[libcamera-devel] [PATCH v2 3/6] android: Add CameraHalConfig class

Jacopo Mondi jacopo at jmondi.org
Mon Mar 29 17:28:04 CEST 2021


Add a CameraHalConfig class to the Android Camera3 HAL layer.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 README.rst                        |   2 +-
 src/android/camera_hal_config.cpp | 463 ++++++++++++++++++++++++++++++
 src/android/camera_hal_config.h   |  53 ++++
 src/android/meson.build           |   2 +
 4 files changed, 519 insertions(+), 1 deletion(-)
 create mode 100644 src/android/camera_hal_config.cpp
 create mode 100644 src/android/camera_hal_config.h

diff --git a/README.rst b/README.rst
index 7a98164bbb0a..f68d435196de 100644
--- a/README.rst
+++ b/README.rst
@@ -88,7 +88,7 @@ for tracing with lttng: [optional]
         liblttng-ust-dev python3-jinja2 lttng-tools
 
 for android: [optional]
-        libexif libjpeg
+        libexif libjpeg libyaml
 
 Using GStreamer plugin
 ~~~~~~~~~~~~~~~~~~~~~~
diff --git a/src/android/camera_hal_config.cpp b/src/android/camera_hal_config.cpp
new file mode 100644
index 000000000000..846dd7357b0a
--- /dev/null
+++ b/src/android/camera_hal_config.cpp
@@ -0,0 +1,463 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * camera_hal_config.cpp - Camera HAL configuration file manager
+ */
+#include "camera_hal_config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <hardware/camera3.h>
+
+#include "libcamera/internal/file.h"
+#include "libcamera/internal/log.h"
+
+using namespace libcamera;
+
+LOG_DEFINE_CATEGORY(HALConfig)
+
+CameraHalConfig::CameraHalConfig()
+{
+	if (!yaml_parser_initialize(&parser_))
+		LOG(HALConfig, Fatal) << "Failed to initialize yaml parser";
+}
+
+CameraHalConfig::~CameraHalConfig()
+{
+	yaml_parser_delete(&parser_);
+}
+
+/*
+ * Configuration files can be stored in system paths, which are identified
+ * through the build configuration.
+ *
+ * However, when running uninstalled - the source location takes precedence.
+ */
+std::string CameraHalConfig::findFilePath(const std::string &filename) const
+{
+	static std::array<std::string, 2> searchPaths = {
+		LIBCAMERA_SYSCONF_DIR,
+		LIBCAMERA_DATA_DIR,
+	};
+
+	if (File::exists(filename))
+		return filename;
+
+	std::string root = utils::libcameraSourcePath();
+	if (!root.empty()) {
+		std::string configurationPath = root + "data/" + filename;
+		if (File::exists(configurationPath))
+			return configurationPath;
+	}
+
+	for (std::string &path : searchPaths) {
+		std::string configurationPath = path + "/" + filename;
+		if (File::exists(configurationPath))
+			return configurationPath;
+	}
+
+	return "";
+}
+
+FILE *CameraHalConfig::openFile(const std::string &filename)
+{
+	const std::string filePath = findFilePath(filename);
+	if (filePath.empty()) {
+		LOG(HALConfig, Error)
+			<< "Configuration file: \"" << filename << "\" not found";
+		return nullptr;
+	}
+
+	LOG(HALConfig, Debug) << "Reading configuration file from " << filePath;
+
+	FILE *fh = fopen(filePath.c_str(), "r");
+	if (!fh) {
+		int ret = -errno;
+		LOG(HALConfig, Error) << "Failed to open configuration file "
+				      << filePath << ": " << strerror(-ret);
+		return nullptr;
+	}
+
+	return fh;
+}
+
+/*
+ * Open the HAL configuration file and validate its content.
