I am using the decoder adv7180 and the encoder adv7179 in order to pass through the fpga the video.
I set the registers as follow:
0x00, 0x04, 0x17, 0x31, 0x3D, 0x3e, 0x3F, 0x0E, 0x55, 0x0E
0x04, 0x57, 0x41, 0x02, 0xf2, 0x6a, 0xa0, 0x80, 0x81, 0x00
for adv7180 and
0x00, 0x01, 0x02, 0x03, 0x04, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D
0x05, 0x10, 0x10, 0x00, 0x00, 0x02, 0x00, 0xCB, 0x8A, 0x09, 0x2A, 0x00
The image i am getting is not clear..there are some shadows lets say..
I am not sure if the problem concern adv7179 or adv7180. The color bars working fine, but the free run mode of adv7180 doesn't work. Instead of blue i am getting grey..
Any help would be appreciated.
I am attaching a screenshot as well.
thanks for your reply. Unfortunately, that's not the solution..I have checked brightness and contrast before, and now i checked the input amplitude but problem isn't solved..
The problem is that "triangle" on the boy's nose and on the face of the girl..It should get a clear b&w picture..
Looking at the attached image, I am not sure what you are calling shadowing. If you are talking about the triangle on the boys nose then I'd look at the analog input amplitude, you might be over driving it. Make sure you have the proper analog termination as shown in the data sheet.
Also check the brightness and contrast setting in the chips.
1) Can you capture the data digital data at the boys nose and verify the Y bytes are close to zero (would be black)?
2) Check the extended output control register 0x04. It's possible you FPGA interprets a Y of 254 wrong and rolls it over to a low number which would be black. Set 0x04 = 0 to limit range
by changing the 0x04 to zero nothing happened.. As for your first question the answer is no.
You really need to capture the digital video stream to verify the data is really bad.
Do you see problems with other images such as SMPTE test patterns or color bar.