capvideo.c

虚拟摄像头驱动

//==========================================================================;
//
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
//  PURPOSE.
//
//  Copyright (c) 1992 - 1999  Microsoft Corporation.  All Rights Reserved.
//
//==========================================================================;

#include "strmini.h"
#include "ksmedia.h"
#include "capmain.h"
#include "capdebug.h"
#include "capxfer.h"
#include "ntstatus.h"

//==========================================================================;
// General queue management routines
//==========================================================================;

/*
** AddToListIfBusy ()
**
**   Grabs a spinlock, checks the busy flag, and if set adds an SRB to a queue
**
** Arguments:
**
**   pSrb - Stream request block
**
**   SpinLock - The spinlock to use when checking the flag
**
**   BusyFlag - The flag to check
**
**   ListHead - The list onto which the Srb will be added if the busy flag is set
**
** Returns:
**
**   The state of the busy flag on entry.  This will be TRUE if we're already
**   processing an SRB, and FALSE if no SRB is already in progress.
**
** Side Effects:  none
*/

BOOL
STREAMAPI
AddToListIfBusy (
    IN PHW_STREAM_REQUEST_BLOCK pSrb,
    IN KSPIN_LOCK              *SpinLock,
    IN OUT BOOL                *BusyFlag,
    IN LIST_ENTRY              *ListHead
    )
{
    KIRQL                       Irql;
    PSRB_EXTENSION              pSrbExt = (PSRB_EXTENSION)pSrb->SRBExtension;

    KeAcquireSpinLock (SpinLock, &Irql);

    // If we're already processing another SRB, add this current request
    // to the queue and return TRUE

    if (*BusyFlag == TRUE) {
        // Save the SRB pointer away in the SRB Extension
        pSrbExt->pSrb = pSrb;
        InsertTailList(ListHead, &pSrbExt->ListEntry);
        KeReleaseSpinLock(SpinLock, Irql);
        return TRUE;
    }

    // Otherwise, set the busy flag, release the spinlock, and return FALSE

    *BusyFlag = TRUE;
    KeReleaseSpinLock(SpinLock, Irql);

    return FALSE;
}

/*
** RemoveFromListIfAvailable ()
**
**   Grabs a spinlock, checks for an available SRB, and removes it from the list
**
** Arguments:
**
**   &pSrb - where to return the Stream request block if available
**
**   SpinLock - The spinlock to use
**
**   BusyFlag - The flag to clear if the list is empty
**
**   ListHead - The list from which an SRB will be removed if available
**
** Returns:
**
**   TRUE if an SRB was removed from the list
**   FALSE if the list is empty
**
** Side Effects:  none
*/

BOOL
STREAMAPI
RemoveFromListIfAvailable (
    IN OUT PHW_STREAM_REQUEST_BLOCK *pSrb,
    IN KSPIN_LOCK                   *SpinLock,
    IN OUT BOOL                     *BusyFlag,
    IN LIST_ENTRY                   *ListHead
    )
{
    KIRQL                       Irql;

    KeAcquireSpinLock (SpinLock, &Irql);

    //
    // If the queue is now empty, clear the busy flag, and return
    //
    if (IsListEmpty(ListHead)) {
        *BusyFlag = FALSE;
        KeReleaseSpinLock(SpinLock, Irql);
        return FALSE;
    }
    //
    // otherwise extract the SRB
    //
    else {
        PUCHAR          ptr;
        PSRB_EXTENSION  pSrbExt;

        ptr = (PUCHAR)RemoveHeadList(ListHead);
        *BusyFlag = TRUE;
        KeReleaseSpinLock(SpinLock, Irql);
        // Get the SRB out of the SRB extension and return it
        pSrbExt = (PSRB_EXTENSION) (((PUCHAR) ptr) -
                     FIELDOFFSET(SRB_EXTENSION, ListEntry));
        *pSrb = pSrbExt->pSrb;
    }
    return TRUE;
}

//==========================================================================;
// Routines for managing the SRB queue on a per stream basis
//==========================================================================;

/*
** VideoQueueAddSRB ()
**
**   Adds a stream data SRB to a stream queue.  The queue is maintained in a
**   first in, first out order.
**
** Arguments:
**
**   pSrb - Stream request block for the Video stream
**
** Returns: nothing
**
** Side Effects:  none
*/

VOID
STREAMAPI
VideoQueueAddSRB (
    IN PHW_STREAM_REQUEST_BLOCK pSrb
    )
{
    PHW_DEVICE_EXTENSION    pHwDevExt = ((PHW_DEVICE_EXTENSION)pSrb->HwDeviceExtension);
    PSTREAMEX               pStrmEx = (PSTREAMEX)pSrb->StreamObject->HwStreamExtension;
    int                     StreamNumber = pSrb->StreamObject->StreamNumber;
    KIRQL                   oldIrql;

    KeAcquireSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], &oldIrql);

    // Save the SRB pointer in the IRP so we can use the IRPs
    // ListEntry to maintain a doubly linked list of pending
    // requests

    pSrb->Irp->Tail.Overlay.DriverContext[0] = pSrb;

    InsertTailList (
                &pHwDevExt->StreamSRBList[StreamNumber],
                &pSrb->Irp->Tail.Overlay.ListEntry);

