+# makeids
+#
+# Calculate cddb disc ids without requiring specialized helper programs.
+# largely copied from cd-discid and musicbrainz examples. some of the steps
+# don't make sense, but they're necessary to match the ids generated by other
+# programs.
+#
+## FIXME ## Right now, we get 2 frames more than with cue2discid ??
+# data@petit:~$ sh /tmp/cue2discid /home/data/tmp/flac/01.Roisin_Murphy--Ruby_Blue.flac
+# processing offsetimes 00:00:00 04:47:10 08:20:37 11:46:46 17:45:36 21:41:57 27:32:21 32:03:73 35:39:28 38:27:33 43:50:38 44:42:34
+# 980b4b0c 12 150 21685 37687 53146 80061 97782 124071 144448 160603 173208 197438 201334 2895
+# data@petit:~$ metaflac --export-cuesheet-to=- /home/data/tmp/flac/01.Roisin_Murphy--Ruby_Blue.flac| python /home/data/sources/abcde/trunk/examples/cue2discid
+# 980b4b0c 12 150 21685 37687 53146 80061 97782 124071 144448 160603 173208 197438 201334 2893
+#
+# Variables: OFFSETS, TRACKS, LEADOUT, [LEADIN]
+makeids ()
+{
+ if [ X"$LEADOUT" = "X" ]; then
+ log warning "Error trying to calculate disc ids without lead-out information."
+ exit 1
+ fi
+
+ # default to a two second lead-in
+ IDMAGICNUM=150
+ LEADIN=${LEADIN:=150}
+
+ # number of cdframes per second
+ CDFRAMES=75
+
+ # reset cddb checksum for cddb disc-id calululation
+ CDDBCKSUM=0
+
+ COOKEDOFFSETS=""
+ for OFFSET in $(echo $OFFSETS)
+ do
+ COOKEDOFFSETS="${COOKEDOFFSETS} $(($OFFSET + $LEADIN))"
+
+ OFFSETTIME=$(( ($OFFSET + $LEADIN) / $CDFRAMES ))
+ while [ $OFFSETTIME -gt 0 ]; do
+ CDDBCKSUM=$(($CDDBCKSUM + $OFFSETTIME % 10))
+ OFFSETTIME=$(($OFFSETTIME / 10))
+ done
+
+ done
+
+ COOKEDOFFSETS="${COOKEDOFFSETS:1}" # eat the leading space
+
+ PREGAP=$(($(echo $OFFSETS | cut -f1 -d' ')))
+ TOTALTIME=$(( (($LEADOUT + $LEADIN + $PREGAP) / $CDFRAMES) - (($LEADIN + $PREGAP) / $CDFRAMES)))
+
+ printf -v HEXSUM "%08lx" $(( ($CDDBCKSUM % 0xff) << 24 | $TOTALTIME << 8 | $TRACKS))
+ TRACKINFO="${HEXSUM} $((TRACKS)) ${COOKEDOFFSETS} $((($LEADOUT + $LEADIN + $IDMAGICNUM) / $CDFRAMES))"
+}
+