def _inject(self, fileobj, padding_func):
        """Write tag data into the Vorbis comment packet/page."""

        # Find the old pages in the file; we'll need to remove them,
        # plus grab any stray setup packet data out of them.
        fileobj.seek(0)
        page = OggPage(fileobj)
        while not page.packets[0].startswith(b"\x03vorbis"):
            page = OggPage(fileobj)

        old_pages = [page]
        while not (old_pages[-1].complete or len(old_pages[-1].packets) > 1):
            page = OggPage(fileobj)
            if page.serial == old_pages[0].serial:
                old_pages.append(page)

        packets = OggPage.to_packets(old_pages, strict=False)

        content_size = get_size(fileobj) - len(packets[0])  # approx
        vcomment_data = b"\x03vorbis" + self.write()
        padding_left = len(packets[0]) - len(vcomment_data)

        info = PaddingInfo(padding_left, content_size)
        new_padding = info._get_padding(padding_func)

        # Set the new comment packet.
        packets[0] = vcomment_data + b"\x00" * new_padding

        new_pages = OggPage._from_packets_try_preserve(packets, old_pages)
        OggPage.replace(fileobj, old_pages, new_pages)

 def test_to_packets(self):
     self.failUnlessEqual(
         [b"foo", b"bar", b"baz"], OggPage.to_packets(self.pages))
     self.pages[0].complete = False
     self.pages[1].continued = True
     self.failUnlessEqual(
         [b"foobar", b"baz"], OggPage.to_packets(self.pages))

    def test_crc_py25(self):
        # Make sure page.write can handle both signed/unsigned int
        # return values of crc32.
        # http://code.google.com/p/mutagen/issues/detail?id=63
        # http://docs.python.org/library/zlib.html#zlib.crc32

        import zlib
        old_crc = zlib.crc32

        def zlib_uint(*args):
            return (old_crc(*args) & 0xffffffff)

        def zlib_int(*args):
            return cdata.int_be(cdata.to_uint_be(old_crc(*args) & 0xffffffff))

        try:
            page = OggPage()
            page.packets = [b"abc"]
            zlib.crc32 = zlib_uint
            uint_data = page.write()
            zlib.crc32 = zlib_int
            int_data = page.write()
        finally:
            zlib.crc32 = old_crc

        self.failUnlessEqual(uint_data, int_data)

    def _inject(self, fileobj):
        """Write tag data into the Speex comment packet/page."""

        fileobj.seek(0)

        # Find the first header page, with the stream info.
        # Use it to get the serial number.
        page = OggPage(fileobj)
        while not page.packets[0].startswith("Speex   "):
            page = OggPage(fileobj)

        # Look for the next page with that serial number, it'll start
        # the comment packet.
        serial = page.serial
        page = OggPage(fileobj)
        while page.serial != serial:
            page = OggPage(fileobj)

        # Then find all the pages with the comment packet.
        old_pages = [page]
        while not (old_pages[-1].complete or len(old_pages[-1].packets) > 1):
            page = OggPage(fileobj)
            if page.serial == old_pages[0].serial:
                old_pages.append(page)

        packets = OggPage.to_packets(old_pages, strict=False)

        # Set the new comment packet.
        packets[0] = self.write(framing=False)

        new_pages = OggPage.from_packets(packets, old_pages[0].sequence)
        OggPage.replace(fileobj, old_pages, new_pages)

    def _inject(self, fileobj, padding_func):
        """Write tag data into the Theora comment packet/page."""

        fileobj.seek(0)
        page = OggPage(fileobj)
        while not page.packets[0].startswith(b"\x81theora"):
            page = OggPage(fileobj)

        old_pages = [page]
        while not (old_pages[-1].complete or len(old_pages[-1].packets) > 1):
            page = OggPage(fileobj)
            if page.serial == old_pages[0].serial:
                old_pages.append(page)

        packets = OggPage.to_packets(old_pages, strict=False)

        content_size = get_size(fileobj) - len(packets[0])  # approx
        vcomment_data = b"\x81theora" + self.write(framing=False)
        padding_left = len(packets[0]) - len(vcomment_data)

        info = PaddingInfo(padding_left, content_size)
        new_padding = info._get_padding(padding_func)

        packets[0] = vcomment_data + b"\x00" * new_padding

        new_pages = OggPage._from_packets_try_preserve(packets, old_pages)
        OggPage.replace(fileobj, old_pages, new_pages)

    def _inject(self, fileobj):
        """Write tag data into the FLAC Vorbis comment packet/page."""

