rkmedia_vi_get_frame_test.c 代码解析

使用示例：

录像：
rkmedia_vi_get_frame_test -a /etc/iqfiles/ -I 1 -o 1080.nv12
然后用yuvplayer.exe可以播放。

录像10帧：
rkmedia_vi_get_frame_test -a /etc/iqfiles/ -I 1 -o 1080.nv12 -c 10

解析代码：

#include <assert.h>
#include <fcntl.h>
#include <getopt.h>
#include <pthread.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>

#include "common/sample_common.h"
#include "rkmedia_api.h"

typedef struct {  //用于传递输出参数
  char *file_path;
  int frame_cnt;
} OutputArgs;

static bool quit = false;
static void sigterm_handler(int sig) {  //用于控制程序退出
  fprintf(stderr, "signal %d\n", sig);
  quit = true;
}

static void *GetMediaBuffer(void *arg) {  //获取视频帧数据并保存到文件
  OutputArgs *outArgs = (OutputArgs *)arg;  //使用`OutputArgs`结构体指针`outArgs`来获取输出参数，其中包括保存路径`save_path`和帧计数`save_cnt`。
  char *save_path = outArgs->file_path;   //保存路径
  int save_cnt = outArgs->frame_cnt;    //帧计数
  int frame_id = 0;
  FILE *save_file = NULL;
  if (save_path) {
    save_file = fopen(save_path, "w");  //打开保存路径指定的文件
    if (!save_file)
      printf("ERROR: Open %s failed!\n", save_path);
  }

  MEDIA_BUFFER mb = NULL;
  while (!quit) { //进入循环，当全局变量`quit`为假时持续循环。
    mb = RK_MPI_SYS_GetMediaBuffer(RK_ID_VI, 0, -1);  //获取视频帧的媒体缓冲区`mb`，并检查是否获取成功
    if (!mb) {
      printf("RK_MPI_SYS_GetMediaBuffer get null buffer!\n");
      break;
    }

    //获取媒体缓冲区的图像信息`stImageInfo`，并打印相关信息，如帧指针、文件描述符、大小、时间戳等。
    MB_IMAGE_INFO_S stImageInfo = {0};
    int ret = RK_MPI_MB_GetImageInfo(mb, &stImageInfo);
    if (ret)
      printf("Warn: Get image info failed! ret = %d\n", ret);

    printf("Get Frame:ptr:%p, fd:%d, size:%zu, mode:%d, channel:%d, "
           "timestamp:%lld, ImgInfo:<wxh %dx%d, fmt 0x%x>\n",
           RK_MPI_MB_GetPtr(mb), RK_MPI_MB_GetFD(mb), RK_MPI_MB_GetSize(mb),
           RK_MPI_MB_GetModeID(mb), RK_MPI_MB_GetChannelID(mb),
           RK_MPI_MB_GetTimestamp(mb), stImageInfo.u32Width,
           stImageInfo.u32Height, stImageInfo.enImgType);

    //如果已经打开了保存文件，则将媒体缓冲区中的帧数据写入到文件中，并打印保存信息。
    if (save_file) { 
      fwrite(RK_MPI_MB_GetPtr(mb), 1, RK_MPI_MB_GetSize(mb), save_file);
      printf("#Save frame-%d to %s\n", frame_id++, save_path);
    }

    RK_MPI_MB_ReleaseBuffer(mb);  //释放媒体缓冲区。

    if (save_cnt > 0) //如果设置了帧计数`save_cnt`且大于0，则递减计数。
      save_cnt--;

    // exit when complete
    if (!save_cnt) {  //当完成保存指定数量的帧后，设置全局变量`quit`为真，退出循环。
      quit = true;
      break;
    }
  }

  if (save_file)
    fclose(save_file);

  return NULL;
}

static RK_CHAR optstr[] = "?::a::w:h:c:o:d:I:M:";
static const struct option long_options[] = {
    {"aiq", optional_argument, NULL, 'a'},
    {"device_name", required_argument, NULL, 'd'},
    {"width", required_argument, NULL, 'w'},
    {"height", required_argument, NULL, 'h'},
    {"frame_cnt", required_argument, NULL, 'c'},
    {"output", required_argument, NULL, 'o'},
    {"camid", required_argument, NULL, 'I'},
    {"multictx", required_argument, NULL, 'M'},
    {"help", optional_argument, NULL, '?'},
    {NULL, 0, NULL, 0},
};

static void print_usage(const RK_CHAR *name) {
  printf("usage example:\n");
#ifdef RKAIQ
  printf("\t%s [-a [iqfiles_dir]] "
         "[-I 0] "
         "[-M 0] "
         "[-w 1920] "
         "[-h 1080]"
         "[-c 10] "
         "[-d rkispp_scale0] "
         "[-o out.nv12] \n",
         name);
  printf("\t-a | --aiq: enable aiq with dirpath provided, eg:-a "
         "/oem/etc/iqfiles/, "
         "set dirpath emtpty to using path by default, without this option aiq "
         "should run in other application\n");
  printf("\t-M | --multictx: switch of multictx in isp, set 0 to disable, set "
         "1 to enable. Default: 0\n");
#else
  printf("\t%s [-w 1920] "
         "[-h 1080] "
         "[-c 10] "
         "[-d rkispp_scale0] "
         "[-I 0] "
         "[-o out.nv12] \n",
         name);
#endif
  printf("\t-w | --width: VI width, Default:1920\n");
  printf("\t-h | --heght: VI height, Default:1080\n");
  printf(
      "\t-d | --device_name: set device node(v4l2), Default:rkispp_scale0\n");
  printf("\t-I | --camid: camera ctx id, Default 0\n");
  printf("\t-c | --frame_cnt: record frame, Default:-1(unlimit)\n");
  printf("\t-o | --output: output path, Default:NULL\n");
  printf("Notice: fmt always NV12\n");
}

