... chip 3.4 channels audio input, RCA socket 4.G.726 Audio compression 8ch h.264 security HD DVR CardModel: ZS-1704HP ... CIF)NTSC: 320×240(CIF)Video Input4 channels of complex analog video signal, NTSC,PAL could be selected ,BNC socket, ... horizontal line 270,vertical line 250 Audio parameterAudio Compression StandardG.726Audio sampling frequency8KHzAudio Input4 channels audio input ,RCA socket Details of ...