Simon Farnsworth authored Oct 30, 2014 and Nicolas Dufresne committed Nov 01, 2014

Rather than try and guess interlace support as part of checking supported
sizes, look for interlace support specifically in its own function.

As a cleanup, use V4L2_FIELD_ANY when probing sizes, which should result in
the driver doing the right thing.

With my capture setup, this gets me the following sample caps:

For 1080i resolution:
video/x-raw, format=(string)YUY2, width=(int)1920, height=(int)1080, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)interleaved, framerate=(fraction){ 25/1, 30/1 }

For 720p resolution:
video/x-raw, format=(string)YUY2, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, framerate=(fraction){ 50/1, 60/1 }

For 576i/p resolution (both possible at the point of query):
video/x-raw, format=(string)YUY2, width=(int)720, height=(int)576, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string){ progressive, interleaved }, framerate=(fraction){ 25/1, 50/1 }

This, in turn, makes 576i work correctly; with the old code,
the caps would be interlace-mode=progressive for interlaced video.

https://bugzilla.gnome.org/show_bug.cgi?id=726194