• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 46 subscribers
  • Views 516 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TVP5151 VBI ancillary data Format

Mark Evensen
Prodigy 20 points
Other Parts Discussed in Thread: TVP5151

I'm trying to interface a TVP5151AM1 with a Broadcom MPEG decoder that accepts BT.656 input. We've found the I2C interface inadequate and are getting dropped data even using FIFO mode. The Broadcom supports a number of ancillary data formats including several variants of SAA7113, SAA7114 and SAA7115. They also support SMPTE 291M Type 1 & 2 formatted data. The TVP5151 seems to output a proprietary format that looks a little like 291M ANC, but uses even/odd parity bits even though the output is not 10-bits. Is it possible to put the TVP5151 in a compliant SMPTE 291M mode?

  • 0
    TI__Genius 16810 points

    Mark,

    Are you getting any good data using the TVP ANC format?

    Do you think this is related to the parity bits,  or possibly other 291M discrepancies?

    Most of the TVP ANC header format is fixed in hardware and cannot be changed.

  • 0 in reply to Larry Taylor
    Prodigy 20 points

    Yes, we're getting ANC data in the published format. I think the parity bits themselves are one source of problem because the MPEG decoder will interpret these as part of the data field. The presence of the parity bits also mandates special handling of the packet length field (i.e. left shift 2 bits and use padding if the payload is not an even multiple of 4). In any case, the ANC data are being rejected by the MPEG decoder.