camera/EmulatedCameraFactory.cpp - device/generic/goldfish - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 /*
  * Contains implementation of a class EmulatedCameraFactory that manages cameras
  * available for emulation.
  */

 //#define LOG_NDEBUG 0
 #define LOG_TAG "EmulatedCamera_Factory"

 #include "EmulatedCameraFactory.h"
 #include "EmulatedCameraHotplugThread.h"
 #include "EmulatedFakeCamera.h"
 #include "EmulatedFakeCamera2.h"
 #include "EmulatedFakeCamera3.h"
 #include "EmulatedQemuCamera.h"
 #include "EmulatedQemuCamera3.h"

 #include <log/log.h>
 #include <cutils/properties.h>

 extern camera_module_t HAL_MODULE_INFO_SYM;

 /*
  * A global instance of EmulatedCameraFactory is statically instantiated and
  * initialized when camera emulation HAL is loaded.
  */
 android::EmulatedCameraFactory gEmulatedCameraFactory;

 namespace android {

 EmulatedCameraFactory::EmulatedCameraFactory() :
         mQemuClient(),
         mConstructedOK(false),
         mGBM(&GraphicBufferMapper::get()),
         mCallbacks(nullptr) {

     /*
      * Figure out how many cameras need to be created, so we can allocate the
      * array of emulated cameras before populating it.
      */

     // QEMU Cameras
     std::vector<QemuCameraInfo> qemuCameras;
     if (mQemuClient.connectClient(nullptr) == NO_ERROR) {
         findQemuCameras(&qemuCameras);
     }

     int fakeCameraNum = 0;
     waitForQemuSfFakeCameraPropertyAvailable();
     // Fake Cameras
     if (isFakeCameraEmulationOn(/* backCamera */ true)) {
         fakeCameraNum++;
     }
     if (isFakeCameraEmulationOn(/* backCamera */ false)) {
         fakeCameraNum++;
     }

     /*
      * We have the number of cameras we need to create, now allocate space for
      * them.
      */
     mEmulatedCameras.reserve(qemuCameras.size() + fakeCameraNum);

     createQemuCameras(qemuCameras);

     // Create fake cameras, if enabled.
     if (isFakeCameraEmulationOn(/* backCamera */ true)) {
         createFakeCamera(/* backCamera */ true);
     }
     if (isFakeCameraEmulationOn(/* backCamera */ false)) {
         createFakeCamera(/* backCamera */ false);
     }

     ALOGE("%zu cameras are being emulated. %d of them are fake cameras.",
             mEmulatedCameras.size(), fakeCameraNum);

     // Create hotplug thread.
     {
         std::vector<int> cameraIdVector;
         for (const auto &camera: mEmulatedCameras) {
             cameraIdVector.push_back(camera->getCameraId());
         }
         mHotplugThread = new EmulatedCameraHotplugThread(std::move(cameraIdVector));
         mHotplugThread->run("EmulatedCameraHotplugThread");
     }

     mConstructedOK = true;
 }

 EmulatedCameraFactory::~EmulatedCameraFactory() {
     mEmulatedCameras.clear();

     if (mHotplugThread != nullptr) {
         mHotplugThread->requestExit();
         mHotplugThread->join();
     }
 }

 /******************************************************************************
  * Camera HAL API handlers.
  *
  * Each handler simply verifies existence of an appropriate EmulatedBaseCamera
  * instance, and dispatches the call to that instance.
  *
  *****************************************************************************/

 int EmulatedCameraFactory::cameraDeviceOpen(int cameraId,
                                             hw_device_t **device) {
     ALOGV("%s: id = %d", __FUNCTION__, cameraId);

     *device = nullptr;

     if (!isConstructedOK()) {
         ALOGE("%s: EmulatedCameraFactory has failed to initialize",
                 __FUNCTION__);
         return -EINVAL;
     }

     if (cameraId < 0 || cameraId >= getEmulatedCameraNum()) {
         ALOGE("%s: Camera id %d is out of bounds (%d)",
                 __FUNCTION__, cameraId, getEmulatedCameraNum());
         return -ENODEV;
     }

     return mEmulatedCameras[cameraId]->connectCamera(device);
 }

 int EmulatedCameraFactory::getCameraInfo(int cameraId,
                                          struct camera_info *info) {
     ALOGV("%s: id = %d", __FUNCTION__, cameraId);

