MTK 双摄算法集成

和你一起终身学习，这里是程序员 Android

经典好文推荐，通过阅读本文，您将收获以下知识点:

一、 双摄算法简介
二、 选择feature和配置feature table
三、挂载算法
四、 APP调用算法
五、结语

一、 双摄算法简介

双摄算法相比单帧算法和多帧算法要复杂的多。无论是用于夜拍，HDR，还是用于虚化（景深/人像/大光圈）的双摄算法，一般都会需要主、辅两个摄像头的图像同步。并且，由于每一组摄像头模组都有一定的差异，还会开发特定的标定程序，在工厂的产线进行标定。标定程序将标定参数（也就是标定的结果）写入到不易被擦除的分区（如NV分区）中。拍照时，双摄算法根据标定参数修正模组差异。并使用主、辅摄像头的图像进行计算，得出深度、曝光之类的参数。使用得出的深度、曝光之类的参数来调整主摄图像，达到夜拍增强、HDR、背景虚化(景深/人像/大光圈)等等效果。

对于算法集成来说，一般有两点：

• 标定程序的集成：包括标定APP以及配置APP的SELinux权限等等。
• 双摄算法的集成：与单帧算法、多帧算法类似，选择对应的feature，实现对应的plugin，挂载算法。

由于预置标定APP比较简单，本文就不介绍，关于配置标定APP的SELinux权限，可参考我的另外一篇文章：SELinux权限。

由于我无法提供一个真正的双摄算法，还是和介绍单帧算法集成时类似，提供一个模拟算法库，这个模拟算法库拼接主、辅摄像头的图像，将辅摄图像拼接到主摄图像中间，最终呈现类似画中画的效果。

二、 选择feature和配置feature table

2.1 选择feature

双摄算法是很常见的算法，在MTK已预置一些双摄的feature，总结下大概有以下feature是用于双摄的：
vendor/mediatek/proprietary/hardware/mtkcam3/include/mtkcam3/3rdparty/mtk/mtk_feature_type.h：

    MTK_FEATURE_DEPTH       = 1ULL << 8, 
    MTK_FEATURE_BOKEH       = 1ULL << 9,
    MTK_FEATURE_VSDOF       = (MTK_FEATURE_DEPTH|MTK_FEATURE_BOKEH),
    MTK_FEATURE_DUAL_YUV    = 1ULL << 14,
    MTK_FEATURE_DUAL_HWDEPTH  = 1ULL << 15,

其中，MTK_FEATURE_DEPTH和MTK_FEATURE_BOKEH用于双摄虚化，并且计算深度和模糊处理是在两个分开的挂载点进行。

vendor/mediatek/proprietary/hardware/mtkcam3/include/mtkcam3/3rdparty/customer/customer_feature_type.h：

    TP_FEATURE_DEPTH        = 1ULL << 37,
    TP_FEATURE_BOKEH        = 1ULL << 38,
    TP_FEATURE_VSDOF        = (TP_FEATURE_DEPTH|TP_FEATURE_BOKEH),
    TP_FEATURE_FUSION       = 1ULL << 39,
    TP_FEATURE_HDR_DC       = 1ULL << 40,
    TP_FEATURE_DUAL_YUV     = 1ULL << 41,
    TP_FEATURE_DUAL_HWDEPTH = 1ULL << 42,
    TP_FEATURE_PUREBOKEH    = 1ULL << 43,

customer部分定义的feature，其中TP_FEATURE_DEPTH和TP_FEATURE_BOKEH也是用于双摄虚化，并且计算深度和模糊处理也是在两个分开的node进行。TP_FEATURE_FUSION和TP_FEATURE_PUREBOKEH是用于双摄虚化的，但是它们将计算深度和虚化处理放在同一个挂载点进行。TP_FEATURE_HDR_DC是用于双摄HDR算法的。

按MTK的设计意图来看，MTK_FEATURE_DUAL_YUV和TP_FEATURE_DUAL_YUV两个feature应该也是可以用于双摄算法的，但是我没有试过，我一般用TP_FEATURE_FUSION或者TP_FEATURE_PUREBOKEH，有兴趣的童鞋可以自己试一下。

既然MTK已经预置好了，这一步我们就对号入座，不用再额外添加feature。由于是第三方算法，所以我们选择TP_FEATURE_PUREBOKEH。

2.2 配置feature table

上一步，我们选择了TP_FEATURE_PUREBOKEH，MTK很贴心的在vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/mtk/mtk_scenario_mgr.cpp中已经定义了一个MTK_FEATURE_COMBINATION_TP_PUREBOKEH。所以定义这一步我们也省了，只需要将MTK_FEATURE_COMBINATION_TP_PUREBOKEH添加到对应的MTK_CAMERA_SCENARIO_CAPTURE_DUALCAM。这里由于我们没有其它双摄算法，将其它两行注释掉。

diff --git a/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/mtk/mtk_scenario_mgr.cpp b/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/mtk/mtk_scenario_mgr.cpp
index 38365e0602..7adc2a76db 100755
--- a/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/mtk/mtk_scenario_mgr.cpp
+++ b/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/mtk/mtk_scenario_mgr.cpp
@@ -363,8 +363,9 @@ const std::vector<std::unordered_map<int32_t, ScenarioFeatures>>  gMtkScenarioFe
         CAMERA_SCENARIO_END
         //
         CAMERA_SCENARIO_START(MTK_CAMERA_SCENARIO_CAPTURE_DUALCAM)
-        ADD_CAMERA_FEATURE_SET(MTK_FEATURE_MFNR,   MTK_FEATURE_COMBINATION_TP_VSDOF_MFNR)
-        ADD_CAMERA_FEATURE_SET(NO_FEATURE_NORMAL,  MTK_FEATURE_COMBINATION_TP_VSDOF)
+        //ADD_CAMERA_FEATURE_SET(MTK_FEATURE_MFNR,   MTK_FEATURE_COMBINATION_TP_VSDOF_MFNR)
+        //ADD_CAMERA_FEATURE_SET(NO_FEATURE_NORMAL,  MTK_FEATURE_COMBINATION_TP_VSDOF)
+        ADD_CAMERA_FEATURE_SET(NO_FEATURE_NORMAL,  MTK_FEATURE_COMBINATION_TP_PUREBOKEH)
         CAMERA_SCENARIO_END
         //
         CAMERA_SCENARIO_START(MTK_CAMERA_SCENARIO_CAPTURE_CSHOT)

