JavaWeb笔记整理+图解——服务器渲染技术之EL表达式与JSTL

linux应用层同时控制TOF和RGB摄像头，为了方便操作，统一接口，这里将TOF和RGB摄像头看成两个对象，对它们分别实现，初始化，去初始化，读取视频流，停止视频流，启动视频流，读取配置文件，保存配置，删除配置，获取参数，设置参数等接口。

1、头文件

/* 对象接口 */
typedef struct {
    char device_name[LV_DEVICE_LENGTH];
    int context_size;
    void *context;

    int (*init)(const char *device_name, void *context);
    int (*deinit)(void *context);

    int (*start_stream)(void *context);
    int (*stop_stream)(void *context, int flag);


    int (*read_stream)(void *context);

    int (*read_config)(void *context);
    int (*save_config)(void *context);
    int (*delete_config)(void *context);

    int (*get_parameter)(void *context, uint16_t command_type, char *data_get, int *data_len);
    int (*set_parameter)(void *context, uint16_t command_type, char *data_set, int data_len);
} LV_STREAM_T;


/* 全局数据，包含TOF对象和RGB对象 */
typedef struct {
    uint8_t lv_start_flag;                   /* 启动采集标志位，0：停止采集；1：开始采集 */
    uint8_t lv_tof_support;                  /* TOF设备支持 */
    uint8_t lv_rgb_support;                  /* RGB设备支持 */

    char device_name_tof[LV_DEVICE_LENGTH];  /* TOF设备名称 */
    char device_name_rgb[LV_DEVICE_LENGTH];  /* RGB设备名称 */

    LV_STREAM_T *lv_stream_tof_p;            /* TOF设备对象 */
    LV_STREAM_T *lv_stream_rgb_p;            /* RGB设备对象 */
} LV_DATA_T;

2.对象实现

LV_STREAM_T g_lv_tof_stream = {
    "/dev/vide0",
    sizeof(LV_IMX_STREAM_T),
    NULL,

    lv_tof_stream_init,
    lv_tof_stream_deinit,

    lv_tof_stream_start,
    lv_tof_stream_stop,

    lv_tof_read_stream,

    lv_tof_read_config,

    lv_tof_save_config,
    lv_tof_delete_config,

    lv_tof_get_parameter,
    lv_tof_set_parameter,
};

LV_STREAM_T g_lv_rgb_stream = {
    "/dev/vide1",
    sizeof(LV_RGB_STREAM_T),
    NULL,

    lv_rgb_stream_init,
    lv_rgb_stream_deinit,

    lv_rgb_stream_start,
    lv_rgb_stream_stop,

    lv_rgb_read_stream,

    lv_rgb_read_config,

    lv_rgb_save_config,
    lv_rgb_delete_config,

    lv_rgb_get_parameter,
    lv_rgb_set_parameter,
};

/* TOF对象接口实现 */
int lv_tof_stream_init(const char *video_device_name, void *context) {

    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;
    

    return 0;
}

int lv_tof_stream_deinit(void *context) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_stream_start(void *context) {

    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_stream_stop(void *context) {

    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_read_stream(void *context) {

    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_read_config(void *context) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_save_config(void *context) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_delete_config(void *context) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}


int lv_tof_get_parameter(void *context, uint16_t command_type, char *data_get, int *data_len) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

int lv_tof_set_parameter(void *context, uint16_t command_type, char *data_set, int data_len) {
    LV_IMX_STREAM_T *lv_imx_stream_p = (LV_IMX_STREAM_T *)context;

    return 0;
}

3.对象调用

/* 对象列表 */
extern LV_STREAM_T g_lv_tof_stream;
extern LV_STREAM_T g_lv_rgb_stream;

static LV_STREAM_T *lv_stream_list[] = {
    &g_lv_tof_stream,
    &g_lv_rgb_stream,
};

/* 根据设备名称来找到对应的相机对象
tof : /dev/video0
rgb : /dev/video1
 */
static LV_STREAM_T *lv_find_stream(const char *device_name) {
    int i = 0;
    LV_STREAM_T *lv_stream_p = NULL;
    int list_size = ARRAY_SIZE(lv_stream_list);

    for (i = 0; i < list_size; i++) {
        if (strncmp(lv_stream_list[i]->device_name, device_name, strlen(lv_stream_list[i]->device_name)) == 0) {
            lv_stream_p = lv_stream_list[i];
            return lv_stream_p;
        }
    }
    LV_WARN("Not find lv_stream, device_name:%s\n", device_name);

    return NULL;
}

/* 创建对象 */
LV_STREAM_T *lv_stream_new(const char *device_name) {
    int ret = 0;
    LV_STREAM_T *lv_stream_p = NULL;

    if (NULL == device_name) {
        LV_ERROR("device_name is NULL!\n");
        return NULL;
    }

    lv_stream_p = lv_find_stream(device_name);
    if (lv_stream_p) {
        if(lv_stream_p->init == NULL) {
            LV_ERROR("init is NULL!\n");
            return NULL;
        }

        LV_DEBUG("find stream, device_name=%s, context_size=%d\n", device_name, lv_stream_p->context_size);

        lv_stream_p->context = calloc(1, lv_stream_p->context_size);
        if (NULL == lv_stream_p->context) {
            LV_ERROR("context calloc failed!\n");
        }

        ret = lv_stream_p->init(device_name, lv_stream_p->context);
        if(ret) {
            LV_ERROR("stream init failed!\n");
            free(lv_stream_p->context);
            return NULL;
        }

        lv_stream_p->read_config(lv_stream_p->context);

    } else {
        LV_ERROR("find stream failed!\n");
    }

    return lv_stream_p;
}

/* 释放对象 */
int lv_stream_free(LV_STREAM_T *lv_stream_p) {
    if (NULL == lv_stream_p) {
        return -1;
    }

    if (NULL == lv_stream_p->deinit) {
        return -2;
    }

    lv_stream_p->stop_stream(lv_stream_p->context);

    if (lv_stream_p->context) {
        lv_stream_p->deinit(lv_stream_p->context);
        free(lv_stream_p->context);
    }

    lv_stream_p = NULL;

    return 0;
}

/* 读取TOF数据流 */
void *start_read_tof_pthread(void *arg) {
    int ret = 0;
    
    LV_DATA_T *lv_data_p = (LV_DATA_T *)arg;

    while (1) {

        ret = lv_data_p->lv_stream_tof_p->read_stream(lv_data_p->lv_stream_tof_p->context);

        if (0 != ret) {
            sleep_ms(10);
        }
    }

    lv_stream_free(lv_data_p->lv_stream_tof_p);

    return 0;
}