On 05/25/2018 05:10 PM, Nicolas Dufresne wrote:
(in text this time, sorry)
Le vendredi 25 mai 2018 à 16:53 -0700, Steve Longerbeam a écrit :
Add a macro that returns true if the given field type is
'sequential',
that is, the data is transmitted, or exists in memory, as all top
field
lines followed by all bottom field lines, or vice-versa.
Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
---
include/uapi/linux/videodev2.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/uapi/linux/videodev2.h
b/include/uapi/linux/videodev2.h
index 600877b..408ee96 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -126,6 +126,10 @@ enum v4l2_field {
(field) == V4L2_FIELD_INTERLACED_BT ||\
(field) == V4L2_FIELD_SEQ_TB ||\
(field) == V4L2_FIELD_SEQ_BT)
+#define V4L2_FIELD_IS_SEQUENTIAL(field) \
+ ((field) == V4L2_FIELD_SEQ_TB ||\
+ (field) == V4L2_FIELD_SEQ_BT ||\
+ (field) == V4L2_FIELD_ALTERNATE)
No, alternate has no place here, in alternate mode each buffers have
only one field.
Then I misunderstand what is meant by "alternate". The name implies
to me that a source sends top or bottom field alternately, or top/bottom
fields exist in memory buffers alternately, but with no information about
which field came first. In other words, "alternate" is either seq-tb or
seq-bt,
without any info about field order.
If it is just one field in a memory buffer, why isn't it called
V4L2_FIELD_TOP_OR_BOTTOM, e.g. we don't know which?
Steve
