[libcamera-devel,v6,02/12] libcamera: camera: Introduce Orientation
diff mbox series

Message ID 20231019140133.32090-3-jacopo.mondi@ideasonboard.com
State Accepted
Headers show
Series
  • libcamera: Replace CameraConfiguration::transform
Related show

Commit Message

Jacopo Mondi Oct. 19, 2023, 2:01 p.m. UTC
Introduce the Orientation enumeration which describes the possible 2D
transformations that can be applied to an image using two basic plane
transformations.

Add to the CameraConfiguration class a new member 'orientation' which is
used to specify the image orientation in the memory buffers delivered to
applications.

The enumeration values follow the ones defined by the EXIF specification at
revision 2.32, Tag 274 'orientation'.

The newly introduced field is meant to replace
CameraConfiguration::transform which is not removed yet not to break
compilation.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
---
 include/libcamera/camera.h      |  2 ++
 include/libcamera/meson.build   |  1 +
 include/libcamera/orientation.h | 28 +++++++++++++++
 src/libcamera/camera.cpp        | 18 +++++++++-
 src/libcamera/meson.build       |  1 +
 src/libcamera/orientation.cpp   | 62 +++++++++++++++++++++++++++++++++
 6 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 include/libcamera/orientation.h
 create mode 100644 src/libcamera/orientation.cpp

Patch
diff mbox series

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index decf4ec0d4db..a4536c72a17e 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -21,6 +21,7 @@ 
 
 #include <libcamera/controls.h>
 #include <libcamera/geometry.h>
+#include <libcamera/orientation.h>
 #include <libcamera/request.h>
 #include <libcamera/stream.h>
 #include <libcamera/transform.h>
@@ -94,6 +95,7 @@  public:
 
 	std::optional<SensorConfiguration> sensorConfig;
 	Transform transform;
+	Orientation orientation;
 
 protected:
 	CameraConfiguration();
diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build
index 408b7acf152c..a24c50d66a82 100644
--- a/include/libcamera/meson.build
+++ b/include/libcamera/meson.build
@@ -12,6 +12,7 @@  libcamera_public_headers = files([
     'framebuffer_allocator.h',
     'geometry.h',
     'logging.h',
+    'orientation.h',
     'pixel_format.h',
     'request.h',
     'stream.h',
diff --git a/include/libcamera/orientation.h b/include/libcamera/orientation.h
new file mode 100644
index 000000000000..ae19d4c44a55
--- /dev/null
+++ b/include/libcamera/orientation.h
@@ -0,0 +1,28 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Ideas On Board Oy
+ *
+ * orientation.h - Image orientation
+ */
+
+#pragma once
+
+#include <iostream>
+
+namespace libcamera {
+
+enum class Orientation {
+	/* EXIF tag 274 starts from '1' */
+	Rotate0 = 1,
+	Rotate0Mirror,
+	Rotate180,
+	Rotate180Mirror,
+	Rotate90Mirror,
+	Rotate270,
+	Rotate270Mirror,
+	Rotate90,
+};
+
+std::ostream &operator<<(std::ostream &out, const Orientation &orientation);
+
+} /* namespace libcamera */
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index b940647d8d09..59ee3c40dc8e 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -291,7 +291,8 @@  bool SensorConfiguration::isValid() const
  * \brief Create an empty camera configuration
  */
 CameraConfiguration::CameraConfiguration()
-	: transform(Transform::Identity), config_({})
+	: transform(Transform::Identity), orientation(Orientation::Rotate0),
+	  config_({})
 {
 }
 
@@ -552,6 +553,21 @@  CameraConfiguration::Status CameraConfiguration::validateColorSpaces(ColorSpaceF
  * may adjust this field at its discretion if the selection is not supported.
  */
 
+/**
+ * \var CameraConfiguration::orientation
+ * \brief The desired orientation of the images produced by the camera
+ *
+ * The orientation field is a user-specified 2D plane transformation that
+ * specifies how the application wants the camera images to be rotated in
+ * the memory buffers.
+ *
+ * If the orientation requested by the application cannot be obtained, the
+ * camera will not rotate or flip the images, and the validate() function will
+ * Adjust this value to the native image orientation produced by the camera.
+ *
+ * By default the orientation field is set to Orientation::Rotate0.
+ */
+
 /**
  * \var CameraConfiguration::config_
  * \brief The vector of stream configurations
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index b24f82965764..d0e26f6b4141 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -34,6 +34,7 @@  libcamera_sources = files([
     'mapped_framebuffer.cpp',
     'media_device.cpp',
     'media_object.cpp',
+    'orientation.cpp',
     'pipeline_handler.cpp',
     'pixel_format.cpp',
     'process.cpp',
diff --git a/src/libcamera/orientation.cpp b/src/libcamera/orientation.cpp
new file mode 100644
index 000000000000..61f26cfda31b
--- /dev/null
+++ b/src/libcamera/orientation.cpp
@@ -0,0 +1,62 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Ideas On Board Oy
+ *
+ * orientation.cpp - Image orientation
+ */
+
+#include <libcamera/orientation.h>
+
+#include <array>
+#include <string>
+
+/**
+ * \file libcamera/orientation.h
+ * \brief Image orientation definition
+ */
+
+namespace libcamera {
+
+/**
+ * \enum Orientation
+ * \brief The image orientation in a memory buffer
+ *
+ * The Orientation enumeration describes the orientation of the images
+ * produced by the camera pipeline as they get received by the application
+ * inside memory buffers.
+ *
+ * The image orientation expressed using the Orientation enumeration can be then
+ * inferred by applying to a naturally oriented image a multiple of a 90 degrees
+ * rotation in the clockwise direction from the origin and then by applying an
+ * optional horizontal mirroring.
+ *
+ * The enumeration numerical values follow the ones defined by the EXIF
+ * Specification version 2.32, Tag 274 "Orientation", while the names of the
+ * enumerated values report the rotation and mirroring operations performed.
+ *
+ * In example Orientation::Rotate90Mirror describes the image transformation
+ * obtained by rotating 90 degrees clockwise first and then applying an
+ * horizontal mirroring.
+ */
+
+/**
+ * \brief Prints human-friendly names for Orientation items
+ * \param[in] out The output stream
+ * \param[in] orientation The Orientation item
+ * \return The output stream \a out
+ */
+std::ostream &operator<<(std::ostream &out, const Orientation &orientation)
+{
+	constexpr std::array<const char *, 9> orientationNames = {
+		"", /* Orientation starts counting from 1. */
+		"Rotate0", "rotate0Flip",
+		"Rotate180", "rotate180Flip",
+		"Rotate90Mirror", "Rotate270",
+		"Rotate270Mirror", "Rotate90",
+	};
+
+	out << orientationNames[static_cast<unsigned int>(orientation)];
+	return out;
+}
+
+} /* namespace libcamera */