media: colorspaces-details.rst: drop tabularcolumns

Those tables have small cells that fit nicely without requiring
line beaks.

So, they don't need tabular columns, as Sphinx/LaTeX
can adjust the width on such tables.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: Fix V4L2_COLORSPACE_470_SYSTEM_BG description

The description of the V4L2_COLORSPACE_470_SYSTEM_BG stated that it was
superseded by SMPTE 170M. That is incorrect. The probably root cause of
this is that the HDMI standard does not support this colorspace and,
unless otherwise signaled, will fall back to SMPTE 170M for SDTV.

However, EBU Tech. 3321 states that sources should signal Rec. 709 as the
colorimetry when using HDMI since the difference between Rec. 709 and
Tech. 3213 are negligible.

Update the text accordingly.

Also drop a spurious " at the end of the Tech 3213 title in the
bibliography.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: docs: use the new SPDX header for GFDL-1.1 on *.rst files

SPDX v3.10 gained support for GFDL-1.1 with no invariant sections:

https://spdx.org/licenses/GFDL-1.1-no-invariants-or-later.html

So, remove the license text, replacing them by this new SPDX
license.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: videodev2.h: RGB BT2020 and HSV are always full range

The default RGB quantization range for BT.2020 is full range (just as for
all the other RGB pixel encodings), not limited range.

Update the V4L2_MAP_QUANTIZATION_DEFAULT macro and documentation
accordingly.

Also mention that HSV is always full range and cannot be limited range.

When RGB BT2020 was introduced in V4L2 it was not clear whether it should
be limited or full range, but full range is the right (and consistent)
choice.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: colorspaces-details.rst: fix V4L2_COLORSPACE_JPEG description

The description was missing V4L2_XFER_FUNC_SRGB in the description
of what V4L2_COLORSPACE_JPEG stands for.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: docs: move uAPI book to userspace-api/media

Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>