[PATCH v12 5/7] libcamera: virtual: Add ImageFrameGenerator

[Harvey Yang]

Besides TestPatternGenerator, this patch adds ImageFrameGenerator that
loads real images (jpg / jpeg for now) as the source and generates
scaled frames.

Signed-off-by: Konami Shu <konamiz at google.com>
Co-developed-by: Harvey Yang <chenghaoyang at chromium.org>
Co-developed-by: Yunke Cao <yunkec at chromium.org>
Co-developed-by: Tomasz Figa <tfiga at chromium.org>
---
 .../virtual/image_frame_generator.cpp         | 175 ++++++++++++++++++
 .../pipeline/virtual/image_frame_generator.h  |  51 +++++
 src/libcamera/pipeline/virtual/meson.build    |   4 +
 3 files changed, 230 insertions(+)
 create mode 100644 src/libcamera/pipeline/virtual/image_frame_generator.cpp
 create mode 100644 src/libcamera/pipeline/virtual/image_frame_generator.h

diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.cpp b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
new file mode 100644
index 00000000..80df9d6b
--- /dev/null
+++ b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Google Inc.
+ *
+ * image_frame_generator.cpp - Derived class of FrameGenerator for
+ * generating frames from images
+ */
+
+#include "image_frame_generator.h"
+
+#include <filesystem>
+#include <memory>
+#include <string>
+
+#include <libcamera/base/file.h>
+#include <libcamera/base/log.h>
+
+#include <libcamera/framebuffer.h>
+
+#include "libcamera/internal/mapped_framebuffer.h"
+
+#include "libyuv/convert.h"
+#include "libyuv/scale.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(Virtual)
+
+/*
+ * Factory function to create an ImageFrameGenerator object.
+ * Read the images and convert them to buffers in NV12 format.
+ * Store the pointers to the buffers to a list (imageFrameDatas)
+ */
+std::unique_ptr<ImageFrameGenerator>
+ImageFrameGenerator::create(ImageFrames &imageFrames)
+{
+	std::unique_ptr<ImageFrameGenerator> imageFrameGenerator =
+		std::make_unique<ImageFrameGenerator>();
+	imageFrameGenerator->imageFrames_ = &imageFrames;
+
+	/*
+	 * For each file in the directory, load the image,
+	 * convert it to NV12, and store the pointer.
+	 */
+	for (unsigned int i = 0; i < imageFrames.number.value_or(1); i++) {
+		std::filesystem::path path;
+		if (!imageFrames.number)
+			/* If the path is to an image */
+			path = imageFrames.path;
+		else
+			/* If the path is to a directory */
+			path = imageFrames.path / (std::to_string(i) + ".jpg");
+
+		File file(path);
+		if (!file.open(File::OpenModeFlag::ReadOnly)) {
+			LOG(Virtual, Error) << "Failed to open image file " << file.fileName()
+					    << ": " << strerror(file.error());
+			return nullptr;
+		}
+
+		/* Read the image file to data */
+		auto fileSize = file.size();
+		auto buffer = std::make_unique<uint8_t[]>(file.size());
+		if (file.read({ buffer.get(), static_cast<size_t>(fileSize) }) != fileSize) {
+			LOG(Virtual, Error) << "Failed to read file " << file.fileName()
+					    << ": " << strerror(file.error());
+			return nullptr;
+		}
+
+		/* Get the width and height of the image */
+		int width, height;
+		if (libyuv::MJPGSize(buffer.get(), fileSize, &width, &height)) {
+			LOG(Virtual, Error) << "Failed to get the size of the image file: "
+					    << file.fileName();
+			return nullptr;
+		}
+
+		std::unique_ptr<uint8_t[]> dstY =
+			std::make_unique<uint8_t[]>(width * height);
+		std::unique_ptr<uint8_t[]> dstUV =
+			std::make_unique<uint8_t[]>(width * height / 2);
+		int ret = libyuv::MJPGToNV12(buffer.get(), fileSize,
+					     dstY.get(), width, dstUV.get(),
+					     width, width, height, width, height);
+		if (ret != 0)
+			LOG(Virtual, Error) << "MJPGToNV12() failed with " << ret;
+
+		imageFrameGenerator->imageFrameDatas_.emplace_back(
+			ImageFrameData{ std::move(dstY), std::move(dstUV),
+					Size(width, height) });
+	}
+
+	return imageFrameGenerator;
+}
+
+/* Scale the buffers for image frames. */
+void ImageFrameGenerator::configure(const Size &size)
+{
+	/* Reset the source images to prevent multiple configuration calls */
+	scaledFrameDatas_.clear();
+	frameCount_ = 0;
+	parameter_ = 0;
+
+	for (unsigned int i = 0; i < imageFrames_->number.value_or(1); i++) {
+		/* Scale the imageFrameDatas_ to scaledY and scaledUV */
+		unsigned int halfSizeWidth = (size.width + 1) / 2;
