diff options
| author | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2020-08-20 12:47:16 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-05 11:51:18 +0100 |
| commit | 0d6d22fb209fb071fb43234969fed2a81a6447bb (patch) | |
| tree | adf8873a65522cc1f8d8d90f5109b5235409cc18 /Documentation | |
| parent | 7edf069b6624b59b2d3cb46f78f515d6dc18a41e (diff) | |
media: videodev2.h: RGB BT2020 and HSV are always full range
[ Upstream commit b305dfe2e93434b12d438434461b709641f62af4 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/colorspaces-defs.rst | 9 | ||||
| -rw-r--r-- | Documentation/userspace-api/media/v4l/colorspaces-details.rst | 5 |
2 files changed, 6 insertions, 8 deletions
diff --git a/Documentation/userspace-api/media/v4l/colorspaces-defs.rst b/Documentation/userspace-api/media/v4l/colorspaces-defs.rst index 01404e1f609a..4089f426258d 100644 --- a/Documentation/userspace-api/media/v4l/colorspaces-defs.rst +++ b/Documentation/userspace-api/media/v4l/colorspaces-defs.rst @@ -36,8 +36,7 @@ whole range, 0-255, dividing the angular value by 1.41. The enum :c:type:`v4l2_hsv_encoding` specifies which encoding is used. .. note:: The default R'G'B' quantization is full range for all - colorspaces except for BT.2020 which uses limited range R'G'B' - quantization. + colorspaces. HSV formats are always full range. .. tabularcolumns:: |p{6.7cm}|p{10.8cm}| @@ -169,8 +168,8 @@ whole range, 0-255, dividing the angular value by 1.41. The enum - Details * - ``V4L2_QUANTIZATION_DEFAULT`` - Use the default quantization encoding as defined by the - colorspace. This is always full range for R'G'B' (except for the - BT.2020 colorspace) and HSV. It is usually limited range for Y'CbCr. + colorspace. This is always full range for R'G'B' and HSV. + It is usually limited range for Y'CbCr. * - ``V4L2_QUANTIZATION_FULL_RANGE`` - Use the full range quantization encoding. I.e. the range [0…1] is mapped to [0…255] (with possible clipping to [1…254] to avoid the @@ -180,4 +179,4 @@ whole range, 0-255, dividing the angular value by 1.41. The enum * - ``V4L2_QUANTIZATION_LIM_RANGE`` - Use the limited range quantization encoding. I.e. the range [0…1] is mapped to [16…235]. Cb and Cr are mapped from [-0.5…0.5] to - [16…240]. + [16…240]. Limited Range cannot be used with HSV. diff --git a/Documentation/userspace-api/media/v4l/colorspaces-details.rst b/Documentation/userspace-api/media/v4l/colorspaces-details.rst index 300c5d2e7d0f..cf1b825ec34a 100644 --- a/Documentation/userspace-api/media/v4l/colorspaces-details.rst +++ b/Documentation/userspace-api/media/v4l/colorspaces-details.rst @@ -377,9 +377,8 @@ Colorspace BT.2020 (V4L2_COLORSPACE_BT2020) The :ref:`itu2020` standard defines the colorspace used by Ultra-high definition television (UHDTV). The default transfer function is ``V4L2_XFER_FUNC_709``. The default Y'CbCr encoding is -``V4L2_YCBCR_ENC_BT2020``. The default R'G'B' quantization is limited -range (!), and so is the default Y'CbCr quantization. The chromaticities -of the primary colors and the white reference are: +``V4L2_YCBCR_ENC_BT2020``. The default Y'CbCr quantization is limited range. +The chromaticities of the primary colors and the white reference are: |