#!/bin/bash
#
# Helper application to convert and import audio files for Rosegarden.
# Copyright 2005-2008 Chris Cannam.  Distributed under the GNU General
# Public License.
#
# Can take audio files of various kinds as input, always produces WAV
# files that are compatible with Rosegarden as output.
#
# Not actually specific to Rosegarden in any way, except that
# Rosegarden needs to know it can rely on its presence and calling
# interface.
#
# Usage:
#
# rosegarden-audiofile-importer -t [<version>]
# rosegarden-audiofile-importer --conftest [<version>]
#  -- Exit successfully if the importer is available and working
#     [and is of at least version <version>].  If some of the
#     required helper applications are missing, also print to
#     stdout a line saying "Required: application1, application2",
#     listing the missing programs.
#
# rosegarden-audiofile-importer -l [<version>]
#  -- List known file extensions (e.g. ogg wav flac).  Return code
#     is same as for -t (so can combine two calls into one)
#
# rosegarden-audiofile-importer [-r <rate>] -w <inputfile>
#  -- Test whether any work is needed to convert <inputfile>, either
#     because it isn't in a Rosegarden-compatible format or because
#     its samplerate differs from <rate>.  Exit successfully if no
#     work is required; return error code 2 if conversion required,
#     3 if resampling required, 4 if both required, 1 for other error.
#
# rosegarden-audiofile-importer [-r <rate>] -c <inputfile> <outputfile>
#  -- Convert <inputfile> [and resample if necessary] and write to
#     <outputfile> as a WAV file
#
# N.B. <outputfile> must not already exist -- this program will not
# overwrite it, but will fail instead if it does

version=1

OTHER_ERROR=1
CONVERSION_REQD=2
RESAMPLE_REQD=3
BOTH_REQD=4

echo "rosegarden-audiofile-importer: $@" 1>&2

conftest() {
    # ssrc is our favourite resampler, but it only works for certain
    # samplerates, so we have to have at least one other just in case
    if [ -x "`type -path sndfile-resample`" ]; then
	return 0
    fi
    if [ -x "`type -path sox`" ] && sox -h 2>&1 | grep -q polyphase; then
	return 0
    fi
    echo "Required: sox OR sndfile-resample"
    echo "rosegarden-audiofile-importer: ERROR: No resampler available, failing configuration test" 1>&2
    return 1
}

[ -x "`type -path oggdec`" ] && have_oggdec=1
[ -x "`type -path flac`" ] && have_flac=1
[ -x "`type -path mpg321`" ] && have_mpg321=1
[ -x "`type -path sndfile-convert`" -a -x "`type -path sndfile-info`" ] && have_sndfile=1

if [ -n "$have_mpg321" ]; then
    if ! mpg321 --help 2>&1 | grep -q 'wav N'; then
	have_mpg321=
    fi
fi

case "$1" in
    -t|--conftest) conftest; exit $?;;
    -l) conftest || exit $?
	{
	[ -n "$have_oggdec" ] && echo ogg
	[ -n "$have_flac" ] && echo flac
	[ -n "$have_mpg321" ] && echo mp3
	[ -n "$have_sndfile" ] && sndfile-convert --help 2>&1 | \
	    grep '^ *[a-z][a-z]* *: ' | awk '{ print $1; }'
	} | sort | uniq | fmt -1000
	exit 0;;
    -r) rate="$2"; shift; shift;;
esac

case "$1" in
    -w) test_work=1;;
    -c) convert=1;;
     *) exit 2;;
esac

conftest || exit $OTHER_ERROR

infile="$2"
if [ ! -r "$infile" ]; then
    echo "rosegarden-audiofile-importer: ERROR: input file \"$infile\" cannot be opened" 1>&2
    exit $OTHER_ERROR
fi

if [ -n "$convert" ]; then
    outfile="$3"
    if [ -z "$outfile" ]; then
	echo "rosegarden-audiofile-importer: ERROR: output file not specified" 1>&2
	exit $OTHER_ERROR
    fi
    if [ -f "$outfile" ]; then
	echo "rosegarden-audiofile-importer: ERROR: output file \"$outfile\" already exists, not overwriting" 1>&2
	exit $OTHER_ERROR
    fi
fi

base=`basename "$infile"`
stem=${base%.*}
extension=${base##*.}

extension=`echo $extension | tr '[A-Z]' '[a-z]'`

# If the file ends in ogg, mp3, wav or flac, we believe it.  Otherwise
# use file to see whether it's actually something else

case "$extension" in
    ogg|mp3|wav|flac) ;;
    *) case "`file $infile`" in
 	   *Ogg*Vorbis*) extension=ogg;;
	   *MP3*) extension=mp3;;
	   *FLAC*) extension=flac;;
       esac;;
esac

case "$extension" in
    ogg) converter=oggdec
	 [ -x "`type -path ogginfo`" ] && filerate=`ogginfo "$infile" | grep '^Rate: ' | awk '{ print $2; }'`;;
    mp3) converter=mpg321
	 # don't have a helper program to work out rate
	;;
      *) filerate=`sndfile-info "$infile" | grep '^Sample Rate :' | awk '{ print $4; }'`;;
esac

case "$extension" in
    wav) ;;
   flac) converter=flac; convert_reqd=1;;
ogg|mp3) convert_reqd=1;;
      *) converter=sndfile-convert; convert_reqd=1;;
esac

echo "Extension is $extension, converter is $converter, reqd is $convert_reqd"

case "$filerate" in [0-9]*);; *) filerate=; intermediate=1;; esac

[ -n "$filerate" ] && echo "File samplerate is $filerate (requested: $rate)"

