2023-11-22_19-57-10Z_Wednesday

bin/audio2image.bash

@@ -0,0 +1,79 @@
+#!/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 | \
+    convert - -background black -alpha remove -alpha off "$TMP1" 2>/dev/null | cat > /dev/null 2>&1
+
+#
+# Not clear what's being done to the image here, but it produces a useful end
+# result, or seems to!
+#
+convert -background black "$TMP1" -gravity center -background black -transparent white - | \
+    convert - -gravity South -background white -splice 0x5 -background black -splice 0x5 - | \
+    convert - -trim - | \
+    convert - -gravity South -chop 0x5 - | \
+    convert - -gravity North -background white -splice 0x5 -background black -splice 0x5 - | \
+    convert - -trim - | \
+    convert - -gravity North -chop 0x5 - | \
+    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
+