Can ADV7184 take VGA signals?

I have TVP5146M2 which suits my needs and very cheap but its output is 10-bit not 8-bit, currently trying to find if it supports 8-bit. It seems that no other dac of adv7343 family is cheap and available while also supports 10-bit.

I am open to suggestions.

ADV7340 seems good enough but it is only available from https://www.win-source.net/ which doesn't seem reliable. Digikey doesn't have it in stock but the price is 35$ which is a lot, same as adv7341.

I've seen ADV7391 but it has only 3 DACs, so can I use 2 of it? one for outputting RGB or YPbPr, and the other for outputting S-video and CVBS.

I mean, connect the 10-bit YCbCr ITU-R signals directly to the 2 of them without buffer or anything, is this ok?

ADV7391 seems cheap from Rochester (6$), are they legit? digikey is about 9$ Mouser is 11$ which is also ok.

I've seen ADV7391 but it has only 3 DACs, so can I use 2 of it? one for outputting RGB or YPbPr, and the other for outputting S-video and CVBS.

I mean, connect the 10-bit YCbCr ITU-R signals directly to the 2 of them without buffer or anything, is this ok?

ADV7391 seems cheap from Rochester (6$), are they legit? digikey is about 9$ Mouser is 11$ which is also ok.

Hi,

Please find below comment,

I found adv7184 to be ok but it doesn't seem to support rgb with separate syncs, so can it?

   YES, ADV7184 extracts syncs embedded in the video data stream but there is currently no support for external HS/VS inputs.

ADV7181C is a high-quality single chip multi-format video decoder, It can meet most of your requirement. Please refer below snap for your reference.

Also when processing component video signals, there are three possible sources for synchronization
information from which the ADV7181C can extract timing:
• Embedded Sync as part of the input video signal, e.g. SOG/SOY
• External HS and VS as logic signals via HS_IN and VS_IN pins
• External CS (composite sync) as logic signal, via the HS_IN pin

And it does not cost more than 20$

ADV7391 but it has only 3 DACs, so can I use 2 of it? one for outputting RGB or YPbPr, and the other for outputting S-video and CVBS.

    Yes, you can use but ADV739x is "Not Recommended for New Designs".

Thanks,

Poornima

hello

thanks for your support.

ADV7181C seems good and relatively cheap, it can support 8\16 bits output which is suitable to ADV7343.

However, here are some questions for it:

1- does it support scart rgb in resolutions such as 240p\288p\480i\576i\480p\576p? do I need different configuration scripts for each one?

2- will the converted signal after passing the output DAC retain the same features such as square pixels and aspect ratio?

3- how to support sync on green for RGB SCART option?

4- I need it to automatically know the NTSC\PAL for input video, not to be inputted manually. is that possible? I guess SDP can use this feature but not sure... YPBPR is recommended to go through CP which requires assigning a standard... how to make this easier? maybe use standard detection first? but if we assigned "480i" first then used standard detection and got "576i" or "480p"... will it be accurate?

5- scart sources will have a CSync in pin 20, not always a CVBS signal.. is that ok?

6- sticking to evaluation board + official scripts is the way to go right? except for modifications needed for above stuff right?

regards 

Hi,

  1- does it support scart rgb in resolutions such as 240p\288p\480i\576i\480p\576p? do I need different configuration scripts for each one ?

       No, using source only you going to change the input format so its not required.

       Reference script available for  ##SCART RGB## is available at 5355.ADV7181C_Evaluation_Software.zip

        It is recommended for the ADV7181C to use the ADC mapping in Table 4 in pg no: 15 INSEL[3:0] = 0000 SDM_SEL[1:0] = 00 PRIM_MODE[3:0] = 0000 VID_STD[3:0] = 0010

     Note:  ADV7181C can support simultaneous processing of CVBS and RGB Standard Definition signals to enable SCART compatibility and overlay functionality. This is available when PRIM_MODE[3:0] is set to 0000 to select Standard Definition Modulated. Once this is selected, timing extraction is always performed by the SDP on the CVBS signal  

2- will the converted signal after passing the output DAC retain the same features such as square pixels and aspect ratio?

       Yes the converted signal also will retain in same way the what we have given from the input end.

3- how to support sync on green for RGB SCART option ?

        Please start with the SCART script and then adjust the sync slicer to use SOG and check out the manual paragraph 7.4.3, Also SYN_SRC[1:0] = 11

4-  I need it to automatically know the NTSC\PAL for input video, not to be inputted manually. is that possible? I guess SDP can use this feature but not sure... YPBPR is recommended to go through CP which requires assigning a standard... how to make this easier? maybe use standard detection first? but if we assigned "480i" first then used standard detection and got "576i" or "480p"... will it be accurate?

     Yes, Under normal circumstances, however, this should not be necessary. The VID_SEL[3:0] bits default to an auto-detection mode that supports PAL, NTSC, SECAM and by using VID_SEL[3:0] register it allows the user to force the digital core into a specific video standard.

Thanks,

Poornima

hello

i will get back to this later on... still need to verify.

however, I got a question: can adv7181c output pure CSYNC always regardless of active input? I mean if the input is cvbs\s-video\component\rgb\rgb vga... can it always outputs csync? regardless of using sdp or cp.

Hi,

   CS is a Digital Composite Synchronization Signal (and can be selected while in CP mode) So its available only in CP mode ( i.e CP module can generate only CSYNC )

can it always outputs csync? regardless of using sdp or cp.

    No its not possible, CVBS\S-Video needs to go through the SDP module so its no reference to CSYNC. 

Thanks,

Poornima

ok so I can use LMH1980 to get csync+Hsync+Vsync from CVBS, S-video, YPbPr, SCART green, SCART pin 20 sync... before they go into ADV7181C.

Then for VGA, I can rely on ADV7181C CP mode to generate the required Csync for it, this is how I can get Csync for all signals.

what do you think?

I say this because eventually I need to feed ADV7181C to ADV7343 DAC to get RGB + S-video + CVBS analog outputs + use a good opamp to make YPbPr from that RGB coming from the DAC. Therefore I need Csync to be available regardless of any input I choose.

what modifications to scripts I need to do in order to make CP outputs CSYNC?

Hi,

LMH1980 to get csync+Hsync+Vsync from CVBS, S-video, YPbPr, SCART green, SCART pin 20 sync... before they go into ADV7181C.

    As stated earlier, Csync option is not available for SDP, So try above approach and let us know.

what modifications to scripts I need to do in order to make CP outputs CSYNC ?

   By using 'HS_OUT_SEL' bit in CP output selection register, we can output CSync on the HS pin.

Also for changing the polarity of CSync signal use 'PIN_INV_HS' bit(invert polarity of HS signal(or CSync if selected).

  CS signal is a logic combination of HS and VS. Its polarity can be inverted by using the PIN_INV_HS bit.

Thanks,

Poornima