1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /** 18 * @addtogroup Camera 19 * @{ 20 */ 21 22 /** 23 * @file NdkCameraManager.h 24 */ 25 26 /* 27 * This file defines an NDK API. 28 * Do not remove methods. 29 * Do not change method signatures. 30 * Do not change the value of constants. 31 * Do not change the size of any of the classes defined in here. 32 * Do not reference types that are not part of the NDK. 33 * Do not #include files that aren't part of the NDK. 34 */ 35 36 #ifndef _NDK_CAMERA_MANAGER_H 37 #define _NDK_CAMERA_MANAGER_H 38 39 #include <sys/cdefs.h> 40 41 #include "NdkCameraError.h" 42 #include "NdkCameraMetadata.h" 43 #include "NdkCameraDevice.h" 44 45 __BEGIN_DECLS 46 47 #if __ANDROID_API__ >= 24 48 49 /** 50 * ACameraManager is opaque type that provides access to camera service. 51 * 52 * A pointer can be obtained using {@link ACameraManager_create} method. 53 */ 54 typedef struct ACameraManager ACameraManager; 55 56 /** 57 * Create ACameraManager instance. 58 * 59 * <p>The ACameraManager is responsible for 60 * detecting, characterizing, and connecting to {@link ACameraDevice}s.</p> 61 * 62 * <p>The caller must call {@link ACameraManager_delete} to free the resources once it is done 63 * using the ACameraManager instance.</p> 64 * 65 * @return a {@link ACameraManager} instance. 66 * 67 */ 68 ACameraManager* ACameraManager_create(); 69 70 /** 71 * <p>Delete the {@link ACameraManager} instance and free its resources. </p> 72 * 73 * @param manager the {@link ACameraManager} instance to be deleted. 74 */ 75 void ACameraManager_delete(ACameraManager* manager); 76 77 /// Struct to hold list of camera devices 78 typedef struct ACameraIdList { 79 int numCameras; ///< Number of connected camera devices 80 const char** cameraIds; ///< list of identifier of connected camera devices 81 } ACameraIdList; 82 83 /** 84 * Create a list of currently connected camera devices, including 85 * cameras that may be in use by other camera API clients. 86 * 87 * <p>Non-removable cameras use integers starting at 0 for their 88 * identifiers, while removable cameras have a unique identifier for each 89 * individual device, even if they are the same model.</p> 90 * 91 * <p>ACameraManager_getCameraIdList will allocate and return an {@link ACameraIdList}. 92 * The caller must call {@link ACameraManager_deleteCameraIdList} to free the memory</p> 93 * 94 * @param manager the {@link ACameraManager} of interest 95 * @param cameraIdList the output {@link ACameraIdList} will be filled in here if the method call 96 * succeeds. 97 * 98 * @return <ul> 99 * <li>{@link ACAMERA_OK} if the method call succeeds.</li> 100 * <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager or cameraIdList is NULL.</li> 101 * <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li> 102 * <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li></ul> 103 */ 104 camera_status_t ACameraManager_getCameraIdList(ACameraManager* manager, 105 /*out*/ACameraIdList** cameraIdList); 106 107 /** 108 * Delete a list of camera devices allocated via {@link ACameraManager_getCameraIdList}. 109 * 110 * @param cameraIdList the {@link ACameraIdList} to be deleted. 111 */ 112 void ACameraManager_deleteCameraIdList(ACameraIdList* cameraIdList); 113 114 /** 115 * Definition of camera availability callbacks. 116 * 117 * @param context The optional application context provided by user in 118 * {@link ACameraManager_AvailabilityCallbacks}. 119 * @param cameraId The ID of the camera device whose availability is changing. The memory of this 120 * argument is owned by camera framework and will become invalid immediately after 121 * this callback returns. 122 */ 123 typedef void (*ACameraManager_AvailabilityCallback)(void* context, const char* cameraId); 124 125 /** 126 * A listener for camera devices becoming available or unavailable to open. 127 * 128 * <p>Cameras become available when they are no longer in use, or when a new 129 * removable camera is connected. They become unavailable when some 130 * application or service starts using a camera, or when a removable camera 131 * is disconnected.