Using the VADC Analog Camera Input

Discussion in 'UDOO NEO' started by Hannes Bo, Jan 15, 2016.

  1. Hannes Bo

    Hannes Bo New Member

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    Hello,

    I have purchased the UDOO NEO full and already installed and run UDOOubuntu 2 successfully. I would like to use one of the Analog Video Inputs to provide a video stream on the network. In UDOO NEO Docs at VADC Analog Camera - Usage it says "coming soon".

    I think with gstreamer this should be possible, but I never worked with this tool before. Can anyone help me or give me any hints where to look?

    When further details about this topic will be provided?

    Thank you very much.
     
  2. Hannes Bo

    Hannes Bo New Member

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    Small update on my issue:

    Today I found QT V4L2 Test Bench and installed it on the UDOO NEO (sudo apt-get install q4vl2). With this tool, I was able to display the VADC-Input with YUV4 (YUV32 (X-Y-U-V)) as capture image format, a frame size of 720x576 and a frame rate of 25 fps. This package uses the v4l2 api, so there should be a way to get the VADC working with gstreamer or avconv (ffmpeg)...

    @Andrea Rovai : It would be really nice, if you could give me a short feedback on the current state of the VADC topic. Is there someone of the UDOO team working on it at the moment? Are there any plans, when this topic will be focused by your team? As I already said in this post , the reason why I bought the UDOO NEO was its VADC interface. This is a real unique feature, which is quite rare to find somewhere else, so it's a bit sad, that there up to now is no support...
    I would be really thankful, if you could help me anyway!
     
  3. ssinfod

    ssinfod New Member

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    Hello, I also want to use the analog video VADC-input on the UDOO Neo.
    Do you know what driver (module) is responsible for the VADC-input ?

    When I start qv4l2, I see "Device: /dev/video0 (wrapped)" and "Driver: mx6s-csi".
    Is this the correct device for the analog ? (it seems to be for CSI camera).

    How do I change the device in qv4l2 to select the analog camera ?

    Thanks
    ssinfod
     
  4. Hannes Bo

    Hannes Bo New Member

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    The device /dev/video0 is definitely the VADC-input. So when you start qv4l2 the default source is already the VADC. Did you managed to display anything via q4vl2? The output I was able to display was not great by the way, but it worked.

    And again the question to @Andrea Rovai : What is the current state of the VADC topic? Does one of the new images on sourceforge (udoobuntu-udoo-neo-desktop_2.0rc2 and udoobuntu-udoo-neo-minimal_2.0rc2) contain any update on that issue, what is new about that images? I could not find any official information about that. It would be really nice to get some support of the UDOO team about this interface.
     
  5. Hannes Bo

    Hannes Bo New Member

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    @jas-mx : Do you think, that it is possible to use the ADV7280 video decoder chip to capture analog video and feed it into the 8bit digital camera interface of the UDOO NEO? Perhaps this could be a temporarily solution as long as the VADC is not working properly?
     
  6. jas-mx

    jas-mx Active Member

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    I'm not sure what you are trying to achieve by using the ADV7280 because it has similar features to the on board VADC therefore you don't gain much. You still have use software decoding to translate YCrCb into h264/mpeg which you are struggling to achieve using VADC. The ADV7280 would make sense with the UDOO or another imx6d/q board, however I'm not sure if you have the skills to do the interfacing both from a hardware and software level based on your experience with the VADC.
     
  7. ssinfod

    ssinfod New Member

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    I bought this board especially for this VDAC interface !
    As of now, it seems the software documentation of the VDAC analog video interface is non existent for the UDOO Neo.

    If the V4L2 driver is working properly, then we could use libav/libavcodec or OpenCV library to query and record compressed video.
    Guvcview is a good example of using the V4L2 API and libav/libavcodec library.

    So my comments/questions are:
    Does the VADC analog video interface is currently working on the UDOO Neo ?
    Can we use the V4L2 API to access it ?

    Otherwise, what part is not working (hardware or software) ?
    Can we help in some way to make this feature work ?

    Thanks
    ssinfod
     
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  8. jas-mx

    jas-mx Active Member

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    The VADC is exposed via V4L2, unfortunately not many people are willing to take the time to understand how it works and what is capabilities/limitations are. To save repeating myself its please refer to the other thread and example code here. Before you starting suggesting using libavcodec or OpenCV spend the time reviewing the VADC capabilities.
     
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  9. Hannes Bo

    Hannes Bo New Member

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    @ssinfod :
    In this post I made in the NXP community you can find some documents, which perhaps could be useful (I think you have to register to download them, perhaps this link works). These documents are about different SABRE boards, where some also use the i.MX6SoloX. I think it should be possible to use the information to build an image which works on the UDOO NEO with VADC support, or extract only the necessary parts and include them in UDOObuntu. You should have a look at:

    • i.MX_Linux_Release_Notes.pdf Table 29. Video codec specification for hardware without VPU acceleration.
    • i.MX_Linux_User's_Guide.pdf Chapter 7 Multimedia
    Perhaps this is useful to you...
     
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