How can I acclerate decoding video without displaying

[plbmw2018]

What I want to do is to decode the living video acclerate by set options avcodec-hw=d3d11va the copy the raw frame yuv or others to memory for objects detect , and I do not want to display the video.
Then I try to save the decoded frame to memory by libvlc_video_set_callbacks, unluckily the decoding process is slowly because it canot accelerate on hw. Thanks.

[mfkl]

I'm not sure you can do that.

[plbmw2018]

Thanks for your attention. I have found another way for ffmpeg to do these job , which I can use the hw to accelerate video decoding. I think vlc it's more comfortable used for video player than others with little code, which not the best choice for my requrinets.