注意:
如果是9.0代码，是区分camera id的，feature table的配置要修改openId = 4中的MTK_CAMERA_SCENARIO_CAPTURE_DUALCAM。

顺带提一下4个摄像头的手机，一般情况下，逻辑camera id的划分：

• 0：后置主摄
• 1：前置主摄
• 2：后置辅摄
• 3：后置广角
• 4：双摄0+2同时开。

市面上的手机已经有5、6个摄像头的。也已经有多组双摄模式的，例如，主摄和辅摄虚化一组，广角加长焦一组，主摄和微距一组。甚至有些手机前摄也有两个摄像头的。而我还没有接触过多个双摄模式的项目，也没有接触过前置双摄的项目，并且每个公司，甚至每个项目可能都会一些差异，所以我这里列举的不一定完整和准确，欢迎了解的童鞋交流补充。

三、挂载算法

3.1 为算法选择plugin

MTK HAL3在vendor/mediatek/proprietary/hardware/mtkcam3/include/mtkcam3/3rdparty/plugin/PipelinePluginType.h 中将三方算法的挂载点大致分为以下几类：

• BokehPlugin： Bokeh算法挂载点，双摄景深算法的虚化部分。
• DepthPlugin： Depth算法挂载点，双摄景深算法的计算深度部分。
• FusionPlugin： Depth和Bokeh放在1个算法中，即合并的双摄景深算法挂载点。
• JoinPlugin： Streaming相关算法挂载点，预览算法都挂载在这里。
• MultiFramePlugin： 多帧算法挂载点，包括YUV与RAW，例如MFNR/HDR
• RawPlugin： RAW算法挂载点，例如remosaic
• YuvPlugin： Yuv单帧算法挂载点，例如美颜、广角镜头畸变校正等。

对号入座，为要集成的算法选择相应的plugin。这里模拟算法库是在同一个挂载点处理的双摄算法，所以选择FusionPlugin。

3.2 添加全局宏控

为了能控制某个项目是否集成此算法，我们在device/mediateksample/[platform]/ProjectConfig.mk中添加一个宏，用于控制新接入算法的编译：

QXT_DUALCAMERA_SUPPORT = yes

当某个项目不需要这个算法时，将device/mediateksample/[platform]/ProjectConfig.mk的QXT_DUALCAMERA_SUPPORT的值设为 no 就可以了。

3.3 编写算法集成文件

vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/customer/cp_dualcamera/
├── Android.mk
├── DualCameraCapture.cpp
├── include
│ └── dual_camera.h
└── lib
├── arm64-v8a
│ └── libdualcamera.so
└── armeabi-v7a
└── libdualcamera.so

文件说明：

• Android.mk中配置算法库、头文件、集成的源代码DualCameraCapture.cpp文件，将它们编译成库libmtkcam.plugin.tp_dc，供libmtkcam_3rdparty.customer依赖调用。

• libdualcamera.so可以将主、辅摄图像拼接成一张画中画效果的图，libdualcamera.so用来模拟需要接入的第三方双摄算法库。dual_camera.h是头文件。

• DualCameraCapture.cpp是集成的源代码CPP文件。

3.3.1 mtkcam3/3rdparty/customer/cp_dualcamera/Android.mk

ifeq ($(QXT_DUALCAMERA_SUPPORT),yes)

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := libdualcamera
LOCAL_SRC_FILES_32 := lib/armeabi-v7a/libdualcamera.so
LOCAL_SRC_FILES_64 := lib/arm64-v8a/libdualcamera.so
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE_CLASS := SHARED_LIBRARIES
LOCAL_MODULE_SUFFIX := .so
LOCAL_PROPRIETARY_MODULE := true
LOCAL_MULTILIB := both
include $(BUILD_PREBUILT)
################################################################################
#
################################################################################
include $(CLEAR_VARS)

#-----------------------------------------------------------
-include $(TOP)/$(MTK_PATH_SOURCE)/hardware/mtkcam/mtkcam.mk

#-----------------------------------------------------------
LOCAL_SRC_FILES += DualCameraCapture.cpp

#-----------------------------------------------------------
LOCAL_C_INCLUDES += $(MTKCAM_C_INCLUDES)
LOCAL_C_INCLUDES += $(TOP)/$(MTK_PATH_SOURCE)/hardware/mtkcam3/include $(MTK_PATH_SOURCE)/hardware/mtkcam/include
LOCAL_C_INCLUDES += $(TOP)/$(MTK_PATH_COMMON)/hal/inc
LOCAL_C_INCLUDES += $(TOP)/$(MTK_PATH_CUSTOM_PLATFORM)/hal/inc
#
LOCAL_C_INCLUDES += system/media/camera/include
LOCAL_C_INCLUDES += $(TOP)/$(MTK_PATH_SOURCE)/hardware/mtkcam3/3rdparty/customer/cp_dualcamera/include

