I have spent a couple of days trying to change the default waveform color in the command line Gnuplot portion with no success. Here is the code that works perfectly it outputs a purple audio waveform on a transparent background. I want to be able to change the purple color to an RGB color (i.e. "#ff0000" format).
ffmpeg -y -i "Traveling Man.mp3" -ac 1 -filter:a aresample=8000 -map 0:a -c:a pcm_s16le -f data - | gnuplot -p -e "set terminal png size 1000,250; set output 'waveform.png'; unset key; set term png transparent truecolor; unset tics; unset border; set lmargin 0; set rmargin 0; set tmargin 0; set bmargin 0; plot '-' binary filetype=bin format='%int16' endian=little array=1:0 with lines;"
I have tried adding:
set linetype 9 lc rgb '0000ff'; set linetype cycle 9;
to the command line in various places and it either throws an error or outputs purple on transparent.
This has to be something very simple, I just can't seem to get it because the documentation does not show any usefull command-line examples. Any ideas are welcome, thank you.
You can change the color for each plot by explicitly specifying it. For the 'lines' style like in your example, you can specify the line color by adding "lc rgb '#ff0000'" after "with lines". The modified plot command will look like this.
plot '-' binary filetype=bin format='%int16' endian=little array=1:0 with lines lc rgb '#ff0000';
You can get more detailed control over the style of each plot by typing the following help command at the gnuplot prompt.
gnuplot> help plot with