mdw@git.distorted.org.uk Git - autoys/blob - flaccrip/flaccrip-offset

   1 #! /bin/bash
   2
   3 set -e
   4 : ${JBDIR=/mnt/jb}
   5
   6 zero_start=0 trim_end=0 offset=0
   7 while getopts flF:L:o:b:a: opt; do
   8   case "$opt" in
   9     f) zero_start=$((588 * 5 - 1)) ;;
  10     l) trim_end=$((588 * 5)) ;;
  11     F) zero_start=$OPTARG ;;
  12     L) trim_end=$OPTARG ;;
  13     o) offset=$OPTARG ;;
  14     b) before=$OPTARG ;;
  15     a) after=$OPTARG ;;
  16     *) exit 1 ;;
  17   esac
  18 done
  19
  20 shift $((OPTIND - 1))
  21 case $# in
  22   1) ;;
  23   *) echo >&2 "missing file argument" ;;
  24 esac
  25 file=$1
  26
  27 len=$(metaflac --show-total-samples "$file")
  28
  29 if ((offset < 0)); then
  30   start=0
  31   stop=$((stop + offset))
  32 elif ((offset >= 0)); then
  33   start=$offset
  34   stop=$len
  35 fi
  36
  37 {
  38   if ((offset < 0)); then
  39     if [ "${before+set}" ]; then
  40       n=$(metaflac --show-total-samples "$before")
  41       flac -d -s -o- --force-raw-format --sign=signed --endian=little \
  42         --skip=$((n + offset)) --until=$n \
  43         "$before"
  44     else
  45       $JBDIR/bin/cat-prefix $((4 * -offset)) </dev/zero
  46     fi
  47   fi
  48
  49   flac -d -s -o- --force-raw-format --sign=signed --endian=little \
  50     --skip=$start --until=$stop \
  51     "$file"
  52
  53   if ((offset > 0)); then
  54     if [ "${after+set}" ]; then
  55       flac -d -s -o- --force-raw-format --sign=signed --endian=little \
  56         --skip=0 --until=$offset \
  57         "$after"
  58     else
  59       $JBDIR/bin/cat-prefix $((4 * offset)) </dev/zero
  60     fi
  61   fi
  62 } | {
  63   if ((zero_start > 0)); then
  64     $JBDIR/bin/cat-prefix $((4 * zero_start)) </dev/zero
  65     $JBDIR/bin/cat-prefix $((4 * zero_start)) >/dev/null
  66     len=$((len - zero_start))
  67   fi
  68   if ((trim_end > 0)); then
  69     $JBDIR/bin/cat-prefix $((4 * (len - trim_end)))
  70     $JBDIR/bin/cat-prefix $((4 * trim_end)) </dev/zero
  71     cat >/dev/null
  72   else
  73     cat
  74   fi
  75 }