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cvbs-out doesn't work

Qing Chang
Intellectual 280 points

Hi,

I have a mistral EVM, the revisions are , main board REV G, proc board REV D.

I have tested the cvbs in and out with the program located in ti-dvsdk_dm3730-evm_4_02_00_06\dmai_2_20_00_15\packages\ti\sdo\dmai\apps, using a PAL video source .

Unfortunately,  the iamges shown on TV looks so bad, eg, unfluent, horizontal stripes.

And what's more, I cannot even get the DSS to output a proper color-bar(I'm using the venc_config_pal_trm defind in drivers/video/omap2/dss/venc.c) , It seems something wrong with both H and V timing.

And, the situation is not better when I used S-video-out  instead of cvbs-out.

Could you please give me some advice on how to configure the video encoder or some reference values?

Thanks in advance!!

  • 0
    TI__Guru 65405 points
    Hi Qing Chang,

    Is the problem appears with PAL or NTSC or both systems?
    Is the problem appears on one board only or it is observed on more boards?
    Could you attach a picture to see the issue?

    BR
    Tsvetolin Shulev
  • 0 in reply to Cvetolin Shulev-XID
    Intellectual 280 points

     

    Thanks for your reply.

    Is the problem appears with PAL or NTSC or both systems?

    - It appears on only PAL system.

    Is the problem appears on one board only or it is observed on more boards?

    - It appers on Both Mistral EVM and our customed board. The DSS driver and cvbs-out circuit of two board are identical.

    Could you attach a picture to see the issue?

      Could you attach a picture to see the issue?

  • 0 in reply to Cvetolin Shulev-XID
    Intellectual 280 points

    I've known the reason. When I force the video encoder of DSS to output  bar images, the timings become to be NTSC.4, when I make it to output realtime video, the timings back to be PAL again, the video source is PAL always.

    why?

    How to make it output colorbar images properly?

  • 0 in reply to Qing Chang
    TI__Guru 65405 points
    Hi Qing Chang,
    To ensure that the VENC module settings are correct for PAL output check the VENC registers whether matching to the values from TRM table 7-74. For the VENC_S_CARR register value can vary according Table 7-42.

    BR
    Tsvetolin Shulev