Help with camera resolution

Hi, i have an OLD HIKVision dvr, with analogic cams (DS-7208HVI-SV/A)
Its resolution is set to maximum (960x576), and i have activated also the SVC function.

When i open the video stream (in fullscreen mode or in a live card), i see a resolution change from:


I wish to keep the “second resolution”.
Also note that all the images taken from the camera are the same resolution as initially appear the video:
(this is a snapshot taken from ISAPI URL):

How i can keep the original resolution of 960x576 in photos and videos, skipping those issues?