        # Ogg FLAC has no convenient data marker like Vorbis, but the
        # second packet - and second page - must be the comment data.
        fileobj.seek(0)
        page = OggPage(fileobj)
        while not page.packets[0].startswith(b"\x7FFLAC"):
            page = OggPage(fileobj)

        first_page = page
        while not (page.sequence == 1 and page.serial == first_page.serial):
            page = OggPage(fileobj)

        old_pages = [page]
        while not (old_pages[-1].complete or len(old_pages[-1].packets) > 1):
            page = OggPage(fileobj)
            if page.serial == first_page.serial:
                old_pages.append(page)

        packets = OggPage.to_packets(old_pages, strict=False)

        # Set the new comment block.
        data = self.write()
        data = bytes((packets[0][0],)) + struct.pack(">I", len(data))[-3:] + data
        packets[0] = data

        new_pages = OggPage.from_packets(packets, old_pages[0].sequence)
        OggPage.replace(fileobj, old_pages, new_pages)

 def test_theora_bad_version(self):
     page = OggPage(open(self.filename, "rb"))
     packet = page.packets[0]
     packet = packet[:7] + b"\x03\x00" + packet[9:]
     page.packets = [packet]
     fileobj = cBytesIO(page.write())
     self.failUnlessRaises(IOError, OggTheoraInfo, fileobj)

 def test_find_last_single_muxed(self):
     page1 = OggPage()
     page1.last = True
     page2 = OggPage()
     page2.serial = page1.serial + 1
     pages = [page1, page2]
     data = BytesIO(b"".join([page.write() for page in pages]))
     assert OggPage.find_last(data, page2.serial).serial == page2.serial

    def test_too_many_packets(self):
        packets = [b"1"] * 3000
        pages = OggPage.from_packets(packets)

        for p in pages:
            OggPage.write(p)

        self.failUnless(len(pages) > 3000//255)

 def test_underestimated_bitrate(self):
     page = OggPage(open(self.filename, "rb"))
     packet = page.packets[0]
     packet = (packet[:16] + b"\x00\x00\x01\x00" + b"\x01\x00\x00\x00" +
               b"\x00\x00\x01\x00" + packet[28:])
     page.packets[0] = packet
     info = OggVorbisInfo(cBytesIO(page.write()))
     self.failUnlessEqual(info.bitrate, 65536)

 def test_negative_bitrate(self):
     page = OggPage(open(self.filename, "rb"))
     packet = page.packets[0]
     packet = (packet[:16] + b"\xff\xff\xff\xff" + b"\xff\xff\xff\xff" +
               b"\xff\xff\xff\xff" + packet[28:])
     page.packets[0] = packet
     info = OggVorbisInfo(cBytesIO(page.write()))
     self.failUnlessEqual(info.bitrate, 0)

 def test_overestimated_bitrate(self):
     page = OggPage(file(self.filename, "rb"))
     packet = page.packets[0]
     packet = (packet[:16] + "\x00\x00\x01\x00" + "\x00\x00\x00\x01" +
               "\x00\x00\x00\x00" + packet[28:])
     page.packets[0] = packet
     info = OggVorbisInfo(StringIO(page.write()))
     self.failUnlessEqual(info.bitrate, 65536)

 def test_avg_bitrate(self):
     page = OggPage(open(self.filename, "rb"))
     packet = page.packets[0]
     packet = (packet[:16] + "\x00\x00\x01\x00" + "\x00\x00\x00\x00" +
               "\x00\x00\x00\x00" + packet[28:])
     page.packets[0] = packet
     info = OggVorbisInfo(StringIO(page.write()))
     self.failUnlessEqual(info.bitrate, 32768)

    def _inject(self, fileobj):
        fileobj.seek(0)
        info = OggOpusInfo(fileobj)
        old_pages = self.__get_comment_pages(fileobj, info)

