[SOLVED] Perl sound synthesis on Debian 9

Issue

How to generate sounds in Perl on Debian 9?

Own research done, not much found. Eg. Audio::NoiseGen, which has problems with dependencies (namely Audio::PortAudio, which in turn is old and doesn't accept portaudio-2.0 on my Debian 9).

I mean sound synthesis, not playing files. The closest to what I'm looking for is using the system command to call the sox program. But that's reaching outside of Perl, so not a good integration. And I need a good one like a Perl module.

Solution

audio is just a curve, so code which makes a point wobble up and down and is sampled at some interval of time will synthesize audio (raw audio in PCM format) ... here perl generates such a curve

perl -e 'for ($c=0; $c<4*44100; $c++) {
             $k=1*sin((1500+$c/16e1)*$c*22e-6); print pack "f", $k;
         } ' |
sox -V -r 44100 -c 1 -b 32 -e floating-point -t raw - \
    -c 2 -b 16 -t wav - trim 0 3 gain -1 dither |
tee test.wav |
aplay

output from perl is piped into sox which effectively just adds a wav format header to the PCM audio ... then the wav file is piped into tee which outputs a wav file while piping to aplay which renders the audio ... for the benefit of others this installs needed debian (ubuntu) packages

sudo apt-get install sox alsa-utils

now just save above code into a file and source it ... vi somefile-with-above-code

source somefile-with-above-code

its handy to separate the process of audio synthesis from its sonic rendering so above division of labor is often justified

Alternatively you can use perl to synthesize the raw audio and dump it directly to a file yourself ... just save following perl snippet into a file vi my-audio-perl-file

perl -e 'for ($c=0; $c<4*44100; $c++) {
             $k=1*sin((1500+$c/16e1)*$c*22e-6); print pack "f", $k;
         } '

then execute it redirecting output to a file using

source ./my-audio-perl-file  > synth_audio.pcm

then use Audacity to visualize and render the PCM file ... File -> Import Raw Data

-> Encoding -> 32 bit float 
-> Byte order -> Little-endian
-> Channels  -> 1 Channel (Mono)

and hit Import

Answered By - Scott Stensland