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4:2:2 8bit ycrcb


I have the EVAL-ADV7612-7511p video evaluation board .I'm using 7612 to receive  HDMI inputs from camera(720p @60) , and then feed to 7511 to output the video to the screen. 

camera -> 7612 --> 7511 --> screen

When adv7612 output 4:4:4 8bit ycrcb,i can see correct image on the screen,

But when i configure it to 4:2:2,the color is incorrect.

i change two registers:

1)ADV7612: 0x98 03            OP_FORMAT_SEL[7:0] 

2)ADV7511: 0x72 15 

if there are any other registers i should configure?



adv7612 7511
[edited by: heaven at 7:54 AM (GMT 0) on 23 Jan 2019]

Top Replies

  • Hi,

     When the ADV7612 pixel output format is set to 4:2:2 (refer to the Pixel Port Output Modes section), the DPP section down converts the 4:4:4 stream from the HDMI section according to DS_WITHOUT_FILTER
    For a 4:4:4 HDMI input stream to the ADV7612
      The DPP section filters and downsamples the video data from 4:4:4 to 4:2:2 format if DS_WITHOUT_FILTER is set to 0. The DPP section only downsamples, without filtering, the video data from the HDMI section if DS_WITHOUT_FILTER is set to 1.
    For a 4:2:2 HDMI input stream, the functionality of DS_WITHOUT_FILTER is reversed.  
    This inversion ensures that for a 4:2:2 HDMI input stream no filtering will be applied if DS_WITHOUT_FILTER is left to its
    default value 0. When a 4:2:2 HDMI input stream is input to the
    ADV7612, the DPP section downsamples, without filtering, the video data from 4:4:4 to 4:2:2 format if DS_WITHOUT_FILTER is set to 0. If DS_WITHOUT_FILTER is set to 1, the DPP filters and downsamples the video data from 4:4:4 to 4:2:2 format.

    And also make sure the sink is interpreting what the ADV7612 is outputting.  Make sure the sink has the correct bus / pin alignment when 422 mode. 422 mode only uses 16 pins instead of 24.Please refer here
     The incoming HDMI can be either RGB 444 or YCbCr 444/422.  It converts the it to 444 internally for processing then converts it again to the output format, either 444 or 422
    422 implies there is one luminance output per input sample with the color information interleaved in the data stream with the output clock doubled.  422 also implies there is one color sample per 2 luminance sample.  The color information is subsampled.  RGB can not be output in 422 format.  Check out for a better description of this format.



  • Thanks for the response.  it seems that his question hasn't been solved.

    I only want to know how to configure the registers. 

  • Hi,

     Could you please your register dump on this?



  • Hi,

      Have you configure the CSC register?

      Have you verified the 4:2:2 Output mode in Pixel Output formats. Refer Page198 in ADV7612 Reference Manual.
      And also Refer to the DLL settings for 656, 8-/10-/12-bit modes in the DLL on LLC Clock Path section. Refer Page 29.
      And crosscheck with OP_CH_SEL[2:0] register for corresponding pin configuration.



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