we use an ADV7180 for getting digital image from analog PAL source (monochrome images). Test source is a Teletest Pro OZT1200 box, providing a video pattern with a grid.
Expecting digital format is 576 lines x 720 pixels. Image seems correctly received but we have a few unexpected constant black pixels (8bit hexa value near 10) on the left (6 pixels) and on the right (3 pixels). You can see the received image below, with vertical black bars on the left and right (areas have been red outlined by myself)
If we select a fully white image as source pattern, the pb is the same (still have the same nb of black pixels on the left and on the right of received image).
We have made a record of the source signal and the measured durations are always
for 1 video line = 64us
for active part in a single video line = 52.6us
for horizontal synchro part in a single video line = 11.4us
Could it be possible that the black pixels received on the left and right are part of the horinzontal synchro considered as active video part when converting ?
Also, as we use the ADV7180 without modifying default register values (the only command sent on i2c to ADV7180 is for selecting input in register 00 when starting video acquisition), could you tell me if this pb could come from a wrong setting of ADV7180 ? I have found in a document ADV7180 - Preliminary register settings recommandations Rev. PrA an example of CVBS autodetect script with many more i2c commands than perfomed by our application but I am a newcomer in video acquisition and do not understand if listed operations are useful for our acquisition process.
Thank you for your help.