#-----------------------------------------------------------
LOCAL_CFLAGS += $(MTKCAM_CFLAGS)
#

#-----------------------------------------------------------
LOCAL_STATIC_LIBRARIES +=
#
LOCAL_WHOLE_STATIC_LIBRARIES +=

#-----------------------------------------------------------
LOCAL_SHARED_LIBRARIES += liblog
LOCAL_SHARED_LIBRARIES += libutils
LOCAL_SHARED_LIBRARIES += libcutils
LOCAL_SHARED_LIBRARIES += libmtkcam_metadata
LOCAL_SHARED_LIBRARIES += libmtkcam_imgbuf
#LOCAL_SHARED_LIBRARIES += libmtkcam_3rdparty

#-----------------------------------------------------------
LOCAL_HEADER_LIBRARIES := libutils_headers liblog_headers libhardware_headers

#-----------------------------------------------------------
LOCAL_MODULE := libmtkcam.plugin.tp_dc
LOCAL_PROPRIETARY_MODULE := true
LOCAL_MODULE_OWNER := mtk
LOCAL_MODULE_TAGS := optional
include $(MTK_STATIC_LIBRARY)

################################################################################
#
################################################################################
include $(call all-makefiles-under,$(LOCAL_PATH))
endif

3.3.2 mtkcam3/3rdparty/customer/cp_dualcamera/include/dual_camera.h

#ifndef QXT_DUAL_CAMERA_H
#define QXT_DUAL_CAMERA_H

typedef unsigned char uchar;

#define CENTER 0
#define LEFT_TOP 1
#define LEFT_BOTTOM 2
#define RIGHT_TOP 3
#define RIGHT_BOTTOM 4

class DualCamera {

public:
    DualCamera();

    ~DualCamera();

    void processI420(uchar *main, int mainWidth, int mainHeight,
                            uchar *sub, int subWidth, int subHeight);

    void processI420(uchar *mainY, uchar *mainU, uchar *mainV, int mainWidth, int mainHeight,
                            uchar *subY, uchar *subU, uchar *subV, int subWidth, int subHeight);

    void processNV21(uchar *main, int mainWidth, int mainHeight,
                            uchar *sub, int subWidth, int subHeight);

    void processNV21(uchar *mainY, uchar *mainUV, int mainWidth, int mainHeight,
                            uchar *subY, uchar *subUV, int subWidth, int subHeight);

private:
    int position;
};

#endif //QXT_DUAL_CAMERA_H

头文件中的接口函数介绍：

• DualCamera： 构造函数，构造函数中会模拟读取标定参数文件，这里模拟的标定参数文件内容只是一个数字，用于指定副摄图像的座标位置。
• processI420：用于将主副摄图像拼接成画中画，输入和输出图像必须是I420格式。
• processNV21：用于将主副摄图像拼接成画中画，输入和输出图像必须是NV21格式。
• ~DualCamera()： 析构函数，没有实际作用。

为了方便有兴趣的童鞋们，实现代码dual_camera.cpp也一并贴上：

#include <cstring>
#include <cstdio>
#include "dual_camera.h"
#include "logger.h"

using namespace std;

DualCamera::DualCamera() {
    const char * path = "/vendor/persist/camera/calibration.cfg";
    FILE *fp;
    if ((fp = fopen(path, "r")) != nullptr) {
        auto buffer = new int[1];
        fread(buffer, 1, sizeof(int), fp);
        position = buffer[0];
    } else {
        LOGE("Failed to open: %s", path);
        position = CENTER;
    }
}

DualCamera::~DualCamera() = default;

void DualCamera::processI420(uchar *main, int mainWidth, int mainHeight,
                                 uchar *sub, int subWidth, int subHeight) {
    uchar *mainY = main;
    uchar *mainU = main + mainWidth * mainHeight;
    uchar *mainV = main + mainWidth * mainHeight * 5 / 4;
    uchar *subY = sub;
    uchar *subU = sub + subWidth * subHeight;
    uchar *subV = sub + subWidth * subHeight * 5 / 4;
    processI420(mainY, mainU, mainV, mainWidth, mainHeight, subY, subU, subV, subWidth, subHeight);
}

void
DualCamera::processI420(uchar *mainY, uchar *mainU, uchar *mainV, int mainWidth, int mainHeight,
                            uchar *subY, uchar *subU, uchar *subV, int subWidth, int subHeight) {
    int mainUVHeight = mainHeight / 2;
    int mainUVWidth = mainWidth / 2;

    int subUVHeight = subHeight / 2;
    int subUVWidth = subWidth / 2;

    //merge
    unsigned char *pDstY;
    unsigned char *pSrcY;

    for (int i = 0; i < subHeight; i++) {
        pSrcY = subY + i * subWidth;
        if (position == LEFT_TOP) {
            pDstY = mainY + i * mainWidth;
        } else if (position == LEFT_BOTTOM) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) * mainWidth);
        } else if (position == RIGHT_TOP) {
            pDstY = mainY + i * mainWidth + (mainWidth - subWidth);
        } else if (position == RIGHT_BOTTOM) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) * mainWidth) +
                    (mainWidth - subWidth);
        } else if (position == CENTER) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) / 2 * mainWidth) +
                    (mainWidth - subWidth) / 2;
        } else {
            LOGE("Unsupported position: %d", position);
            return;
        }
        memcpy(pDstY, pSrcY, subWidth);
    }

