hpr_hub/bin/audio2image.bash

80 lines
2.5 KiB
Bash
Executable File

#!/bin/bash -
#
# Copied from a 'history' file on archive.org and turned into a script
#
set -o nounset # Treat unset variables as an error
SCRIPT=${0##*/}
#=== FUNCTION ================================================================
# NAME: cleanup_temp
# DESCRIPTION: Cleanup temporary files in case of a keyboard interrupt
# (SIGINT) or a termination signal (SIGTERM) and at script
# exit
# PARAMETERS: * - names of temporary files to delete
# RETURNS: Nothing
#===============================================================================
function cleanup_temp {
for tmp in "$@"; do
[ -e "$tmp" ] && rm --force "$tmp"
done
exit 0
}
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
if [[ $# -eq 0 ]]; then
echo "Usage: $SCRIPT audio_file"
exit 1
fi
AUDIO="$1"
IMAGE="${AUDIO%.*}.png"
if [[ ! -e $AUDIO ]]; then
echo "$SCRIPT: audio file $AUDIO not found"
exit 1
fi
#
# Make a temporary file (called /tmp/XXXX.png) and set traps to delete them
#
TMP1=$(mktemp -p /tmp XXXXXXXX.png) || {
echo "$SCRIPT: creation of temporary file failed!"
exit 1
}
trap 'cleanup_temp $TMP1' SIGHUP SIGINT SIGPIPE SIGTERM EXIT
#
# Make a temporary PNG file from the audio. The original uses a 'timeout' call
# but I can't get it to work for me.
#
ffmpeg -v 0 -analyzeduration 900000000000 -probesize 200M -threads 2 -i "$AUDIO" \
-filter_complex aformat=channel_layouts=mono,showwavespic=colors=white:s=3200x800 \
-frames:v 1 -f apng - 2>/dev/null | \
magick convert - -background black -alpha remove -alpha off "$TMP1" 2>/dev/null | cat > /dev/null 2>&1
#
# Not clear what's being done to the image here, but it produces a useful end
# result, or seems to!
#
magick convert -background black "$TMP1" -gravity center -background black -transparent white - | \
magick convert - -gravity South -background white -splice 0x5 -background black -splice 0x5 - | \
magick convert - -trim - | \
magick convert - -gravity South -chop 0x5 - | \
magick convert - -gravity North -background white -splice 0x5 -background black -splice 0x5 - | \
magick convert - -trim - | \
magick convert - -gravity North -chop 0x5 - | \
magick convert - -resize '800x200!' "$IMAGE"
#
# The original renamed the temporary file to be the target image file, but
# that's probably becausae part of this is done in a Docker container. Doesn't
# seem appropriate here
#
# vim: syntax=sh:ts=8:sw=4:ai:et:tw=78:fo=tcrqn21