video: Add GST_VIDEO_INFO_FIELD_RATE_N() macro

Add a new macro that gives you the rate of the fields, which is the
numerator of the field-rate for ALTERNATE interlacing video and FPS for
progressive and other interlacing formats.

https://bugzilla.gnome.org/show_bug.cgi?id=796106

diff --git a/gst-libs/gst/video/video-info.h b/gst-libs/gst/video/video-info.h
index 674ac6a..ce4a4d0 100644 (file)
--- a/gst-libs/gst/video/video-info.h
+++ b/gst-libs/gst/video/video-info.h
@@ -365,6 +365,9 @@ GType gst_video_info_get_type            (void);
 #define GST_VIDEO_INFO_PAR_N(i)          ((i)->par_n)
 #define GST_VIDEO_INFO_PAR_D(i)          ((i)->par_d)
 #define GST_VIDEO_INFO_FPS_N(i)          ((i)->fps_n)
+#define GST_VIDEO_INFO_FIELD_RATE_N(i)   ((GST_VIDEO_INFO_INTERLACE_MODE ((i)) == \
+                                           GST_VIDEO_INTERLACE_MODE_ALTERNATE) ? \
+                                           (i)->fps_n * 2 : (i)->fps_n)
 #define GST_VIDEO_INFO_FPS_D(i)          ((i)->fps_d)
 
 #define GST_VIDEO_INFO_COLORIMETRY(i) ((i)->colorimetry)