# File gstreamer/sample/media-type2.rb, line 148
  def find_streaminfo
    @pipeline.play
    while @streaminfo == nil && @pipeline.iterate do end
    @pipeline.pause
    streaminfo = @streaminfo
    @streaminfo = nil

    track_format = Gst::Format.find 'logical_stream'
    if track_format != nil
      start = @decoder_pad.query(Gst::QueryType::POSITION, track_format.type_id)
      track_num = start
      # XXX: need Gst::Pad#convert
    end
    return streaminfo
  end