PFNUSBCAMD_BulkReadWrite callback function (usbcamdi.h)
The USBCAMD_BulkReadWrite service performs a read or write operation on the specified bulk pipe.
Syntax
PFNUSBCAMD_BulkReadWrite PfnusbcamdBulkreadwrite;
NTSTATUS PfnusbcamdBulkreadwrite(
[in] PVOID DeviceContext,
[in] USHORT PipeIndex,
[in] PVOID Buffer,
[in] ULONG BufferLength,
[in] PCOMMAND_COMPLETE_FUNCTION CommandComplete,
[in] PVOID CommandContext
)
{...}
Parameters
[in] DeviceContext
Pointer to the camera minidriver's device context.
[in] PipeIndex
Specifies the index of the bulk pipe.
[in] Buffer
Pointer to the read or write buffer. If this parameter is set to NULL for a read request, USBCAMD pulls a data SRB from the SRB read queue of the stream associated with this pipe. Write requests with a NULL buffer pointer are only permitted on the still pin if an SRB_WRITE_DATA request has been submitted to the still pin.
[in] BufferLength
Specifies the length of the read/write buffer in bytes.
[in] CommandComplete
Pointer to a camera minidriver defined CommandCompleteFunction, which is called when the bulk read or write is completed. This value can be NULL.
[in] CommandContext
Pointer to a block of memory, that is passed as an argument to the camera minidriver defined CommandCompleteFunction.
Return value
USBCAMD_BulkReadWrite returns STATUS_SUCCESS if the call was successful. Other possible error codes include:
| Return code | Description |
|---|---|
| STATUS_FILE_CLOSED | The device has been removed. |
| STATUS_INVALID_PARAMETER | USBCAMD may return STATUS_INVALID_PARAMETER for a number of reasons, including: The value passed in the PipeIndex argument is invalid. The type of the pipe specified by the PipeIndex argument represents an invalid type of pipe. A bulk read/write request already exists. The Buffer argument is NULL. |
| STATUS_INSUFFICIENT_RESOURCES | There are insufficient resources to schedule a transfer. |
Remarks
USBCAMD can accept one read and one write request at a time.
USBCAMD_BulkReadWrite is not available in USBCAMD version 1.0.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | usbcamdi.h (include Usbcamdi.h) |