DM368 BT1120 YUV in working but black bars round picture

Bob The Gerbil

With massive thanks to Marko's help and a lot of fiddling I have finally got video into our board.

We're using a Leopardboard DM368 and Appro IPNC MT5 SDK, I have modified the TVP514X imager source.

So, we now have a picture, but it has big black bars around it. I have looked all through the imager code, AV capture, etc. but can't see anything about offsets or cropping. I'm sure I've seen someone mention this problem before but can't find the thread in question.

over 12 years ago

0 Renjith Thomas over 12 years ago

Guru 31670 points

Bob,

Looks like the black bars is the H/V sync info. Can you check the polarity of the H and V Sync pulses. Try to reverse one by one?

0 Bob The Gerbil over 12 years ago in reply to Renjith Thomas

Expert 1100 points

Thanks Renjith - the polarity made no difference (I expected it to stop working with the wrong polarity, but it just carried on!

I found that the IMGS_H_PAD and IMGS_V_PAD values move the picture and remove the black bars, so problem is solved!

0 g.f. over 12 years ago in reply to Bob The Gerbil

Guru 15520 points

Hi,

I'm having same problem.
We are not using Appro SDK but DVSDKv4.02

I would like to know which VPFE register does IMGS_H_PAD and IMGS_V_PAD affect to?
May I have an information ?

best regards,
g.f.

0 Bob The Gerbil over 12 years ago in reply to g.f.

Expert 1100 points

I think (by tracing through the code) it's CSL_IPIPE_SRC_HPS / CSL_IPIPE_SRC_VPS, but I can't be sure as there's so much code to trace through!

0 g.f. over 12 years ago in reply to Bob The Gerbil

Guru 15520 points

Hi, Bob

Thank you for the answer.

May I ask you a few more question?
What value did you set to IMGS_H_PAD and IMGS_V_PAD,
and how did you figure the value?
Is it from camera module's datasheet which you are using?

best regards,
g.f.

0 Bob The Gerbil over 12 years ago in reply to g.f.

Expert 1100 points

I found that the numbers given in data-sheets were not entirely useful - also the code (undocumented as it is) takes the IMGS_x_PAD values and divides them by 2, which assumes the padding is equal all round the image.

In the end I took a screenshot in VLC and counted the black pixels.

I may modify the code to account for different padding around each side later, but for now there is too much other stuff to do.

0 g.f. over 12 years ago in reply to Bob The Gerbil

Guru 15520 points

Hi, Bob

Thank you so much.
I understood.

best regards,
g.f.

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DM368 BT1120 YUV in working but black bars round picture