• State
  • Locked Locked
  • Replies 7 replies
  • Subscribers 98 subscribers
  • Views 515 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.

RGB666 output issue

smilexj
Prodigy 190 points

Hi,

My platform is dm355 with dvsdk_1_30_01_41. I use parellel RGB 640x480 as output from dm355.

While navigating on the menu items or playing video, white lines will appeared on the horizontal.

While playing cvbs use ./encodedecode -p -d, there is no this issue, but use ./encodedecode without -p -d, white lines will appeared on the horizontal.

While showing jpeg files, there is no this issue.

Can anyone give me some hint?

Thanks!

  • 0
    TI__Mastermind 37340 points

    This issue has come up before and there is good information covered in the following thread

    https://community.ti.com/forums/t/4969.aspx

    Please note that the -p (passthrough, no encoding or decoding) and -d (disable interlacing) both alleviate DDR bandwidth consumption, hence I would expect these to help.  But I would probrably start with PBBPR register (see above thread for details).

  • 0 in reply to Juan Gonzales
    Prodigy 190 points

    Hi Juan,

    Many thanks for your information. I tried to change PBBPR and TC RDRATE registers, but it seemed to no any improvement.

    Attached the picture for you refer.  White lines will appear randomly on menu operation or playing video.

     

     

     

  • 0 in reply to smilexj
    TI__Mastermind 37340 points

    This looks a bit different than what we have seen in the past (white horizontal lines all over the screen); of course it is hard to tell since the background is white; however, I would expect the white lines to appear in the middle of the text as well and not necessarily nicely aligned in between menu choices.  Do you only see the lines in between menu boxes; if so, this could be an aliasing issue or similar...

  • 0 in reply to Juan Gonzales
    Prodigy 190 points

    The attached picture just for the reference. While playing video, white lines also can be seen on the horizontal.

  • 0 in reply to smilexj
    TI__Mastermind 37340 points

    as we have suggested, the white horizontal lines are likely due to DDR2 bandwidth constraints, especially if they go away with -d or -p option ad you suggested in the first post.  At this point you have three options.

    1) If PBBPR did not help, you will need to consider ways of reducing DDR2 bandwith; for example, are you enabling both video and osd windows?  Can you get away with a smaller OSD window positioned correctly in the screen?  Are you using resizer to deinterlace and can you get away without this?  Can you lower the refresh rate?....

    2) try to obtain 270 MHZ DM355; I hear these are pretty hard to come by, but if you are able to get this, it should help a little.

    3) Consider using DM365 instead (there is a 270 MHz and 300 MHz version)

     

  • 0 in reply to Juan Gonzales
    Prodigy 190 points

    Hello Juan,

    Many thanks for your suggestions. A good news to share with you. After changing PBBPR to 8, those lines disappear.

    I tried to change PBBPR before, but due to my mistake, this change did not take effect.

     

  • 0 in reply to smilexj
    TI__Mastermind 37340 points

    This is great news and very encouraging for others that may be dealing with this issue.

    FYI, for you and others that may come across similar issues, there is a new wiki article detailing some things to keep in mind when runnign into issues with digital output display on DM355. http://wiki.davincidsp.com/index.php?title=TMS320DM355_High-Definition_%28HD%29_Display