From: Hans Verkuil Date: Sat, 27 Mar 2010 17:10:37 +0000 (-0300) Subject: V4L/DVB: v4l spec: document what odd and even fields are X-Git-Tag: v2.6.35-rc1~480^2~115 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=37089368c1b1bea3c71217163e6d5d3b01ef1f19;p=karo-tx-linux.git V4L/DVB: v4l spec: document what odd and even fields are Document that odd == top and even == bottom. I can never remember this, so it is probably worth documenting. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/Documentation/DocBook/v4l/io.xml b/Documentation/DocBook/v4l/io.xml index e870330cbf77..bb685ed6fe7b 100644 --- a/Documentation/DocBook/v4l/io.xml +++ b/Documentation/DocBook/v4l/io.xml @@ -918,8 +918,8 @@ order. When the driver provides or accepts images field by field rather than interleaved, it is also important applications understand -how the fields combine to frames. We distinguish between top and -bottom fields, the spatial order: The first line +how the fields combine to frames. We distinguish between top (aka odd) and +bottom (aka even) fields, the spatial order: The first line of the top field is the first line of an interlaced frame, the first line of the bottom field is the second line of that frame. @@ -972,12 +972,12 @@ between V4L2_FIELD_TOP and V4L2_FIELD_TOP 2 - Images consist of the top field only. + Images consist of the top (aka odd) field only. V4L2_FIELD_BOTTOM 3 - Images consist of the bottom field only. + Images consist of the bottom (aka even) field only. Applications may wish to prevent a device from capturing interlaced images because they will have "comb" or "feathering" artefacts around moving objects.