ADV212: Delay in Video

Question

Hi all, 
 I am using ADV212 for video compression. 
 I have read from adv212 FAQ that in encoder it takes 1.5 Filed delay and in decoder it takes 
 1.5 field. 
 it means delay should be 3 filed( 60 MS). but i have observed more delay in video(around 1Sec). 
 what i am doing is that as i get field from encoder i fed it to decoder without buffer. 
 Does image index play any role in delay or might be another factor? 
 I have doubt that in decoder first field should be odd with zero image index. 
 Is it like that or any other reason for it. 
 with regards 
 JSH

DaveD · Accepted Answer

Hi JS, 
 Master mode should eliminate most of the conflicts. Without the FIELD pin, it will start expecting the field polarity to match what you set it to in the PICFG options. If that was wrong you would add another field of latency at most though if you are alternating field polarity as you should. If field polarity is not alternating, then it will simply throw away the data until if gets the polarity it's expecting. 
 Bottom line is that there isn't enough memory to buffer for a 1 sec latency regardless unless all you have is black frames, so something else is going on in your system I think. 
 Dave