Thursday, April 21, 2011

Resampling - If you can't avoid it...

(Last update: Mar-28-2018)

Intro 


I've been looking at the subject of audio data resampling now and than.
Somehow you can't avoid looking into it - for several reasons.
In my case some of my HW setups suggest to use resampled data 
to achieve a potentially better performance. 

While scanning the net I stepped over a lot of very fragmented and also incomplete 
information. 
Quite some stuff out there has a marketing flavor attached to it. 
And obviously you'll find numerous different opinions about the best way doing things.

With this post I'm trying to cover certain aspects, such as

* What is resampling or upsampling/downsampling or oversampling?
* Why resampling?

* Quality factors and quality targets
* What tools and applications 
* Conclusion

* Implementation on LogitechMediaServer
* Offline resampling
* Sox installation/update and compilation (script)


Let's get started.


Annex 1: Script to compile latest Sox for Debian/Ubuntu systems
Annex 2: Sox LMS upgrade on Debian/Ubuntu systems