Hello
Thanks for the answer
Le 26.12.2010 12:20, Clemens Ladisch a écrit :
Laurent Epinat wrote:
I try to developpe a usb sound driver for a Alesis Multix 8 USB2.0
http://www.alesis.com/multimix8usb20
The output interface is allready fonctional, but the Input not :-( Because there is 2 end point for it. The first one is on Isochronous mode and the other is on Bulk mode
I don't know how to declare the second endpoint in the quirks_table.
There is no predefined quirk for such an endpoint; you'd have to write your own code.
Where can I get a good documentation or help about the alsa USB sound structure.
At the moment, the only documentation is the source code.
The only informations I have about the devices, are dump from windows
What is the bulk endpoint used for?
I don't know exactly, I think the Isochrone endpoint is used for control and the bulk one is the data, because the size is bigger and the interval is short than the isochrone one
on the device you can record 10 inputs channels at the same time
Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 1 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 5 Transfer Type Isochronous Synch Type Asynchronous Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 4 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x86 EP 6 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 1
Regards, Clemens