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author | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2019-12-02 12:46:17 +0100 |
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committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2019-12-13 09:23:09 +0100 |
commit | 7b575b6d8de03ca6b6ab85fa1dd53d2ce921a4a0 (patch) | |
tree | 82e9db1a2c412872c86deb931155fad0ccd34f8c /Documentation/media | |
parent | 3d15c7643ba78b71c5c8fae25d7d9af52442882a (diff) | |
download | linux-7b575b6d8de03ca6b6ab85fa1dd53d2ce921a4a0.tar.bz2 |
media: vidioc-g-dv-timings.rst: fix wrong porch
It is the vfrontporch of field 1 that is one half-line longer,
not the backporch.
The order of the vertical signals in an interlaced system is:
Field 1:
vsync
vbackporch
active video of field 1
vfrontporch + 0.5
Field 2:
il_vsync
il_vbackporch - 0.5
active video of field 2
il_vfrontporch
Interlaced systems that use HALF_LINE set the il_ fields as follows:
il_vfrontporch = vfrontporch
il_vsync = vsync
il_vbackporch = vbackporch + 1
So the total vertical blanking for field 1 is:
vsync + vbackporch + vfrontporch + 0.5
and for field 2:
vsync + vbackporch + 1 + vfrontporch - 0.5 ==
vsync + vbackporch + vfrontporch + 0.5
So each field has the same number of half-lines.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'Documentation/media')
-rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst b/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst index 5712bd48e687..5c675cbac4cf 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst @@ -279,7 +279,7 @@ EBUSY then it will set this flag to signal this to the application. * - ``V4L2_DV_FL_HALF_LINE`` - Specific to interlaced formats: if set, then the vertical - backporch of field 1 (aka the odd field) is really one half-line + frontporch of field 1 (aka the odd field) is really one half-line longer and the vertical backporch of field 2 (aka the even field) is really one half-line shorter, so each field has exactly the same number of half-lines. Whether half-lines can be detected or |