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ADV7180 and VBI data on the captured picture

Question asked by llmike on Jun 17, 2015
Latest reply on Jul 10, 2015 by llmike

Hi,

 

Just for information: my configuration is Renesas R-CarM2 EVM board (Koelsch) with ADV7180 onboard, but configuration doesn't matter in my case. Almost all ADV7180 registers are in power on default state.

 

I've connected NTSC DVD player to ADV7180 CVBS Ain1 pin and used this test pattern DVD: my TV Test Disc - television test pattern DVD download

 

Also I've attached sample picture which I captured using ADV7180. Two NTSC fields were interleaved in a result picture (weave deinterlacing). If you take a look on to top part of image you can notice some VBI data transmitted by DVD player, or it is SMPTE timecode - I do not know, but I'd like to get rid of them completely during capture. Also if you look at bottom, you can see that some bottom lines of picture is missing, because viewport is shifted up.

 

1) I tried to set NTSC_V_BIT_END (0xE6) register to 0x50 value, it helps to get rid of VBI data and I can receive whole picture, including last line, but in a free-run mode decoder transmits 12 lines less than it should. It transmits about 468 lines of blue picture. Can we fix this somehow ?

2) I tried to switch ADV7180 to BT656.4 protocol (0x04 register, bit 7) which according to specification must start transmission from line 20 instead of line 10 (BT656.3) of NTSC image. But it doesn't work at all. There is no difference between BT656.3 and BT656.4 at all.

3)  I tried to switch VS/FIELD Control 1 register (0x31, bit 4) to automatic mode, but it doesn't help me too.

 

Do you have any suggestions how I can get rid of VBI data or at least fix issue described in 1).

 

Thanks in advance!

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