[ -n "$filerate" -a -n "$rate" ] && [ "$filerate" -ne "$rate" ] && resample_reqd=1
[ -n "$resample_reqd" -a -n "$convert_reqd" ] && intermediate=1

[ -n "$intermediate" ] && echo "Using intermediate file"

if [ -z "$convert" ]; then # -w option
    if [ -n "$convert_reqd" ]; then
	[ -n "$intermediate" -o -n "$resample_reqd" ] && exit $BOTH_REQD
	exit $CONVERSION_REQD;
    else
	[ -n "$intermediate" -o -n "$resample_reqd" ] && exit $RESAMPLE_REQD
	exit 0;
    fi
fi

target="$outfile"
if [ -n "$intermediate" ]; then
    target="$outfile.tmp.wav"
    if [ -f "$target" ]; then
	echo "rosegarden-audiofile-importer: ERROR: intermediate file \"$target\" already exists, not overwriting" 1>&2
	exit $OTHER_ERROR
    fi
    trap "rm -f \"$target\"" 0
    trap "rm -f \"$target\" \"$outfile\"" 1 2 9 11 15
else
    trap "rm -f \"$outfile\"" 1 2 9 11 15
fi

resample() {
    _source=$1; shift
    _target=$1; shift
    simple=""
    case "$filerate" in
        192000|176400|96000|88200|48000|44100|24000|22050|12000|11025)
	case "$rate" in
	    192000|176400|96000|88200|48000|44100|24000|22050|12000|11025)
	    simple=1;;
	esac
    esac
    done=""
    if [ -x "`type -path ssrc`" -a -n "$simple" ]; then
	echo "Resampling using ssrc..." 1>&2
	ssrc --rate "$rate" --twopass --dither 4 --profile standard "$_source" "$_target" && done=1
    fi
    if [ -z "$done" ]; then
	if [ -x "`type -path sndfile-resample`" ]; then
	    echo "Resampling using sndfile-resample..." 1>&2
	    sndfile-resample -to "$rate" -c 0 "$_source" "$_target" || return 4
	else
	    echo "Resampling using sox..." 1>&2
	    sox "$_source" -r "$rate" "$_target" polyphase || return 4
	fi
    fi
    return 0
}    

if [ -n "$convert_reqd" ]; then
    case "$converter" in
	flac) [ -z "$have_flac" -a -n "$have_sndfile" ] && converter=sndfile-convert;;
    esac
    case "$converter" in
	oggdec)
	    [ -n "$have_oggdec" ] || exit $OTHER_ERROR
	    oggdec --output "$target" "$infile" || exit $OTHER_ERROR
	    ;;
	mpg321)
	    [ -n "$have_mpg321" ] || exit $OTHER_ERROR
	    mpg321 --wav "$target" "$infile" || exit $OTHER_ERROR
	    ;;
	flac)
	    [ -n "$have_flac" ] || exit $OTHER_ERROR
	    flac --decode --output-name="$target" "$infile" || exit $OTHER_ERROR
	    ;;
	   *)
	    [ -n "$have_sndfile" ] || exit $OTHER_ERROR
	    sndfile-convert -pcm16 "$infile" "$target" || exit $OTHER_ERROR
	    ;;
    esac
elif [ -n "$resample_reqd" ]; then
    resample "$infile" "$target" || exit $OTHER_ERROR
    resample_reqd=
fi

if [ ! -f "$target" ]; then
    echo "rosegarden-audiofile-importer: ERROR: target file not found" 1>&2
    exit $OTHER_ERROR
fi

if [ -z "$intermediate" ]; then
    echo "rosegarden-audiofile-importer: Done" 1>&2
    exit 0
fi

if [ -n "$intermediate" -a -n "$rate" -a -z "$filerate" ]; then
    filerate=`sndfile-info "$target" | grep '^Sample Rate :' | awk '{ print $4; }'`
    case "$filerate" in
   [0-9]*) if [ "$filerate" -ne "$rate" ]; then
	       resample_reqd=1
	   fi;;
	*) echo "rosegarden-audiofile-importer: ERROR: failed to extract samplerate of intermediate file" 1>&2
	   rm "$target"
	   exit $OTHER_ERROR
	   ;;
    esac
fi

if [ -n "$resample_reqd" ]; then
    resample "$target" "$outfile" || exit $OTHER_ERROR
    rm "$target"
else
    mv "$target" "$outfile"
fi

echo "rosegarden-audiofile-importer: Done" 1>&2
exit 0