     if (!isConstructedOK()) {
         ALOGE("%s: EmulatedCameraFactory has failed to initialize",
                 __FUNCTION__);
         return -EINVAL;
     }

     if (cameraId < 0 || cameraId >= getEmulatedCameraNum()) {
         ALOGE("%s: Camera id %d is out of bounds (%d)",
                 __FUNCTION__, cameraId, getEmulatedCameraNum());
         return -ENODEV;
     }

     return mEmulatedCameras[cameraId]->getCameraInfo(info);
 }

 int EmulatedCameraFactory::setCallbacks(
         const camera_module_callbacks_t *callbacks) {
     ALOGV("%s: callbacks = %p", __FUNCTION__, callbacks);

     mCallbacks = callbacks;

     return OK;
 }

 void EmulatedCameraFactory::getVendorTagOps(vendor_tag_ops_t* ops) {
     ALOGV("%s: ops = %p", __FUNCTION__, ops);
     // No vendor tags defined for emulator yet, so not touching ops.
 }

 /****************************************************************************
  * Camera HAL API callbacks.
  ***************************************************************************/

 int EmulatedCameraFactory::device_open(const hw_module_t *module, const char
         *name, hw_device_t **device) {
     /*
      * Simply verify the parameters, and dispatch the call inside the
      * EmulatedCameraFactory instance.
      */

     if (module != &HAL_MODULE_INFO_SYM.common) {
         ALOGE("%s: Invalid module %p expected %p",
                 __FUNCTION__, module, &HAL_MODULE_INFO_SYM.common);
         return -EINVAL;
     }
     if (name == nullptr) {
         ALOGE("%s: NULL name is not expected here", __FUNCTION__);
         return -EINVAL;
     }

     return gEmulatedCameraFactory.cameraDeviceOpen(atoi(name), device);
 }

 int EmulatedCameraFactory::get_number_of_cameras() {
     return gEmulatedCameraFactory.getEmulatedCameraNum();
 }

 int EmulatedCameraFactory::get_camera_info(int camera_id,
                         struct camera_info *info) {
     return gEmulatedCameraFactory.getCameraInfo(camera_id, info);
 }

 int EmulatedCameraFactory::set_callbacks(
         const camera_module_callbacks_t *callbacks) {
     return gEmulatedCameraFactory.setCallbacks(callbacks);
 }

 void EmulatedCameraFactory::get_vendor_tag_ops(vendor_tag_ops_t *ops) {
     gEmulatedCameraFactory.getVendorTagOps(ops);
 }

 int EmulatedCameraFactory::open_legacy(const struct hw_module_t *module,
         const char *id, uint32_t halVersion, struct hw_device_t **device) {
     // Not supporting legacy open.
     return -ENOSYS;
 }

 /********************************************************************************
  * Internal API
  *******************************************************************************/

 /*
  * Camera information tokens passed in response to the "list" factory query.
  */

 // Device name token.
 static const char *kListNameToken = "name=";
 // Frame dimensions token.
 static const char *kListDimsToken = "framedims=";
 // Facing direction token.
 static const char *kListDirToken = "dir=";


 bool EmulatedCameraFactory::getTokenValue(const char *token,
         const std::string &s, char **value) {
     // Find the start of the token.
     size_t tokenStart = s.find(token);
     if (tokenStart == std::string::npos) {
         return false;
     }

     // Advance to the beginning of the token value.
     size_t valueStart = tokenStart + strlen(token);

     // Find the length of the token value.
     size_t valueLength = s.find(' ', valueStart) - valueStart;

     // Extract the value substring.
     std::string valueStr = s.substr(valueStart, valueLength);

     // Convert to char*.
     *value = new char[valueStr.length() + 1];
     if (*value == nullptr) {
         return false;
     }
     strcpy(*value, valueStr.c_str());

     ALOGV("%s: Parsed value is \"%s\"", __FUNCTION__, *value);

     return true;
 }

 void EmulatedCameraFactory::findQemuCameras(
         std::vector<QemuCameraInfo> *qemuCameras) {
     // Obtain camera list.
     char *cameraList = nullptr;
     status_t res = mQemuClient.listCameras(&cameraList);

     /*
      * Empty list, or list containing just an EOL means that there were no
      * connected cameras found.
      */
     if (res != NO_ERROR || cameraList == nullptr || *cameraList == '\0' ||
         *cameraList == '\n') {
         if (cameraList != nullptr) {
             free(cameraList);
         }
         return;
     }

