Re: [Qemu-devel] [RFC PATCH 0/2] Add USB Video Class device emulation.

["David S. Ahern" <daahern@cisco.com>]

On 06/10/10 12:26, Natalia Portillo wrote:
> Hi David,
> 
>> Attempting to try out your patches, but it's failing with the following:
>>
>> usb-uvc: Init called
>> usb-uvc: Trying to open /dev/video0
>> .usb-uvc: Device opened correctly.
>> usb-uvc: Querying capabilities.
>> usb-uvc: Device driver: uvcvideo
>> usb-uvc: Device name: Laptop_Integrated_Webcam_0.3M
>> usb-uvc: Device bus: usb-0000:00:1a.7-6
>> usb-uvc: Driver version: 0.1.0
>> usb-uvc: Device capabilities: 0x04000001
>> usb-uvc: Enumerating video inputs.
>> usb-uvc: Setting video input to index 0
>> usb-uvc: Video input correctly set.
>> usb-uvc: Trying to set 320x240 MJPEG.
>> qemu-system-x86_64: -device usb-uvc-webcam,device=/dev/video0: Invalid
>> format.
> 
> As for now only cameras that allow MJPEG format will work.
> Check your camera specifications (lsusb -v works if your real camera is UVC, check driver's source otherwise).
> Cameras with RAW frames (YUYV and NV12 formats) do not work, yet. I'm on it.

Trying to guess the relevant descriptors:

    VideoStreaming Interface Descriptor:
        bLength                            50
        bDescriptorType                    36
        bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
        bFrameIndex                         3
        bmCapabilities                   0x00
          Still image unsupported
        wWidth                            320
        wHeight                           240
        dwMinBitRate                   768000
        dwMaxBitRate                  4608000
        dwMaxVideoFrameBufferSize      153600
        dwDefaultFrameInterval         333333
        bFrameIntervalType                  6
        dwFrameInterval( 0)            333333
        dwFrameInterval( 1)            400000
        dwFrameInterval( 2)            500000
        dwFrameInterval( 3)            666666
        dwFrameInterval( 4)           1000000
        dwFrameInterval( 5)           2000000

      VideoStreaming Interface Descriptor:
        bLength                             6
        bDescriptorType                    36
        bDescriptorSubtype                 13 (COLORFORMAT)
        bColorPrimaries                     1 (BT.709,sRGB)
        bTransferCharacteristics            1 (BT.709)
        bMatrixCoefficients                 4 (SMPTE 170M (BT.601))

> 
>>
>> Also, I tried a PWC camera which is not a V4L2_INPUT_TYPE_CAMERA and
>> noticed that video_input_index is used uninitialized in usb_uvc_initfn
> It's a webcam?
> Could you give me more information?
> Manufacturer, model, linux's module name.

usb 7-1: new full speed USB device using uhci_hcd and address 3
usb 7-1: New USB device found, idVendor=046d, idProduct=08b6
usb 7-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
pwc: Logitech/Cisco VT Camera webcam detected.

David


> 
> All webcams SHOULD (and MUST) implement V4L2_INPUT_TYPE_CAMERA.
> Not the same for video cameras or capture devices (PAL/NTSC, DVB/ATSC).
> 
> Regards,
> Natalia Portillo