{"id":548,"date":"2013-05-20T09:37:28","date_gmt":"2013-05-20T01:37:28","guid":{"rendered":"http:\/\/guoh.ai\/lifelog\/?p=548"},"modified":"2013-09-16T09:22:14","modified_gmt":"2013-09-16T01:22:14","slug":"android-camera-architecture","status":"publish","type":"post","link":"https:\/\/guoh.ai\/lifelog\/2013\/05\/android-camera-architecture\/","title":{"rendered":"Android Camera\u7cfb\u7edf\u7ed3\u6784"},"content":{"rendered":"
<p>\u8bf4\u5230\u67b6\u6784\/\u6784\u67b6\u5c31\u89c9\u5f97\u5fc3\u865a\uff0c\u611f\u89c9\u8fd9\u4e24\u4e2a\u5b57\u592a\u9ad8\u7aef\u4e86\uff0c\u6240\u4ee5\u6211\u53ea\u6562\u7528\u7ed3\u6784\u6765\u8868\u8fbe\u3002<\/p>\n<p>\u4ee5\u4e0b\u8868\u8ff0\u5982\u679c\u5b58\u5728\u9519\u8bef\uff0c\u8bf7\u6307\u6559\uff01<\/p>\n<p>\u4e4b\u524d\u6709\u5728\u4e00\u7bc7\u535a\u5ba2\u4e2d\u63d0\u5230Camera\u76f8\u5173\u7684\u4e1c\u897f<br \/>\n<a href="http:\/\/guoh.ai\/lifelog\/2012\/09\/asop-camera-source-code-reading-video-snapshot\/" target="_blank">http:\/\/guoh.ai\/lifelog\/2012\/09\/asop-camera-source-code-reading-video-snapshot\/<\/a><\/p>\n<p>\u6bd4\u5982<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/frameworks\/base\/core\/java\/android\/hardware\/Camera.java\r\n$ANDROID_SRC_HOME\/frameworks\/base\/core\/jni\/android_hardware_Camera.cpp<\/pre>\n<p>\/\/ \u6ce8\uff1a\u76ee\u524d\u4ee5\u4e0b\u8fd9\u4e24\u4e2a\u6587\u4ef6\u5728JB\u5f53\u4e2d\u5e94\u8be5\u88ab\u79fb\u52a8\u4f4d\u7f6e\u4e86\uff0c\u7531\u6b64\u53ef\u89c1Android\u4e5f\u662f\u4e2a\u6d3b\u8dc3\u7684\u9879\u76ee<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/frameworks\/base\/include\/camera\/Camera.h\r\n$ANDROID_SRC_HOME\/frameworks\/base\/libs\/camera\/Camera.cpp<\/pre>\n<p>\u8fd9\u7bc7\u535a\u5ba2\u662f\u9605\u8bfb<a href="http:\/\/source.android.com\/devices\/camera.html" target="_blank">http:\/\/source.android.com\/devices\/camera.html<\/a>\uff0c\u7ed3\u5408\u5728JB\u4ee3\u7801\u7684\u57fa\u7840\u4e0a\u5199\u7684\u7b14\u8bb0\uff0c\u53ef\u80fd\u4e0d\u662f\u90a3\u4e48\u8be6\u7ec6\u548c\u6709\u903b\u8f91\uff0c\u53ea\u5173\u6ce8\u91cd\u70b9\u548c\u8981\u6ce8\u610f\u7684\u5730\u65b9\uff0c\u6240\u4ee5\u5982\u679c\u4f60\u521a\u597d\u8bfb\u5230\uff0c\u4f46\u662f\u4f60\u53c8\u6ca1\u6709\u4ec0\u4e48Android Camera\u7684\u57fa\u7840\u7684\u8bdd\uff0c\u5efa\u8bae\u8fd8\u662f\u5148\u770b\u770b<a href="http:\/\/developer.android.com\/guide\/topics\/media\/camera.html" target="_blank">http:\/\/developer.android.com\/guide\/topics\/media\/camera.html<\/a>\u548c<a href="http:\/\/developer.android.com\/reference\/android\/hardware\/Camera.html" target="_blank">Reference<\/a><\/p>\n<p>\u6b63\u5f0f\u5f00\u59cb<br \/>\n\u5927\u4f53\u6765\u8bf4Camera\u5206\u4e3a\u8fd9\u4e48\u591a\u90e8\u5206<br \/>\n<em><strong>APP — JNI — NATIVE — BINDER — CAMERA SERVICE — HAL — DRIVER<\/strong><\/em><\/p>\n<p>\u4e0b\u9762\u5217\u51fa\u8fd9\u6bcf\u4e00\u90e8\u5206\u5bf9\u5e94\u4e8eAOSP\u5f53\u4e2d\u7684\u4ee3\u7801<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">APP($ANDROID_SRC_HOME\/frameworks\/base\/core\/java\/android\/hardware\/Camera.java)\r\n\r\nJNI($ANDROID_SRC_HOME\/frameworks\/base\/core\/jni\/android_hardware_Camera.cpp)\r\n\r\nNATIVE($ANDROID_SRC_HOME\/frameworks\/av\/camera\/Camera.cpp)\r\n\r\nBINDER($ANDROID_SRC_HOME\/frameworks\/av\/camera\/ICameraService.cpp\r\n $ANDROID_SRC_HOME\/frameworks\/av\/camera\/ICameraClient.cpp)\r\n\r\nCAMERA SERVICE($ANDROID_SRC_HOME\/frameworks\/av\/services\/camera\/libcameraservice\/CameraService.cpp)\r\n\r\nHAL($ANDROID_SRC_HOME\/hardware\/libhardware\/include\/hardware\/camera.h\r\n $ANDROID_SRC_HOME\/hardware\/libhardware\/include\/hardware\/camera_common.h\r\n $ANDROID_SRC_HOME\/frameworks\/av\/services\/camera\/libcameraservice\/CameraHardwareInterface.h)<\/pre>\n<p>\u5bf9\u4e8eGalaxy Nexus\u6765\u8bb2\uff0cHAL\u7684\u5177\u4f53\u5b9e\u73b0\u4f4d\u4e8e<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/CameraHal.cpp\r\n$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/CameraHalCommon.cpp<\/pre>\n<p>\u5934\u6587\u4ef6\u4f4d\u4e8e<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/inc\/<\/pre>\n<p>\u5bf9\u4e8eGalaxy Nexus\u6765\u8bb2<\/p>\n<pre class="brush: bash; title: ; notranslate" title="">DRIVER(https:\/\/developers.google.com\/android\/nexus\/drivers)<\/pre>\n<p>\u4e0d\u77e5\u9053\u770b\u4e86\u5bf9Camera\u6709\u6ca1\u6709\u4e2a\u5927\u4f53\u7684\u8ba4\u8bc6\uff1f<br \/>\n\u5927\u81f4\u4e86\u89e3\u4e86\u7684\u8bdd\uff0c\u5c31\u7ffb\u4ee3\u7801\u51fa\u6765\u770b\u770b\u81ea\u5df1\u611f\u5174\u8da3\u7684\u90e8\u5206\u5427<\/p>\n<p>\u4f60\u53ef\u4ee5\u901a\u8fc7repo\u62c9\u53d6\u6240\u6709\u4ee3\u7801\u5230\u672c\u5730\u770b\uff0c\u4e5f\u53ef\u4ee5\u5728\u7ebf\u67e5\u770b\u3002<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/base\/+\/android-4.2.2_r1.2\/core\/java\/android\/hardware\/Camera.java" target="_blank">android\/hardware\/Camera.java<\/a><\/strong><\/p>\n<pre class="brush: java; title: ; notranslate" title="">public static Camera open(int cameraId) {\r\n return new Camera(cameraId);\r\n}<\/pre>\n<pre class="brush: java; title: ; notranslate" title="">Camera(int cameraId) {\r\n mShutterCallback = null;\r\n mRawImageCallback = null;\r\n mJpegCallback = null;\r\n mPreviewCallback = null;\r\n mPostviewCallback = null;\r\n mZoomListener = null;\r\n\r\n Looper looper;\r\n if ((looper = Looper.myLooper()) != null) {\r\n mEventHandler = new EventHandler(this, looper);\r\n } else if ((looper = Looper.getMainLooper()) != null) {\r\n mEventHandler = new EventHandler(this, looper);\r\n } else {\r\n mEventHandler = null;\r\n }\r\n\r\n native_setup(new WeakReference<Camera>(this), cameraId);\r\n}<\/pre>\n<p>\u4ee5\u4e0a\u4ee3\u7801\u63cf\u8ff0\u4e86\u6211\u4eec\u6240\u8981\u7814\u7a76\u7684\u4e1c\u897f\u7684\u57fa\u7840\uff0c\u5f00\u542fcamera\uff0c\u8ddf\u6240\u6709\u7684\u786c\u4ef6\u4e00\u6837\uff0c\u4f7f\u7528\u4e4b\u524d\u9700\u8981\u5148\u5f00\u542f\u3002<br \/>\n\u8fd9\u91cc\u6709\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u5730\u65b9\u5c31\u662fmEventHandler\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u505a\u4ec0\u4e48\u7528\u7684\uff0c\u6587\u6863\u6709\u89e3\u91ca\u7684\u6bd4\u8f83\u6e05\u695a\uff0c\u5982\u4e0b\uff1a<\/p>\n<blockquote><p>Callbacks from other methods are delivered to the event loop of the<br \/>\nthread which called open(). If this thread has no event loop, then<br \/>\ncallbacks are delivered to the main application event loop. If there<br \/>\nis no main application event loop, callbacks are not delivered.