+ _player_video_connection = _player->Video.connect (bind (&DCPEncoder::video, this, _1, _2));
+ _player_audio_connection = _player->Audio.connect (bind (&DCPEncoder::audio, this, _1, _2));
+ _player_subtitle_connection = _player->Subtitle.connect (bind (&DCPEncoder::subtitle, this, _1, _2));
+