Patent ID: 8291137

Claim:
A method for USB image capturing with two isochronous transfers, which is applied for data transfer between a USB image capturing device and a host, the USB image capturing device having a first endpoint and a second endpoint for transferring a video stream obtained by the USB image capturing device, the host having a USB and a driver for receiving the video stream through the USB, the method comprising the steps of: (A) the driver using a function â€œUSBCAMD_ReadChannelâ€ to read the video stream of the USB image capturing device; (B) the driver creating a read extension data structure of â€œUSBCAMD ReadExtensionâ€ to process packets of the first and the second endpoints of the USB image capturing device respectively; (C) the driver dispatching the packets received through the USB; (D) the driver managing and copying data of the packets into a first buffer and a second buffer, respectively; (E) the driver determining whether a first end frame flag in a packet of the first endpoint is set and a second end frame flag in a packet of the second endpoint is are set or not; and (F) the driver combining data of the first and the second buffers when the first and second end frame flags are set, thereby generating a frame to the host.