Android TV box to RGBS input (RGB CSYNC)

Discussion in 'General Electronics Chat' started by Engineerer, Mar 24, 2016.

  1. Engineerer

    Thread Starter New Member

    May 22, 2013
    18
    0
    Hi,

    I'm trying send video from Android TV box to OEM navigation screen in my car. I have a video inserter installed that injects image straight to OEM screen. Video inserter accepts CVBS composite video or RGBS video. After fighting with CVBS video for a time I came to a conclusion that image quality is too poor with CVBS. Colors are leaking, ghosting etc normal things for composite are ruining the image.

    How could I convert HDMI output to RGBS? If I understood correctly, regular RGBS signal should be synced at ~15 kHz, so HDMI-VGA converter alone can't be used(~31 kHz H+V sync).

    Output source:
    [​IMG]
    Android box

    Input:
    [​IMG]
    Video inserter manual.
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,151
    3,058
  3. Engineerer

    Thread Starter New Member

    May 22, 2013
    18
    0
  4. wayneh

    Expert

    Sep 9, 2010
    12,151
    3,058
    Oops, my bad. I had searched for component and didn't notice that this was composite only.
     
  5. Engineerer

    Thread Starter New Member

    May 22, 2013
    18
    0
    Well, I ordered GBS-8100 VGA to CGA (15 kHz RGBS) converter. This unit has one serious fault though - It loses its settings on power off. I'm hoping I can get good picture out of it with its default settings. Luckily I do have brightness and contrast adjustment on my video inserter that remembers its settings.

    Somebody might be wondering why all this trouble to use better analog video signal. Here is a good example of RGB vs composite image. Composite effectively loses significant amount of resolution:
    [​IMG]

    When I first tried to input video with CVBS I got oversaturated image. I measured my CVBS signal DC voltage with white screen signal, and got around 1,6 volts. I attenuated white screen signal to around 0,7 V with resistors to achieve correct colors. After that I still got usual composite errors on image - color bleeding and ghosting.

    Here's a picture before I attenuated CVBS signal. There are some reflections on the screen, but you can see that colors are too birght and there are no contrast. Image is also smudgy with terrible ghosting effect.
    [​IMG]
     
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