     /*
      * Calculate number of connected cameras. Number of EOLs in the camera list
      * is the number of the connected cameras.
      */

     std::string cameraListStr(cameraList);
     free(cameraList);

     size_t lineBegin = 0;
     size_t lineEnd = cameraListStr.find('\n');
     while (lineEnd != std::string::npos) {
         std::string cameraStr = cameraListStr.substr(lineBegin, lineEnd - lineBegin);
         // Parse the 'name', 'framedims', and 'dir' tokens.
         char *name, *frameDims, *dir;
         if (getTokenValue(kListNameToken, cameraStr, &name) &&
                 getTokenValue(kListDimsToken, cameraStr, &frameDims) &&
                 getTokenValue(kListDirToken, cameraStr, &dir)) {
             // Push the camera info if it was all successfully parsed.
             qemuCameras->push_back(QemuCameraInfo{
                 .name = name,
                 .frameDims = frameDims,
                 .dir = dir,
             });
         } else {
             ALOGW("%s: Bad camera information: %s", __FUNCTION__,
                     cameraStr.c_str());
         }
         // Skip over the newline for the beginning of the next line.
         lineBegin = lineEnd + 1;
         lineEnd = cameraListStr.find('\n', lineBegin);
     }
 }

 std::unique_ptr<EmulatedBaseCamera>
 EmulatedCameraFactory::createQemuCameraImpl(int halVersion,
                                             const QemuCameraInfo& camInfo,
                                             int cameraId,
                                             struct hw_module_t* module) {
     status_t res;

     switch (halVersion) {
     case 1: {
             auto camera = std::make_unique<EmulatedQemuCamera>(cameraId, module, mGBM);
             res = camera->Initialize(camInfo.name, camInfo.frameDims, camInfo.dir);
             if (res == NO_ERROR) {
                 return camera;
             }
         }
         break;

     case 3: {
             auto camera = std::make_unique<EmulatedQemuCamera3>(cameraId, module, mGBM);
             res = camera->Initialize(camInfo.name, camInfo.frameDims, camInfo.dir);
             if (res == NO_ERROR) {
                 return camera;
             }
         }
         break;

     default:
         ALOGE("%s: QEMU support for camera hal version %d is not "
               "implemented", __func__, halVersion);
         break;
     }

     return nullptr;
 }

 void EmulatedCameraFactory::createQemuCameras(
         const std::vector<QemuCameraInfo> &qemuCameras) {
     /*
      * Iterate the list, creating, and initializing emulated QEMU cameras for each
      * entry in the list.
      */

     /*
      * We use this index only for determining which direction the webcam should
      * face. Otherwise, mEmulatedCameraNum represents the camera ID and the
      * index into mEmulatedCameras.
      */
     int qemuIndex = 0;
     for (const auto &cameraInfo : qemuCameras) {
         /*
          * Here, we're assuming the first webcam is intended to be the back
          * camera and any other webcams are front cameras.
          */
         const bool isBackcamera = (qemuIndex == 0);
         const int halVersion = getCameraHalVersion(isBackcamera);

         std::unique_ptr<EmulatedBaseCamera> camera =
             createQemuCameraImpl(halVersion,
                                  cameraInfo,
                                  mEmulatedCameras.size(),
                                  &HAL_MODULE_INFO_SYM.common);
         if (camera) {
             mEmulatedCameras.push_back(std::move(camera));
         }

         qemuIndex++;
     }
 }

 std::unique_ptr<EmulatedBaseCamera>
 EmulatedCameraFactory::createFakeCameraImpl(bool backCamera,
                                             int halVersion,
                                             int cameraId,
                                             struct hw_module_t* module) {
     switch (halVersion) {
     case 1:
         return std::make_unique<EmulatedFakeCamera>(cameraId, backCamera, module, mGBM);

     case 2:
         return std::make_unique<EmulatedFakeCamera2>(cameraId, backCamera, module, mGBM);

     case 3: {
             static const char key[] = "ro.kernel.qemu.camera.fake.rotating";
             char prop[PROPERTY_VALUE_MAX];

             if (property_get(key, prop, nullptr) > 0) {
                 return std::make_unique<EmulatedFakeCamera>(cameraId, backCamera, module, mGBM);
             } else {
                 return std::make_unique<EmulatedFakeCamera3>(cameraId, backCamera, module, mGBM);
             }
         }

