代码如下，在RK_MPI_AI_GetFrame中返回值为0xA00A800D，查阅手册发现是RK_ERR_AI_NOBUF，这是什么情况

void*sendDataThread(void*ptr) {
   TEST_AI_CTX_S*params= reinterpret_cast<TEST_AI_CTX_S*>(ptr);
   RK_S32result=0;
   RK_S32s32MilliSec=10;
   AUDIO_FRAME_Sframe;
   if (params->dstFilePath) {
       AUDIO_SAVE_FILE_INFO_Ssave;
       save.bCfg=RK_TRUE;
       save.u32FileSize=1024;
       snprintf(save.aFilePath, sizeof(save.aFilePath), "%s", params->dstFilePath);
       snprintf(save.aFileName, sizeof(save.aFileName), "%s", "cap_out.pcm");
       RK_MPI_AI_SaveFile(params->s32DevId, params->s32ChnIndex, &save);
       //printf("save_file\r\n");
   }
   while (!gAiExit) {
       result=RK_MPI_AI_GetFrame(params->s32DevId, params->s32ChnIndex, &frame, RK_NULL, s32MilliSec);
       printf("result=%x\r\n",result);
       if (result==0) {
           void*data=RK_MPI_MB_Handle2VirAddr(frame.pMbBlk);
           RK_U32len=RK_MPI_MB_GetSize(frame.pMbBlk);
           RK_LOGV("data = %p, len = %d", data, len);
           RK_MPI_AI_ReleaseFrame(params->s32DevId, params->s32ChnIndex, &frame, RK_NULL);
       }
   }
   returnRK_NULL;
}