    unsigned char *pDstU;
    unsigned char *pDstV;
    unsigned char *pSrcU;
    unsigned char *pSrcV;
    for (int i = 0; i < subUVHeight; i++) {
        pSrcU = subU + i * subUVWidth;
        pSrcV = subV + i * subUVWidth;
        if (position == LEFT_TOP) {
            pDstU = mainU + i * mainUVWidth;
            pDstV = mainV + i * mainUVWidth;
        } else if (position == LEFT_BOTTOM) {
            pDstU = mainU + ((mainUVHeight - subUVHeight) * mainUVWidth) + i * mainUVWidth;
            pDstV = mainV + ((mainUVHeight - subUVHeight) * mainUVWidth) + i * mainUVWidth;
        } else if (position == RIGHT_TOP) {
            pDstU = mainU + i * mainUVWidth + mainUVWidth - subUVWidth;
            pDstV = mainV + i * mainUVWidth + mainUVWidth - subUVWidth;
        } else if (position == RIGHT_BOTTOM) {
            pDstU = mainU + ((mainUVHeight - subUVHeight) * mainUVWidth) +
                    i * mainUVWidth + (mainUVWidth - subUVWidth);
            pDstV = mainV + ((mainUVHeight - subUVHeight) * mainUVWidth) +
                    i * mainUVWidth + (mainUVWidth - subUVWidth);
        } else if (position == CENTER) {
            pDstU = mainU + ((mainUVHeight - subUVHeight) / 2 * mainUVWidth) +
                    i * mainUVWidth + (mainUVWidth - subUVWidth) / 2;
            pDstV = mainV + ((mainUVHeight - subUVHeight) / 2 * mainUVWidth) +
                    i * mainUVWidth + (mainUVWidth - subUVWidth) / 2;
        } else {
            LOGE("Unsupported position: %d", position);
            return;
        }
        memcpy(pDstU, pSrcU, subUVWidth);
        memcpy(pDstV, pSrcV, subUVWidth);

    }
}

void DualCamera::processNV21(uchar *main, int mainWidth, int mainHeight,
                 uchar *sub, int subWidth, int subHeight) {
    uchar *mainY = main;
    uchar *mainUV = main + mainWidth * mainHeight;
    uchar *subY = sub;
    uchar *subUV = sub + subWidth * subHeight;
    processNV21(mainY, mainUV, mainWidth, mainHeight, subY, subUV, subWidth, subHeight);
}

void DualCamera::processNV21(uchar *mainY, uchar *mainUV, int mainWidth, int mainHeight,
                 uchar *subY, uchar *subUV, int subWidth, int subHeight) {
    LOGD("[processNV21] mainY:%p, mainUV:%p, mainWidth:%d, mainHeight:%d, subY:%p, subUV:%p, subWidth:%d, subHeight:%d, position:%d",
            mainY, mainUV, mainWidth, mainHeight, subY, subUV, subWidth, subHeight, position);
    int mainUVHeight = mainHeight / 2;
    int mainUVWidth = mainWidth / 2;
    unsigned char *pDstY;
    unsigned char *pSrcY;

    for (int i = 0; i < subHeight; i++) {
        pSrcY = subY + i * subWidth;
        if (position == LEFT_TOP) {
            pDstY = mainY + i * mainWidth;
        } else if (position == LEFT_BOTTOM) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) * mainWidth);
        } else if (position == RIGHT_TOP) {
            pDstY = mainY + i * mainWidth + (mainWidth - subWidth);
        } else if (position == RIGHT_BOTTOM) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) * mainWidth) +
                    (mainWidth - subWidth);
        } else if (position == CENTER) {
            pDstY = mainY + i * mainWidth + ((mainHeight - subHeight) / 2 * mainWidth) +
                    (mainWidth - subWidth) / 2;
        } else {
            LOGE("Unsupported position: %d", position);
            return;
        }
        memcpy(pDstY, pSrcY, subWidth);
    }

    int subUVHeight = subHeight / 2;
    int subUVWidth = subWidth / 2;
    unsigned char *pDstUV;
    unsigned char *pSrcUV;
    for (int i = 0; i < subUVHeight; i++) {
        pSrcUV = subUV + i * subUVWidth * 2;
        if (position == LEFT_TOP) {
            pDstUV = mainUV + i * mainUVWidth * 2;
        } else if (position == LEFT_BOTTOM) {
            pDstUV = mainUV + ((mainUVHeight - subUVHeight) * mainUVWidth + i * mainUVWidth) * 2;
        } else if (position == RIGHT_TOP) {
            pDstUV = mainUV + (i * mainUVWidth + mainUVWidth - subUVWidth) * 2;
        } else if (position == RIGHT_BOTTOM)  {
            pDstUV = mainUV + ((mainUVHeight - subUVHeight) * mainUVWidth +
                    i * mainUVWidth + mainUVWidth - subUVWidth) * 2;
        } else if (position == CENTER) {
            pDstUV = mainUV + ((mainUVHeight - subUVHeight) / 2 * mainUVWidth +
                    i * mainUVWidth + (mainUVWidth - subUVWidth) / 2) * 2;
        } else {
            LOGE("Unsupported position: %d", position);
            return;
        }
        memcpy(pDstUV, pSrcUV, subUVWidth * 2);
    }
}

3.3.3 mtkcam3/3rdparty/customer/cp_dualcamera/DualCameraCapture.cpp

#define LOG_TAG "DualCamera"

// Standard C header file
#include <stdlib.h>
#include <chrono>
#include <random>
#include <thread>
// Android system/core header file