     default:
         ALOGE("%s: Unknown %s camera hal version requested: %d",
               __func__, backCamera ? "back" : "front", halVersion);
         return nullptr;
     }
 }

 void EmulatedCameraFactory::createFakeCamera(bool backCamera) {
     const int halVersion = getCameraHalVersion(backCamera);

     std::unique_ptr<EmulatedBaseCamera> camera = createFakeCameraImpl(
         backCamera, halVersion, mEmulatedCameras.size(),
         &HAL_MODULE_INFO_SYM.common);

     status_t res = camera->Initialize();
     if (res == NO_ERROR) {
         mEmulatedCameras.push_back(std::move(camera));
     } else {
         ALOGE("%s: Unable to initialize %s camera %zu: %s (%d)",
               __func__, backCamera ? "back" : "front",
               mEmulatedCameras.size(), strerror(-res), res);
     }
 }

 void EmulatedCameraFactory::waitForQemuSfFakeCameraPropertyAvailable() {
     /*
      * Camera service may start running before qemu-props sets
      * qemu.sf.fake_camera to any of the follwing four values:
      * "none,front,back,both"; so we need to wait.
      *
      * android/camera/camera-service.c
      * bug: 30768229
      */
     int numAttempts = 100;
     char prop[PROPERTY_VALUE_MAX];
     bool timeout = true;
     for (int i = 0; i < numAttempts; ++i) {
         if (property_get("qemu.sf.fake_camera", prop, nullptr) != 0 ) {
             timeout = false;
             break;
         }
         usleep(5000);
     }
     if (timeout) {
         ALOGE("timeout (%dms) waiting for property qemu.sf.fake_camera to be set\n", 5 * numAttempts);
     }
 }

 bool EmulatedCameraFactory::isFakeCameraEmulationOn(bool backCamera) {
     // Always return false, because another HAL (Google Camera HAL)
     // will create the fake cameras
     if (!property_get_bool("ro.kernel.qemu.legacy_fake_camera", false)) {
         return false;
     }
     char prop[PROPERTY_VALUE_MAX];
     if ((property_get("qemu.sf.fake_camera", prop, nullptr) > 0) &&
         (!strcmp(prop, "both") ||
          !strcmp(prop, backCamera ? "back" : "front"))) {
         return true;
     } else {
         return false;
     }
 }

 int EmulatedCameraFactory::getCameraHalVersion(bool backCamera) {
     /*
      * Defined by 'qemu.sf.front_camera_hal_version' and
      * 'qemu.sf.back_camera_hal_version' boot properties. If the property
      * doesn't exist, it is assumed we are working with HAL v1.
      */
     char prop[PROPERTY_VALUE_MAX];
     const char *propQuery = backCamera ?
             "qemu.sf.back_camera_hal" :
             "qemu.sf.front_camera_hal";
     if (property_get(propQuery, prop, nullptr) > 0) {
         char *propEnd = prop;
         int val = strtol(prop, &propEnd, 10);
         if (*propEnd == '\0') {
             return val;
         }
         // Badly formatted property. It should just be a number.
         ALOGE("qemu.sf.back_camera_hal is not a number: %s", prop);
     }
     return 3;
 }

 void EmulatedCameraFactory::onStatusChanged(int cameraId, int newStatus) {

     EmulatedBaseCamera *cam = mEmulatedCameras[cameraId].get();
     if (!cam) {
         ALOGE("%s: Invalid camera ID %d", __FUNCTION__, cameraId);
         return;
     }

     /*
      * (Order is important)
      * Send the callback first to framework, THEN close the camera.
      */

     if (newStatus == cam->getHotplugStatus()) {
         ALOGW("%s: Ignoring transition to the same status", __FUNCTION__);
         return;
     }

     const camera_module_callbacks_t* cb = mCallbacks;
     if (cb != nullptr && cb->camera_device_status_change != nullptr) {
         cb->camera_device_status_change(cb, cameraId, newStatus);
     }

     if (newStatus == CAMERA_DEVICE_STATUS_NOT_PRESENT) {
         cam->unplugCamera();
     } else if (newStatus == CAMERA_DEVICE_STATUS_PRESENT) {
         cam->plugCamera();
     }
 }

 /********************************************************************************
  * Initializer for the static member structure.
  *******************************************************************************/

 // Entry point for camera HAL API.
 struct hw_module_methods_t EmulatedCameraFactory::mCameraModuleMethods = {
     .open = EmulatedCameraFactory::device_open
 };

