Re: [libusb] Descriptors Changing After Plugging in to Android Device

[michel <dia...@ya...>]

it's 3 time the same images no ?

notice that interface 1 and 2 have multiple alternate setting 
typically a given alternate setting could be made active if you start
playing or recording audio  with different  setting or if bus as limited
bandwidth availability.
on my webcam i cans see that alternate setting# 0 if off mode (no ep) and
aletrnate setting  #1 is the active 


          ===>Interface Descriptor<===
bLength:                           0x09
bDescriptorType:                   0x04
bInterfaceNumber:                  0x03
bAlternateSetting:                 0x00
bNumEndpoints:                     0x00
bInterfaceClass:                   0x01  -> Audio Interface Class
bInterfaceSubClass:                0x02  -> Audio Streaming Interface
SubClass
bInterfaceProtocol:                0x00
iInterface:                        0x00

          ===>Interface Descriptor<===
bLength:                           0x09
bDescriptorType:                   0x04
bInterfaceNumber:                  0x03
bAlternateSetting:                 0x01
bNumEndpoints:                     0x01
bInterfaceClass:                   0x01  -> Audio Interface Class
bInterfaceSubClass:                0x02  -> Audio Streaming Interface
SubClass
bInterfaceProtocol:                0x00
iInterface:                        0x00

changes of active alternate setting ( different bandwidth iso ep  i guess ) 
may change how device is  dumped.





--
View this message in context: http://libusb.6.n5.nabble.com/Descriptors-Changing-After-Plugging-in-to-Android-Device-tp5714741p5714754.html
Sent from the LibUSB Dev mailing list archive at Nabble.com.