// mtkcam custom header file

// mtkcam global header file
#include <mtkcam/utils/std/Log.h>
// Module header file
#include <mtkcam/drv/iopipe/SImager/IImageTransform.h>
#include <mtkcam/utils/metastore/IMetadataProvider.h>
#include <mtkcam3/3rdparty/plugin/PipelinePlugin.h>
#include <mtkcam3/3rdparty/plugin/PipelinePluginType.h>
//
#include <mtkcam/utils/metadata/client/mtk_metadata_tag.h>
#include <mtkcam/utils/metadata/hal/mtk_platform_metadata_tag.h>
// Local header file
#include <dual_camera.h>

using namespace NSCam;
using namespace android;
using namespace std;
using namespace NSCam::NSPipelinePlugin;
/******************************************************************************
 *
 ******************************************************************************/
#define MY_LOGV(fmt, arg...)        CAM_LOGV("(%d)[%s] " fmt, ::gettid(), __FUNCTION__, ##arg)
#define MY_LOGD(fmt, arg...)        CAM_LOGD("(%d)[%s] " fmt, ::gettid(), __FUNCTION__, ##arg)
#define MY_LOGI(fmt, arg...)        CAM_LOGI("(%d)[%s] " fmt, ::gettid(), __FUNCTION__, ##arg)
#define MY_LOGW(fmt, arg...)        CAM_LOGW("(%d)[%s] " fmt, ::gettid(), __FUNCTION__, ##arg)
#define MY_LOGE(fmt, arg...)        CAM_LOGE("(%d)[%s] " fmt, ::gettid(), __FUNCTION__, ##arg)
//
#define MY_LOGV_IF(cond, ...)       do { if( (cond) ) { MY_LOGV(__VA_ARGS__); } }while(0)
#define MY_LOGD_IF(cond, ...)       do { if( (cond) ) { MY_LOGD(__VA_ARGS__); } }while(0)
#define MY_LOGI_IF(cond, ...)       do { if( (cond) ) { MY_LOGI(__VA_ARGS__); } }while(0)
#define MY_LOGW_IF(cond, ...)       do { if( (cond) ) { MY_LOGW(__VA_ARGS__); } }while(0)
#define MY_LOGE_IF(cond, ...)       do { if( (cond) ) { MY_LOGE(__VA_ARGS__); } }while(0)

/*******************************************************************************
* MACRO Utilities Define.
********************************************************************************/
namespace { // anonymous namespace for debug MARCO function
using AutoObject = std::unique_ptr<const char, std::function<void(const char*)>>;
//
auto
createAutoScoper(const char* funcName) -> AutoObject
{
    CAM_LOGD("[%s] +", funcName);
    return AutoObject(funcName, [](const char* p)
    {
        CAM_LOGD("[%s] -", p);
    });
}
#define SCOPED_TRACER() auto scoped_tracer = ::createAutoScoper(__FUNCTION__)
//
auto
createAutoTimer(const char* funcName, const char* text) -> AutoObject
{
    using Timing = std::chrono::time_point<std::chrono::high_resolution_clock>;
    using DuationTime = std::chrono::duration<float, std::milli>;

    Timing startTime = std::chrono::high_resolution_clock::now();
    return AutoObject(text, [funcName, startTime](const char* p)
    {
        Timing endTime = std::chrono::high_resolution_clock::now();
        DuationTime duationTime = endTime - startTime;
        CAM_LOGD("[%s] %s, elapsed(ms):%.4f",funcName, p, duationTime.count());
    });
}
#define AUTO_TIMER(TEXT) auto auto_timer = ::createAutoTimer(__FUNCTION__, TEXT)
//
#define UNREFERENCED_PARAMETER(param) (param)
//
} // end anonymous namespace for debug MARCO function

/*******************************************************************************
* Alias.
********************************************************************************/
using namespace NSCam;
using namespace NSCam::NSPipelinePlugin;
using namespace NSCam::NSIoPipe::NSSImager;

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  Type Alias..
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
using Property = FusionPlugin::Property;
using Selection = FusionPlugin::Selection;
using RequestPtr = FusionPlugin::Request::Ptr;
using RequestCallbackPtr = FusionPlugin::RequestCallback::Ptr;
//
template<typename T>
using AutoPtr             = std::unique_ptr<T, std::function<void(T*)>>;
//
using ImgPtr              = AutoPtr<IImageBuffer>;
using MetaPtr             = AutoPtr<IMetadata>;
using ImageTransformPtr   = AutoPtr<IImageTransform>;

/*******************************************************************************
* Namespace Start.
********************************************************************************/
namespace { // anonymous namespace

/*******************************************************************************
* Class Definition
********************************************************************************/
/**
 * @brief third party pure bokeh algo. provider
 */
class DualCameraCapture final: public FusionPlugin::IProvider
{
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  Instantiation.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public:
    DualCameraCapture();

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  FusionPlugin::IProvider Public Operations.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public:
    void set(MINT32 iOpenId, MINT32 iOpenId2) override;

    const Property& property() override;

    MERROR negotiate(Selection& sel) override;

    void init() override;

    MERROR process(RequestPtr requestPtr, RequestCallbackPtr callbackPtr) override;

    void abort(vector<RequestPtr>& requestPtrs) override;

    void uninit() override;

    ~DualCameraCapture();
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  DualCameraCapture Private Operator.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
private:
    MERROR processDone(const RequestPtr& requestPtr, const RequestCallbackPtr& callbackPtr, MERROR status);

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  DualCameraCapture Private Data Members.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
private:
    MINT32 mEnable;
    //
    MINT32 mOpenId;
    MINT32 mOpenId2;
    MINT32 mDump;
    DualCamera* mDualCamera = NULL;
};
REGISTER_PLUGIN_PROVIDER(Fusion, DualCameraCapture);

/**
 * @brief utility class
 */
class DualCameraUtility final
{
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  Instantiation.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public:
    DualCameraUtility() = delete;

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  DualCameraUtility Public Operations.
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public:
    static inline ImageTransformPtr createImageTransformPtr();

    static inline ImgPtr createImgPtr(BufferHandle::Ptr& hangle);

    static inline MetaPtr createMetaPtr(MetadataHandle::Ptr& hangle);

    static inline MVOID dump(const IImageBuffer* pImgBuf, const std::string& dumpName);

    static inline MVOID dump(IMetadata* pMetaData, const std::string& dumpName);

    static inline const char * format2String(MINT format);

    static inline MVOID saveImg(NSCam::IImageBuffer* pImgBuf, const std::string& fileName);
};

