AnsweredAssumed Answered

Delay in getting the first frame

Question asked by on Dec 10, 2010
Latest reply on Aug 19, 2011 by DaveD



We are working in IMX51 platform. We have two video channels in our system and a single ADV7180 (64-LEAD). Input to ADV is from NTSC camera. Since we have a single ADV7180, we can see the data from only one video channel at a time.


User selects the video channel from the available two channels. We face an issue during channel switching. If we take the immediate frame after channel switching,it will be a mix of the video data from the two video channels or it is not stable. We have to read a minimum of 10 frames to get a complete frame from the new video channel. Otherwise we can say there is a delay observed for getting the first frame after channel switching. Successive frames are correct.


1) Is this delay expected? Is it possible to avoid or reduce this delay?

2) As per our understanding, we should get the full and correct frame from the new channel immediately after channel switching. Is this understanding 

3) What is the time required for getting the first complete frame from the new channel after switching?
4) ADV output is now YUV420. Is it possible to get RGB output from ADV7180? If possible, then please tell us the modifications required.
5) Input to ADV is from NTSC camera. Is it possible to increase the frame rate to 60 or 120 by configuring ADV?
    Or Is the NTSC frame rate fixed?
6) For channel switching we are just writing channel index to register 0x00. Is it required to reset ADV after this?


Thank you.