gstv4l2object: is a typo here about mpegversion number?
is a mistake ?
https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/blob/master/sys/v4l2/gstv4l2object.c#L1440
case V4L2_PIX_FMT_MPEG1:
structure = gst_structure_new ("video/mpeg",
"mpegversion", G_TYPE_INT, 2, NULL);
break;