第18讲 Camera Java Framework AIDL概述

Charles · 2024 年8 月 26 日 00:08

本讲是Android Camera Native Framework专题的第18讲，我们介绍Camera Java Framework AIDL概述。

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Wechat	极客笔记圈

Camera Java Framework AIDL文件路径

路径：/frameworks/av/camera/aidl/android/hardware/

Android 13 ICameraService.aidl代码如下:

/*
 * Copyright (C) 2013 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.
 */
package android.hardware;
import android.hardware.ICamera;

import android.hardware.ICameraClient;

import android.hardware.camera2.ICameraDeviceUser;

import android.hardware.camera2.ICameraDeviceCallbacks;

import android.hardware.camera2.ICameraInjectionCallback;

import android.hardware.camera2.ICameraInjectionSession;

import android.hardware.camera2.params.VendorTagDescriptor;

import android.hardware.camera2.params.VendorTagDescriptorCache;

import android.hardware.camera2.utils.ConcurrentCameraIdCombination;

import android.hardware.camera2.utils.CameraIdAndSessionConfiguration;

import android.hardware.camera2.impl.CameraMetadataNative;

import android.hardware.ICameraServiceListener;

import android.hardware.CameraInfo;

import android.hardware.CameraStatus;
/**


Binder interface for the native camera service running in mediaserver.



@hide

/

interface ICameraService

{

/*

All camera service and device Binder calls may return a
ServiceSpecificException with the following error codes

*/

const int ERROR_PERMISSION_DENIED = 1;

const int ERROR_ALREADY_EXISTS = 2;

const int ERROR_ILLEGAL_ARGUMENT = 3;

const int ERROR_DISCONNECTED = 4;

const int ERROR_TIMED_OUT = 5;

const int ERROR_DISABLED = 6;

const int ERROR_CAMERA_IN_USE = 7;

const int ERROR_MAX_CAMERAS_IN_USE = 8;

const int ERROR_DEPRECATED_HAL = 9;

const int ERROR_INVALID_OPERATION = 10;

/**

Types for getNumberOfCameras

*/

const int CAMERA_TYPE_BACKWARD_COMPATIBLE = 0;

const int CAMERA_TYPE_ALL = 1;

/**

Return the number of camera devices available in the system

*/

int getNumberOfCameras(int type);

/**

Fetch basic camera information for a camera device

*/

CameraInfo getCameraInfo(int cameraId);

/**

Default UID/PID values for non-privileged callers of
connect() and connectDevice()

*/

const int USE_CALLING_UID = -1;

const int USE_CALLING_PID = -1;

/**

Open a camera device through the old camera API

*/

ICamera connect(ICameraClient client,

int cameraId,

String opPackageName,

int clientUid, int clientPid,

int targetSdkVersion);

/**

Open a camera device through the new camera API
Only supported for device HAL versions >= 3.2

*/

ICameraDeviceUser connectDevice(ICameraDeviceCallbacks callbacks,

String cameraId,

String opPackageName,

@nullable String featureId,

int clientUid, int oomScoreOffset,

int targetSdkVersion);

/**

Add listener for changes to camera device and flashlight state.

Also returns the set of currently-known camera IDs and state of each device.
Adding a listener will trigger the torch status listener to fire for all
devices that have a flash unit.

*/

CameraStatus addListener(ICameraServiceListener listener);

/**

Get a list of combinations of camera ids which support concurrent streaming.


*/

ConcurrentCameraIdCombination getConcurrentCameraIds();
/**

Check whether a particular set of session configurations are concurrently supported by the
corresponding camera ids.

@param sessions the set of camera id and session configuration pairs to be queried.
@param targetSdkVersion the target sdk level of the application calling this function.
@return true  - the set of concurrent camera id and stream combinations is supported.

    false - the set of concurrent camera id and stream combinations is not supported



            OR the method was called with a set of camera ids not returned by



            getConcurrentCameraIds().



*/

boolean isConcurrentSessionConfigurationSupported(

in CameraIdAndSessionConfiguration sessions,

int targetSdkVersion);
/**

Remove listener for changes to camera device and flashlight state.