 }; // end of namespace android
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/*
	* Contains implementation of a class EmulatedCameraFactory that manages cameras
	* available for emulation.
	*/

	//#define LOG_NDEBUG 0
	#define LOG_TAG "EmulatedCamera_Factory"

	#include "EmulatedCameraFactory.h"
	#include "EmulatedCameraHotplugThread.h"
	#include "EmulatedFakeCamera.h"
	#include "EmulatedFakeCamera2.h"
	#include "EmulatedFakeCamera3.h"
	#include "EmulatedQemuCamera.h"
	#include "EmulatedQemuCamera3.h"

	#include <log/log.h>
	#include <cutils/properties.h>

	extern camera_module_t HAL_MODULE_INFO_SYM;

	/*
	* A global instance of EmulatedCameraFactory is statically instantiated and
	* initialized when camera emulation HAL is loaded.
	*/
	android::EmulatedCameraFactory gEmulatedCameraFactory;

	namespace android {

	EmulatedCameraFactory::EmulatedCameraFactory() :
	mQemuClient(),
	mConstructedOK(false),
	mGBM(&GraphicBufferMapper::get()),
	mCallbacks(nullptr) {

	/*
	* Figure out how many cameras need to be created, so we can allocate the
	* array of emulated cameras before populating it.
	*/

	// QEMU Cameras
	std::vector<QemuCameraInfo> qemuCameras;
	if (mQemuClient.connectClient(nullptr) == NO_ERROR) {
	findQemuCameras(&qemuCameras);
	}

	int fakeCameraNum = 0;
	waitForQemuSfFakeCameraPropertyAvailable();
	// Fake Cameras
	if (isFakeCameraEmulationOn(/* backCamera */ true)) {
	fakeCameraNum++;
	}
	if (isFakeCameraEmulationOn(/* backCamera */ false)) {
	fakeCameraNum++;
	}

	/*
	* We have the number of cameras we need to create, now allocate space for
	* them.
	*/
	mEmulatedCameras.reserve(qemuCameras.size() + fakeCameraNum);

	createQemuCameras(qemuCameras);

	// Create fake cameras, if enabled.
	if (isFakeCameraEmulationOn(/* backCamera */ true)) {
	createFakeCamera(/* backCamera */ true);
	}
	if (isFakeCameraEmulationOn(/* backCamera */ false)) {
	createFakeCamera(/* backCamera */ false);
	}

	ALOGE("%zu cameras are being emulated. %d of them are fake cameras.",
	mEmulatedCameras.size(), fakeCameraNum);

	// Create hotplug thread.
	{
	std::vector<int> cameraIdVector;
	for (const auto &camera: mEmulatedCameras) {
	cameraIdVector.push_back(camera->getCameraId());
	}
	mHotplugThread = new EmulatedCameraHotplugThread(std::move(cameraIdVector));
	mHotplugThread->run("EmulatedCameraHotplugThread");
	}

	mConstructedOK = true;
	}

	EmulatedCameraFactory::~EmulatedCameraFactory() {
	mEmulatedCameras.clear();

	if (mHotplugThread != nullptr) {
	mHotplugThread->requestExit();
	mHotplugThread->join();
	}
	}

	/******************************************************************************
	* Camera HAL API handlers.
	*
	* Each handler simply verifies existence of an appropriate EmulatedBaseCamera
	* instance, and dispatches the call to that instance.
	*
	*****************************************************************************/

	int EmulatedCameraFactory::cameraDeviceOpen(int cameraId,
	hw_device_t **device) {
	ALOGV("%s: id = %d", __FUNCTION__, cameraId);

	*device = nullptr;

	if (!isConstructedOK()) {
	ALOGE("%s: EmulatedCameraFactory has failed to initialize",
	__FUNCTION__);
	return -EINVAL;
	}

	if (cameraId < 0 \|\| cameraId >= getEmulatedCameraNum()) {
	ALOGE("%s: Camera id %d is out of bounds (%d)",
	__FUNCTION__, cameraId, getEmulatedCameraNum());
	return -ENODEV;
	}

	return mEmulatedCameras[cameraId]->connectCamera(device);
	}

	int EmulatedCameraFactory::getCameraInfo(int cameraId,
	struct camera_info *info) {
	ALOGV("%s: id = %d", __FUNCTION__, cameraId);