+		unsigned int halfSizeHeight = (size.height + 1) / 2;
+		std::unique_ptr<uint8_t[]> scaledY =
+			std::make_unique<uint8_t[]>(size.width * size.height);
+		std::unique_ptr<uint8_t[]> scaledUV =
+			std::make_unique<uint8_t[]>(halfSizeWidth * halfSizeHeight * 2);
+		auto &src = imageFrameDatas_[i];
+
+		/*
+		 * \todo Some platforms might enforce stride due to GPU, like
+		 * ChromeOS ciri (64). The weight needs to be a multiple of
+		 * the stride to work properly for now.
+		 */
+		libyuv::NV12Scale(src.Y.get(), src.size.width,
+				  src.UV.get(), src.size.width,
+				  src.size.width, src.size.height,
+				  scaledY.get(), size.width, scaledUV.get(), size.width,
+				  size.width, size.height, libyuv::FilterMode::kFilterBilinear);
+
+		scaledFrameDatas_.emplace_back(
+			ImageFrameData{ std::move(scaledY), std::move(scaledUV), size });
+	}
+}
+
+void ImageFrameGenerator::generateFrame(const Size &size, const FrameBuffer *buffer)
+{
+	/* Don't do anything when the list of buffers is empty*/
+	ASSERT(!scaledFrameDatas_.empty());
+
+	MappedFrameBuffer mappedFrameBuffer(buffer, MappedFrameBuffer::MapFlag::Write);
+
+	auto planes = mappedFrameBuffer.planes();
+
+	/* Make sure the frameCount does not over the number of images */
+	frameCount_ %= imageFrames_->number.value_or(1);
+
+	/* Write the scaledY and scaledUV to the mapped frame buffer */
+	libyuv::NV12Copy(scaledFrameDatas_[frameCount_].Y.get(), size.width,
+			 scaledFrameDatas_[frameCount_].UV.get(), size.width, planes[0].begin(),
+			 size.width, planes[1].begin(), size.width,
+			 size.width, size.height);
+
+	/* Proceed an image every 4 frames */
+	/* \todo Consider setting the proceed interval in the config file  */
+	parameter_++;
+	if (parameter_ % frameInterval == 0)
+		frameCount_++;
+}
+
+/*
+ * \var ImageFrameGenerator::imageFrameDatas_
+ * \brief List of pointers to the not scaled image buffers
+ */
+
+/*
+ * \var ImageFrameGenerator::scaledFrameDatas_
+ * \brief List of pointers to the scaled image buffers
+ */
+
+/*
+ * \var ImageFrameGenerator::imageFrames_
+ * \brief Pointer to the imageFrames_ in VirtualCameraData
+ */
+
+/*
+ * \var ImageFrameGenerator::parameter_
+ * \brief Speed parameter. Change to the next image every parameter_ frames
+ */
+
+} /* namespace libcamera */
diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.h b/src/libcamera/pipeline/virtual/image_frame_generator.h
new file mode 100644
index 00000000..bbbe77c8
--- /dev/null
+++ b/src/libcamera/pipeline/virtual/image_frame_generator.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Google Inc.
+ *
+ * image_frame_generator.h - Derived class of FrameGenerator for
+ * generating frames from images
+ */
+
+#pragma once
+
+#include <filesystem>
+#include <memory>
+#include <optional>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "frame_generator.h"
+
+namespace libcamera {
+
+/* Frame configuration provided by the config file */
+struct ImageFrames {
+	std::filesystem::path path;
+	std::optional<unsigned int> number;
+};
+
+class ImageFrameGenerator : public FrameGenerator
+{
+public:
+	static std::unique_ptr<ImageFrameGenerator> create(ImageFrames &imageFrames);
+
+private:
+	static constexpr unsigned int frameInterval = 4;
+
+	struct ImageFrameData {
+		std::unique_ptr<uint8_t[]> Y;
+		std::unique_ptr<uint8_t[]> UV;
+		Size size;
+	};
+
+	void configure(const Size &size) override;
+	void generateFrame(const Size &size, const FrameBuffer *buffer) override;
+
+	std::vector<ImageFrameData> imageFrameDatas_;
+	std::vector<ImageFrameData> scaledFrameDatas_;
+	ImageFrames *imageFrames_;
+	unsigned int frameCount_;
+	unsigned int parameter_;
+};
+
+} /* namespace libcamera */
diff --git a/src/libcamera/pipeline/virtual/meson.build b/src/libcamera/pipeline/virtual/meson.build
index 0c537777..73d10cc3 100644
--- a/src/libcamera/pipeline/virtual/meson.build
+++ b/src/libcamera/pipeline/virtual/meson.build
@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: CC0-1.0
 
 libcamera_internal_sources += files([
+    'image_frame_generator.cpp',
     'test_pattern_generator.cpp',
     'virtual.cpp',
 ])
 
+libjpeg = dependency('libjpeg', required : false)
+
 libcamera_deps += [libyuv_dep]
+libcamera_deps += [libjpeg]
-- 
2.46.0.598.g6f2099f65c-goog