"""Convert "arbitrary" sound files to AIFF (Apple and SGI's audio format).

Input may be compressed.

Uncompressed file type may be AIFF, WAV, VOC, 8SVX, NeXT/Sun, and others.

An exception is raised if the file is not of a recognized type.

Returned filename is either the input filename or a temporary filename;

in the latter case the caller must ensure that it is removed.

Other temporary files used are removed by the function.

"""

import os

import tempfile

import pipes

import sndhdr

__all__ = ["error", "toaiff"]

table = {}

t = pipes.Template()

t.append('sox -t au - -t aiff -r 8000 -', '--')

table['au'] = t

# XXX The following is actually sub-optimal.

# XXX The HCOM sampling rate can be 22k, 22k/2, 22k/3 or 22k/4.

# XXX We must force the output sampling rate else the SGI won't play

# XXX files sampled at 5.5k or 7.333k; however this means that files

# XXX sampled at 11k are unnecessarily expanded.

# XXX Similar comments apply to some other file types.

t = pipes.Template()

t.append('sox -t hcom - -t aiff -r 22050 -', '--')

table['hcom'] = t

t = pipes.Template()

t.append('sox -t voc - -t aiff -r 11025 -', '--')

table['voc'] = t

t = pipes.Template()

t.append('sox -t wav - -t aiff -', '--')

table['wav'] = t

t = pipes.Template()

t.append('sox -t 8svx - -t aiff -r 16000 -', '--')

table['8svx'] = t

t = pipes.Template()

t.append('sox -t sndt - -t aiff -r 16000 -', '--')

table['sndt'] = t

t = pipes.Template()

t.append('sox -t sndr - -t aiff -r 16000 -', '--')

table['sndr'] = t

uncompress = pipes.Template()

uncompress.append('uncompress', '--')

class error(Exception):

    pass

def toaiff(filename):

    temps = []

    ret = None

    try:

        ret = _toaiff(filename, temps)

    finally:

        for temp in temps[:]:

            if temp != ret:

                try:

                    os.unlink(temp)

                except os.error:

                    pass

                temps.remove(temp)

    return ret

def _toaiff(filename, temps):

    if filename[-2:] == '.Z':

        (fd, fname) = tempfile.mkstemp()

        os.close(fd)

        temps.append(fname)

        sts = uncompress.copy(filename, fname)

        if sts:

            raise error, filename + ': uncompress failed'

    else:

        fname = filename

    try:

        ftype = sndhdr.whathdr(fname)

        if ftype:

            ftype = ftype[0] # All we're interested in

    except IOError, msg:

        if type(msg) == type(()) and len(msg) == 2 and \

                type(msg[0]) == type(0) and type(msg[1]) == type(''):

            msg = msg[1]

        if type(msg) != type(''):

            msg = repr(msg)

        raise error, filename + ': ' + msg

    if ftype == 'aiff':

        return fname

    if ftype is None or not ftype in table:

        raise error, '%s: unsupported audio file type %r' % (filename, ftype)

    (fd, temp) = tempfile.mkstemp()

    os.close(fd)

    temps.append(temp)

    sts = table[ftype].copy(fname, temp)

    if sts:

        raise error, filename + ': conversion to aiff failed'

    return temp