<\/p><\/blockquote>\n<p>\u5982\u679c\u4f60\u4e0d\u662f\u5199\u4e00\u4e2a\u73a9\u5177\u7a0b\u5e8f\u7684\u8bdd\uff0c\u4f60\u5c31\u5e94\u5f53\u6ce8\u610f\u8fd9\u91cc\u7684\u63cf\u8ff0\u3002<\/p>\n<p>\u968f\u7740<em><strong>native_setup(new WeakReference<Camera>(this), cameraId);<\/strong><\/em>\uff0c\u4ee3\u7801\u8d70\u5230\u4e86<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/base\/+\/android-4.2.2_r1.2\/core\/jni\/android_hardware_Camera.cpp" target="_blank">android_hardware_Camera.cpp<\/a><\/strong><\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ connect to camera service\r\nstatic void android_hardware_Camera_native_setup(JNIEnv *env, jobject thiz,\r\n jobject weak_this, jint cameraId)\r\n{\r\n sp<Camera> camera = Camera::connect(cameraId);\r\n\r\n if (camera == NULL) {\r\n jniThrowRuntimeException(env, "Fail to connect to camera service");\r\n return;\r\n }\r\n\r\n \/\/ make sure camera hardware is alive\r\n if (camera->getStatus() != NO_ERROR) {\r\n jniThrowRuntimeException(env, "Camera initialization failed");\r\n return;\r\n }\r\n\r\n jclass clazz = env->GetObjectClass(thiz);\r\n if (clazz == NULL) {\r\n jniThrowRuntimeException(env, "Can't find android\/hardware\/Camera");\r\n return;\r\n }\r\n\r\n \/\/ We use a weak reference so the Camera object can be garbage collected.\r\n \/\/ The reference is only used as a proxy for callbacks.\r\n sp<JNICameraContext> context = new JNICameraContext(env, weak_this, clazz, camera);\r\n context->incStrong(thiz);\r\n camera->setListener(context);\r\n\r\n \/\/ save context in opaque field\r\n env->SetIntField(thiz, fields.context, (int)context.get());\r\n}<\/pre>\n<p>\u968f\u7740<em><strong>sp<Camera> camera = Camera::connect(cameraId);<\/strong><\/em>\uff0c\u4ee3\u7801\u8d70\u5230\u4e86<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/include\/camera\/Camera.h" target="_blank">av\/include\/camera\/Camera.h<\/a><\/strong>\uff0c\u5f53\u7136\u5b9e\u73b0\u90fd\u5728<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/camera\/Camera.cpp" target="_blank">av\/camera\/Camera.cpp<\/a><\/strong><\/p>\n<pre class="brush: java; title: ; notranslate" title="">sp<Camera> Camera::connect(int cameraId)\r\n{\r\n ALOGV("connect");\r\n sp<Camera> c = new Camera();\r\n const sp<ICameraService>& cs = getCameraService();\r\n if (cs != 0) {\r\n c->mCamera = cs->connect(c, cameraId);\r\n }\r\n if (c->mCamera != 0) {\r\n c->mCamera->asBinder()->linkToDeath(c);\r\n c->mStatus = NO_ERROR;\r\n } else {\r\n c.clear();\r\n }\r\n return c;\r\n}<\/pre>\n<p>\u8fd9\u91cc<em><strong>getCameraService()<\/strong><\/em>\u662f\u4e00\u4e2a\u6bd4\u8f83\u5173\u952e\u7684\u4e1c\u897f\uff0c\u9700\u8981\u4ed4\u7ec6\u770b\u770b\u3002<\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ establish binder interface to camera service\r\nconst sp<ICameraService>& Camera::getCameraService()\r\n{\r\n Mutex::Autolock _l(mLock);\r\n if (mCameraService.get() == 0) {\r\n sp<IServiceManager> sm = defaultServiceManager();\r\n sp<IBinder> binder;\r\n do {\r\n binder = sm->getService(String16("media.camera"));\r\n if (binder != 0)\r\n break;\r\n ALOGW("CameraService not published, waiting...");\r\n usleep(500000); \/\/ 0.5 s\r\n } while(true);\r\n if (mDeathNotifier == NULL) {\r\n mDeathNotifier = new DeathNotifier();\r\n }\r\n binder->linkToDeath(mDeathNotifier);\r\n mCameraService = interface_cast<ICameraService>(binder);\r\n }\r\n ALOGE_IF(mCameraService==0, "no CameraService!?");\r\n return mCameraService;\r\n}<\/pre>\n<p>\u7136\u540e\u5c31\u662f<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/camera\/ICameraService.cpp" target="_blank">av\/camera\/ICameraService.cpp<\/a><\/strong>\u5f53\u4e2d\u4ee3\u7406\u7c7b<em><strong>BpCameraService<\/strong><\/em>\u7684<\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ connect to camera service\r\nvirtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId)\r\n{\r\n Parcel data, reply;\r\n data.writeInterfaceToken(ICameraService::getInterfaceDescriptor());\r\n data.writeStrongBinder(cameraClient->asBinder());\r\n data.writeInt32(cameraId);\r\n remote()->transact(BnCameraService::CONNECT, data, &reply);\r\n return interface_cast<ICamera>(reply.readStrongBinder());\r\n}<\/pre>\n<p>\u6700\u7ec8\u8f6c\u79fb\u5230<em><strong>BnCameraService<\/strong><\/em>\u7684<em><strong>connect<\/strong><\/em>\u65b9\u6cd5\uff0c\u4f46\u662f\u8fd9\u662f\u4e2a\u7eaf\u865a\u51fd\u6570\uff0c\u800c\u4e14<em><strong>CameraService<\/strong><\/em>\u7ee7\u627f\u4e86<em><strong>BnCameraService<\/strong><\/em>\uff0c\u6240\u4ee5\u8bf7\u770b<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/services\/camera\/libcameraservice\/CameraService.h" target="_blank">av\/services\/camera\/libcameraservice\/CameraService.h<\/a><\/strong>\uff0c\u5f53\u7136\u5177\u4f53\u5b9e\u73b0\u8fd8\u662f\u5728<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/services\/camera\/libcameraservice\/CameraService.h" target="_blank">av\/services\/camera\/libcameraservice\/CameraService.cpp<\/a><\/strong>\u5f53\u4e2d\u3002<\/p>\n<pre class="brush: java; title: ; notranslate" title="">sp<ICamera> CameraService::connect(\r\n const sp<ICameraClient>& cameraClient, int cameraId) {\r\n int callingPid = getCallingPid();\r\n\r\n LOG1("CameraService::connect E (pid %d, id %d)", callingPid, cameraId);\r\n\r\n if (!mModule) {\r\n ALOGE("Camera HAL module not loaded");\r\n return NULL;\r\n }\r\n\r\n sp<Client> client;\r\n if (cameraId < 0 || cameraId >= mNumberOfCameras) {\r\n ALOGE("CameraService::connect X (pid %d) rejected (invalid cameraId %d).",\r\n callingPid, cameraId);\r\n return NULL;\r\n }\r\n\r\n char value[PROPERTY_VALUE_MAX];\r\n property_get("sys.secpolicy.camera.disabled", value, "0");\r\n if (strcmp(value, "1") == 0) {\r\n \/\/ Camera is disabled by DevicePolicyManager.