#!/bin/sh
#
-# Copyright © 2019-2020 Nick Bowler
+# Copyright © 2019-2022 Nick Bowler
#
# Generate thumbnails for cover art retrieved from MPD.
#
: "${THUMBNAILDIR=$XDG_CACHE_HOME/mpdthumb}"
# Try to find mpdexec...
-case $0 in
-/*) self=$0 ;;
-*/*) self=$PWD/${0#./} ;;
-*) self=`command -v $0` ;;
+argv0=$0
+case $argv0 in
+/*) self=$argv0 ;;
+*/*) self=$PWD/${argv0#./} ;;
+*) self=`command -v $argv0` ;;
esac
owndir=${self%/*}
: "${CONVERT=convert}"
fi
-size=x128
+print_version () {
+ cat <<'EOF'
+mpdthumb.sh 0.9
+Copyright © 2021 Nick Bowler
+License GPLv3+: GNU General Public License version 3 or any later version.
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+EOF
+}
+
+print_usage () {
+ test $# -eq 0 || { printf '%s: ' "$argv0"; printf "$@"; }
+ printf 'Usage: %s [options] file [file ...]\n' "$argv0"
+ test $# -eq 0 || printf 'Try %s --help for more information.\n' "$argv0"
+}
+
+print_help () {
+ print_usage
+ cat <<EOF
+This is "mpdthumb": a tool to retrieve cover art thumbnails from MPD.
+
+One or more filenames may be specified. The cover art (if any) for each
+file is retrieved and scaled to the requested size. The thumbnails are
+cached locally so that subsequent lookups return results very quickly.
+
+The filenames of the generated thumbnails are printed one per line in
+the same order of the associated files specified on the command line.
+If a given file has no cover art, then a blank line is printed.
+
+Options:
+ --size=[W][xH] Specify the dimensions (in pixels) of a bounding
+ rectangle into which the image will be scaled to fit.
+ One (but not both) of the dimensions may be omitted
+ to indicate no limit in that direction. The default
+ size is x128.
+ --small Equivalent to --size=56
+ --binarylimit[=ARG]
+ If ARG is omitted or 'yes', force the use of the
+ binarylimit command to reduce the amount of data
+ transferred in the hot cache case. If ARG is 'no',
+ then the old "large offset" method is used which is
+ incompatible with newer MPD servers. The default is
+ 'auto', which queries the server to determine the
+ appropriate method.
+ --no-binarylimit Equivalent to --binarylimit=no
+ --embedded Attempt to retrieve embedded covers using readpicture.
+ This requires (and implies) --binarylimit.
+ --no-embedded Use only album-level covers. This is the default.
+ --version Print a version message and then exit.
+ --help Print this message and then exit.
+
+Report bugs to <nbowler@draconx.ca>.
+EOF
+}
+opt_binarylimit=auto
+opt_embedded=no
+
+size=x128
lastarg=
dashdash=
for arg; do
fi
case $dashdash$arg in
+ --binarylimit=*) opt_binarylimit=${arg#--*=} ;;
+ --no-binarylimit) opt_binarylimit=no ;;
+ --binarylimit) opt_binarylimit=yes ;;
+ --embedded) opt_embedded=yes ;;
+ --no-embedded) opt_embedded=no ;;
--size=*) size=${arg#--size=} ;;
--small) size=56 ;;
--size) lastarg=$arg ;;
+ --version) print_version; exit ;;
+ --help) print_help; exit ;;
--) dashdash=: ;;
- -*) printf '%s: unrecognized argument: %s\n' "$0" "$arg" 1>&2; exit 1 ;;
+ -*) print_usage 'unrecognized argument: %s\n' "$arg" 1>&2; exit 1 ;;
*) set x "$@" "$arg"; shift
esac
w=${size%x*} h=${size#*x}
if expr "$w$h" : '[0-9][0-9]*$' >/dev/null; then :; else
- printf '%s: invalid --size setting: %s\n' "$0" "$size" 1>&2
+ print_usage 'invalid --size setting: %s\n' "$size" 1>&2
exit 1
fi
case $# in 0)
- printf 'usage: %s [options] file [file ...]\n' "$0" 1>&2
+ print_usage 'at least one filename is required\n' 1>&2
exit 1
esac
exec 5>"$tmp" 6<"$tmp"
rm -f "$tmp"
-for arg; do
- arg=${arg%/*}/
- shift; set x "$@" "$arg"; shift
+# --embedded implies --binarylimit
+case $opt_embedded in
+yes) use_embedded=true ;;
+*) use_embedded=false ;;
+esac
+$use_embedded && opt_binarylimit=yes
- printf '%s\n' "$arg" | sed '/[ \\"'\'']/ {
+# Test for binarylimit command in MPD server. We want to minimize data
+# transfer in order to make cache hits as fast as possible.