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  DualCameraUtility implementation.
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ImageTransformPtr
DualCameraUtility::
createImageTransformPtr()
{
    return ImageTransformPtr(IImageTransform::createInstance(), [](IImageTransform *p)
    {
        p->destroyInstance();
    });
}

ImgPtr
DualCameraUtility::
createImgPtr(BufferHandle::Ptr& hangle)
{
    return ImgPtr(hangle->acquire(), [hangle](IImageBuffer* p)
    {
        UNREFERENCED_PARAMETER(p);
        hangle->release();
    });
};

MetaPtr
DualCameraUtility::
createMetaPtr(MetadataHandle::Ptr& hangle)
{
    return MetaPtr(hangle->acquire(), [hangle](IMetadata* p)
    {
        UNREFERENCED_PARAMETER(p);
        hangle->release();
    });
};

MVOID
DualCameraUtility::
dump(const IImageBuffer* pImgBuf, const std::string& dumpName)
{
    MY_LOGD("dump image info, dumpName:%s, info:[a:%p, si:%dx%d, st:%zu, f:0x%x, va:%p]",
        dumpName.c_str(), pImgBuf,
        pImgBuf->getImgSize().w, pImgBuf->getImgSize().h,
        pImgBuf->getBufStridesInBytes(0),
        pImgBuf->getImgFormat(),
        reinterpret_cast<void*>(pImgBuf->getBufVA(0)));
}

MVOID
DualCameraUtility::
dump(IMetadata* pMetaData, const std::string& dumpName)
{
    MY_LOGD("dump meta info, dumpName:%s, addr::%p, count:%u",
        dumpName.c_str(), pMetaData, pMetaData->count());
}

MVOID
DualCameraUtility::
saveImg(NSCam::IImageBuffer* pImgBuf, const std::string& fileName)
{

    char path[256];
    snprintf(path, sizeof(path), "/data/vendor/camera_dump/%s_%zu_%dx%d.%s", fileName.c_str(), pImgBuf->getBufStridesInBytes(0),
             pImgBuf->getImgSize().w, pImgBuf->getImgSize().h, format2String(pImgBuf->getImgFormat()));
    pImgBuf->saveToFile(path);
}

const char* 
DualCameraUtility::
format2String(MINT format) {
    switch(format) {
       case NSCam::eImgFmt_RGBA8888:          return "rgba";
       case NSCam::eImgFmt_RGB888:            return "rgb";
       case NSCam::eImgFmt_RGB565:            return "rgb565";
       case NSCam::eImgFmt_STA_BYTE:          return "byte";
       case NSCam::eImgFmt_YVYU:              return "yvyu";
       case NSCam::eImgFmt_UYVY:              return "uyvy";
       case NSCam::eImgFmt_VYUY:              return "vyuy";
       case NSCam::eImgFmt_YUY2:              return "yuy2";
       case NSCam::eImgFmt_YV12:              return "yv12";
       case NSCam::eImgFmt_YV16:              return "yv16";
       case NSCam::eImgFmt_NV16:              return "nv16";
       case NSCam::eImgFmt_NV61:              return "nv61";
       case NSCam::eImgFmt_NV12:              return "nv12";
       case NSCam::eImgFmt_NV21:              return "nv21";
       case NSCam::eImgFmt_I420:              return "i420";
       case NSCam::eImgFmt_I422:              return "i422";
       case NSCam::eImgFmt_Y800:              return "y800";
       case NSCam::eImgFmt_BAYER8:            return "bayer8";
       case NSCam::eImgFmt_BAYER10:           return "bayer10";
       case NSCam::eImgFmt_BAYER12:           return "bayer12";
       case NSCam::eImgFmt_BAYER14:           return "bayer14";
       case NSCam::eImgFmt_FG_BAYER8:         return "fg_bayer8";
       case NSCam::eImgFmt_FG_BAYER10:        return "fg_bayer10";
       case NSCam::eImgFmt_FG_BAYER12:        return "fg_bayer12";
       case NSCam::eImgFmt_FG_BAYER14:        return "fg_bayer14";
       default:                               return "unknown";
    }
}

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//  ThirdPartyFusionProvider implementation.
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
DualCameraCapture::
DualCameraCapture()
: mEnable(-1)
, mOpenId(-1)
, mOpenId2(-1)
, mDump(-1)
{
    // on:1/off:0/auto:-1
    mEnable = ::property_get_int32("vendor.debug.camera.dualcamera.enable", mEnable);
    mDump = ::property_get_int32("vendor.debug.camera.dualcamera.dump", mDump);
    mDualCamera = new DualCamera();
    MY_LOGD("ctor:%p, mEnable:%d", this, mEnable);
}

void
DualCameraCapture::
set(MINT32 iOpenId, MINT32 iOpenId2)
{
    mOpenId = iOpenId;
    mOpenId2 = iOpenId2;
    MY_LOGD("set openId:%d openId2:%d", mOpenId, mOpenId2);
}

const Property&
DualCameraCapture::
property()
{
    static const Property prop = []() -> const Property
    {
        Property ret;
        ret.mName = "DualCamera";
        ret.mFeatures = TP_FEATURE_PUREBOKEH;
        ret.mFaceData = eFD_Cache;
        ret.mBoost = eBoost_CPU;
        ret.mInitPhase = ePhase_OnPipeInit;
        return ret;
    }();
    return prop;
}