\r\n ALOGI("Camera is disabled. connect X (pid %d) rejected", callingPid);\r\n return NULL;\r\n }\r\n\r\n Mutex::Autolock lock(mServiceLock);\r\n if (mClient[cameraId] != 0) {\r\n client = mClient[cameraId].promote();\r\n if (client != 0) {\r\n if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {\r\n LOG1("CameraService::connect X (pid %d) (the same client)",\r\n callingPid);\r\n return client;\r\n } else {\r\n ALOGW("CameraService::connect X (pid %d) rejected (existing client).",\r\n callingPid);\r\n return NULL;\r\n }\r\n }\r\n mClient[cameraId].clear();\r\n }\r\n\r\n if (mBusy[cameraId]) {\r\n ALOGW("CameraService::connect X (pid %d) rejected"\r\n " (camera %d is still busy).", callingPid, cameraId);\r\n return NULL;\r\n }\r\n\r\n struct camera_info info;\r\n if (mModule->get_camera_info(cameraId, &info) != OK) {\r\n ALOGE("Invalid camera id %d", cameraId);\r\n return NULL;\r\n }\r\n\r\n int deviceVersion;\r\n if (mModule->common.module_api_version == CAMERA_MODULE_API_VERSION_2_0) {\r\n deviceVersion = info.device_version;\r\n } else {\r\n deviceVersion = CAMERA_DEVICE_API_VERSION_1_0;\r\n }\r\n\r\n switch(deviceVersion) {\r\n case CAMERA_DEVICE_API_VERSION_1_0:\r\n client = new CameraClient(this, cameraClient, cameraId,\r\n info.facing, callingPid, getpid());\r\n break;\r\n case CAMERA_DEVICE_API_VERSION_2_0:\r\n client = new Camera2Client(this, cameraClient, cameraId,\r\n info.facing, callingPid, getpid());\r\n break;\r\n default:\r\n ALOGE("Unknown camera device HAL version: %d", deviceVersion);\r\n return NULL;\r\n }\r\n\r\n if (client->initialize(mModule) != OK) {\r\n return NULL;\r\n }\r\n\r\n cameraClient->asBinder()->linkToDeath(this);\r\n\r\n mClient[cameraId] = client;\r\n LOG1("CameraService::connect X (id %d, this pid is %d)", cameraId, getpid());\r\n return client;\r\n}<\/pre>\n<p>\u6bd4\u5982\u6211\u4eec\u8fd9\u91cc\u4ee5HAL 1.0\u6765\u770b\uff0c\u53c2\u89c1<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/services\/camera\/libcameraservice\/CameraClient.h" target="_blank">av\/services\/camera\/libcameraservice\/CameraClient.h<\/a><\/strong><br \/>\n\u548c<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/services\/camera\/libcameraservice\/CameraClient.cpp" target="_blank">av\/services\/camera\/libcameraservice\/CameraClient.cpp<\/a><\/strong><\/p>\n<pre class="brush: java; title: ; notranslate" title="">CameraClient::CameraClient(const sp<CameraService>& cameraService,\r\n const sp<ICameraClient>& cameraClient,\r\n int cameraId, int cameraFacing, int clientPid, int servicePid):\r\n Client(cameraService, cameraClient,\r\n cameraId, cameraFacing, clientPid, servicePid)\r\n{\r\n int callingPid = getCallingPid();\r\n LOG1("CameraClient::CameraClient E (pid %d, id %d)", callingPid, cameraId);\r\n\r\n mHardware = NULL;\r\n mMsgEnabled = 0;\r\n mSurface = 0;\r\n mPreviewWindow = 0;\r\n mDestructionStarted = false;\r\n\r\n \/\/ Callback is disabled by default\r\n mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;\r\n mOrientation = getOrientation(0, mCameraFacing == CAMERA_FACING_FRONT);\r\n mPlayShutterSound = true;\r\n LOG1("CameraClient::CameraClient X (pid %d, id %d)", callingPid, cameraId);\r\n}\r\n<\/pre>\n<pre class="brush: java; title: ; notranslate" title="">status_t CameraClient::initialize(camera_module_t *module) {\r\n int callingPid = getCallingPid();\r\n LOG1("CameraClient::initialize E (pid %d, id %d)", callingPid, mCameraId);\r\n\r\n char camera_device_name[10];\r\n status_t res;\r\n snprintf(camera_device_name, sizeof(camera_device_name), "%d", mCameraId);\r\n\r\n mHardware = new CameraHardwareInterface(camera_device_name);\r\n res = mHardware->initialize(&module->common);\r\n if (res != OK) {\r\n ALOGE("%s: Camera %d: unable to initialize device: %s (%d)",\r\n __FUNCTION__, mCameraId, strerror(-res), res);\r\n mHardware.clear();\r\n return NO_INIT;\r\n }\r\n\r\n mHardware->setCallbacks(notifyCallback,\r\n dataCallback,\r\n dataCallbackTimestamp,\r\n (void *)mCameraId);\r\n\r\n \/\/ Enable zoom, error, focus, and metadata messages by default\r\n enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM | CAMERA_MSG_FOCUS |\r\n CAMERA_MSG_PREVIEW_METADATA | CAMERA_MSG_FOCUS_MOVE);\r\n\r\n LOG1("CameraClient::initialize X (pid %d, id %d)", callingPid, mCameraId);\r\n return OK;\r\n}<\/pre>\n<p>\u5f53\u7136\u8fd8\u4f1a\u7528\u5230<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/hardware\/libhardware\/+\/android-4.2.2_r1.2\/include\/hardware\/camera.h" target="_blank">libhardware\/\/include\/hardware\/camera.h<\/a><\/strong><br \/>\n\u548c<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/hardware\/libhardware\/+\/android-4.2.2_r1.2\/include\/hardware\/camera_common.h" target="_blank">libhardware\/\/include\/hardware\/camera_common.h<\/a><\/strong><br \/>\n\u548c<br \/>\n<strong><a href="https:\/\/android.googlesource.com\/platform\/frameworks\/av\/+\/android-4.2.2_r1.2\/services\/camera\/libcameraservice\/CameraHardwareInterface.h" target="_blank">av\/services\/camera\/libcameraservice\/CameraHardwareInterface.h<\/a><\/strong><\/p>\n<pre class="brush: java; title: ; notranslate" title="">status_t initialize(hw_module_t *module)\r\n{\r\n ALOGI("Opening camera %s", mName.string());\r\n int rc = module->methods->open(module, mName.string(),\r\n (hw_device_t **)&mDevice);\r\n if (rc != OK) {\r\n ALOGE("Could not open camera %s: %d", mName.string(), rc);\r\n return rc;\r\n }\r\n initHalPreviewWindow();\r\n return rc;\r\n}<\/pre>\n<p>\u8fd9\u53ea\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u5177\u4f53\u7684\u5b9e\u73b0\u662f\u5382\u5546\u6765\u505a\u7684\u5566<\/p>\n<p>\u4ee5\u4e0a\u662f\u4ece\u4e0a\u5c42\u8c03\u7528\u5230\u5e95\u5c42\uff0c\u63a5\u7740\u6211\u4eec\u8fd8\u4f1a\u770b\u4e00\u4e2a\u4ece\u5e95\u5c42\u8c03\u7528\u5230\u4e0a\u5c42\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u4ece\u4ee3\u7801\u770b\u51fa\u6709\u7ed1\u5b9a3\u4e2acallback\u5230driver<\/p>\n<pre class="brush: java; title: ; notranslate" title="">mHardware->setCallbacks(notifyCallback,\r\n dataCallback,\r\n dataCallbackTimestamp,\r\n (void *)mCameraId);<\/pre>\n<p>\u6240\u4ee5\u8fd9\u4e09\u4e2acallback\u4f1a\u6709\u673a\u4f1a\u88abcall\u5230<br \/>\n\u4ee5dataCallback\u4e3a\u4f8b\u5b50\uff0c\u5176\u4e2d\u6709\u4e00\u4e2a\u662f<\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ picture callback - compressed picture ready\r\nvoid CameraClient::handleCompressedPicture(const sp<IMemory>& mem) {\r\n disableMsgType(CAMERA_MSG_COMPRESSED_IMAGE);\r\n\r\n sp<ICameraClient> c = mCameraClient;\r\n mLock.unlock();\r\n if (c != 0) {\r\n c->dataCallback(CAMERA_MSG_COMPRESSED_IMAGE, mem, NULL);\r\n }\r\n}<\/pre>\n<p>\u901a\u8fc7ICameraClient\u8c03\u7528\u4f1aapp\uff0c\u8fd9\u91cc\u7684ICameraClient\u662fBpCameraClient(\u4e3a\u4ec0\u4e48\u662fBp\uff0c\u540e\u9762\u4f1a\u7a0d\u52a0\u89e3\u91ca)<\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ generic data callback from camera service to app with image data\r\nvoid BpCameraClient::dataCallback(int32_t msgType, const sp<IMemory>& imageData,\r\n camera_frame_metadata_t *metadata)\r\n{\r\n ALOGV("dataCallback");\r\n Parcel data, reply;\r\n data.writeInterfaceToken(ICameraClient::getInterfaceDescriptor());\r\n data.writeInt32(msgType);\r\n data.writeStrongBinder(imageData->asBinder());\r\n if (metadata) {\r\n data.writeInt32(metadata->number_of_faces);\r\n data.write(metadata->faces, sizeof(camera_face_t) * metadata->number_of_faces);\r\n }\r\n remote()->transact(DATA_CALLBACK, data, &reply, IBinder::FLAG_ONEWAY);\r\n}\r\n<\/pre>\n<p>\u4e8e\u662f<\/p>\n<pre class="brush: java; title: ; notranslate" title="">status_t BnCameraClient::onTransact(\r\n uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)\r\n{\r\n switch(code) {\r\n case NOTIFY_CALLBACK: {\r\n ...\r\n } break;\r\n case DATA_CALLBACK: {\r\n ALOGV("DATA_CALLBACK");\r\n CHECK_INTERFACE(ICameraClient, data, reply);\r\n int32_t msgType = data.readInt32();\r\n sp<IMemory> imageData = interface_cast<IMemory>(data.readStrongBinder());\r\n camera_frame_metadata_t *metadata = NULL;\r\n if (data.dataAvail() > 0) {\r\n metadata = new camera_frame_metadata_t;\r\n metadata->number_of_faces = data.readInt32();\r\n metadata->faces = (camera_face_t *) data.readInplace(\r\n sizeof(camera_face_t) * metadata->number_of_faces);\r\n }\r\n dataCallback(msgType, imageData, metadata); \/\/ \u56e0\u4e3apure virtual function\u7684\u5173\u7cfb\uff0c\u6240\u4ee5\u4f1acall\u5230Camera\u5f53\u4e2d\u7684\u5b9e\u73b0\r\n if (metadata) delete metadata;\r\n return NO_ERROR;\r\n } break;\r\n case DATA_CALLBACK_TIMESTAMP: {\r\n ...\r\n } break;\r\n default:\r\n return BBinder::onTransact(code, data, reply, flags);\r\n }\r\n}<\/pre>\n<p>\u4e8e\u662f<\/p>\n<pre class="brush: java; title: ; notranslate" title="">\/\/ callback from camera service when frame or image is ready\r\nvoid Camera::dataCallback(int32_t msgType, const sp<IMemory>& dataPtr,\r\n camera_frame_metadata_t *metadata)\r\n{\r\n sp<CameraListener> listener;\r\n {\r\n Mutex::Autolock _l(mLock);\r\n listener = mListener;\r\n }\r\n if (listener != NULL) {\r\n listener->postData(msgType, dataPtr, metadata);\r\n }\r\n}\r\n<\/pre>\n<p>\u4eceapp call\u5230service\u662fBnCameraClient(client\u662f\u5b9e\u4f53\uff0cservice\u662f\u4ee3\u7406\uff0c\u4ecenew\u7684\u4ee3\u7801\u5c31\u53ef\u4ee5\u89c2\u5bdf\u51fa\u6765)<br \/>\n\u4eceservice call\u5230app\u662fBpCameraClient(service\u662f\u5b9e\u4f53\uff0cclient\u662f\u4ee3\u7406)<br \/>\n\u800c\u8fd9\u4e2aBn\u5230Bp\u7684\u8f6c\u6362\u662f\u901a\u8fc7<\/p>\n<pre class="brush: java; title: ; notranslate" title="">sp<ICameraClient> cameraClient = interface_cast<ICameraClient>(data.readStrongBinder());<\/pre>\n<p>\u5b8c\u6210\u7684\u3002<\/p>\n<p>\u540e\u9762\u6211\u4eec\u4f1a\u5217\u4e3e\u4e9b\u9700\u8981\u6ce8\u610f\u7684\u70b9\uff1a<\/p>\n<p>ICameraClient\u7ee7\u627f\u81eaIInterface<br \/>\nBnCameraClient\u7ee7\u627f\u81eaBnInterface<ICameraClient>\uff0c\u7136\u800cBnInterface<ICameraClient>\u53c8\u7ee7\u627f\u81eaICameraClient\uff0cBBinder<\/p>\n<p>Camera\u7ee7\u627f\u81eaBnCameraClient<\/p>\n<p>ICameraService\u7ee7\u627f\u81eaIInterface<br \/>\nBnCameraService\u7ee7\u627f\u81eaBnInterface<ICameraService>\uff0c\u7136\u800cBnInterface<ICameraService>\u53c8\u7ee7\u627f\u81eaICameraService\uff0cBBinder<\/p>\n<p>ICamera\u7ee7\u627f\u81eaIInterface<br \/>\nBnCamera\u7ee7\u627f\u81eaBnInterface<ICamera>\uff0c\u7136\u800cBnInterface<ICamera>\u53c8\u7ee7\u627f\u81eaICamera\uff0cBBinder<\/p>\n<p>CameraService\u7ee7\u627f\u81eaBinderService\uff0cBnCameraService\uff0cIBinder::DeathRecipient<br \/>\n\u800cBinderService\u4e3b\u8981\u662f\u7528\u6765\u5b9e\u4f8b\u5316service\u7684\u7edf\u4e00\u63a5\u53e3<\/p>\n<p>CameraService\u6709\u4e2a\u5d4c\u5957\u7c7bClient\u7ee7\u627f\u81eaBnCamera<br \/>\n\u771f\u6b63\u7684\u5b9e\u73b0\u5927\u90e8\u5206\u5728CameraClient\u5f53\u4e2d(Camera2Client\u662fGoogle\u63d0\u4f9b\u7684\u8c03\u7528\u65b0\u7684HAL\u7684\u4e00\u79cd\u65b9\u5f0f\uff0c\u90e8\u5206\u5382\u5546\u4f1a\u7528\u8fd9\u6837\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\u81ea\u5df1\u7684HAL\uff0c\u6bd4\u5982Qualcomm)<br \/>\n\u8fd9\u624d\u662f\u771f\u6b63\u7684client\uff0c\u76f4\u63a5\u8c03\u7528HW\u6216\u8005\u88abHW\u8c03\u7528\u3002<\/p>\n<p>sendCommand\u5f80driver\u9001\u53c2\u6570\u7684\u65f6\u5019\u4f1a\u5148\u68c0\u9a8c\u662f\u4e0d\u662fCameraService\u8fd9\u5c42\u53ef\u4ee5\u5904\u7406\u7684\u4e1c\u897f(\u6709\u4e9b\u4e1c\u897f\u4e0d\u9700\u8981\u5230driver\u7684)<\/p>\n<p>cmd == CAMERA_CMD_SET_DISPLAY_ORIENTATION<br \/>\ncmd == CAMERA_CMD_ENABLE_SHUTTER_SOUND<br \/>\ncmd == CAMERA_CMD_PLAY_RECORDING_SOUND<br \/>\ncmd == CAMERA_CMD_SET_VIDEO_BUFFER_COUNT<br \/>\ncmd == CAMERA_CMD_PING<br \/>\n\u4ee5\u4e0a\u8fd9\u4e9b\u90fdCameraService\u81ea\u5df1\u5904\u7406\u4e86<br \/>\n\u5176\u4ed6\u5747\u4e22\u7ed9driver(mHardware->sendCommand(cmd, arg1, arg2);)<\/p>\n<p>\u63a5\u4e0b\u6765\u662f\u4e00\u4e9b\u7591\u95ee\u70b9\uff1a<\/p>\n<p>\/\/ these are initialized in the constructor.<br \/>\nsp<CameraHardwareInterface> mHardware; \/\/ cleared after disconnect()<br \/>\nmHardware\u5728disconnect\u5f53\u4e2d\u88abclear<\/p>\n<p>\/\/ Make sure disconnect() is done once and once only, whether it is called<br \/>\n\/\/ from the user directly, or called by the destructor.<br \/>\nif (mHardware == 0) return;<br \/>\n\u8fd9\u662f\u9632\u6b62disconnect\u8c03\u7528\u4e00\u6b21\u4e4b\u540e\uff0c\u6790\u6784\u51fd\u6570\u53c8\u8c03\u7528\u4e00\u6b21\u3002<\/p>\n<\/div>

\u8bf4\u5230\u67b6\u6784\/\u6784\u67b6\u5c31\u89c9\u5f97\u5fc3\u865a\uff0c\u611f\u89c9\u8fd9\u4e24\u4e2a\u5b57\u592a\u9ad8\u7aef\u4e86\uff0c\u6240\u4ee5\u6211\u53ea\u6562\u7528\u7ed3\u6784\u6765\u8868\u8fbe\u3002<\/p>\n

\u4ee5\u4e0b\u8868\u8ff0\u5982\u679c\u5b58\u5728\u9519\u8bef\uff0c\u8bf7\u6307\u6559\uff01<\/p>\n

\u4e4b\u524d\u6709\u5728\u4e00\u7bc7\u535a\u5ba2\u4e2d\u63d0\u5230Camera\u76f8\u5173\u7684\u4e1c\u897f
\nhttp:\/\/guoh.ai\/lifelog\/2012\/09\/asop-camera-source-code-reading-video-snapshot\/<\/a><\/p>\n

\u6bd4\u5982<\/p>\n

$ANDROID_SRC_HOME\/frameworks\/base\/core\/java\/android\/hardware\/Camera.java\r\n$ANDROID_SRC_HOME\/frameworks\/base\/core\/jni\/android_hardware_Camera.cpp<\/pre>\n
