options: add --deinterlace-field-parity option

Previously there was no way to specify the field order of interlaced videos
when deinterlacing with inbuilt filters. Lavfi deinterlacers seemed to prefer
top field order while inbuilt ones (vdpaupp, vavpp, d3d11vpp) seemed to prefer
bottom field order. The default "auto" option should work exactly as before
while specifying either "tff" or "bff" should force the specified field order

1 files changed, 11 insertions, 0 deletions

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 178b739c8d..6a09cf3884 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -1676,6 +1676,17 @@ Video
     inserted deinterlacing filters, and that this will make video look worse if
     it's not actually interlaced.
 
+``--deinterlace-field-parity=<tff|bff|auto>``
+    Specify the field parity/order when deinterlacing(default: auto)
+    Each frame of an interlaced video is divided into two fields, which are
+    then separately transmitted. Top field represents even lines while bottom
+    field represents odd lines. When deinterlacing the deinterlacer needs to
+    know the correct temporal order of the fields else the video will appear
+    jittery.
+
+    ``auto`` will automatically try to detect the field order of the video,
+    ``tff`` forces top field first while ``bff`` forces bottom field first.
+
 ``--frames=<number>``
     Play/convert only first ``<number>`` video frames, then quit.