+ * Return 0 on success, a negative error code otherwise
+ */
+int CameraHalConfig::open()
+{
+	int ret;
+
+	FILE *fh = openFile("camera_hal.yaml");
+	if (!fh)
+		return -ENOENT;
+
+	yaml_parser_set_input_file(&parser_, fh);
+	ret = parseConfigFile();
+	fclose(fh);
+	if (ret)
+		return ret;
+
+	LOG(HALConfig, Info) << "Device model: " << model_;
+	LOG(HALConfig, Info) << "Device maker: " << maker_;
+	for (const auto &c : cameras_) {
+		const std::string &cameraId = c.first;
+		const CameraProps &camera = c.second;
+		LOG(HALConfig, Info) << "'" << cameraId << "' "
+				     << " model: " << camera.model
+				     << "(" << camera.location << ")["
+				     << camera.rotation << "]";
+	}
+
+	return 0;
+}
+
+int CameraHalConfig::cameraLocation(const std::string &camera) const
+{
+	const auto &it = cameras_.find(camera);
+	if (it == cameras_.end()) {
+		LOG(HALConfig, Error)
+			<< "Camera '" << camera
+			<< "' not described in the HAL configuration file";
+		return -EINVAL;
+	}
+
+	const CameraProps &cam = it->second;
+	if (cam.location.empty()) {
+		LOG(HALConfig, Error) << "Location for camera '" << camera
+				      << "' not available";
+		return -EINVAL;
+	}
+
+	if (cam.location == "front")
+		return CAMERA_FACING_FRONT;
+	else if (cam.location == "back")
+		return CAMERA_FACING_BACK;
+	else if (cam.location == "external")
+		return CAMERA_FACING_EXTERNAL;
+
+	LOG(HALConfig, Error) << "Unsupported camera location " << cam.location;
+	return -EINVAL;
+}
+
+unsigned int CameraHalConfig::cameraRotation(const std::string &camera) const
+{
+	const auto &it = cameras_.find(camera);
+	if (it == cameras_.end()) {
+		LOG(HALConfig, Error)
+			<< "Camera '" << camera
+			<< "' not described in the HAL configuration file";
+		return 0;
+	}
+
+	const CameraProps &cam = it->second;
+	return cam.rotation;
+}
+
+const std::string &CameraHalConfig::cameraModel(const std::string &camera) const
+{
+	static const std::string empty("");
+	const auto &it = cameras_.find(camera);
+	if (it == cameras_.end()) {
+		LOG(HALConfig, Error)
+			<< "Camera '" << camera
+			<< "' not described in the HAL configuration file";
+		return empty;
+	}
+
+	const CameraProps &cam = it->second;
+	return cam.model;
+}
+
+std::string CameraHalConfig::parseValue(yaml_token_t &token)
+{
+	/* Make sure the token type is a value and get its content. */
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_VALUE_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return "";
+	}
+	yaml_token_delete(&token);
+
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_SCALAR_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return "";
+	}
+
+	char *scalar = reinterpret_cast<char *>(token.data.scalar.value);
+	std::string value(scalar, token.data.scalar.length);
+	yaml_token_delete(&token);
+
+	return value;
+}
+
+std::string CameraHalConfig::parseKey(yaml_token_t &token)
+{
+	/* Make sure the token type is a key and get its value. */
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_SCALAR_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return "";
+	}
+
+	char *scalar = reinterpret_cast<char *>(token.data.scalar.value);
+	std::string key(scalar, token.data.scalar.length);
+	yaml_token_delete(&token);
+
+	return key;
+}
+
+int CameraHalConfig::parseCameraProps(yaml_token_t &token,
+				      const std::string &cameraID)
+{
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_VALUE_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_BLOCK_MAPPING_START_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	/*
+	 * Parse the camera properties and store them in a cameraBlock instance.
+	 *
+	 * Add a safety counter to make sure we don't loop indefinitely in case
+	 * the configuration file is malformed.
+	 */
+	unsigned int sentinel = 100;
+	CameraProps cameraBlock{};
+	bool blockEnd = false;
+	do {
+		yaml_parser_scan(&parser_, &token);
+		switch (token.type) {
+		case YAML_KEY_TOKEN: {
+			yaml_token_delete(&token);
+
+			/*
+			 * Parse the camera property key and make sure it is
+			 * valid.
