[RK1108][Linux3.1]应用笔记 - 摄像头数据的获取

平台	内核版本
RK1108	Linux3.1

创建线程

static pthread_t   g_isp_camera      = -1;
RK_CAM_ATTACHED_TO_e isp_camera = RK_CAM_ATTACHED_TO_ISP;
pthread_create(&g_isp_camera, nullptr, start_camera, &isp_camera);

其中RK_CAM_ATTACHED_TO_e定义如下：

enum RK_CAM_ATTACHED_TO_e {
  RK_CAM_ATTACHED_TO_INVALID,
  RK_CAM_ATTACHED_TO_ISP,
  RK_CAM_ATTACHED_TO_CIF,
  RK_CAM_ATTACHED_TO_USB
};

线程中主要做这些事情：

• 摄像头参数的读取
• open
• pu操作

获取摄像头个数

int camera_num = rv1108_space::Camera::getNumberOfCameras();

定义如下：

int Camera::getNumberOfCameras() {
    if(!is_device_get_) {
        CamHwItf::getCameraInfos(&camera_devive_);
        is_device_get_ = true;
    }
    return camera_devive_.num_camers;
}

因为线程指定了摄像头类型为RK_CAM_ATTACHED_TO_ISP，因此我们需要找到相应的ISP摄像头的索引：

for (int i = 0; i < camera_num; ++i) {
            rv1108_space::CameraInfo info;
            rv1108_space::Camera::getCameraInfo(i, info);
            ARCLOG_PRINT_INFO("start_camera", "idx %d name %s type %d\n", info.index, info.pName, info.type);
            if (info.type == camera_type) {
                printf("yang ok type = %d\n", info.type);
                camera_index = i;
            }
        }

摄像头初始化操作

shared_ptr<rv1108_space::Camera> camera = rv1108_space::Camera::Open(camera_index);

定义如下：

	shared_ptr<Camera> instance(new Camera);
	int ret = instance->getParameters(camera_devive_.cam[camera_id]->name,instance->parameters_);
    
    switch (instance->parameters_.type) {
        case RK_CAM_ATTACHED_TO_ISP : {
            instance->camera_instance_  = getCamHwItf(&camera_devive_.isp_dev);
            if(instance->camera_instance_.get() == nullptr) {
                ARCLOG_PRINT_ERROR("Camera", "Get ISP Camera Failed!\n ");
                return nullptr;
            }            
        break;
        }
        case RK_CAM_ATTACHED_TO_CIF : {
            int cif_num =
                ((struct rk_cif_dev_info*)(camera_devive_.cam[camera_id]->dev))->cif_index;
            instance->camera_instance_ = shared_ptr<CamHwItf>(new CamCifDevHwItf(&(camera_devive_.cif_devs.cif_devs[cif_num])));
            if(instance->camera_instance_.get() == nullptr) {
                ARCLOG_PRINT_ERROR("Camera", "Get CIF Camera Failed!\n ");
                return nullptr;
            } 
        break;    
        }
        default: {
            assert(false);
        }            
    }
    bool init_ret = instance->camera_instance_->initHw(camera_devive_.cam[camera_id]->index);
    ret = instance->camera_instance_->tryFormat(instance->parameters_.format, instance->parameters_.format);

启动

rv1108_space::CameraParameters param = camera->getParameters();
	int ret = camera->startPreview();

定义如下：

int Camera::startPreview() {
    switch (parameters_.type) {
        case RK_CAM_ATTACHED_TO_ISP:
            camera_path_ = camera_instance_->getPath(CamHwItf::SP);
            break;
        case RK_CAM_ATTACHED_TO_CIF:
            camera_path_ = camera_instance_->getPath(CamHwItf::MP);
            break;
        default:
            break;
    }
    if(camera_path_.get() == nullptr) {
        ARCLOG_PRINT_ERROR("Camera", "get camera path error!\n");
        camera_instance_->deInitHw();
        camera_instance_.reset();
        return -1;
    }

    camera_buffer_allocator = make_shared<IonCameraBufferAllocator>();
    if(camera_path_->prepare(parameters_.format, kCameraBufferPoolBufferNumber,
		                                *(camera_buffer_allocator.get()), false, 0) == false) {
		ARCLOG_PRINT_ERROR("Camera", "camera path prepare error!\n");
		camera_path_->stop();
		camera_path_->releaseBuffers();
        camera_path_.reset();
        return -1;
	}

    if(camera_path_->start() == false) {
		ARCLOG_PRINT_ERROR("Camera", "camera path start error!\n");
		camera_path_->stop();
		camera_path_->releaseBuffers();
        camera_path_.reset();
        return -1;
	}
    ARCLOG_PRINT_INFO("Camera", "camera path start ok!\n");
    return 0;
}

addBufferNotifier

shared_ptr<DsmProcess> dsm_process = make_shared<DsmProcess>(camera_type);
camera->addProcessUnit(dsm_process, param.format, 0, NULL);

定义：

int Camera::addProcessUnit( shared_ptr<StreamPUBase> next,
            frm_info_t &frmFmt, unsigned int num, shared_ptr<CameraBufferAllocator> allocator) {
    if (!camera_path_.get() || !next.get()) {
        ARCLOG_PRINT_ERROR("Camera", "%s: PU is NULL\n", __func__);
        return -1;
    }
    camera_path_->addBufferNotifier(next.get());
    next->prepare(frmFmt, num, allocator);
    if (!next->start()) {
        ARCLOG_PRINT_ERROR("Camera", "PU start failed!\n");
        return -1;
    }
    return 0;
}