</p> 132 * 133 * @see ACameraManager_registerAvailabilityCallback 134 */ 135 typedef struct ACameraManager_AvailabilityListener { 136 /// Optional application context. 137 void* context; 138 /// Called when a camera becomes available 139 ACameraManager_AvailabilityCallback onCameraAvailable; 140 /// Called when a camera becomes unavailable 141 ACameraManager_AvailabilityCallback onCameraUnavailable; 142 } ACameraManager_AvailabilityCallbacks; 143 144 /** 145 * Register camera availability callbacks. 146 * 147 * <p>onCameraUnavailable will be called whenever a camera device is opened by any camera API client. 148 * Other camera API clients may still be able to open such a camera device, evicting the existing 149 * client if they have higher priority than the existing client of a camera device. 150 * See {@link ACameraManager_openCamera} for more details.</p> 151 * 152 * <p>The callbacks will be called on a dedicated thread shared among all ACameraManager 153 * instances.</p> 154 * 155 * <p>Since this callback will be registered with the camera service, remember to unregister it 156 * once it is no longer needed; otherwise the callback will continue to receive events 157 * indefinitely and it may prevent other resources from being released. Specifically, the 158 * callbacks will be invoked independently of the general activity lifecycle and independently 159 * of the state of individual ACameraManager instances.</p> 160 * 161 * @param manager the {@link ACameraManager} of interest. 162 * @param callback the {@link ACameraManager_AvailabilityCallbacks} to be registered. 163 * 164 * @return <ul> 165 * <li>{@link ACAMERA_OK} if the method call succeeds.</li> 166 * <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager or callback is NULL, or 167 * {ACameraManager_AvailabilityCallbacks#onCameraAvailable} or 168 * {ACameraManager_AvailabilityCallbacks#onCameraUnavailable} is NULL.</li></ul> 169 */ 170 camera_status_t ACameraManager_registerAvailabilityCallback( 171 ACameraManager* manager, const ACameraManager_AvailabilityCallbacks* callback); 172 173 /** 174 * Unregister camera availability callbacks. 175 * 176 * <p>Removing a callback that isn't registered has no effect.</p> 177 * 178 * @param manager the {@link ACameraManager} of interest. 179 * @param callback the {@link ACameraManager_AvailabilityCallbacks} to be unregistered. 180 * 181 * @return <ul> 182 * <li>{@link ACAMERA_OK} if the method call succeeds.</li> 183 * <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if callback, 184 * {ACameraManager_AvailabilityCallbacks#onCameraAvailable} or 185 * {ACameraManager_AvailabilityCallbacks#onCameraUnavailable} is NULL.</li></ul> 186 */ 187 camera_status_t ACameraManager_unregisterAvailabilityCallback( 188 ACameraManager* manager, const ACameraManager_AvailabilityCallbacks* callback); 189 190 /** 191 * Query the capabilities of a camera device. These capabilities are 192 * immutable for a given camera. 193 * 194 * <p>See {@link ACameraMetadata} document and {@link NdkCameraMetadataTags.h} for more details.</p> 195 * 196 * <p>The caller must call {@link ACameraMetadata_free} to free the memory of the output 197 * characteristics.</p> 198 * 199 * @param manager the {@link ACameraManager} of interest. 200 * @param cameraId the ID string of the camera device of interest. 201 * @param characteristics the output {@link ACameraMetadata} will be filled here if the method call 202 * succeeeds. 203 * 204 * @return <ul> 205 * <li>{@link ACAMERA_OK} if the method call succeeds.</li> 206 * <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager, cameraId, or characteristics 207 * is NULL, or cameraId does not match any camera devices connected.</li> 208 * <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li> 209 * <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li> 210 * <li>{@link ACAMERA_ERROR_UNKNOWN} if the method fails for some other reasons.