+			 */
+			std::string key = parseKey(token);
+			std::string value = parseValue(token);
+			if (key.empty() || value.empty()) {
+				LOG(HALConfig, Error)
+					<< "Configuration file is not valid";
+				return -EINVAL;
+			}
+
+			if (key == "location") {
+				if (value != "front" && value != "back" &&
+				    value != "external") {
+					LOG(HALConfig, Error)
+						<< "Unknown location: " << value;
+					return -EINVAL;
+				}
+				cameraBlock.location = value;
+			} else if (key == "rotation") {
+				cameraBlock.rotation = strtoul(value.c_str(),
+							       NULL, 10);
+				if (cameraBlock.rotation < 0) {
+					LOG(HALConfig, Error)
+						<< "Unknown rotation: "
+						<< cameraBlock.rotation;
+					return -EINVAL;
+				}
+			} else if (key == "model") {
+				cameraBlock.model = value;
+			} else {
+				LOG(HALConfig, Error)
+					<< "Configuration file is not valid "
+					<< "unknown key: " << key;
+				return -EINVAL;
+			}
+			break;
+		}
+		case YAML_BLOCK_END_TOKEN:
+			yaml_token_delete(&token);
+			blockEnd = true;
+			break;
+		default:
+			yaml_token_delete(&token);
+			break;
+		}
+
+		--sentinel;
+	} while (!blockEnd && sentinel);
+	if (!sentinel) {
+		LOG(HALConfig, Error) << "Configuration file is not valid ";
+		return -EINVAL;
+	}
+
+	cameras_[cameraID] = cameraBlock;
+
+	return 0;
+}
+
+int CameraHalConfig::parseCameras(yaml_token_t &token)
+{
+	int ret;
+
+	/* The 'cameras' key maps a BLOCK_MAPPING_START block. */
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_VALUE_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_BLOCK_MAPPING_START_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	/*
+	 * Parse the camera properties.
+	 *
+	 * Each camera properties block is a list of properties associated
+	 * with the ID (as assembled by CameraSensor::generateId()) of the
+	 * camera they refer to.
+	 *
+	 * cameras:
+	 *   "camera0 id":
+	 *     key: value
+	 *     key: value
+	 *     ...
+	 *
+	 *   "camera1 id":
+	 *     key: value
+	 *     key: value
+	 *     ...
+	 */
+	bool blockEnd = false;
+	do {
+		yaml_parser_scan(&parser_, &token);
+		switch (token.type) {
+		case YAML_KEY_TOKEN: {
+			yaml_token_delete(&token);
+
+			/* Parse the camera ID as key of the property list. */
+			std::string cameraId = parseKey(token);
+			if (cameraId.empty()) {
+				LOG(HALConfig, Error)
+					<< "Configuration file is not valid";
+				return -EINVAL;
+			}
+
+			ret = parseCameraProps(token, cameraId);
+			if (ret) {
+				LOG(HALConfig, Error)
+					<< "Configuration file is not valid";
+				return -EINVAL;
+			}
+			break;
+		}
+		case YAML_BLOCK_END_TOKEN:
+			yaml_token_delete(&token);
+			blockEnd = true;
+			break;
+		default:
+			yaml_token_delete(&token);
+			LOG(HALConfig, Error)
+				<< "Configuration file is not valid";
+			return -EINVAL;
+		}
+	} while (!blockEnd);
+
+	return 0;
+}
+
+int CameraHalConfig::parseEntry(yaml_token_t &token)
+{
+	int ret;
+
+	/*
+	 * Parse each key we find in the file.
+	 *
+	 * Keys like 'model' and 'maker' are device properties and gets
+	 * stored as class members.
+	 *
+	 * The 'cameras' keys maps to a list of (lists) of camera properties.