MERROR
DualCameraCapture::
negotiate(Selection& sel)
{
    SCOPED_TRACER();

    if( mEnable == 0 )
    {
        MY_LOGD("force off tp dual camera");
        return BAD_VALUE;
    }
    // INPUT
    {
        sel.mIBufferFull
            .setRequired(MTRUE)
            .addAcceptedFormat(eImgFmt_NV21)
            .addAcceptedSize(eImgSize_Full);

        sel.mIBufferFull2
            .setRequired(MTRUE)
            .addAcceptedFormat(eImgFmt_NV21)
            .addAcceptedSize(eImgSize_Full);

        sel.mIMetadataApp.setRequired(MTRUE);
        sel.mIMetadataHal.setRequired(MTRUE);
        sel.mIMetadataHal2.setRequired(MTRUE);
        sel.mIMetadataDynamic.setRequired(MTRUE);
        sel.mIMetadataDynamic2.setRequired(MTRUE);
    }
    // OUTPUT
    {
        sel.mOBufferFull
            .setRequired(MTRUE)
            .addAcceptedFormat(eImgFmt_NV21)
            .addAcceptedSize(eImgSize_Full);

        sel.mOMetadataApp.setRequired(MTRUE);
        sel.mOMetadataHal.setRequired(MTRUE);
    }
    return OK;
}

void
DualCameraCapture::
init()
{
    SCOPED_TRACER();
    ::srand(time(nullptr));
}

MERROR
DualCameraCapture::
process(RequestPtr requestPtr, RequestCallbackPtr callbackPtr)
{
    SCOPED_TRACER();

    auto isValidInput = [](const RequestPtr& requestPtr) -> MBOOL
    {
        const MBOOL ret = requestPtr->mIBufferFull != nullptr
                    && requestPtr->mIBufferFull2 != nullptr
                    && requestPtr->mIMetadataApp != nullptr
                    && requestPtr->mIMetadataHal != nullptr
                    && requestPtr->mIMetadataHal2 != nullptr;
        if( !ret )
        {
            MY_LOGE("invalid request with input, req:%p, inFullImg:%p, inFullImg2:%p, inAppMeta:%p, inHalMeta:%p, inHalMeta2:%p",
                requestPtr.get(),
                requestPtr->mIBufferFull.get(),
                requestPtr->mIBufferFull2.get(),
                requestPtr->mIMetadataApp.get(),
                requestPtr->mIMetadataHal.get(),
                requestPtr->mIMetadataHal2.get());
        }
        return ret;
    };

    auto isValidOutput = [](const RequestPtr& requestPtr) -> MBOOL
    {
        const MBOOL ret = requestPtr->mOBufferFull != nullptr
                    && requestPtr->mOMetadataApp != nullptr
                    && requestPtr->mOMetadataHal != nullptr;
        if( !ret )
        {
            MY_LOGE("invalid request with input, req:%p, outFullImg:%p, outAppMeta:%p, outHalMeta:%p",
                requestPtr.get(),
                requestPtr->mOBufferFull.get(),
                requestPtr->mOMetadataApp.get(),
                requestPtr->mOMetadataHal.get());
        }
        return ret;
    };

    MY_LOGD("process, reqAdrr:%p", requestPtr.get());

    if( !isValidInput(requestPtr) )
    {
        return processDone(requestPtr, callbackPtr, BAD_VALUE);
    }

    if( !isValidOutput(requestPtr) )
    {
        return processDone(requestPtr, callbackPtr, BAD_VALUE);
    }
    //
    //
    {
        // note: we can just call createXXXXPtr one time for a specified handle
        ImgPtr inMainImgPtr = DualCameraUtility::createImgPtr(requestPtr->mIBufferFull);
        ImgPtr inSubImgPtr = DualCameraUtility::createImgPtr(requestPtr->mIBufferFull2);
        ImgPtr outFSImgPtr = DualCameraUtility::createImgPtr(requestPtr->mOBufferFull);
        //
        MetaPtr inAppMetaPtr = DualCameraUtility::createMetaPtr(requestPtr->mIMetadataApp);
        MetaPtr inMainHalMetaPtr = DualCameraUtility::createMetaPtr(requestPtr->mIMetadataHal);
        MetaPtr inSubHalMetaPtr = DualCameraUtility::createMetaPtr(requestPtr->mIMetadataHal2);
        MetaPtr outAppMetaPtr = DualCameraUtility::createMetaPtr(requestPtr->mOMetadataApp);
        MetaPtr outHalMetaPtr = DualCameraUtility::createMetaPtr(requestPtr->mOMetadataHal);
        // dump info
        {
            DualCameraUtility::dump(inMainImgPtr.get(), "inputMainImg");
            DualCameraUtility::dump(inSubImgPtr.get(), "inputSubImg");
            DualCameraUtility::dump(outFSImgPtr.get(), "outFSImg");
            //
            DualCameraUtility::dump(inAppMetaPtr.get(), "inAppMeta");
            DualCameraUtility::dump(inMainHalMetaPtr.get(), "inMainHalMeta");
            DualCameraUtility::dump(inSubHalMetaPtr.get(), "inSubHalMeta");
            DualCameraUtility::dump(outAppMetaPtr.get(), "outAppMeta");
            DualCameraUtility::dump(outHalMetaPtr.get(), "outHalMeta");
        }

