# -*- coding: utf-8 -*-
# enzyme - Video metadata parser
# Copyright (C) 2011 Antoine Bertin <diaoulael@gmail.com>
# Copyright (C) 2003-2006 Thomas Schueppel <stain@acm.org>
# Copyright (C) 2003-2006 Dirk Meyer <dischi@freevo.org>
#
# This file is part of enzyme.
#
# enzyme is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# enzyme is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

__all__ = ['Parser']

import struct
import logging
from exceptions import *
import core

# http://www.pcisys.net/~melanson/codecs/rmff.htm
# http://www.pcisys.net/~melanson/codecs/

# get logging object
log = logging.getLogger(__name__)

class RealVideo(core.AVContainer):
    def __init__(self,file):
        core.AVContainer.__init__(self)
        self.mime = 'video/real'
        self.type = 'Real Video'
        h = file.read(10)
        try:
            (object_id,object_size,object_version) = struct.unpack('>4sIH',h)
        except struct.error:
            # EOF.
            raise ParseError()

        if not object_id == '.RMF':
            raise ParseError()

        file_version, num_headers = struct.unpack('>II', file.read(8))
        log.debug("size: %d, ver: %d, headers: %d" % \
                  (object_size, file_version,num_headers))
        for i in range(0,num_headers):
            try:
                oi = struct.unpack('>4sIH',file.read(10))
            except (struct.error, IOError):
                # Header data we expected wasn't there.  File may be
                # only partially complete.
                break

            if object_id == 'DATA' and oi[0] != 'INDX':
                log.debug('INDX chunk expected after DATA but not found -- file corrupt')
                break

            (object_id,object_size,object_version) = oi
            if object_id == 'DATA':
                # Seek over the data chunk rather than reading it in.
                file.seek(object_size - 10, 1)
            else:
                self._read_header(object_id, file.read(object_size-10))
            log.debug("%s [%d]" % (object_id,object_size-10))
        # Read all the following headers


    def _read_header(self,object_id,s):
        if object_id == 'PROP':
            prop = struct.unpack('>9IHH', s)
            log.debug(prop)
        if object_id == 'MDPR':
            mdpr = struct.unpack('>H7I', s[:30])
            log.debug(mdpr)
            self.length = mdpr[7]/1000.0
            (stream_name_size,) = struct.unpack('>B', s[30:31])
            stream_name = s[31:31+stream_name_size]
            pos = 31+stream_name_size
            (mime_type_size,) = struct.unpack('>B', s[pos:pos+1])
            mime = s[pos+1:pos+1+mime_type_size]
            pos += mime_type_size+1
            (type_specific_len,) = struct.unpack('>I', s[pos:pos+4])
            type_specific = s[pos+4:pos+4+type_specific_len]
            pos += 4+type_specific_len
            if mime[:5] == 'audio':
                ai = core.AudioStream()
                ai.id = mdpr[0]
                ai.bitrate = mdpr[2]
                self.audio.append(ai)
            elif mime[:5] == 'video':
                vi = core.VideoStream()
                vi.id = mdpr[0]
                vi.bitrate = mdpr[2]
                self.video.append(vi)
            else:
                log.debug("Unknown: %s" % mime)
        if object_id == 'CONT':
            pos = 0
            (title_len,) = struct.unpack('>H', s[pos:pos+2])
            self.title = s[2:title_len+2]
            pos += title_len+2
            (author_len,) = struct.unpack('>H', s[pos:pos+2])
            self.artist = s[pos+2:pos+author_len+2]
            pos += author_len+2
            (copyright_len,) = struct.unpack('>H', s[pos:pos+2])
            self.copyright = s[pos+2:pos+copyright_len+2]
            pos += copyright_len+2
            (comment_len,) = struct.unpack('>H', s[pos:pos+2])
            self.comment = s[pos+2:pos+comment_len+2]


Parser = RealVideo