Re: [Libusb-devel] Problems of getting video data using libusb

[Xiaofan C. <xia...@gm...>]

On Wed, Apr 25, 2012 at 8:07 AM, Xiaofan Chen <xia...@gm...> wrote:
> On Fri, Apr 20, 2012 at 1:10 AM, Tim Roberts <ti...@pr...> wrote:
>> You have a USB video camera that delivers frames over a bulk pipe?  Are
>> you sure?  That's very unusual.  Most video cameras use an isochronous
>> pipe.  What camera is this?  Do you have a VID and PID?
>>
>
> I believe there are quite some cheap ones do that.
> Maybe some of them are here.
> http://linuxtv.org/wiki/index.php/Webcam_Devices
>
> Even Microsoft's USBCAMD2 supports different configuration
> of device, including those use bulk pipe.
> http://msdn.microsoft.com/en-us/library/windows/hardware/ff568566(v=vs.85).aspx
> "Two bulk I/O pipes and an optional interrupt pipe. One bulk pipe
> streams video and the other bulk pipe transfers still images.
> The optional interrupt pipe signals notification of external trigger
> events to registered applications.".
>

I think I have one, bought in year 2002.

Information from Apple Mac OS X USB Prober. It
works under XP and I remember once upon
a time also under Linux.

Vendor-specific device: "USB Dual-mode Camera"
    Port Information:   0x0018
           Not Captive
           External Device
           Connected
           Enabled
    Number Of Endpoints (includes EP0):
        Total Endpoints for Configuration 1 (unconfigured):   2
    Device Descriptor
        Descriptor Version Number:   0x0110
        Device Class:   255   (Vendor-specific)
        Device Subclass:   0   (Vendor-specific)
        Device Protocol:   0
        Device MaxPacketSize:   8
        Device VendorID/ProductID:   0x0553/0x0202   (VLSI Vision Ltd.)
        Device Version Number:   0x0000
        Number of Configurations:   1
        Manufacturer String:   1 "STMicroelectronics"
        Product String:   2 "USB Dual-mode Camera"
        Serial Number String:   0 (none)
    Current configuration:   0 (unconfigured)
    Configuration Descriptor
        Length (and contents):   34
            Raw Descriptor (hex)    0000: 09 02 22 00 01 01 00 A0  23
09 04 00 00 00 FF 00
            Raw Descriptor (hex)    0010: 00 00 09 04 00 01 01 FF  00
00 00 07 05 82 02 40
            Raw Descriptor (hex)    0020: 00 00
        Number of Interfaces:   1
        Configuration Value:   1
        Attributes:   0xA0 (bus-powered, remote wakeup)
        MaxPower:   70 ma
        Interface #0 - Vendor-specific
            Alternate Setting   0
            Number of Endpoints   0
            Interface Class:   255   (Vendor-specific)
            Interface Subclass;   0   (Vendor-specific)
            Interface Protocol:   0
        Interface #0 - Vendor-specific (#1)
            Alternate Setting   1
            Number of Endpoints   1
            Interface Class:   255   (Vendor-specific)
            Interface Subclass;   0   (Vendor-specific)
            Interface Protocol:   0
            Endpoint 0x82 - Bulk Input
                Address:   0x82  (IN)
                Attributes:   0x02  (Bulk no synchronization data endpoint)
                Max Packet Size:   64
                Polling Interval:   0 ms

-- 
Xiaofan