Re: [libusb] I have trouble with libusb_control_transfer

[Tim R. <ti...@pr...>]

On Apr 26, 2019, at 9:51 AM, 손창범 <ckd...@gm...> wrote:
> 
> I'm dealing with usb headset(audio device).

Why are you doing this with libusb instead of using the standard audio APIs for your operating system?


> bmRequest Type : 10100001= 0xA1
> bRequest : 0x81 GET_CUR
> wValue : COPY_PROTECT_CONTROL 0x0100
> wIndex : 0x0100(0x01 :terminal ID  0x00 : Interface 0(alternate 0) )
> wLength : 0x0001(1byte)
> Data : I declared it like uint8_t data;
> And my code here 
> r1 = libusb_control_transfer(dev_handle, 0xA1, 0x81, 0x0100, 0x0100, &data, 0x0001, 1);
> 
> can it be the Issues like byte_ordering(my VS is little_endian order) 

No, the issue is that your audio hardware does not support this request.

> Can you guys help me with correct this error?

It's not an error.  You'll just need to continue with your app, assuming that the hardware does not support copy protection.
— 
Tim Roberts, ti...@pr...
Providenza & Boekelheide, Inc.