i gave colour bar with ﬁxed colours input to adv7180,but the output colour bar color distortion.Why?
It is very hard to solve this without the following information:
What source are you using? (PAL, PAL-M, NTSC, NTSC 4.433)
Is there anything between the ADV7180 and the source and is there anything between the ADV7180 and the video sink? (An encoder?)
What script/I2C writes are you doing? If there is an encoder do you have the correct I2C writes.
If you are using the default scripts provided with ADV7180 and a standard video source then there should be no issue.
This leads me to believe that the problem is either your script or your video source.
First thing to do is use our standard script and see if the issue is still there. If the issue persists then I would look in more detail at the source and then we can come up with a script to handle it correctly.
From a general perspective it looks like the luma levels are fine and the syncs are being detected correctly. The chroma is there but is incorrect which means that the chroma phase is incorrectly out of phase to the colour burst phase. So I just setup the ADV7180 at my desk and I manually adjusted the phase of the chroma. (Register 0x7F) I wrote a value of 0x3F to 0x7F to it which gives a phase shift of 45 degrees and I got the same colour problem you have. Therefore you have introduced a chroma phase shift of 45 degrees somewhere in your system, could be the encoder, the ADV7180 or the source.
output colour bar
At first first I would look at the Luma and Color gain settings if you are in the manual mode, refer to
http://ez.analog.com/docs/DOC-1622 Manual Notes, ChromaGainCalibration and LumaGainCalibration notes.
Also on this page are variuos script files for setting the part for different operating modes.
Are you using one of our evaluation boards or is this a custom design?
I am very sorry that i wrote a wrong value to register 0x08.
In late yesterday, i had modify the Luma and Color gain,i wrote a value of 0x80 to register 0x08,as a result,the output of colour bar is ok.
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