rv1126利用rkmedia、opencv、rockx……完成人脸识别

一、总体框架

视频采集、处理使用rkmedia：vi模块进行视频输入、rga模块进行视频处理

人脸识别：先获取rga输出码流，再调用rkmedia的模型对人脸进行推理（线程1）

打框框：opencv（线程2），且在打完框后把视频输入至venc（编码）

rtsp推流：获得venc编码数据后进行rtsp推流

根据这些模块、整体码流流向如下图：

二、部分笔记

首先初始化了人脸数据库（init_face_data（））其内容如下：

1.连接sql数据库，打开后可以看到其中也是简单的封装函数sqlite3_open

2.初始化了一个特殊类S_THREAD_MAP

3.map<string,rockx_face_feature_t>就是一个姓名与人脸特征的map

4.QueryFaceFeature是获取数据库中所有信息到map中。涉及到对sql的操作

5.set_thread_map是对获取的所有人脸信息map保存到了一个全局表量数组里，保存在第task_id

void init_face_data()
{
  Connection_Sqlite3DataBase();
  int task_id = 0;
  S_THREAD_MAP thread_map;
  map<string, rockx_face_feature_t> maps = QueryFaceFeature();
  thread_map.thread_map = maps;
  set_thread_map(task_id, &thread_map);
}

Connection_Sqlite3DataBase内容如下

int Connection_Sqlite3DataBase()
{
    rc = sqlite3_open("/mnt/nfs/face.db", &db);
    if (rc != SQLITE_OK)
    {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        exit(1);
    }
    else
    {
        printf("You have opened a sqlite3 database named bind.db successfully!\nCongratulation! Have fun!\n");
    }
    return 0;
}

S_THREAD_MAP内部如下，map_id 以及一个姓名与人脸特征结构体

class S_THREAD_MAP{

  public:
     int map_id;
     map<string, rockx_face_feature_t> thread_map;
};

QueryFaceFeature内容如下：

map<string, rockx_face_feature_t> QueryFaceFeature()
{
    rockx_face_feature_t rockx_face_feature = {0, 0};
    map<string, rockx_face_feature_t> rockx_face_feature_map;
    sqlite3_stmt *stmt;
    char *sql = "select name, feature_size, face_feature from face_data_table";
    //准备查询语句 准备从db数据库查找sql（name feature_size face_feature）
    int ret = sqlite3_prepare(db, sql, strlen(sql), &stmt, 0);
    int id = 0, len = 0;
    char * name;
    int feature_size;

    if (ret == SQLITE_OK)
    {
        //真正开始查找 当一行查找成功后执行下面代码
        while (sqlite3_step(stmt) == SQLITE_ROW)
        {
            name = (char *)sqlite3_column_text(stmt, 0);
            printf("name = %s\n", name);
            feature_size = sqlite3_column_int(stmt, 1);
            printf("feature_size = %d\n", feature_size);
            //rockx_face_feature.feature = (MByte *)malloc(feature_size);
            const void *feature = sqlite3_column_blob(stmt, 2);   
            memset(rockx_face_feature.feature, 0, feature_size);
            memcpy(rockx_face_feature.feature, feature, feature_size);
            rockx_face_feature.len = feature_size;
            string str(name);
            //插入人脸数据
            rockx_face_feature_map.insert(pair<string, rockx_face_feature_t>(str, rockx_face_feature));
        }
    }
    
    sqlite3_finalize(stmt);
    sqlite3_close(db); 
   //返回所有信息 
    return rockx_face_feature_map;
}

set_thread_map

int set_thread_map(unsigned int map_id, S_THREAD_MAP *map)
{
    pthread_mutex_lock(&g_thread_maps_mutex);
    g_thread_maps[map_id] = *map;
    pthread_mutex_unlock(&g_thread_maps_mutex);
    return 0;
}