Re: [LAU] keeping same perceived level on mp3 files

On 10/09/2012 06:25 PM, Atte André Jensen wrote:
> On 10/09/2012 03:27 AM, Roger wrote:
>> On 10/09/2012 05:01 AM, Atte André Jensen wrote:
>>> "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."
>
> 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"
>
>> 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.
>
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.
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Received on Tue Oct 9 16:15:01 2012