black and white sensor using USB video class driver

Discussion in 'Windows Vista Drivers' started by Julia Cip, Jun 10, 2005.

  1. Julia Cip

    Julia Cip Guest

    Hi everyone,

    We are developing a black and white sensor using USB video class driver. We
    want to get as high frame rate as possible.

    My question is if the USB video class driver has black/white mode. In this
    mode only black/white information is transmitted through USB.

    Any help would be very much appreciated!!!

    Thank you,

    Julia Cip, Jun 10, 2005
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  2. Julia Cip

    JC Guest

    Could anyone give me a hint?

    JC, Jun 13, 2005
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  3. Julia Cip

    RonM Guest

    I did a B/W USB camera a few years ago. As I recall we submitted the video data
    to Windows as YUV data. Since our info was B/W and the data coming from the
    camera was YCrCb when we did the conversion we adjusted the output YUV
    to be "color neutral" In other words the only output we would send was all the
    shades between black and white. Cr and Cb and therefore U and V were fixed
    values denoting "gray" or for the UK "grey" HTH
    RonM, Jun 14, 2005
  4. Julia Cip

    JC Guest

    Thank you Ron,

    The method you described tells me that the USB channel is still transmitting
    color information. What we are trying to find out is not sending color
    information for black and white camera so that the frame rate could be

    We want to use a chip that support USB Video Class driver. But we are not
    sure if the USB Video Class provides this capability.

    Any idea?

    JC, Jun 15, 2005
  5. Julia Cip

    RonM Guest

    When I worked on this, I worked for a "chip" company. Our USB Cam chip was
    proprietary so we took the USB CAM example and carved it up to our liking.
    We were going after a color camera but in the development stages
    we did not have an imager with color (colour) filters so we just started
    with B/W. Since it was our own chip we turned off the CrCb USB ISO pipe
    in our chip. Once we got an imager with color filters we enabled
    the second ISO pipe and did the YCrCb to YUV conversion. The key
    is our chip could do this. The question is, can the chip set you are using
    do this? If you are not developing your own driver then you have no
    control of the chip and therefore no control of the stream. I believe the
    bone stock USB CAM example just streams YUV data and compliant
    chips supply this format only. If you want your own USB ISO stream format
    that only streams Y video, you have to be able to turn the chip's
    USB isochronous color channel off and have the driver be happy with that.
    If the chip will not do that or the driver is "off-the shelf" then you can't get
    there from here.
    RonM, Jun 15, 2005
  6. Julia Cip

    JC Guest

    Thank you very much, Ron!

    We have no control on the chip itself at all. But this chip would come up
    with a USB Video Class compliant. I am just wondering if USB Video Class
    driver support black and white mode, which turn off the color channel. Any
    By the way, I am also looking into the USB Video Class, not find anything

    Thanks again,

    JC, Jun 16, 2005
  7. Julia Cip

    RonM Guest

    I believe that you need to find out if you can get the chip into a mode
    where it will send what you want through USB. If you don't have control
    over the endpoints you are done. IF you can get the chip to shut
    off color info then you will have to modify the driver to accept this unexpected
    I have a not up to date DDK. Here is the path to USB a camera:
    That's what I started with to make our driver.
    RonM, Jun 20, 2005
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