we use the ADV7391 with BT656 input to standard PAL CVBS output 625i, SD mode 0.
For special purpose we need to put data into the input stream during VBI in video line 12 + 13 and 324 + 325. The input stream comes out of a fpga, so it ist possible to manipulate the stream.
My question is, is the video encoder able to output this data in the CVBS signal and how are the correct settings for the register?
Thank you for any suggestions
Your question has been forwarded to the part specialist and you will get an update soon
Data can be inserted between lines 7 and 22 for the PAL standard you are using, but not possible for lines 324 and 325.
To enable data insertion, set bit of register 0x83. All other register values should be the same as for the timing mode you are using.
I hope this helps!
thanks for the reply.
I understand the device is not the solution for our issue, because we have to insert data into the mentioned video lines.
I don't want to use the "vbi data service insertion" interface of the device but rather insert the data into the BT656 data stream. Is this possible?
Or could you propose me an alternate device for this issue?
Strictly speaking, whatever data is inserted via the BT.656 interface is encoded, as the encoder does not alter the video data that is input. So any data you insert should be encoded to the output.
That being said, your use case is different to the normal operation of the device, so i would urge you to try this out with an ADV7391 evaluation board first to prove that the device meets your requirements.
I tried out my use case with an evaluationboard EVAL-ADV7182A and it works. The board is assembled with an ADV7182A and ADV7391, video decoder and encoder in serie. Switch on the VBI data enable in the registers and all the data in the VBI area goes through both devices.
Thank you and best regards,