Nvenc interlaced video

Hello, I would like to ask what input format should be used for interlaced-scan h264 encoded by nvenc. I set nvenc encodig config to

encodeConfig.pictureStruct = NV_ENC_PIC_STRUCT_FIELD_TOP_BOTTOM;

but I can’t find(not even in docs) what the input should look like. Should be the input buffer with raw samples already interleaved by even and odd lines of video, or fields should be dense one after another? According to T-REC-H264.200305 chapter 0.5.2 Coding of progressive and interlaced video the h264 can works in both modes dense or sparse, which is nvenc using ? Thank you