On Tue, Sep 02, 2014 at 04:12:29PM -0700, Kevin Cosgrove wrote: > > 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. If the speed is important, Praat [1] also is a possible alternative. There is a script in this message as a proof of concept. Usage: ./sf2png [options] SNDFILE... Write the images of the waveform of one or more soundfiles. -h n heigth of the viewport [1.2]. -n suppress the plot annotations. -s fontsize size of the font [4]. -w n width of the viewport [1.6]. Examples: ./sf2png /path/to/sndfiles/*.wav The png files are in the same directory of the related soundfiles. ./sf2png -n -w 0.8 -h 0.5 /path/to/sndfiles/*.wav ./sf2png -w 4 -h 3 -s 5 /path/to/sndfiles/*.wav [1] http://www.fon.hum.uva.nl/praat/ ><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< #!/bin/bash # # Write the images of the waveform of one or more soundfiles. usage() { cat <<EOF Usage: $0 [options] SNDFILE... Write the images of the waveform of one or more soundfiles. -h n heigth of the viewport [${height}]. -n suppress the plot annotations. -s fontsize size of the font [${fontsize}]. -w n width of the viewport [${width}]. EOF exit 1 } write_img() { local sndfile=$(realpath "$1") local imgfile="${sndfile%%.*}.png" echo "${sndfile} -> ${imgfile}" # # Warning: if there are trailing spaces after the copy-and-paste # of this script, remember to remove at least the spaces after # ${sndfile} and ${imgfile} in the follow praat script. # praat /dev/stdin <<EOF Read from file... ${sndfile} Select inner viewport... 0 $2 0 $3 Font size... $5 ${inner_box} Draw... 0 0 0 0 $4 Save as 300-dpi PNG file... ${imgfile} EOF } main() { local width="1.6" local height="1.2" local has_text="1" local fontsize="4" local inner_box="" [ $# -lt 1 ] && usage while getopts "h:ns:w:" arg; do case "${arg}" in h) height="${OPTARG}" ;; n) has_text="0" fontsize="1" inner_box="Draw inner box" ;; s) fontsize="${OPTARG}" ;; w) width="${OPTARG}" ;; *) usage ;; esac done shift $(expr "${OPTIND}" - 1) for sf in "$@"; do if [[ ! -f "${sf}" ]]; then echo "WARN: file ${sf} not found." else write_img "${sf}" "${width}" "${height}" "${has_text}" \ "${fontsize}" fi done } main "$@" tito _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
