I had to change the NTSC source be 1440 wide instead of 720 wide in order to see the video well. Do you guys know why the ADV7842 outputs double pixels when in interlaced mode?
SD video is normally 1440 samples wide for YCbCr 4:2:2. It's hard to comment though without a lot more information-- were you using our evaluation board with our software running on it?
Thanks for the quick reply.
No I do not use the eval board with the software running on it. I use our custom board which has ADV7842 on it. What other information would you like to have which will help to answer my question ? My expectation would be to have 720 samples instead of 1440 for interlaced NTSC source.
If you don't have an evaluation board to duplicate the problem on, the scope of support we can provide is pretty limited.
About all we can do is get some idea of what registers settings you are using. So what script did you start with to program the ADV7842 board? What modifications did you make to customize it for your hardware?
I haven't customize the hardware, so I am using the existing one. My script just uses low-level register read/write access.
My question relates to the default behavior of the device which I haven't found in UG 206/214.
If it's not our eval board, that is what I mean by "custom".
The register writes are what I'm talking about. If your problem has to do with ADV7842 then what you are writing is most likely the problem.
I'm not sure what you mean by default behavior-- the part does what you program it to. "Default" behavior would be to do nothing on power-up.
It'd be a little bit complicated to explain our hardware setup, so I'll be specific on ADV7842 part.
The used ADV7842 is configured to get NTSC source (in interlaced mode). What I'd like to know whether the output format should be 1440 wide by default for the mentioned above signal.
NTSC is a defined analog standard. ADV7842 expects the input signal to comply with that standard. That is the bottom line.
After conversion to digital there are normally 1440 samples per line which is 720 pixels. It's not defined that way in analog domain in terms of pixels, so I'm not sure I understand your question as it reflects on the source.
Thanks for your assistance.
Retrieving data ...