*/

void removeListener(ICameraServiceListener listener);

/**

Read the static camera metadata for a camera device.
Only supported for device HAL versions >= 3.2

*/

CameraMetadataNative getCameraCharacteristics(String cameraId, int targetSdkVersion);

/**

Read in the vendor tag descriptors from the camera module HAL.
Intended to be used by the native code of CameraMetadataNative to correctly
interpret camera metadata with vendor tags.

*/

VendorTagDescriptor getCameraVendorTagDescriptor();

/**

Retrieve the vendor tag descriptor cache which can have multiple vendor
providers.
Intended to be used by the native code of CameraMetadataNative to correctly
interpret camera metadata with vendor tags.

*/

VendorTagDescriptorCache getCameraVendorTagCache();

/**

Read the legacy camera1 parameters into a String

*/

String getLegacyParameters(int cameraId);

/**

apiVersion constants for supportsCameraApi

*/

const int API_VERSION_1 = 1;

const int API_VERSION_2 = 2;

// Determines if a particular API version is supported directly for a cameraId.

boolean supportsCameraApi(String cameraId, int apiVersion);

// Determines if a cameraId is a hidden physical camera of a logical multi-camera.

boolean isHiddenPhysicalCamera(String cameraId);

// Inject the external camera to replace the internal camera session.

ICameraInjectionSession injectCamera(String packageName, String internalCamId,

String externalCamId, in ICameraInjectionCallback CameraInjectionCallback);
void setTorchMode(String cameraId, boolean enabled, IBinder clientBinder);
// Change the brightness level of the flash unit associated with cameraId to strengthLevel.

// If the torch is in OFF state and strengthLevel > 0 then the torch will also be turned ON.

void turnOnTorchWithStrengthLevel(String cameraId, int strengthLevel, IBinder clientBinder);
// Get the brightness level of the flash unit associated with cameraId.

int getTorchStrengthLevel(String cameraId);
/**

Notify the camera service of a system event.  Should only be called from system_server.

Callers require the android.permission.CAMERA_SEND_SYSTEM_EVENTS permission.

*/

const int EVENT_NONE = 0;

const int EVENT_USER_SWITCHED = 1; // The argument is the set of new foreground user IDs.

const int EVENT_USB_DEVICE_ATTACHED = 2; // The argument is the deviceId and vendorId

const int EVENT_USB_DEVICE_DETACHED = 3; // The argument is the deviceId and vendorId

oneway void notifySystemEvent(int eventId, in int args);

/**

Notify the camera service of a display configuration change.

Callers require the android.permission.CAMERA_SEND_SYSTEM_EVENTS permission.

*/

oneway void notifyDisplayConfigurationChange();

/**

Notify the camera service of a device physical status change. May only be called from
a privileged process.

newState is a bitfield consisting of DEVICE_STATE_* values combined together. Valid state
combinations are device-specific. At device startup, the camera service will assume the device
state is NORMAL until otherwise notified.

Callers require the android.permission.CAMERA_SEND_SYSTEM_EVENTS permission.

*/

oneway void notifyDeviceStateChange(long newState);

// Bitfield constants for notifyDeviceStateChange

// All bits >= 32 are for custom vendor states

// Written as ints since AIDL does not support long constants.

const int DEVICE_STATE_NORMAL = 0;

const int DEVICE_STATE_BACK_COVERED = 1;

const int DEVICE_STATE_FRONT_COVERED = 2;

const int DEVICE_STATE_FOLDED = 4;

const int DEVICE_STATE_LAST_FRAMEWORK_BIT = 0x80000000; // 1 << 31;


}

Camera Java Framework AIDL产生的库/文件

AIDL产生的Java源文件：

out\soong\.intermediates\frameworks\base\framework-minus-apex\android_common\gen\aidl\ aidl36.srcjar

AIDL产生的C++源文件：

out\soong\.intermediates\frameworks\av\camera\libcamera_client\android_arm64_armv8-a_cortex-a55_shared_cfi\gen\aidl\android\hardware

Camera Java Framework AIDL核心类

Class	Description
ICameraService.aidl	Cameraserver进程对外提供的入口接口
ICameraServiceListener.aidl	ICameraService的回调类，通知CameraService相关状态
ICameraDeviceUser.aidl	用于操作某一颗Camera Device
ICameraDeviceCallbacks.aidl	Camera Device的回调类

Camera Java Framework AIDL核心类之间的调用关系如下图所示：