I dug into this a bit more.
Getting the time & amplitude data out of the WAV file was easy with
sox file.wav -t dat - | tail -n +3 > file.dat
My beloved xgraph is not available on Fedora anymore. That made me
relearn gnuplot, a good move regardless. I wrote a script to build
a gnuplot input file, file.gpl, which contains something like
set terminal png notransparent nocrop
set output file.png
plot [] [-1:1] "file.dat" with lines
Then I run gnuplot on its input file like so
gnuplot file.gpl > file.png
I left out a lot of housekeeping related to my scripting. But, the
above does all of the work needed to produce a nice graph of my audio
files.
Of course, this isn't fast. It takes about 4 minutes on my
3.4GHz i7 with 16GB of RAM to create a plot from a 0.5GB mono WAV
file. Audacity and Ardour are faster than sox + gnuplot at creating
their waveform views. But, I can script with sox + gnuplot.
I hope this is useful for someone trolling the archive someday.
Cheerio...
--
Kevin