	if (!isConstructedOK()) {
	ALOGE("%s: EmulatedCameraFactory has failed to initialize",
	__FUNCTION__);
	return -EINVAL;
	}

	if (cameraId < 0 \|\| cameraId >= getEmulatedCameraNum()) {
	ALOGE("%s: Camera id %d is out of bounds (%d)",
	__FUNCTION__, cameraId, getEmulatedCameraNum());
	return -ENODEV;
	}

	return mEmulatedCameras[cameraId]->getCameraInfo(info);
	}

	int EmulatedCameraFactory::setCallbacks(
	const camera_module_callbacks_t *callbacks) {
	ALOGV("%s: callbacks = %p", __FUNCTION__, callbacks);

	mCallbacks = callbacks;

	return OK;
	}

	void EmulatedCameraFactory::getVendorTagOps(vendor_tag_ops_t* ops) {
	ALOGV("%s: ops = %p", __FUNCTION__, ops);
	// No vendor tags defined for emulator yet, so not touching ops.
	}

	/****************************************************************************
	* Camera HAL API callbacks.
	***************************************************************************/

	int EmulatedCameraFactory::device_open(const hw_module_t *module, const char
	name, hw_device_t *device) {
	/*
	* Simply verify the parameters, and dispatch the call inside the
	* EmulatedCameraFactory instance.
	*/

	if (module != &HAL_MODULE_INFO_SYM.common) {
	ALOGE("%s: Invalid module %p expected %p",
	__FUNCTION__, module, &HAL_MODULE_INFO_SYM.common);
	return -EINVAL;
	}
	if (name == nullptr) {
	ALOGE("%s: NULL name is not expected here", __FUNCTION__);
	return -EINVAL;
	}

	return gEmulatedCameraFactory.cameraDeviceOpen(atoi(name), device);
	}

	int EmulatedCameraFactory::get_number_of_cameras() {
	return gEmulatedCameraFactory.getEmulatedCameraNum();
	}

	int EmulatedCameraFactory::get_camera_info(int camera_id,
	struct camera_info *info) {
	return gEmulatedCameraFactory.getCameraInfo(camera_id, info);
	}

	int EmulatedCameraFactory::set_callbacks(
	const camera_module_callbacks_t *callbacks) {
	return gEmulatedCameraFactory.setCallbacks(callbacks);
	}

	void EmulatedCameraFactory::get_vendor_tag_ops(vendor_tag_ops_t *ops) {
	gEmulatedCameraFactory.getVendorTagOps(ops);
	}

	int EmulatedCameraFactory::open_legacy(const struct hw_module_t *module,
	const char id, uint32_t halVersion, struct hw_device_t *device) {
	// Not supporting legacy open.
	return -ENOSYS;
	}

	/********************************************************************************
	* Internal API
	*******************************************************************************/

	/*
	* Camera information tokens passed in response to the "list" factory query.
	*/

	// Device name token.
	static const char *kListNameToken = "name=";
	// Frame dimensions token.
	static const char *kListDimsToken = "framedims=";
	// Facing direction token.
	static const char *kListDirToken = "dir=";


	bool EmulatedCameraFactory::getTokenValue(const char *token,
	const std::string &s, char **value) {
	// Find the start of the token.
	size_t tokenStart = s.find(token);
	if (tokenStart == std::string::npos) {
	return false;
	}

	// Advance to the beginning of the token value.
	size_t valueStart = tokenStart + strlen(token);

	// Find the length of the token value.
	size_t valueLength = s.find(' ', valueStart) - valueStart;

	// Extract the value substring.
	std::string valueStr = s.substr(valueStart, valueLength);

	// Convert to char*.
	*value = new char[valueStr.length() + 1];
	if (*value == nullptr) {
	return false;
	}
	strcpy(*value, valueStr.c_str());

	ALOGV("%s: Parsed value is \"%s\"", __FUNCTION__, *value);

	return true;
	}

	void EmulatedCameraFactory::findQemuCameras(
	std::vector<QemuCameraInfo> *qemuCameras) {
	// Obtain camera list.
	char *cameraList = nullptr;
	status_t res = mQemuClient.listCameras(&cameraList);

	/*
	* Empty list, or list containing just an EOL means that there were no
	* connected cameras found.
	*/
	if (res != NO_ERROR \|\| cameraList == nullptr \|\| *cameraList == '\0' \|\|
	*cameraList == '\n') {
	if (cameraList != nullptr) {
	free(cameraList);
	}
	return;
	}

