[media] vivid: do not allow video loopback for SEQ_TB/BT
Sequential top-bottom/bottom-top fields are not supported as video loopback.
This is too much work to implement for field settings that are rarely used.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/Documentation/video4linux/vivid.txt b/Documentation/video4linux/vivid.txt
index 6cfc854..cd4b5a1 100644
--- a/Documentation/video4linux/vivid.txt
+++ b/Documentation/video4linux/vivid.txt
@@ -912,6 +912,11 @@
sequence and field counting in struct v4l2_buffer on the capture side may not
be 100% accurate.
+- field settings V4L2_FIELD_SEQ_TB/BT are not supported. While it is possible to
+ implement this, it would mean a lot of work to get this right. Since these
+ field values are rarely used the decision was made not to implement this for
+ now.
+
- on the input side the "Standard Signal Mode" for the S-Video input or the
"DV Timings Signal Mode" for the HDMI input should be configured so that a
valid signal is passed to the video input.