</li></ul> 211 */ 212 camera_status_t ACameraManager_getCameraCharacteristics( 213 ACameraManager* manager, const char* cameraId, 214 /*out*/ACameraMetadata** characteristics); 215 216 /** 217 * Open a connection to a camera with the given ID. The opened camera device will be 218 * returned in the `device` parameter. 219 * 220 * <p>Use {@link ACameraManager_getCameraIdList} to get the list of available camera 221 * devices. Note that even if an id is listed, open may fail if the device 222 * is disconnected between the calls to {@link ACameraManager_getCameraIdList} and 223 * {@link ACameraManager_openCamera}, or if a higher-priority camera API client begins using the 224 * camera device.</p> 225 * 226 * <p>Devices for which the 227 * {@link ACameraManager_AvailabilityCallbacks#onCameraUnavailable} callback has been called due to 228 * the device being in use by a lower-priority, background camera API client can still potentially 229 * be opened by calling this method when the calling camera API client has a higher priority 230 * than the current camera API client using this device. In general, if the top, foreground 231 * activity is running within your application process, your process will be given the highest 232 * priority when accessing the camera, and this method will succeed even if the camera device is 233 * in use by another camera API client. Any lower-priority application that loses control of the 234 * camera in this way will receive an 235 * {@link ACameraDevice_StateCallbacks#onDisconnected} callback.</p> 236 * 237 * <p>Once the camera is successfully opened,the ACameraDevice can then be set up 238 * for operation by calling {@link ACameraDevice_createCaptureSession} and 239 * {@link ACameraDevice_createCaptureRequest}.</p> 240 * 241 * <p>If the camera becomes disconnected after this function call returns, 242 * {@link ACameraDevice_StateCallbacks#onDisconnected} with a 243 * ACameraDevice in the disconnected state will be called.</p> 244 * 245 * <p>If the camera runs into error after this function call returns, 246 * {@link ACameraDevice_StateCallbacks#onError} with a 247 * ACameraDevice in the error state will be called.</p> 248 * 249 * @param manager the {@link ACameraManager} of interest. 250 * @param cameraId the ID string of the camera device to be opened. 251 * @param callback the {@link ACameraDevice_StateCallbacks} associated with the opened camera device. 252 * @param device the opened {@link ACameraDevice} will be filled here if the method call succeeds. 253 * 254 * @return <ul> 255 * <li>{@link ACAMERA_OK} if the method call succeeds.</li> 256 * <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager, cameraId, callback, or device 257 * is NULL, or cameraId does not match any camera devices connected.</li> 258 * <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li> 259 * <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li> 260 * <li>{@link ACAMERA_ERROR_CAMERA_IN_USE} if camera device is being used by a higher 261 * priority camera API client.</li> 262 * <li>{@link ACAMERA_ERROR_MAX_CAMERA_IN_USE} if the system-wide limit for number of open 263 * cameras or camera resources has been reached, and more camera devices cannot be 264 * opened until previous instances are closed.</li> 265 * <li>{@link ACAMERA_ERROR_CAMERA_DISABLED} if the camera is disabled due to a device 266 * policy, and cannot be opened.</li> 267 * <li>{@link ACAMERA_ERROR_PERMISSION_DENIED} if the application does not have permission 268 * to open camera.</li> 269 * <li>{@link ACAMERA_ERROR_UNKNOWN} if the method fails for some other reasons.</li></ul> 270 */ 271 camera_status_t ACameraManager_openCamera( 272 ACameraManager* manager, const char* cameraId, 273 ACameraDevice_StateCallbacks* callback, 274 /*out*/ACameraDevice** device); 275 276 #endif /* __ANDROID_API__ >= 24 */ 277 278 __END_DECLS 279 280 #endif /* _NDK_CAMERA_MANAGER_H */ 281 282 /** @} */ 283
