Typically, hkv to mp4 conversion is searched by users that would like to convert Eyesight IP Camera video recordings to standard MPEG-4 format. It should be possible to convert hkv to avi using the SYSM Monitor utility that is part of the camera package. Once you have the .avi file, you can simply convert it to .mp4 file using any of the common video converters.
It is unlikely that without the software from the manufacturer you will be able to convert .hvk files to any other format.Open HKV file Open MP4 file
A media player for Eyesight IP cameras