int main(int argc, char *argv[]) {
  RK_U32 u32Width = 1920;
  RK_U32 u32Height = 1080;
  int frameCnt = -1;
  RK_CHAR *pDeviceName = "rkispp_scale0";
  RK_CHAR *pOutPath = NULL;
  RK_CHAR *pIqfilesPath = NULL;
  RK_S32 s32CamId = 0;
#ifdef RKAIQ
  RK_BOOL bMultictx = RK_FALSE;
#endif
  int c;
  int ret = 0;
  //使用了 getopt_long 函数对命令行参数进行解析。然后根据解析得到的参数配置相应的采集参数，比如视频宽高、帧率等。
  while ((c = getopt_long(argc, argv, optstr, long_options, NULL)) != -1) {
    const char *tmp_optarg = optarg;
    switch (c) {
    case 'a':
      if (!optarg && NULL != argv[optind] && '-' != argv[optind][0]) {
        tmp_optarg = argv[optind++];
      }
      if (tmp_optarg) {
        pIqfilesPath = (char *)tmp_optarg;
      } else {
        pIqfilesPath = "/oem/etc/iqfiles/";
      }
      break;
    case 'w':
      u32Width = atoi(optarg);
      break;
    case 'h':
      u32Height = atoi(optarg);
      break;
    case 'c':
      frameCnt = atoi(optarg);
      break;
    case 'o':
      pOutPath = optarg;
      break;
    case 'd':
      pDeviceName = optarg;
      break;
    case 'I':
      s32CamId = atoi(optarg);
      break;
#ifdef RKAIQ
    case 'M':
      if (atoi(optarg)) {
        bMultictx = RK_TRUE;
      }
      break;
#endif
    case '?':
    default:
      print_usage(argv[0]);
      return 0;
    }
  }

  printf("#####Device: %s\n", pDeviceName);
  printf("#####Resolution: %dx%d\n", u32Width, u32Height);
  printf("#####Frame Count to save: %d\n", frameCnt);
  printf("#####Output Path: %s\n", pOutPath);
  printf("#CameraIdx: %d\n\n", s32CamId);
  signal(SIGINT, sigterm_handler);

  if (pIqfilesPath) {
#ifdef RKAIQ
    printf("#####Aiq xml dirpath: %s\n\n", pIqfilesPath);
    printf("#bMultictx: %d\n\n", bMultictx);
    // rk_aiq_working_mode_t hdr_mode = RK_AIQ_WORKING_MODE_NORMAL;
    rk_aiq_working_mode_t hdr_mode = RK_AIQ_WORKING_MODE_ISP_HDR2; //替换为HDR模式
    int fps = 30;
    SAMPLE_COMM_ISP_Init(s32CamId, hdr_mode, bMultictx, pIqfilesPath);
    SAMPLE_COMM_ISP_Run(s32CamId);
    SAMPLE_COMM_ISP_SetFrameRate(s32CamId, fps);
#endif
  }

  //在相机初始化部分，通过 RK_MPI_VI_SetChnAttr 和 RK_MPI_VI_EnableChn 函数配置并启用了视频输入通道。
  RK_MPI_SYS_Init();
  VI_CHN_ATTR_S vi_chn_attr;
  vi_chn_attr.pcVideoNode = pDeviceName;
  vi_chn_attr.u32BufCnt = 3;
  vi_chn_attr.u32Width = u32Width;
  vi_chn_attr.u32Height = u32Height;
  vi_chn_attr.enPixFmt = IMAGE_TYPE_NV12;
  vi_chn_attr.enWorkMode = VI_WORK_MODE_NORMAL;
  vi_chn_attr.enBufType = VI_CHN_BUF_TYPE_MMAP;
  ret = RK_MPI_VI_SetChnAttr(s32CamId, 0, &vi_chn_attr);
  ret |= RK_MPI_VI_EnableChn(s32CamId, 0);
  if (ret) {
    printf("Create VI[0] failed! ret=%d\n", ret);
    return -1;
  }

  printf("%s initial finish\n", __func__);

  //在视频采集和处理部分，创建了一个线程用于获取媒体缓冲区，并通过 RK_MPI_VI_StartStream 开始采集。然后通过一个循环来等待退出信号，最后在退出时释放资源。
  pthread_t read_thread;
  OutputArgs outArgs = {pOutPath, frameCnt};
  pthread_create(&read_thread, NULL, GetMediaBuffer, &outArgs); //
  ret = RK_MPI_VI_StartStream(s32CamId, 0);
  if (ret) {
    printf("Start VI[0] failed! ret=%d\n", ret);
    return -1;
  }

  while (!quit) {
    usleep(500000);
  }

  RK_MPI_VI_DisableChn(s32CamId, 0);

#ifdef RKAIQ
  if (pIqfilesPath)
    SAMPLE_COMM_ISP_Stop(s32CamId);
#endif

  printf("%s exit!\n", __func__);
  return 0;
}