Plotting waveform of audiofile data in gnuplot using stats from sox

gnuplot-waveform.sh

#!/bin/bash

# -----------------------------------------------------------------------------
# file: gnuplot-waveform.sh
# -----------------------------------------------------------------------------
#
#   author: turbulentie
#  created: 2024-09-29 (09:48:25)
#  updated: 2024-09-29 (17:02:03)
# revision: 1.0
#
# -- Description --------------------------------------------------------------
#
#       Plotting waveform of audiofile data in gnuplot using stats from sox
#
# -----------------------------------------------------------------------------


req_bins="sox gnuplot"

for binary in $req_bins; do
	if [[ ! -x "$(command -v $binary)" ]]; then
		printf "[\e[0;31m+\e[0m] - This script requires $binary\n"
		exit 1
	fi
done

if [[ "$#" -ge 1 ]]; then

	if [[ -e "$1" ]]; then 
		datafile="$1"
	else
		printf "[\e[0;31m+\e[0m] - File $1 not found! Exiting...\n"
		exit 2
	fi

	if [[ -n "$2" ]]; then
		outpic="$2"
	else
		outpic="$1.png"
		printf "[\e[0;31m+\e[0m] - Output file not defined. Using name from file: $outpic ...\n"
	fi

	setfont="Helvetica"
	fontsize="10"
	bgcolor="#1f1f1f"
	brlcolor="#00bfff"
	tltcolor="#a0a0b0"
	xlbltcolor="#80c0ff"
	ylbltcolor="#80c0ff"
	p1lcolor="#73db78"
	p2lcolor="#73db78"

	gnuplot << EOF
		set datafile commentschars ";"

		set terminal png enhanced background rgbcolor "$bgcolor" enhanced font "$setfont,$fontsize"
		set output "$outpic"

		set border lc rgbcolor "$brlcolor"
		set title "file: $1" tc rgbcolor "$tltcolor"

		set multiplot layout 2,1

		set ylabel "sample value" tc rgbcolor "$ylbltcolor"
		set bmargin 0
		set format x ""
		set ytics -0.8,0.2
		set key bottom
		plot "< sox $datafile -t dat -" using 1:2 every 100 with lines lc rgb "$p1lcolor" title "left channel"

		set xlabel "time (s)" tc rgbcolor "$xlbltcolor"
		set bmargin
		set tmargin 0
		set format x "%g"
		set ytics -1.0,0.2,0.8
		set key top

		unset title
		plot ""         using 1:3 every 100 with lines lc rgb "$p2lcolor" title "right channel"
		unset multiplot
EOF

	if [[ "$?" -eq 0 ]]; then
		printf "[\e[0;31m+\e[0m] - Date: $(date +%d-%m-%Y) | $(date +%H:%M:%S)\n"
		printf "[\e[0;31m+\e[0m] - Processed file: $datafile \n[\e[0;31m+\e[0m] - Output file: $outpic\n"
		[[ -n DISPLAY && -n $(which display) ]] && exec display "$outpic" || printf "[\e[0;31m+\e[0m] - Skipping attempt to open file: not X11 session or ImageMagick not found!"
		exit 0
	fi
else
	printf "Usage: $(basename $0) <datafile> <wavepic>\n"
	exit 1
fi