\/\/ \u6ce8\uff1a\u76ee\u524d\u4ee5\u4e0b\u8fd9\u4e24\u4e2a\u6587\u4ef6\u5728JB\u5f53\u4e2d\u5e94\u8be5\u88ab\u79fb\u52a8\u4f4d\u7f6e\u4e86\uff0c\u7531\u6b64\u53ef\u89c1Android\u4e5f\u662f\u4e2a\u6d3b\u8dc3\u7684\u9879\u76ee<\/p>\n
$ANDROID_SRC_HOME\/frameworks\/base\/include\/camera\/Camera.h\r\n$ANDROID_SRC_HOME\/frameworks\/base\/libs\/camera\/Camera.cpp<\/pre>\n
\u8fd9\u7bc7\u535a\u5ba2\u662f\u9605\u8bfbhttp:\/\/source.android.com\/devices\/camera.html<\/a>\uff0c\u7ed3\u5408\u5728JB\u4ee3\u7801\u7684\u57fa\u7840\u4e0a\u5199\u7684\u7b14\u8bb0\uff0c\u53ef\u80fd\u4e0d\u662f\u90a3\u4e48\u8be6\u7ec6\u548c\u6709\u903b\u8f91\uff0c\u53ea\u5173\u6ce8\u91cd\u70b9\u548c\u8981\u6ce8\u610f\u7684\u5730\u65b9\uff0c\u6240\u4ee5\u5982\u679c\u4f60\u521a\u597d\u8bfb\u5230\uff0c\u4f46\u662f\u4f60\u53c8\u6ca1\u6709\u4ec0\u4e48Android Camera\u7684\u57fa\u7840\u7684\u8bdd\uff0c\u5efa\u8bae\u8fd8\u662f\u5148\u770b\u770bhttp:\/\/developer.android.com\/guide\/topics\/media\/camera.html<\/a>\u548cReference<\/a><\/p>\n
\u6b63\u5f0f\u5f00\u59cb
\n\u5927\u4f53\u6765\u8bf4Camera\u5206\u4e3a\u8fd9\u4e48\u591a\u90e8\u5206
\nAPP — JNI — NATIVE — BINDER — CAMERA SERVICE — HAL — DRIVER<\/strong><\/em><\/p>\n
\u4e0b\u9762\u5217\u51fa\u8fd9\u6bcf\u4e00\u90e8\u5206\u5bf9\u5e94\u4e8eAOSP\u5f53\u4e2d\u7684\u4ee3\u7801<\/p>\n
APP($ANDROID_SRC_HOME\/frameworks\/base\/core\/java\/android\/hardware\/Camera.java)\r\n\r\nJNI($ANDROID_SRC_HOME\/frameworks\/base\/core\/jni\/android_hardware_Camera.cpp)\r\n\r\nNATIVE($ANDROID_SRC_HOME\/frameworks\/av\/camera\/Camera.cpp)\r\n\r\nBINDER($ANDROID_SRC_HOME\/frameworks\/av\/camera\/ICameraService.cpp\r\n       $ANDROID_SRC_HOME\/frameworks\/av\/camera\/ICameraClient.cpp)\r\n\r\nCAMERA SERVICE($ANDROID_SRC_HOME\/frameworks\/av\/services\/camera\/libcameraservice\/CameraService.cpp)\r\n\r\nHAL($ANDROID_SRC_HOME\/hardware\/libhardware\/include\/hardware\/camera.h\r\n    $ANDROID_SRC_HOME\/hardware\/libhardware\/include\/hardware\/camera_common.h\r\n    $ANDROID_SRC_HOME\/frameworks\/av\/services\/camera\/libcameraservice\/CameraHardwareInterface.h)<\/pre>\n
\u5bf9\u4e8eGalaxy Nexus\u6765\u8bb2\uff0cHAL\u7684\u5177\u4f53\u5b9e\u73b0\u4f4d\u4e8e<\/p>\n
$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/CameraHal.cpp\r\n$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/CameraHalCommon.cpp<\/pre>\n
\u5934\u6587\u4ef6\u4f4d\u4e8e<\/p>\n
$ANDROID_SRC_HOME\/hardware\/ti\/omap4xxx\/camera\/inc\/<\/pre>\n
\u5bf9\u4e8eGalaxy Nexus\u6765\u8bb2<\/p>\n
DRIVER(https:\/\/developers.google.com\/android\/nexus\/drivers)<\/pre>\n
\u4e0d\u77e5\u9053\u770b\u4e86\u5bf9Camera\u6709\u6ca1\u6709\u4e2a\u5927\u4f53\u7684\u8ba4\u8bc6\uff1f
\n\u5927\u81f4\u4e86\u89e3\u4e86\u7684\u8bdd\uff0c\u5c31\u7ffb\u4ee3\u7801\u51fa\u6765\u770b\u770b\u81ea\u5df1\u611f\u5174\u8da3\u7684\u90e8\u5206\u5427<\/p>\n
\u4f60\u53ef\u4ee5\u901a\u8fc7repo\u62c9\u53d6\u6240\u6709\u4ee3\u7801\u5230\u672c\u5730\u770b\uff0c\u4e5f\u53ef\u4ee5\u5728\u7ebf\u67e5\u770b\u3002
\nandroid\/hardware\/Camera.java<\/a><\/strong><\/p>\n
public static Camera open(int cameraId) {\r\n    return new Camera(cameraId);\r\n}<\/pre>\n
Camera(int cameraId) {\r\n    mShutterCallback = null;\r\n    mRawImageCallback = null;\r\n    mJpegCallback = null;\r\n    mPreviewCallback = null;\r\n    mPostviewCallback = null;\r\n    mZoomListener = null;\r\n\r\n    Looper looper;\r\n    if ((looper = Looper.myLooper()) != null) {\r\n        mEventHandler = new EventHandler(this, looper);\r\n    } else if ((looper = Looper.getMainLooper()) != null) {\r\n        mEventHandler = new EventHandler(this, looper);\r\n    } else {\r\n        mEventHandler = null;\r\n    }\r\n\r\n    native_setup(new WeakReference<Camera>(this), cameraId);\r\n}<\/pre>\n
\u4ee5\u4e0a\u4ee3\u7801\u63cf\u8ff0\u4e86\u6211\u4eec\u6240\u8981\u7814\u7a76\u7684\u4e1c\u897f\u7684\u57fa\u7840\uff0c\u5f00\u542fcamera\uff0c\u8ddf\u6240\u6709\u7684\u786c\u4ef6\u4e00\u6837\uff0c\u4f7f\u7528\u4e4b\u524d\u9700\u8981\u5148\u5f00\u542f\u3002
\n\u8fd9\u91cc\u6709\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u5730\u65b9\u5c31\u662fmEventHandler\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u505a\u4ec0\u4e48\u7528\u7684\uff0c\u6587\u6863\u6709\u89e3\u91ca\u7684\u6bd4\u8f83\u6e05\u695a\uff0c\u5982\u4e0b\uff1a<\/p>\n
Callbacks from other methods are delivered to the event loop of the
\nthread which called open(). If this thread has no event loop, then
\ncallbacks are delivered to the main application event loop.  If there
\nis no main application event loop, callbacks are not delivered.<\/p><\/blockquote>\n
\u5982\u679c\u4f60\u4e0d\u662f\u5199\u4e00\u4e2a\u73a9\u5177\u7a0b\u5e8f\u7684\u8bdd\uff0c\u4f60\u5c31\u5e94\u5f53\u6ce8\u610f\u8fd9\u91cc\u7684\u63cf\u8ff0\u3002<\/p>\n
\u968f\u7740native_setup(new WeakReference(this), cameraId);<\/strong><\/em>\uff0c\u4ee3\u7801\u8d70\u5230\u4e86
\nandroid_hardware_Camera.cpp<\/a><\/strong><\/p>\n
\/\/ connect to camera service\r\nstatic void android_hardware_Camera_native_setup(JNIEnv *env, jobject thiz,\r\n    jobject weak_this, jint cameraId)\r\n{\r\n    sp<Camera> camera = Camera::connect(cameraId);\r\n\r\n    if (camera == NULL) {\r\n        jniThrowRuntimeException(env, "Fail to connect to camera service");\r\n        return;\r\n    }\r\n\r\n    \/\/ make sure camera hardware is alive\r\n    if (camera->getStatus() != NO_ERROR) {\r\n        jniThrowRuntimeException(env, "Camera initialization failed");\r\n        return;\r\n    }\r\n\r\n    jclass clazz = env->GetObjectClass(thiz);\r\n    if (clazz == NULL) {\r\n        jniThrowRuntimeException(env, "Can't find android\/hardware\/Camera");\r\n        return;\r\n    }\r\n\r\n    \/\/ We use a weak reference so the Camera object can be garbage collected.\r\n    \/\/ The reference is only used as a proxy for callbacks.\r\n    sp<JNICameraContext> context = new JNICameraContext(env, weak_this, clazz, camera);\r\n    context->incStrong(thiz);\r\n    camera->setListener(context);\r\n\r\n    \/\/ save context in opaque field\r\n    env->SetIntField(thiz, fields.context, (int)context.get());\r\n}<\/pre>\n
\u968f\u7740sp camera = Camera::connect(cameraId);<\/strong><\/em>\uff0c\u4ee3\u7801\u8d70\u5230\u4e86
\nav\/include\/camera\/Camera.h<\/a><\/strong>\uff0c\u5f53\u7136\u5b9e\u73b0\u90fd\u5728av\/camera\/Camera.cpp<\/a><\/strong><\/p>\n
