matroska-demux: Use gst_video_multiview_guess_half_aspect()
matroska-demux: Use gst_video_multiview_guess_half_aspect()

Use the gst_video_multiview_guess_half_aspect() utility function
to set the half-aspect flag (or not) on stereoscopic frame-packed
videos.

sebras/gst-plugins-good,shelsonjava/gst-plugins-good,vatavuserban/gst-plugins-good,kittee/gst-plugins-good,chamois94/gst-plugins-good,GStreamer/gst-plugins-good,GrokImageCompression/gst-plugins-good,chamois94/gst-plugins-good,hizukiayaka/gst-plugins-good,shelsonjava/gst-plugins-good,GStreamer/gst-plugins-good,sebras/gst-plugins-good,vatavuserban/gst-plugins-good,ikonst/gst-plugins-good,chamois94/gst-plugins-good,stfl/gst-plugins-good,pexip/gst-plugins-good,rawoul/gst-plugins-good,shelsonjava/gst-plugins-good,shelsonjava/gst-plugins-good,vatavuserban/gst-plugins-good,vatavuserban/gst-plugins-good,ikonst/gst-plugins-good,GStreamer/gst-plugins-good,rawoul/gst-plugins-good,StreamUtils/gst-plugins-good,Kurento/gst-plugins-good,sebras/gst-plugins-good,froggatt/gst-plugins-good-m,Kurento/gst-plugins-good,Kurento/gst-plugins-good,froggatt/gst-plugins-good-m,ikonst/gst-plugins-good,stfl/gst-plugins-good,StreamUtils/gst-plugins-good,froggatt/gst-plugins-good-m,pexip/gst-plugins-good,GrokImageCompression/gst-plugins-good,GStreamer/gst-plugins-good,rawoul/gst-plugins-good,stfl/gst-plugins-good,hizukiayaka/gst-plugins-good,kittee/gst-plugins-good,pexip/gst-plugins-good,hizukiayaka/gst-plugins-good,ikonst/gst-plugins-good,pexip/gst-plugins-good,stfl/gst-plugins-good,StreamUtils/gst-plugins-good,kittee/gst-plugins-good,pexip/gst-plugins-good,froggatt/gst-plugins-good-m,sebras/gst-plugins-good,kittee/gst-plugins-good,Kurento/gst-plugins-good,GrokImageCompression/gst-plugins-good,Kurento/gst-plugins-good,rawoul/gst-plugins-good,GrokImageCompression/gst-plugins-good,hizukiayaka/gst-plugins-good,StreamUtils/gst-plugins-good,chamois94/gst-plugins-good