# Post Audio Realtime Processing Compressor Limiter

**URL:** <https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249>\
**Category:** Get Help\
**Created:** [March 3, 2019, 12:47pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249 "2019-03-03T12:47:24Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 3, 2019, 12:47pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/1 "2019-03-03T12:47:24Z")

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Hi.

my libretime is up and running since yesterday, very happy to find this great software.  
thank you to all developers !!

I see replaygain just put an gain value into the file. but as i see there so no realtime audioprocessing.  
i think liquidsoap has the possibility to handle this.  
maybe you can add this feature ?

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**Author:** ![frecuencialibre](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/frecuencialibre/32/102_2.png) [@frecuencialibre](https://discourse.libretime.org/u/frecuencialibre)\
**Post date:** [March 4, 2019, 1:24pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/2 "2019-03-04T13:24:50Z")

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great! for the record here’s some relevant liquidsoap documentation: [https://www.liquidsoap.info/doc-1.3.0/replay\_gain.html](https://www.liquidsoap.info/doc-1.3.0/replay_gain.html)

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<div class="post-metadata">

**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 4, 2019, 6:47pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/3 "2019-03-04T18:47:59Z")

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hello thank you for the link  
it would be great if you can add the “nrj” and “normalize” from liquidsoap  
replay gain is not optimal in the most cases for listening experience

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**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 4, 2019, 10:58pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/4 "2019-03-04T22:58:31Z")

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btw not sure if replaygain work correct.  
there is many imported tracks without replaygain tag

can i force them to reanalyze ?

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**Author:** ![robbt](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/robbt/32/15_2.png) [@robbt](https://discourse.libretime.org/u/robbt)\
**Post date:** [March 5, 2019, 11:30am UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/5 "2019-03-05T11:30:12Z")

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There is no setup provision to reanalyze tracks. It could be written but currently only happens during importation by the analyzer script.

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<div class="post-metadata">

**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 5, 2019, 11:57am UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/6 "2019-03-05T11:57:44Z")

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would be nice when you can add reanalyze feature, also rescanning id3 tags.  
is there also no way to get it rescanned from command line ?

btw replaygain is not scanning files without id3tag, i think its a bug, see also github issue.

for liquidsoap i would recommend to add some “scripting window” to the frontend for using own scripting  
like nrj normalize or compression

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<div class="post-metadata">

**Author:** ![robbt](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/robbt/32/15_2.png) [@robbt](https://discourse.libretime.org/u/robbt)\
**Post date:** [March 5, 2019, 12:04pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/7 "2019-03-05T12:04:39Z")

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There are some CLI scripts in the util folder and this [https://github.com/LibreTime/libretime/pull/324](https://github.com/LibreTime/libretime/pull/324)

It could probably be modified to also do replay gain analysis. I haven’t really played with it so if you are interested in testing and contributing that would be useful.

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<div class="post-metadata">

**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 6, 2019, 1:07am UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/8 "2019-03-06T01:07:32Z")

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thank you for the tip

so i find a way to force replaygain processing the files with empty replaygain from console  
replaygain -f /path/to/file  
see also replaygain manpage  
[http://manpages.ubuntu.com/manpages/bionic/man1/replaygain.1.html](http://manpages.ubuntu.com/manpages/bionic/man1/replaygain.1.html)

you can check replaygainvalue with  
replaygain --show /path/to/file

but i didnt figure out how to re-read tags from file into libretime library  
any ideas ? they are still empty in LT library

i think this will fix this

> <https://github.com/LibreTime/libretime/issues/70>

  
so we have to wait for “watched folder” feature

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<div class="post-metadata">

**Author:** ![maydo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/maydo/32/122_2.png) [@maydo](https://discourse.libretime.org/u/maydo)\
**Post date:** [March 6, 2019, 10:42am UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/9 "2019-03-06T10:42:03Z")

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ok, i see replaygain is working  
when you process all files from console, replaygain is written and noticed by liquidsoap in the stream

i understand that the LT database is not updating from files, it does do once while importing.

also i see when changing tags in LT, they are written into database but not into file  
would be nice if database can update from files and into files.  
sometimes its needed to tag files from console

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<div class="post-metadata">

**Author:** ![robbt](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.libretime.org/robbt/32/15_2.png) [@robbt](https://discourse.libretime.org/u/robbt)\
**Post date:** [March 7, 2019, 2:34pm UTC](https://discourse.libretime.org/t/post-audio-realtime-processing-compressor-limiter/249/10 "2019-03-07T14:34:02Z")

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I agree that our metadata handling could be improved, the code in its current state is just kind of convoluted due to dependencies on outdated software stacks and thus it can be tricky to add new features. It would benefit a lot from a complete refresh to the tech stack but this is even more time consuming especially for volunteers with limited free time.