AnsweredAssumed Answered

HS sync VS sync definition in EDID

Question asked by S.Griebsch on Sep 20, 2016
Latest reply on Oct 5, 2016 by GuenterL


I have the following issue. I have done some testing with the evalboard EVAL-ADV7612-7511P.

With the help from the community I could adopt the settings from the evalboard into my own hardware. My system can be described as following:


HDMI source -> ADV7611 -> 16bit YUV 4:2:2 -> H.264 encoder (transport stream output) -> ASI transmitter


I analyse the output as following:


ASI transmitter -> hardware analysing tool (outputs the incoming video as a udp stream) -> display via software decoder (like VLC player)


Now I discovered a misalignment in horizontal and vertical position. With some hints of the community I could figure out a setup to adjust the video in horizontal direction into the correct position. (changing polarity of HS, setting up register 0x7C and 0x7D in cp map).

But I were not lucky on the vertical misalignment. I tried changing START_VS and END_VS, but without success.

That brought me to the question about general understanding the relationship between EDID information and the video receiving from the source.


EDID are basicly used to tell the source which timing, format, blanking time and so on the receiver is able to handle.

Am I right on that?

I that case if there is a misalignment, it could be fixed by changing the EDID content. Do you agree on that?


The blanking between to frames also depend on the video format. For a 720p frame there would be a different timing as for a 1080i/p frame?

I can also "move" the sync pulse by changing the front and back porch value.

So I'm using the EEditZ tool. I have loaded the example file. There are two tabs one is named VESA the other one CEA.

Which standard is prefered by the source? Do I have to change the values for the porch timing within both standards?

Where exactly do I need to change the timing?