#!/usr/bin/python
# -*- coding: utf-8 -*-
# vi:si:et:sw=4:sts=4:ts=4
# GPL 2008
import gobject
gobject.threads_init()

import os
import pygst
pygst.require("0.10")
import gst

codec_list = {
    'MPEG-1 layer 3': 'MPEG-1 layer 3',
    'MPEG-1 layer 3 audio': 'MPEG-1 layer 3',
    'VP6 Flash video': 'VP6',
    'AC-3 audio': 'AC-3',
    'Uncompressed 16-bit PCM audio': 'Uncompressed 16-bit PCM',
    'Generic DV': 'DV Video',
}

class Info:
    video_done = True
    audio_done = True
    video = None
    audio = None
    metadata = {}
    tags = {}

    def __init__(self, videofile):
        self.mainloop = gobject.MainLoop()
        self.pipeline = gst.parse_launch('filesrc name=input ! decodebin name=dbin')
        self.input  = self.pipeline.get_by_name('input')
        self.input.props.location = videofile
        self.dbin  = self.pipeline.get_by_name('dbin')

        self.metadata['size'] = os.stat(videofile).st_size
        if self.metadata['size'] != 0:
            self.bus = self.pipeline.get_bus()
            self.dbin.connect('new-decoded-pad', self.demux_pad_added)

            self.bus.add_signal_watch()
            self.watch_id = self.bus.connect("message", self.onBusMessage)
            self.pipeline.set_state(gst.STATE_PAUSED)
            self.pipeline.get_state()

            #duration
            pads = None
            if self.video:
                pads = self.video.sink_pads()
            elif self.audio:
                pads = self.audio.sink_pads()
            if pads:
                q = gst.query_new_duration(gst.FORMAT_TIME)
                for pad in pads:
                    if pad.get_peer() and pad.get_peer().query(q):
                        format, self.duration = q.parse_duration()
                        self.metadata["duration"] = self.duration/gst.MSECOND
 
            self.mainloop.run()

            if 'video-codec' in self.tags:
                self.metadata['video-codec'] = codec_list.get(self.tags['video-codec'], self.tags['video-codec'])
            if 'audio-codec' in self.tags:
                self.metadata['audio-codec'] = codec_list.get(self.tags['audio-codec'], self.tags['audio-codec'])

    def get_audio_info_cb(self, sink, buffer, pad):
        caps = sink.sink_pads().next().get_negotiated_caps()
        for s in caps:
            self.metadata["channels"] = s['channels']
            self.metadata["samplerate"] = s['rate']
        self.audio.disconnect(self.audio_cb)
        self.audio_done = True
        if self.audio_done and self.video_done:
            self.bus.post(gst.message_new_eos(self.pipeline))

    def get_frame_info_cb(self, sink, buffer, pad):
        caps = sink.sink_pads().next().get_negotiated_caps()
        for s in caps:
            self.metadata["width"] = s['width']
            self.metadata["height"] = s['height']
            self.metadata["framerate"] = float(s['framerate'])
            if 'pixel-aspect-ratio' in s.keys():
                self.metadata["pixel-aspect-ratio"] = "%d:%d" % (s['pixel-aspect-ratio'].num, s['pixel-aspect-ratio'].denom)
        self.video.disconnect(self.video_cb)
        self.video_done = True
        if self.audio_done and self.video_done:
            self.bus.post(gst.message_new_eos(self.pipeline))

    def demux_pad_added(self, element, pad, bool):
        caps = pad.get_caps()
        structure = caps[0]
        stream_type = structure.get_name()
        if stream_type.startswith('video'):
            colorspace = gst.element_factory_make("ffmpegcolorspace");
            self.pipeline.add (colorspace);
            colorspace.set_state (gst.STATE_PLAYING);
            pad.link (colorspace.get_pad("sink"));

            self.video_done = False
            self.video = gst.element_factory_make("fakesink")
            self.video.props.signal_handoffs = True
            self.pipeline.add(self.video)
            self.video.set_state (gst.STATE_PLAYING);
            colorspace.link (self.video);
            self.video_cb = self.video.connect("handoff", self.get_frame_info_cb)
        elif stream_type.startswith('audio'):
            self.audio_done = False
            self.audio = gst.element_factory_make("fakesink")
            self.audio.props.signal_handoffs = True
            self.pipeline.add(self.audio)
            self.audio.set_state (gst.STATE_PLAYING);
            pad.link(self.audio.get_pad('sink'))
            self.audio_cb = self.audio.connect("handoff", self.get_audio_info_cb)

    def quit(self):
        self.pipeline.set_state(gst.STATE_NULL)
        self.pipeline.get_state()
        self.mainloop.quit()

    def onBusMessage(self, bus, message):
        if message.type == gst.MESSAGE_TAG:
            for key in message.parse_tag().keys():
                self.tags[key] = message.structure[key]
        if message.type == gst.MESSAGE_ERROR:
            self.quit()
        if message.src == self.pipeline and message.type == gst.MESSAGE_EOS:
            self.quit()