        packets = OggPage.to_packets(old_pages)
        packets[0] = "OpusTags" + self.write(framing=False)
        new_pages = OggPage.from_packets(packets, old_pages[0].sequence)
        OggPage.replace(fileobj, old_pages, new_pages)

 def test_renumber_reread(self):
     try:
         filename = get_temp_copy(
             os.path.join(DATA_DIR, "multipagecomment.ogg"))
         with open(filename, "rb+") as fileobj:
             OggPage.renumber(fileobj, 1002429366, 20)
         with open(filename, "rb+") as fileobj:
             OggPage.renumber(fileobj, 1002429366, 0)
     finally:
         os.unlink(filename)

    def test_unsupported_version(self):
        page = OggPage(open(self.filename, "rb"))
        data = list(page.packets[0])

        data[8] = "\x03"
        page.packets[0] = "".join(data)
        OggOpusInfo(StringIO(page.write()))

        data[8] = "\x10"
        page.packets[0] = "".join(data)
        self.failUnlessRaises(IOError, OggOpusInfo, StringIO(page.write()))

 def test_random_data_roundtrip(self):
     try:
         random_file = open("/dev/urandom", "rb")
     except (IOError, OSError):
         print "WARNING: Random data round trip test disabled."
         return
     for i in range(10):
         num_packets = random.randrange(2, 100)
         lengths = [random.randrange(10, 10000) for i in range(num_packets)]
         packets = map(random_file.read, lengths)
         self.failUnlessEqual(packets, OggPage.to_packets(OggPage.from_packets(packets)))

    def test_unsupported_version(self):
        page = OggPage(open(self.filename, "rb"))
        data = bytearray(page.packets[0])

        data[8] = 0x03
        page.packets[0] = bytes(data)
        OggOpusInfo(BytesIO(page.write()))

        data[8] = 0x10
        page.packets[0] = bytes(data)
        self.failUnlessRaises(IOError, OggOpusInfo, BytesIO(page.write()))

def main(argv):
    from mutagen.ogg import OggPage
    parser = OptionParser(
        usage="%prog [options] filename.ogg ...",
        description="Split Ogg logical streams using Mutagen.",
        version="Mutagen %s" % ".".join(map(str, mutagen.version))
    )

    parser.add_option(
        "--extension", dest="extension", default="ogg", metavar='ext',
        help="use this extension (default 'ogg')")
    parser.add_option(
        "--pattern", dest="pattern", default="%(base)s-%(stream)d.%(ext)s",
        metavar='pattern', help="name files using this pattern")
    parser.add_option(
        "--m3u", dest="m3u", action="store_true", default=False,
        help="generate an m3u (playlist) file")

    (options, args) = parser.parse_args(argv[1:])
    if not args:
        raise SystemExit(parser.print_help() or 1)

    format = {'ext': options.extension}
    for filename in args:
        with _sig.block():
            fileobjs = {}
            format["base"] = os.path.splitext(os.path.basename(filename))[0]
            fileobj = open(filename, "rb")
            if options.m3u:
                m3u = open(format["base"] + ".m3u", "w")
                fileobjs["m3u"] = m3u
            else:
                m3u = None
            while True:
                try:
                    page = OggPage(fileobj)
                except EOFError:
                    break
                else:
                    format["stream"] = page.serial
                    if page.serial not in fileobjs:
                        new_filename = options.pattern % format
                        new_fileobj = open(new_filename, "wb")
                        fileobjs[page.serial] = new_fileobj
                        if m3u:
                            m3u.write(new_filename + "\r\n")
                    fileobjs[page.serial].write(page.write())
            for f in fileobjs.values():
                f.close()

 def test_renumber_muxed(self):
     pages = [OggPage() for i in range(10)]
     for seq, page in enumerate(pages[0:1] + pages[2:]):
         page.serial = 0
         page.sequence = seq
     pages[1].serial = 2
     pages[1].sequence = 100
     data = BytesIO(bytearray().join([page.write() for page in pages]))
     OggPage.renumber(data, 0, 20)
     data.seek(0)
     pages = [OggPage(data) for i in range(10)]
     self.failUnlessEqual(pages[1].serial, 2)
     self.failUnlessEqual(pages[1].sequence, 100)
     pages.pop(1)
     self.failUnlessEqual([page.sequence for page in pages], list(range(20, 29)))