My question is about CVITEK multimedia framework (MMF).

I found a great tutorial of camera-sample in file cvitek-tdl-sdk-cv180x/sample/cvi_tdl/sample_vi_fd.c at main · milkv-duo/cvitek-tdl-sdk-cv180x · GitHub
I examine it and I cannot understand one place. Could you please explain what exactly happens in the line 205…209, line by line? Thank you very much!

  stMWConfig.stVPSSPoolConfig.stVpssMode.aenInput[0] = VPSS_INPUT_MEM;
  stMWConfig.stVPSSPoolConfig.stVpssMode.enMode = VPSS_MODE_DUAL;
  stMWConfig.stVPSSPoolConfig.stVpssMode.ViPipe[0] = 0;
  stMWConfig.stVPSSPoolConfig.stVpssMode.aenInput[1] = VPSS_INPUT_ISP;
  stMWConfig.stVPSSPoolConfig.stVpssMode.ViPipe[1] = 0;

In particular, I cannot understand what is VPSS_INPUT_ISP and VPSS_INPUT_MEM.
In common, I want to change this example to online mode (VI_ONLINE_VPSS_ONLINE), so as I understand VI may send data to VPSS directly, omitting DDR. So I will have more DDR for other tasks.