        //dual camera algo
        {
            AUTO_TIMER("proces dual camera algo.");
            NSCam::IImageBuffer* inMainImgBuf = inMainImgPtr.get();
            NSCam::IImageBuffer* inSubImgBuf = inSubImgPtr.get();
            NSCam::IImageBuffer* outImgBuf = outFSImgPtr.get();
            if (mDump) {
                DualCameraUtility::saveImg(inMainImgBuf, "inputMainImg");
                DualCameraUtility::saveImg(inSubImgBuf, "inputSubImg");
            }
            memcpy(reinterpret_cast<uchar*>(outImgBuf->getBufVA(0)), reinterpret_cast<uchar*>(inMainImgBuf->getBufVA(0)), inMainImgBuf->getBufSizeInBytes(0));
            memcpy(reinterpret_cast<uchar*>(outImgBuf->getBufVA(1)), reinterpret_cast<uchar*>(inMainImgBuf->getBufVA(1)), inMainImgBuf->getBufSizeInBytes(1));
            if (mDualCamera != NULL) {
                mDualCamera->processNV21(reinterpret_cast<uchar*>(outImgBuf->getBufVA(0)), reinterpret_cast<uchar*>(outImgBuf->getBufVA(1)),
                                         outImgBuf->getImgSize().w, outImgBuf->getImgSize().h,
                                         reinterpret_cast<uchar*>(inSubImgBuf->getBufVA(0)), reinterpret_cast<uchar*>(inSubImgBuf->getBufVA(1)),
                                         inSubImgBuf->getImgSize().w, inSubImgBuf->getImgSize().h);
            }
        }
    }
    return processDone(requestPtr, callbackPtr, OK);
}

MERROR
DualCameraCapture::
processDone(const RequestPtr& requestPtr, const RequestCallbackPtr& callbackPtr, MERROR status)
{
    SCOPED_TRACER();

    MY_LOGD("process done, call complete, reqAddr:%p, callbackPtr:%p, status:%d",
        requestPtr.get(), callbackPtr.get(), status);

    if( callbackPtr != nullptr )
    {
        callbackPtr->onCompleted(requestPtr, status);
    }
    return OK;
}

void
DualCameraCapture::
abort(vector<RequestPtr>& requestPtrs)
{
    SCOPED_TRACER();

    for(auto& item : requestPtrs)
    {
        MY_LOGD("abort request, reqAddr:%p", item.get());
    }
}

void
DualCameraCapture::
uninit()
{
    SCOPED_TRACER();
}

DualCameraCapture::
~DualCameraCapture()
{
    MY_LOGD("dtor:%p", this);
    if (mDualCamera != NULL) {
        delete mDualCamera;
        mDualCamera = NULL;
    }
}

}  // anonymous namespace

主要函数介绍：

• 在property函数中feature类型设置成TP_FEATURE_PUREBOKEH，并设置名称等属性。

• 在negotiate函数中配置算法需要的输入、输出图像的格式、尺寸。注意，双摄算法有2个输入Buffer，但是只有1个输出Buffer。

• 在process函数中接入算法。调用算法接口函数processNV21进行处理。

集成时，可以参照MTK提供的实例文件TPPureBokehImpl.cpp或者TPFusionImpl.cpp。

3.3.4 mtkcam3/3rdparty/customer/Android.mk

最终vendor.img需要的目标共享库是libmtkcam_3rdparty.customer.so。因此，我们还需要修改Android.mk，使模块libmtkcam_3rdparty.customer依赖libmtkcam.plugin.tp_dc。

同时，为了避免冲突以及出图更快，我们还需要移除MTK示例的libmtkcam.plugin.tp_purebokeh。

diff --git a/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/customer/Android.mk b/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/customer/Android.mk
index 5e5dd6524f..bf2f6ffeae 100755
--- a/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/customer/Android.mk
+++ b/vendor/mediatek/proprietary/hardware/mtkcam3/3rdparty/customer/Android.mk
@@ -65,7 +65,7 @@ LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_bokeh
 LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_depth
 LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_fusion
 LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_dc_hdr
-LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_purebokeh
+#LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_purebokeh
 #
 LOCAL_SHARED_LIBRARIES += libcam.iopipe
 LOCAL_SHARED_LIBRARIES += libmtkcam_modulehelper
@@ -83,6 +83,11 @@ LOCAL_SHARED_LIBRARIES += libyuv.vendor
 LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_mfnr
 endif

+ifeq ($(QXT_DUALCAMERA_SUPPORT), yes)
+LOCAL_SHARED_LIBRARIES += libdualcamera
+LOCAL_WHOLE_STATIC_LIBRARIES += libmtkcam.plugin.tp_dc
+endif
+

由于MTK已经定义了相关的metadata，因此，我们也无需再自定义metadata。

前面这些步骤完成之后，集成工作就基本完成了。我们需要重新编译一下系统源码，为节约时间，可以只编译vendor.img。

四、 APP调用算法

由于MTK原生的Camera APP本身就有双摄stereo模式，我们也无需再写APP来验证算法。为样机刷入系统整包或者vendor.img，开机后，进入MTK 原生Camera APP的stereo模式。我们来拍一张看看效果：

辅摄的色彩效果似乎有些异常，但是不管怎样，模拟算法库是运行正常的，已经将主、辅摄图像拼成画中画效果了。

五、结语

双摄算法是所有算法中最复杂的，涉及到标定、主副摄同步、深度计算、模糊调优、边缘处理等等。算法和集成两部分只要出一点点小问题，双摄的效果可能会天差地别。集成双摄算法时，请一定仔细，仔细，再仔细。

MTK HAL算法集成系列的三篇文章到这里就收官了。农历2020年马上要结束了，这应该也是我农历2020年最后一篇文章了。也临近放假了，提前祝大家假期愉快！

原文链接：https://www.jianshu.com/p/d4a2aacc1760

至此，本篇已结束。转载网络的文章，小编觉得很优秀，欢迎点击阅读原文，支持原创作者，如有侵权，恳请联系小编删除，欢迎您的建议与指正。同时期待您的关注，感谢您的阅读，谢谢！