+	 */
+
+	std::string key = parseKey(token);
+	if (key.empty()) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+
+	if (key == "cameras") {
+		ret = parseCameras(token);
+		if (ret)
+			return ret;
+	} else if (key == "manufacturer") {
+		maker_ = parseValue(token);
+		if (maker_.empty()) {
+			LOG(HALConfig, Error) << "Configuration file is not valid";
+			return -EINVAL;
+		}
+	} else if (key == "model") {
+		model_ = parseValue(token);
+		if (model_.empty()) {
+			LOG(HALConfig, Error) << "Configuration file is not valid";
+			return -EINVAL;
+		}
+	} else {
+		LOG(HALConfig, Error) << "Unknown key " << key;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int CameraHalConfig::parseConfigFile()
+{
+	yaml_token_t token;
+	int ret;
+
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_STREAM_START_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	yaml_parser_scan(&parser_, &token);
+	if (token.type != YAML_BLOCK_MAPPING_START_TOKEN) {
+		LOG(HALConfig, Error) << "Configuration file is not valid";
+		return -EINVAL;
+	}
+	yaml_token_delete(&token);
+
+	/* Parse the file and parse each single key one by one. */
+	do {
+		yaml_parser_scan(&parser_, &token);
+		switch (token.type) {
+		case YAML_KEY_TOKEN:
+			yaml_token_delete(&token);
+			ret = parseEntry(token);
+			break;
+		case YAML_STREAM_END_TOKEN:
+			/* Resources are released after the loop exit. */
+			break;
+		default:
+			yaml_token_delete(&token);
+			break;
+		}
+	} while (token.type != YAML_STREAM_END_TOKEN && ret >= 0);
+	yaml_token_delete(&token);
+
+	return ret;
+}
diff --git a/src/android/camera_hal_config.h b/src/android/camera_hal_config.h
new file mode 100644
index 000000000000..ce77b1ee1582
--- /dev/null
+++ b/src/android/camera_hal_config.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * camera_hal_config.h - Camera HAL configuration file manager
+ */
+#ifndef __ANDROID_CAMERA_HAL_CONFIG_H__
+#define __ANDROID_CAMERA_HAL_CONFIG_H__
+
+#include <map>
+#include <string>
+#include <yaml.h>
+
+class CameraHalConfig
+{
+public:
+	CameraHalConfig();
+	~CameraHalConfig();
+
+	int open();
+
+	const std::string &deviceModel() const { return model_; }
+	const std::string &deviceMaker() const { return maker_; }
+
+	int cameraLocation(const std::string &camera) const;
+	unsigned int cameraRotation(const std::string &camera) const;
+	const std::string &cameraModel(const std::string &camera) const;
+
+private:
+	yaml_parser_t parser_;
+
+	std::string model_;
+	std::string maker_;
+	class CameraProps
+	{
+	public:
+		std::string location;
+		std::string model;
+		unsigned int rotation;
+	};
+	std::map<std::string, CameraProps> cameras_;
+
+	std::string findFilePath(const std::string &filename) const;
+	FILE *openFile(const std::string &filename);
+	std::string parseValue(yaml_token_t &token);
+	std::string parseKey(yaml_token_t &token);
+	int parseCameraProps(yaml_token_t &token, const std::string &cameraID);
+	int parseCameras(yaml_token_t &token);
+	int parseEntry(yaml_token_t &token);
+	int parseConfigFile();
+};
+
+#endif /* __ANDROID_CAMERA_HAL_CONFIG_H__ */
diff --git a/src/android/meson.build b/src/android/meson.build
index 8e7d07d9be3c..c0ede407bc38 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -3,6 +3,7 @@
 android_deps = [
     dependency('libexif', required : get_option('android')),
     dependency('libjpeg', required : get_option('android')),
+    dependency('yaml-0.1', required : get_option('android')),
 ]
 
 android_enabled = true
@@ -41,6 +42,7 @@ android_hal_sources = files([
     'camera3_hal.cpp',
     'camera_hal_manager.cpp',
     'camera_device.cpp',
+    'camera_hal_config.cpp',
     'camera_metadata.cpp',
     'camera_ops.cpp',
     'camera_stream.cpp',
-- 
2.30.0



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