sp<Camera> Camera::connect(int cameraId)\r\n{\r\n    ALOGV("connect");\r\n    sp<Camera> c = new Camera();\r\n    const sp<ICameraService>& cs = getCameraService();\r\n    if (cs != 0) {\r\n        c->mCamera = cs->connect(c, cameraId);\r\n    }\r\n    if (c->mCamera != 0) {\r\n        c->mCamera->asBinder()->linkToDeath(c);\r\n        c->mStatus = NO_ERROR;\r\n    } else {\r\n        c.clear();\r\n    }\r\n    return c;\r\n}<\/pre>\n
\u8fd9\u91ccgetCameraService()<\/strong><\/em>\u662f\u4e00\u4e2a\u6bd4\u8f83\u5173\u952e\u7684\u4e1c\u897f\uff0c\u9700\u8981\u4ed4\u7ec6\u770b\u770b\u3002<\/p>\n
\/\/ establish binder interface to camera service\r\nconst sp<ICameraService>& Camera::getCameraService()\r\n{\r\n    Mutex::Autolock _l(mLock);\r\n    if (mCameraService.get() == 0) {\r\n        sp<IServiceManager> sm = defaultServiceManager();\r\n        sp<IBinder> binder;\r\n        do {\r\n            binder = sm->getService(String16("media.camera"));\r\n            if (binder != 0)\r\n                break;\r\n            ALOGW("CameraService not published, waiting...");\r\n            usleep(500000); \/\/ 0.5 s\r\n        } while(true);\r\n        if (mDeathNotifier == NULL) {\r\n            mDeathNotifier = new DeathNotifier();\r\n        }\r\n        binder->linkToDeath(mDeathNotifier);\r\n        mCameraService = interface_cast<ICameraService>(binder);\r\n    }\r\n    ALOGE_IF(mCameraService==0, "no CameraService!?");\r\n    return mCameraService;\r\n}<\/pre>\n
\u7136\u540e\u5c31\u662fav\/camera\/ICameraService.cpp<\/a><\/strong>\u5f53\u4e2d\u4ee3\u7406\u7c7bBpCameraService<\/strong><\/em>\u7684<\/p>\n
\/\/ connect to camera service\r\nvirtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId)\r\n{\r\n    Parcel data, reply;\r\n    data.writeInterfaceToken(ICameraService::getInterfaceDescriptor());\r\n    data.writeStrongBinder(cameraClient->asBinder());\r\n    data.writeInt32(cameraId);\r\n    remote()->transact(BnCameraService::CONNECT, data, &reply);\r\n    return interface_cast<ICamera>(reply.readStrongBinder());\r\n}<\/pre>\n
\u6700\u7ec8\u8f6c\u79fb\u5230BnCameraService<\/strong><\/em>\u7684connect<\/strong><\/em>\u65b9\u6cd5\uff0c\u4f46\u662f\u8fd9\u662f\u4e2a\u7eaf\u865a\u51fd\u6570\uff0c\u800c\u4e14CameraService<\/strong><\/em>\u7ee7\u627f\u4e86BnCameraService<\/strong><\/em>\uff0c\u6240\u4ee5\u8bf7\u770b
\nav\/services\/camera\/libcameraservice\/CameraService.h<\/a><\/strong>\uff0c\u5f53\u7136\u5177\u4f53\u5b9e\u73b0\u8fd8\u662f\u5728av\/services\/camera\/libcameraservice\/CameraService.cpp<\/a><\/strong>\u5f53\u4e2d\u3002<\/p>\n
sp<ICamera> CameraService::connect(\r\n        const sp<ICameraClient>& cameraClient, int cameraId) {\r\n    int callingPid = getCallingPid();\r\n\r\n    LOG1("CameraService::connect E (pid %d, id %d)", callingPid, cameraId);\r\n\r\n    if (!mModule) {\r\n        ALOGE("Camera HAL module not loaded");\r\n        return NULL;\r\n    }\r\n\r\n    sp<Client> client;\r\n    if (cameraId < 0 || cameraId >= mNumberOfCameras) {\r\n        ALOGE("CameraService::connect X (pid %d) rejected (invalid cameraId %d).",\r\n            callingPid, cameraId);\r\n        return NULL;\r\n    }\r\n\r\n    char value[PROPERTY_VALUE_MAX];\r\n    property_get("sys.secpolicy.camera.disabled", value, "0");\r\n    if (strcmp(value, "1") == 0) {\r\n        \/\/ Camera is disabled by DevicePolicyManager.\r\n        ALOGI("Camera is disabled. connect X (pid %d) rejected", callingPid);\r\n        return NULL;\r\n    }\r\n\r\n    Mutex::Autolock lock(mServiceLock);\r\n    if (mClient[cameraId] != 0) {\r\n        client = mClient[cameraId].promote();\r\n        if (client != 0) {\r\n            if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {\r\n                LOG1("CameraService::connect X (pid %d) (the same client)",\r\n                     callingPid);\r\n                return client;\r\n            } else {\r\n                ALOGW("CameraService::connect X (pid %d) rejected (existing client).",\r\n                      callingPid);\r\n                return NULL;\r\n            }\r\n        }\r\n        mClient[cameraId].clear();\r\n    }\r\n\r\n    if (mBusy[cameraId]) {\r\n        ALOGW("CameraService::connect X (pid %d) rejected"\r\n                " (camera %d is still busy).", callingPid, cameraId);\r\n        return NULL;\r\n    }\r\n\r\n    struct camera_info info;\r\n    if (mModule->get_camera_info(cameraId, &info) != OK) {\r\n        ALOGE("Invalid camera id %d", cameraId);\r\n        return NULL;\r\n    }\r\n\r\n    int deviceVersion;\r\n    if (mModule->common.module_api_version == CAMERA_MODULE_API_VERSION_2_0) {\r\n        deviceVersion = info.device_version;\r\n    } else {\r\n        deviceVersion = CAMERA_DEVICE_API_VERSION_1_0;\r\n    }\r\n\r\n    switch(deviceVersion) {\r\n      case CAMERA_DEVICE_API_VERSION_1_0:\r\n        client = new CameraClient(this, cameraClient, cameraId,\r\n                info.facing, callingPid, getpid());\r\n        break;\r\n      case CAMERA_DEVICE_API_VERSION_2_0:\r\n        client = new Camera2Client(this, cameraClient, cameraId,\r\n                info.facing, callingPid, getpid());\r\n        break;\r\n      default:\r\n        ALOGE("Unknown camera device HAL version: %d", deviceVersion);\r\n        return NULL;\r\n    }\r\n\r\n    if (client->initialize(mModule) != OK) {\r\n        return NULL;\r\n    }\r\n\r\n    cameraClient->asBinder()->linkToDeath(this);\r\n\r\n    mClient[cameraId] = client;\r\n    LOG1("CameraService::connect X (id %d, this pid is %d)", cameraId, getpid());\r\n    return client;\r\n}<\/pre>\n
\u6bd4\u5982\u6211\u4eec\u8fd9\u91cc\u4ee5HAL 1.0\u6765\u770b\uff0c\u53c2\u89c1
\nav\/services\/camera\/libcameraservice\/CameraClient.h<\/a><\/strong>
\n\u548c
\nav\/services\/camera\/libcameraservice\/CameraClient.cpp<\/a><\/strong><\/p>\n
CameraClient::CameraClient(const sp<CameraService>& cameraService,\r\n        const sp<ICameraClient>& cameraClient,\r\n        int cameraId, int cameraFacing, int clientPid, int servicePid):\r\n        Client(cameraService, cameraClient,\r\n                cameraId, cameraFacing, clientPid, servicePid)\r\n{\r\n    int callingPid = getCallingPid();\r\n    LOG1("CameraClient::CameraClient E (pid %d, id %d)", callingPid, cameraId);\r\n\r\n    mHardware = NULL;\r\n    mMsgEnabled = 0;\r\n    mSurface = 0;\r\n    mPreviewWindow = 0;\r\n    mDestructionStarted = false;\r\n\r\n    \/\/ Callback is disabled by default\r\n    mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;\r\n    mOrientation = getOrientation(0, mCameraFacing == CAMERA_FACING_FRONT);\r\n    mPlayShutterSound = true;\r\n    LOG1("CameraClient::CameraClient X (pid %d, id %d)", callingPid, cameraId);\r\n}\r\n<\/pre>\n
