Force recalculating of MP3 gain. - Airtime Support Discussions on Sourcefabric Forum

FrancescoP

This is not a real need so far, but just in case, what should be the right way to force Airtime 2.2 to redo the MP3 gain calculation?

Emptying the replay_gain field in the database would be enough?

Thanks!

curiosamente,
Francesco P.

Martin Konecny

If you simply clear this field to null, then Airtime will automatically recalculate the ReplayGain value.

UPDATE cc_files set replay_gain = null;

Albert FR

Hi martin !

how to change the replay gain value ?

Martin Konecny

You would have to do it manually, by accessing the Airtime database. What exactly do you want to do?

Albert FR

put it at 94db :-D

Martin Konecny

Hmm, ok be careful, because that value in the database is an offset.

That target value of ReplayGain is 89dB so to make it 94dB, you will want to add +5 to each row.

Albert FR

ok,

into cc_files table ?

Martin Konecny

yup, into the replay_gain column.

Albert FR

ok for the present files,
but for the futures ?
where can i change the default value ?

Topea · Post edited by Topea at 2012-11-04 17:21:18

I am having a problem the sound seems to loud and i get at peak high echoes and messy "shhhsss" like sounds anyone knows what can it be?

Martin Konecny

The ReplayGain algorithm is targetted for 89dB, so you will need to modify the Python source.

https://github.com/sourcefabric/Airtime/blob/master/python_apps/media-monitor2/media/update/replaygain.py#L127

At line 127, change it to

return float(replay_gain) + 5

Martin Konecny

Reply to @Topea:

What is the replay_gain value of this track? Look into the "library" page, and make this column visible.

Topea · Post edited by Topea at 2012-11-04 17:39:09

Reply to @Martin+Konecny:

All my library is at 0 replay_gain value

If found this in utils.liq

def nrj(s)

compress(threshold=-15.,ratio=3.,gain=3.,normalize(s))

end

# Multiband-compression.

# @category Source / Sound Processing

# @param s The input source.

def sky(s)

# 3-band crossover

low = filter.iir.eq.low(frequency = 168.)

mh = filter.iir.eq.high(frequency = 100.)

mid = filter.iir.eq.low(frequency = 1800.)

high = filter.iir.eq.high(frequency = 1366.)

# Add back

add(normalize = false,

[ compress(attack = 100., release = 200., threshold = -20.,

ratio = 6., gain = 6.7, knee = 0.3,

low(s)),

compress(attack = 100., release = 200., threshold = -20.,

ratio = 6., gain = 6.7, knee = 0.3,

mid(mh(s))),

compress(attack = 100., release = 200., threshold = -20.,

ratio = 6., gain = 6.7, knee = 0.3,

high(s))

])

end

would that help reduce the noise i get sometimes at peaks or echoes? and in which file should i place this?

Martin Konecny

Hmm, I'm not familiar with that file (it's written by the Liquidsoap team), and wouldn't recommend editing it without asking them first.

If you play these tracks through any standard desktop music player, do you still hear the high echoes + messy sound?

Topea · Post edited by Topea at 2012-11-04 17:52:50

Does not happen to every song just some which sometimes peak at high they get a little messy and i have desktop player AIMP and yes it happen while listening with it

Maybe i should try another player? Could be my network also?

Martin Konecny

Reply to @Topea:

Your files shouldn't all have a 0dB offset.

What is the outputs of

which metaflac

which mp3gain

which vorbisgain

?

Topea

Reply to @Martin+Konecny:

I am playing .flac

:~# which metaflac

:~# which mp3gain

/usr/bin/mp3gain

~# which vorbisgain

/usr/bin/vorbisgain

As you can see i am missing metaflac what to do? install packet flac?

Martin Konecny

Yes,

sudo apt-get install flac

Afterwards, you will need to regenerate all your flac replaygain values by running the command outline here:

http://forum.sourcefabric.org/discussion/comment/20430#Comment_20430

It's strange that this package is not installed on your system, did you install Airtime via debian package or tarball?

Topea · Post edited by Topea at 2012-11-04 19:15:35

Reply to @Martin+Konecny:

I edited the source added deb http://apt.sourcefabric.org/ precise main for my distrubution

then apt-get install airtime 2.1.3 before 2.2.0 was out then apt-get upgrade and upgraded to 2.2.0

I did that http://forum.sourcefabric.org/discussion/comment/20430#Comment_20430

And now all values are back to 0 on all songs

2012/11/05 02:11:32 [queue:3] Prepared "/var/tmp/airtime/pypo/cache/scheduler/1184.flac" (RID 0).

2012/11/05 02:11:32 [cue_cut_5233:2] Ignoring negative cue-in point.

2012/11/05 02:11:32 [amplify_5238:3] Overriding amplification: 1.000000.

Martin Konecny

Reply to @Topea:

After you clear the replay gain values from the db, it takes some time before they are recalculated. I think every 5 min, we query the database for tracks that need to be analyzed and we only do a batch of a 100 at a time.

Topea

Reply to @Martin+Konecny:

Is it normal that all songs are back to value 0 replay gain data? they are .flac files

Daniel James · Post edited by Daniel James at 2012-11-05 07:12:03

Hi Topea, this seems to be a bug in Airtime 2.2.0, I have opened a ticket here:

http://dev.sourcefabric.org/browse/CC-4665

Thanks for the feedback!

Daniel

Topea · Post edited by Topea at 2012-11-06 06:42:40

Reply to @Daniel+James:

Is this related to the strange noises i keep hearing sometimes at peak high? Thanks.

Martin Konecny

Reply to @Topea:

Try this quick test:

metaflac --add-replay-gain filename.flac

Now upload this file, and play it through Airtime to see what happens.

FrancescoP

Reply to @Martin+Konecny:

Thanks! :)

ritardatamente,
Francesco P.

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