node->add_child("AudioChannels")->add_child_text (lexical_cast<string> (_audio_channels));
node->add_child("AudioLength")->add_child_text (lexical_cast<string> (_audio_length));
node->add_child("AudioFrameRate")->add_child_text (lexical_cast<string> (_audio_frame_rate));
node->add_child("AudioChannels")->add_child_text (lexical_cast<string> (_audio_channels));
node->add_child("AudioLength")->add_child_text (lexical_cast<string> (_audio_length));
node->add_child("AudioFrameRate")->add_child_text (lexical_cast<string> (_audio_frame_rate));