isochronous transfer for UVC camera

[SAITOU Toshihide]

In message: <20121030.000648.193690728.toshi at ruby.ocn.ne.jp>
            SAITOU Toshihide <toshi at ruby.ocn.ne.jp> writes:
> In message: <201210291436.08940.hselasky at c2i.net>
>             Hans Petter Selasky <hselasky at c2i.net> writes:
>> On Monday 29 October 2012 13:54:34 SAITOU Toshihide wrote:
>>> #define PKT_LEN        0x1400
>> 
>> The packet length is not this value I think.
>> 
>> The 0x1000 is part of the packet multiplier for High-Speed USB's 
>> wMaxPacketSize.
>> 
>> It is (1+2) * 0x400. Try that and see what happens.
> 
> Thank you for your quick response.
> 
> I can't use the FreeBSD now so I will try this tomorrow.  But Mac OS X 10.6.8 with libus 1.0.9, callback is not invoked too with some combination of the value below:
> 
> #define PKT_LEN        0x400
> #define PKTS_PER_XFER  8

It dose not affect on the FreeBSD.

>> Also there is usbdump -i usbusX -f Y -s 65536 -vvv, which will show the actual 
>> traffic.

! This is very useful.

   $ usbdump -i usbus2 -f 4.0 -s 65536 -vvv       (unit 4)
   $ usbdump -i usbus2 -f 4.130 -s 65536 -vvv     (unit 4, endpoint 0x82)

I have compared with other application (pwcview).

There are a lot of VS_PROBE_CONTROL transfer than expected. But it may
not be a problem because I have tried these transfer reproduced from
dump data. The problem I noticed is that the libusb_claim_interface of
my code is not logged. Is this function really implemented?

   libusb_set_interface_alt_setting(handle, 1, 1);
   libusb_control_transfer(handle, 0x01, 0x0b, 0x0100, 0x0100, NULL, 0, TIMEOUT);

Thank you.

---
SAITOU Toshihide