	/*
	* Calculate number of connected cameras. Number of EOLs in the camera list
	* is the number of the connected cameras.
	*/

	std::string cameraListStr(cameraList);
	free(cameraList);

	size_t lineBegin = 0;
	size_t lineEnd = cameraListStr.find('\n');
	while (lineEnd != std::string::npos) {
	std::string cameraStr = cameraListStr.substr(lineBegin, lineEnd - lineBegin);
	// Parse the 'name', 'framedims', and 'dir' tokens.
	char name, frameDims, *dir;
	if (getTokenValue(kListNameToken, cameraStr, &name) &&
	getTokenValue(kListDimsToken, cameraStr, &frameDims) &&
	getTokenValue(kListDirToken, cameraStr, &dir)) {
	// Push the camera info if it was all successfully parsed.
	qemuCameras->push_back(QemuCameraInfo{
	.name = name,
	.frameDims = frameDims,
	.dir = dir,
	});
	} else {
	ALOGW("%s: Bad camera information: %s", __FUNCTION__,
	cameraStr.c_str());
	}
	// Skip over the newline for the beginning of the next line.
	lineBegin = lineEnd + 1;
	lineEnd = cameraListStr.find('\n', lineBegin);
	}
	}

	std::unique_ptr<EmulatedBaseCamera>
	EmulatedCameraFactory::createQemuCameraImpl(int halVersion,
	const QemuCameraInfo& camInfo,
	int cameraId,
	struct hw_module_t* module) {
	status_t res;

	switch (halVersion) {
	case 1: {
	auto camera = std::make_unique<EmulatedQemuCamera>(cameraId, module, mGBM);
	res = camera->Initialize(camInfo.name, camInfo.frameDims, camInfo.dir);
	if (res == NO_ERROR) {
	return camera;
	}
	}
	break;

	case 3: {
	auto camera = std::make_unique<EmulatedQemuCamera3>(cameraId, module, mGBM);
	res = camera->Initialize(camInfo.name, camInfo.frameDims, camInfo.dir);
	if (res == NO_ERROR) {
	return camera;
	}
	}
	break;

	default:
	ALOGE("%s: QEMU support for camera hal version %d is not "
	"implemented", __func__, halVersion);
	break;
	}

	return nullptr;
	}

	void EmulatedCameraFactory::createQemuCameras(
	const std::vector<QemuCameraInfo> &qemuCameras) {
	/*
	* Iterate the list, creating, and initializing emulated QEMU cameras for each
	* entry in the list.
	*/

	/*
	* We use this index only for determining which direction the webcam should
	* face. Otherwise, mEmulatedCameraNum represents the camera ID and the
	* index into mEmulatedCameras.
	*/
	int qemuIndex = 0;
	for (const auto &cameraInfo : qemuCameras) {
	/*
	* Here, we're assuming the first webcam is intended to be the back
	* camera and any other webcams are front cameras.
	*/
	const bool isBackcamera = (qemuIndex == 0);
	const int halVersion = getCameraHalVersion(isBackcamera);

	std::unique_ptr<EmulatedBaseCamera> camera =
	createQemuCameraImpl(halVersion,
	cameraInfo,
	mEmulatedCameras.size(),
	&HAL_MODULE_INFO_SYM.common);
	if (camera) {
	mEmulatedCameras.push_back(std::move(camera));
	}

	qemuIndex++;
	}
	}

	std::unique_ptr<EmulatedBaseCamera>
	EmulatedCameraFactory::createFakeCameraImpl(bool backCamera,
	int halVersion,
	int cameraId,
	struct hw_module_t* module) {
	switch (halVersion) {
	case 1:
	return std::make_unique<EmulatedFakeCamera>(cameraId, backCamera, module, mGBM);

	case 2:
	return std::make_unique<EmulatedFakeCamera2>(cameraId, backCamera, module, mGBM);

	case 3: {
	static const char key[] = "ro.kernel.qemu.camera.fake.rotating";
	char prop[PROPERTY_VALUE_MAX];

	if (property_get(key, prop, nullptr) > 0) {
	return std::make_unique<EmulatedFakeCamera>(cameraId, backCamera, module, mGBM);
	} else {
	return std::make_unique<EmulatedFakeCamera3>(cameraId, backCamera, module, mGBM);
	}
	}

	default:
	ALOGE("%s: Unknown %s camera hal version requested: %d",
	__func__, backCamera ? "back" : "front", halVersion);
	return nullptr;
	}
	}