status_t CameraClient::initialize(camera_module_t *module) {\r\n    int callingPid = getCallingPid();\r\n    LOG1("CameraClient::initialize E (pid %d, id %d)", callingPid, mCameraId);\r\n\r\n    char camera_device_name[10];\r\n    status_t res;\r\n    snprintf(camera_device_name, sizeof(camera_device_name), "%d", mCameraId);\r\n\r\n    mHardware = new CameraHardwareInterface(camera_device_name);\r\n    res = mHardware->initialize(&module->common);\r\n    if (res != OK) {\r\n        ALOGE("%s: Camera %d: unable to initialize device: %s (%d)",\r\n                __FUNCTION__, mCameraId, strerror(-res), res);\r\n        mHardware.clear();\r\n        return NO_INIT;\r\n    }\r\n\r\n    mHardware->setCallbacks(notifyCallback,\r\n            dataCallback,\r\n            dataCallbackTimestamp,\r\n            (void *)mCameraId);\r\n\r\n    \/\/ Enable zoom, error, focus, and metadata messages by default\r\n    enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM | CAMERA_MSG_FOCUS |\r\n                  CAMERA_MSG_PREVIEW_METADATA | CAMERA_MSG_FOCUS_MOVE);\r\n\r\n    LOG1("CameraClient::initialize X (pid %d, id %d)", callingPid, mCameraId);\r\n    return OK;\r\n}<\/pre>\n
\u5f53\u7136\u8fd8\u4f1a\u7528\u5230
\nlibhardware\/\/include\/hardware\/camera.h<\/a><\/strong>
\n\u548c
\nlibhardware\/\/include\/hardware\/camera_common.h<\/a><\/strong>
\n\u548c
\nav\/services\/camera\/libcameraservice\/CameraHardwareInterface.h<\/a><\/strong><\/p>\n
status_t initialize(hw_module_t *module)\r\n{\r\n    ALOGI("Opening camera %s", mName.string());\r\n    int rc = module->methods->open(module, mName.string(),\r\n                                   (hw_device_t **)&mDevice);\r\n    if (rc != OK) {\r\n        ALOGE("Could not open camera %s: %d", mName.string(), rc);\r\n        return rc;\r\n    }\r\n    initHalPreviewWindow();\r\n    return rc;\r\n}<\/pre>\n
\u8fd9\u53ea\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u5177\u4f53\u7684\u5b9e\u73b0\u662f\u5382\u5546\u6765\u505a\u7684\u5566<\/p>\n
\u4ee5\u4e0a\u662f\u4ece\u4e0a\u5c42\u8c03\u7528\u5230\u5e95\u5c42\uff0c\u63a5\u7740\u6211\u4eec\u8fd8\u4f1a\u770b\u4e00\u4e2a\u4ece\u5e95\u5c42\u8c03\u7528\u5230\u4e0a\u5c42\u7684\u60c5\u51b5\u3002<\/p>\n
\u4ece\u4ee3\u7801\u770b\u51fa\u6709\u7ed1\u5b9a3\u4e2acallback\u5230driver<\/p>\n
mHardware->setCallbacks(notifyCallback,\r\n        dataCallback,\r\n        dataCallbackTimestamp,\r\n        (void *)mCameraId);<\/pre>\n
\u6240\u4ee5\u8fd9\u4e09\u4e2acallback\u4f1a\u6709\u673a\u4f1a\u88abcall\u5230
\n\u4ee5dataCallback\u4e3a\u4f8b\u5b50\uff0c\u5176\u4e2d\u6709\u4e00\u4e2a\u662f<\/p>\n
\/\/ picture callback - compressed picture ready\r\nvoid CameraClient::handleCompressedPicture(const sp<IMemory>& mem) {\r\n    disableMsgType(CAMERA_MSG_COMPRESSED_IMAGE);\r\n\r\n    sp<ICameraClient> c = mCameraClient;\r\n    mLock.unlock();\r\n    if (c != 0) {\r\n        c->dataCallback(CAMERA_MSG_COMPRESSED_IMAGE, mem, NULL);\r\n    }\r\n}<\/pre>\n
\u901a\u8fc7ICameraClient\u8c03\u7528\u4f1aapp\uff0c\u8fd9\u91cc\u7684ICameraClient\u662fBpCameraClient(\u4e3a\u4ec0\u4e48\u662fBp\uff0c\u540e\u9762\u4f1a\u7a0d\u52a0\u89e3\u91ca)<\/p>\n
\/\/ generic data callback from camera service to app with image data\r\nvoid BpCameraClient::dataCallback(int32_t msgType, const sp<IMemory>& imageData,\r\n                  camera_frame_metadata_t *metadata)\r\n{\r\n    ALOGV("dataCallback");\r\n    Parcel data, reply;\r\n    data.writeInterfaceToken(ICameraClient::getInterfaceDescriptor());\r\n    data.writeInt32(msgType);\r\n    data.writeStrongBinder(imageData->asBinder());\r\n    if (metadata) {\r\n        data.writeInt32(metadata->number_of_faces);\r\n        data.write(metadata->faces, sizeof(camera_face_t) * metadata->number_of_faces);\r\n    }\r\n    remote()->transact(DATA_CALLBACK, data, &reply, IBinder::FLAG_ONEWAY);\r\n}\r\n<\/pre>\n
\u4e8e\u662f<\/p>\n
status_t BnCameraClient::onTransact(\r\n    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)\r\n{\r\n    switch(code) {\r\n        case NOTIFY_CALLBACK: {\r\n            ...\r\n        } break;\r\n        case DATA_CALLBACK: {\r\n            ALOGV("DATA_CALLBACK");\r\n            CHECK_INTERFACE(ICameraClient, data, reply);\r\n            int32_t msgType = data.readInt32();\r\n            sp<IMemory> imageData = interface_cast<IMemory>(data.readStrongBinder());\r\n            camera_frame_metadata_t *metadata = NULL;\r\n            if (data.dataAvail() > 0) {\r\n                metadata = new camera_frame_metadata_t;\r\n                metadata->number_of_faces = data.readInt32();\r\n                metadata->faces = (camera_face_t *) data.readInplace(\r\n                        sizeof(camera_face_t) * metadata->number_of_faces);\r\n            }\r\n            dataCallback(msgType, imageData, metadata); \/\/ \u56e0\u4e3apure virtual function\u7684\u5173\u7cfb\uff0c\u6240\u4ee5\u4f1acall\u5230Camera\u5f53\u4e2d\u7684\u5b9e\u73b0\r\n            if (metadata) delete metadata;\r\n            return NO_ERROR;\r\n        } break;\r\n        case DATA_CALLBACK_TIMESTAMP: {\r\n            ...\r\n        } break;\r\n        default:\r\n            return BBinder::onTransact(code, data, reply, flags);\r\n    }\r\n}<\/pre>\n
\u4e8e\u662f<\/p>\n
\/\/ callback from camera service when frame or image is ready\r\nvoid Camera::dataCallback(int32_t msgType, const sp<IMemory>& dataPtr,\r\n                          camera_frame_metadata_t *metadata)\r\n{\r\n    sp<CameraListener> listener;\r\n    {\r\n        Mutex::Autolock _l(mLock);\r\n        listener = mListener;\r\n    }\r\n    if (listener != NULL) {\r\n        listener->postData(msgType, dataPtr, metadata);\r\n    }\r\n}\r\n<\/pre>\n
\u4eceapp call\u5230service\u662fBnCameraClient(client\u662f\u5b9e\u4f53\uff0cservice\u662f\u4ee3\u7406\uff0c\u4ecenew\u7684\u4ee3\u7801\u5c31\u53ef\u4ee5\u89c2\u5bdf\u51fa\u6765)
\n\u4eceservice call\u5230app\u662fBpCameraClient(service\u662f\u5b9e\u4f53\uff0cclient\u662f\u4ee3\u7406)
\n\u800c\u8fd9\u4e2aBn\u5230Bp\u7684\u8f6c\u6362\u662f\u901a\u8fc7<\/p>\n
