cam: Add Image class

The new Image class represents a multi-planar image with direct access
to pixel data. It currently duplicates the function of the
MappedFrameBuffer class which is internal to libcamera, and will serve
as a design playground to improve the API until it is considered ready
to be made part of the libcamera public API.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/src/cam/image.h b/src/cam/image.h
new file mode 100644
index 00000000..f7fc5b27
--- /dev/null
+++ b/src/cam/image.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Ideas on Board Oy
+ *
+ * image.h - Multi-planar image with access to pixel data
+ */
+#ifndef __CAM_IMAGE_H__
+#define __CAM_IMAGE_H__
+
+#include <memory>
+#include <stdint.h>
+#include <vector>
+
+#include <libcamera/base/class.h>
+#include <libcamera/base/flags.h>
+#include <libcamera/base/span.h>
+
+#include <libcamera/framebuffer.h>
+
+class Image
+{
+public:
+	enum class MapMode {
+		ReadOnly = 1 << 0,
+		WriteOnly = 1 << 1,
+		ReadWrite = ReadOnly | WriteOnly,
+	};
+
+	static std::unique_ptr<Image> fromFrameBuffer(const libcamera::FrameBuffer *buffer,
+						      MapMode mode);
+
+	~Image();
+
+	unsigned int numPlanes() const;
+
+	libcamera::Span<uint8_t> data(unsigned int plane);
+	libcamera::Span<const uint8_t> data(unsigned int plane) const;
+
+private:
+	LIBCAMERA_DISABLE_COPY(Image)
+
+	Image();
+
+	std::vector<libcamera::Span<uint8_t>> maps_;
+	std::vector<libcamera::Span<uint8_t>> planes_;
+};
+
+namespace libcamera {
+LIBCAMERA_FLAGS_ENABLE_OPERATORS(Image::MapMode)
+}
+
+#endif /* __CAM_IMAGE_H__ */