	void EmulatedCameraFactory::createFakeCamera(bool backCamera) {
	const int halVersion = getCameraHalVersion(backCamera);

	std::unique_ptr<EmulatedBaseCamera> camera = createFakeCameraImpl(
	backCamera, halVersion, mEmulatedCameras.size(),
	&HAL_MODULE_INFO_SYM.common);

	status_t res = camera->Initialize();
	if (res == NO_ERROR) {
	mEmulatedCameras.push_back(std::move(camera));
	} else {
	ALOGE("%s: Unable to initialize %s camera %zu: %s (%d)",
	__func__, backCamera ? "back" : "front",
	mEmulatedCameras.size(), strerror(-res), res);
	}
	}

	void EmulatedCameraFactory::waitForQemuSfFakeCameraPropertyAvailable() {
	/*
	* Camera service may start running before qemu-props sets
	* qemu.sf.fake_camera to any of the follwing four values:
	* "none,front,back,both"; so we need to wait.
	*
	* android/camera/camera-service.c
	* bug: 30768229
	*/
	int numAttempts = 100;
	char prop[PROPERTY_VALUE_MAX];
	bool timeout = true;
	for (int i = 0; i < numAttempts; ++i) {
	if (property_get("qemu.sf.fake_camera", prop, nullptr) != 0 ) {
	timeout = false;
	break;
	}
	usleep(5000);
	}
	if (timeout) {
	ALOGE("timeout (%dms) waiting for property qemu.sf.fake_camera to be set\n", 5 * numAttempts);
	}
	}

	bool EmulatedCameraFactory::isFakeCameraEmulationOn(bool backCamera) {
	// Always return false, because another HAL (Google Camera HAL)
	// will create the fake cameras
	if (!property_get_bool("ro.kernel.qemu.legacy_fake_camera", false)) {
	return false;
	}
	char prop[PROPERTY_VALUE_MAX];
	if ((property_get("qemu.sf.fake_camera", prop, nullptr) > 0) &&
	(!strcmp(prop, "both") \|\|
	!strcmp(prop, backCamera ? "back" : "front"))) {
	return true;
	} else {
	return false;
	}
	}

	int EmulatedCameraFactory::getCameraHalVersion(bool backCamera) {
	/*
	* Defined by 'qemu.sf.front_camera_hal_version' and
	* 'qemu.sf.back_camera_hal_version' boot properties. If the property
	* doesn't exist, it is assumed we are working with HAL v1.
	*/
	char prop[PROPERTY_VALUE_MAX];
	const char *propQuery = backCamera ?
	"qemu.sf.back_camera_hal" :
	"qemu.sf.front_camera_hal";
	if (property_get(propQuery, prop, nullptr) > 0) {
	char *propEnd = prop;
	int val = strtol(prop, &propEnd, 10);
	if (*propEnd == '\0') {
	return val;
	}
	// Badly formatted property. It should just be a number.
	ALOGE("qemu.sf.back_camera_hal is not a number: %s", prop);
	}
	return 3;
	}

	void EmulatedCameraFactory::onStatusChanged(int cameraId, int newStatus) {

	EmulatedBaseCamera *cam = mEmulatedCameras[cameraId].get();
	if (!cam) {
	ALOGE("%s: Invalid camera ID %d", __FUNCTION__, cameraId);
	return;
	}

	/*
	* (Order is important)
	* Send the callback first to framework, THEN close the camera.
	*/

	if (newStatus == cam->getHotplugStatus()) {
	ALOGW("%s: Ignoring transition to the same status", __FUNCTION__);
	return;
	}

	const camera_module_callbacks_t* cb = mCallbacks;
	if (cb != nullptr && cb->camera_device_status_change != nullptr) {
	cb->camera_device_status_change(cb, cameraId, newStatus);
	}

	if (newStatus == CAMERA_DEVICE_STATUS_NOT_PRESENT) {
	cam->unplugCamera();
	} else if (newStatus == CAMERA_DEVICE_STATUS_PRESENT) {
	cam->plugCamera();
	}
	}

	/********************************************************************************
	* Initializer for the static member structure.
	*******************************************************************************/

	// Entry point for camera HAL API.
	struct hw_module_methods_t EmulatedCameraFactory::mCameraModuleMethods = {
	.open = EmulatedCameraFactory::device_open
	};

	}; // end of namespace android