+#
+# On older servers we can set a ridiculously large offset which causes the
+# server to send no data, but this is rejected by new servers. On new servers
+# we can limit the data transferred explicitly, but not less than 64 bytes
+# for some reason (probably not a big problem).
+
+use_binarylimit=true
+case $opt_binarylimit in
+auto) $MPDEXEC binarylimit 64 2>/dev/null || use_binarylimit=false ;;
+no) use_binarylimit=false ;;
+yes) :;;
+*)
+ print_usage 'invalid --binarylimit argument; must be yes, no or auto' 1>&2
+ exit 1
+esac
+
+if $use_binarylimit; then
+ printf 'binarylimit 64\n' >&3
+ binarylimit_offset=0
+else
+ binarylimit_offset=2147483647
+fi
+
+for file; do
+ case $file in
+ */*) dir=${file%/*}/ ;;
+ *) dir=/ ;;
+ esac
+
+ if $use_embedded; then
+ shift; set x "$@" "$file" "$dir"; shift
+ else
+ file=
+ fi
+
+ printf '%s\n' "$dir" ${file:+"$file"} | sed -n '/[ \\"'\'']/ {
s/[\\"]/\\&/g
s/.*/"&"/
}
- s/.*/albumart & 2147483647/' >&3;
+ s/.*/albumart & '"$binarylimit_offset"'/
+ 1h
+ 2s/^albumart/readpicture/p
+ $ {
+ g
+ p
+ }' >&3;
done
-<&4 $MPDEXEC --ignore-errors >&5 2>&1 || exit
+valid=
+<&4 $MPDEXEC --verbose --ignore-errors >&5 2>&1 || exit
while read a b <&6; do
case $a in
- size:) :;;
- ACK) echo; shift || exit; continue ;;
+ readpicture|albumart)
+ prevn=$# file=$1 mode=$a; shift || exit; continue
+ ;;
+ size:)
+ if test x"$mode/$valid" = x"albumart/readpicture$prevn"; then
+ # readpicture result was OK, skip over albumart result
+ continue
+ fi
+ valid=$mode$#
+ ;;
+ ACK)
+ case $b in
+ *'{binarylimit}'*|*'{readpicture}'*)
+ printf '%s: %s\n' "$argv0" "$a $b" 1>&2; exit 1 ;;
+ esac
+ test x"$valid" = x"readpicture$prevn" || echo
+ continue
+ ;;
*) continue ;;
esac
# We combine the filename and the size to compute the cache key and
# hope this suffices to detect stale entries. Unfortunately MPD does
# not currently give us the modified date which would be more useful...
- file=$1; shift || exit
cache_id=`printf 'MPD:%s:%s' "$file" "$b" | md5sum`
cache_id=${cache_id:+${cache_id%% *}_$size.png}
fi
# Not cached, retrieve the entire image
- $MPDEXEC --binary --download albumart "$file" >&3 || exit
+ $MPDEXEC --binary --download "$mode" "$file" >&3 || exit
<&4 $CONVERT -scale "$size" - "$THUMBNAILDIR/tmp.$cache_id" ||
{ rc=$? rm -f "$THUMBNAILDIR/tmp.$cache_id"; exit $rc; }
mv -f "$THUMBNAILDIR/tmp.$cache_id" "$THUMBNAILDIR/$cache_id"
projects / mpdhacks.git / blobdiff