sp<ICameraClient> cameraClient = interface_cast<ICameraClient>(data.readStrongBinder());<\/pre>\n
\u5b8c\u6210\u7684\u3002<\/p>\n
\u540e\u9762\u6211\u4eec\u4f1a\u5217\u4e3e\u4e9b\u9700\u8981\u6ce8\u610f\u7684\u70b9\uff1a<\/p>\n
ICameraClient\u7ee7\u627f\u81eaIInterface
\nBnCameraClient\u7ee7\u627f\u81eaBnInterface\uff0c\u7136\u800cBnInterface\u53c8\u7ee7\u627f\u81eaICameraClient\uff0cBBinder<\/p>\n
Camera\u7ee7\u627f\u81eaBnCameraClient<\/p>\n
ICameraService\u7ee7\u627f\u81eaIInterface
\nBnCameraService\u7ee7\u627f\u81eaBnInterface\uff0c\u7136\u800cBnInterface\u53c8\u7ee7\u627f\u81eaICameraService\uff0cBBinder<\/p>\n
ICamera\u7ee7\u627f\u81eaIInterface
\nBnCamera\u7ee7\u627f\u81eaBnInterface\uff0c\u7136\u800cBnInterface\u53c8\u7ee7\u627f\u81eaICamera\uff0cBBinder<\/p>\n
CameraService\u7ee7\u627f\u81eaBinderService\uff0cBnCameraService\uff0cIBinder::DeathRecipient
\n\u800cBinderService\u4e3b\u8981\u662f\u7528\u6765\u5b9e\u4f8b\u5316service\u7684\u7edf\u4e00\u63a5\u53e3<\/p>\n
CameraService\u6709\u4e2a\u5d4c\u5957\u7c7bClient\u7ee7\u627f\u81eaBnCamera
\n\u771f\u6b63\u7684\u5b9e\u73b0\u5927\u90e8\u5206\u5728CameraClient\u5f53\u4e2d(Camera2Client\u662fGoogle\u63d0\u4f9b\u7684\u8c03\u7528\u65b0\u7684HAL\u7684\u4e00\u79cd\u65b9\u5f0f\uff0c\u90e8\u5206\u5382\u5546\u4f1a\u7528\u8fd9\u6837\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\u81ea\u5df1\u7684HAL\uff0c\u6bd4\u5982Qualcomm)
\n\u8fd9\u624d\u662f\u771f\u6b63\u7684client\uff0c\u76f4\u63a5\u8c03\u7528HW\u6216\u8005\u88abHW\u8c03\u7528\u3002<\/p>\n
sendCommand\u5f80driver\u9001\u53c2\u6570\u7684\u65f6\u5019\u4f1a\u5148\u68c0\u9a8c\u662f\u4e0d\u662fCameraService\u8fd9\u5c42\u53ef\u4ee5\u5904\u7406\u7684\u4e1c\u897f(\u6709\u4e9b\u4e1c\u897f\u4e0d\u9700\u8981\u5230driver\u7684)<\/p>\n
cmd == CAMERA_CMD_SET_DISPLAY_ORIENTATION
\ncmd == CAMERA_CMD_ENABLE_SHUTTER_SOUND
\ncmd == CAMERA_CMD_PLAY_RECORDING_SOUND
\ncmd == CAMERA_CMD_SET_VIDEO_BUFFER_COUNT
\ncmd == CAMERA_CMD_PING
\n\u4ee5\u4e0a\u8fd9\u4e9b\u90fdCameraService\u81ea\u5df1\u5904\u7406\u4e86
\n\u5176\u4ed6\u5747\u4e22\u7ed9driver(mHardware->sendCommand(cmd, arg1, arg2);)<\/p>\n
\u63a5\u4e0b\u6765\u662f\u4e00\u4e9b\u7591\u95ee\u70b9\uff1a<\/p>\n
\/\/ these are initialized in the constructor.
\nsp     mHardware;       \/\/ cleared after disconnect()
\nmHardware\u5728disconnect\u5f53\u4e2d\u88abclear<\/p>\n
\/\/ Make sure disconnect() is done once and once only, whether it is called
\n\/\/ from the user directly, or called by the destructor.
\nif (mHardware == 0) return;
\n\u8fd9\u662f\u9632\u6b62disconnect\u8c03\u7528\u4e00\u6b21\u4e4b\u540e\uff0c\u6790\u6784\u51fd\u6570\u53c8\u8c03\u7528\u4e00\u6b21\u3002<\/p>\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"
<p>\u8bf4\u5230\u67b6\u6784\/\u6784\u67b6\u5c31\u89c9\u5f97\u5fc3\u865a\uff0c\u611f\u89c9\u8fd9\u4e24\u4e2a\u5b57\u592a\u9ad8\u7aef\u4e86\uff0c\u6240\u4ee5\u6211\u53ea\u6562\u7528\u7ed3\u6784\u6765\u8868\u8fbe\u3002<\/p> <p>\u4ee5\u4e0b\u8868\u8ff0\u5982\u679c\u5b58\u5728\u9519\u8bef\uff0c\u8bf7\u6307\u6559\uff01<\/p> <p>\u4e4b\u524d\u6709\u5728\u4e00\u7bc7\u535a\u5ba2\u4e2d\u63d0\u5230Camera\u76f8\u5173\u7684\u4e1c\u897f<br \/> <a href="http:\/\/guoh.ai\/lifelog\/2012\/09\/asop-camera-source-code-reading-video-snapshot\/" target="_blank">http:\/\/guoh.ai\/lifelog\/2012\/09\/asop-camera-source-code-reading-video-snapshot\/<\/a><\/p> <p>\u6bd4\u5982<\/p> <pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/frameworks\/base\/core\/java\/android\/hardware\/Camera.java $ANDROID_SRC_HOME\/frameworks\/base\/core\/jni\/android_hardware_Camera.cpp<\/pre> <p>\/\/ \u6ce8\uff1a\u76ee\u524d\u4ee5\u4e0b\u8fd9\u4e24\u4e2a\u6587\u4ef6\u5728JB\u5f53\u4e2d\u5e94\u8be5\u88ab\u79fb\u52a8\u4f4d\u7f6e\u4e86\uff0c\u7531\u6b64\u53ef\u89c1Android\u4e5f\u662f\u4e2a\u6d3b\u8dc3\u7684\u9879\u76ee<\/p> <pre class="brush: bash; title: ; notranslate" title="">$ANDROID_SRC_HOME\/frameworks\/base\/include\/camera\/Camera.h $ANDROID_SRC_HOME\/frameworks\/base\/libs\/camera\/Camera.cpp<\/pre> <p>\u8fd9\u7bc7\u535a\u5ba2\u662f\u9605\u8bfb<a href="http:\/\/source.android.com\/devices\/camera.html" target="_blank">http:\/\/source.android.com\/devices\/camera.html<\/a>\uff0c\u7ed3\u5408\u5728JB\u4ee3\u7801\u7684\u57fa\u7840\u4e0a\u5199\u7684\u7b14\u8bb0\uff0c\u53ef\u80fd\u4e0d\u662f\u90a3\u4e48\u8be6\u7ec6\u548c\u6709\u903b\u8f91\uff0c\u53ea\u5173\u6ce8\u91cd\u70b9\u548c\u8981\u6ce8\u610f\u7684\u5730\u65b9\uff0c\u6240\u4ee5\u5982\u679c\u4f60\u521a\u597d\u8bfb\u5230\uff0c\u4f46\u662f\u4f60\u53c8\u6ca1\u6709\u4ec0\u4e48Android Camera\u7684\u57fa\u7840\u7684\u8bdd\uff0c\u5efa\u8bae\u8fd8\u662f\u5148\u770b\u770b<a href="http:\/\/developer.android.com\/guide\/topics\/media\/camera.html" target="_blank">http:\/\/developer.android.com\/guide\/topics\/media\/camera.html<\/a>\u548c<a href="http:\/\/developer.android.com\/reference\/android\/hardware\/Camera.html" target="_blank">Reference<\/a><\/p> <p>\u6b63\u5f0f\u5f00\u59cb<br \/> \u5927\u4f53\u6765\u8bf4Camera\u5206\u4e3a\u8fd9\u4e48\u591a\u90e8\u5206<br \/> <em><strong>APP — JNI — NATIVE — BINDER — CAMERA SERVICE — HAL — DRIVER<\/strong><\/em><\/p> <p>\u4e0b\u9762\u5217\u51fa\u8fd9\u6bcf\u4e00\u90e8\u5206\u5bf9\u5e94\u4e8eAOSP\u5f53\u4e2d\u7684\u4ee3\u7801<\/p> <pre class="brush: … Continue reading Android Camera\u7cfb\u7edf\u7ed3\u6784<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_gfmr_meta_descriptions":[],"_gfmr_multilingual_taxonomy_terms":[],"footnotes":""},"categories":[7,34],"tags":[27],"class_list":["post-548","post","type-post","status-publish","format-standard","hentry","category-android","category-multimedia","tag-camera"],"_links":{"self":[{"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/posts\/548","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/comments?post=548"}],"version-history":[{"count":43,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/posts\/548\/revisions"}],"predecessor-version":[{"id":562,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/posts\/548\/revisions\/562"}],"wp:attachment":[{"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/media?parent=548"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/categories?post=548"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/guoh.ai\/lifelog\/wp-json\/wp\/v2\/tags?post=548"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}