's ears"
"mp3gain optionally writes gain adjustments
directly into the encoded
data. In this case, the adjustment works with all mp3 players, i.e. no
support for a special tag is required. This mode is activated by any
of the options -r, -a, -g, or -l."
From http://www.replaygain.org/ :
Player requirements
"Loudness normalization, pre-amplification and clipping prevention are
the operations performed by a ReplayGain player." These two sources are confusing. It would be good
to get a definitive
explanation of what mp3gain does to the audio part of the file. I guess
mp3gain uses replaygain method to determine levels and then writes the
audio file? This would not require support in the player.
By default mp3gain uses tags, but with the above options (-r, -a, -g,
or -l), the audio stream is directly modified instead. The great thing
is that mp3gain is able to change the gain of the audio without
decoding and re-encoding the mp3-file, which besides being *alot*
faster, also means it doesn't introduce further loss of quality.
Vorbisgain does require player support (
http://www.sjeng.org/vorbisgain.html ). I assumed that mp3gain worked
similarly, but maybe not.
See above. I guess the reason mp3gain have been developed to be able
to modify the audio and not rely on tags, is the fact that alot of
players are confused about how to figure out the tags, to the point
that few actually work with tags, at least with a single tagging method.