    // Increment the count of outstanding SRBs in this queue
    pHwDevExt->StreamSRBListSize[StreamNumber]++;

    KeReleaseSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], oldIrql);

}

/*
** VideoQueueRemoveSRB ()
**
**   Removes a stream data SRB from a stream queue
**
** Arguments:
**
**   pHwDevExt - Device Extension
**
**   StreamNumber - Index of the stream
**
** Returns: SRB or NULL
**
** Side Effects:  none
*/

PHW_STREAM_REQUEST_BLOCK
STREAMAPI
VideoQueueRemoveSRB (
    PHW_DEVICE_EXTENSION pHwDevExt,
    int StreamNumber
    )
{
    PUCHAR ptr;
    PIRP pIrp;
    PHW_STREAM_REQUEST_BLOCK pSrb = NULL;
    KIRQL oldIrql;

    KeAcquireSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], &oldIrql);

    //
    // Get the SRB out of the IRP out of the pending list
    //
    if (!IsListEmpty (&pHwDevExt->StreamSRBList[StreamNumber])) {

        ptr = (PUCHAR) RemoveHeadList(
                         &pHwDevExt->StreamSRBList[StreamNumber]);

        pIrp = (PIRP) (((PUCHAR) ptr) -
                     FIELDOFFSET(IRP, Tail.Overlay.ListEntry));

        pSrb = (PHW_STREAM_REQUEST_BLOCK) pIrp->Tail.Overlay.DriverContext[0];

        // Decrement the count of SRBs in this queue
        pHwDevExt->StreamSRBListSize[StreamNumber]--;

    }

    KeReleaseSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], oldIrql);

    return pSrb;
}

/*
** VideoQueueCancelAllSRBs()
**
**    In case of a client crash, this empties the stream queue when the stream closes
**
** Arguments:
**
**    pStrmEx - pointer to the stream extension
**
** Returns:
**
** Side Effects:  none
*/

VOID
STREAMAPI
VideoQueueCancelAllSRBs (
    PSTREAMEX pStrmEx
    )
{
    PHW_DEVICE_EXTENSION        pHwDevExt = (PHW_DEVICE_EXTENSION)pStrmEx->pHwDevExt;
    int                         StreamNumber = pStrmEx->pStreamObject->StreamNumber;
    PUCHAR                      ptr;
    PIRP                        pIrp;
    PHW_STREAM_REQUEST_BLOCK    pSrb;
    KIRQL                       oldIrql;

    if (pStrmEx->KSState != KSSTATE_STOP) {

        DbgLogInfo(("TestCap: VideoQueueCancelAllSRBs without being in the stopped state\n"));
        // May need to force the device to a stopped state here
        // may need to disable interrupts here !
    }

    //
    // The stream class will cancel all outstanding IRPs for us
    // (but only if we've set TurnOffSynchronization = FALSE)
    //

    KeAcquireSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], &oldIrql);

    //
    // Get the SRB out of the IRP out of the pending list
    //
    while (!IsListEmpty (&pHwDevExt->StreamSRBList[StreamNumber])) {

        ptr = (PUCHAR) RemoveHeadList(
                         &pHwDevExt->StreamSRBList[StreamNumber]);

        pIrp = (PIRP) (((PUCHAR) ptr) -
                     FIELDOFFSET(IRP, Tail.Overlay.ListEntry));

        pSrb = (PHW_STREAM_REQUEST_BLOCK) pIrp->Tail.Overlay.DriverContext[0];

        // Decrement the count of SRBs in this queue
        pHwDevExt->StreamSRBListSize[StreamNumber]--;

        //
        // Make the length zero, and status cancelled
        //

        pSrb->CommandData.DataBufferArray->DataUsed = 0;
        pSrb->Status = STATUS_CANCELLED;

        DbgLogInfo(("TestCap: VideoQueueCancelALLSRBs FOUND Srb=%p, Stream=%d\n", pSrb, StreamNumber));

        CompleteStreamSRB (pSrb);

    }

    KeReleaseSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], oldIrql);

    DbgLogInfo(("TestCap: VideoQueueCancelAll Completed\n"));

}

/*
** VideoQueueCancelOneSRB()
**
**    Called when cancelling a particular SRB
**
** Arguments:
**
**    pStrmEx - pointer to the stream extension
**
**    pSRBToCancel - pointer to the SRB
**
** Returns:
**
**    TRUE if the SRB was found in this queue
**
** Side Effects:  none
*/

BOOL
STREAMAPI
VideoQueueCancelOneSRB (
    PSTREAMEX pStrmEx,
    PHW_STREAM_REQUEST_BLOCK pSrbToCancel
    )
{
    PHW_DEVICE_EXTENSION        pHwDevExt = (PHW_DEVICE_EXTENSION)pStrmEx->pHwDevExt;
    int                         StreamNumber = pStrmEx->pStreamObject->StreamNumber;
    KIRQL                       oldIrql;
    BOOL                        Found = FALSE;
    PIRP                        pIrp;
    PHW_STREAM_REQUEST_BLOCK    pSrb;
    PLIST_ENTRY                 Entry;

    KeAcquireSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], &oldIrql);

    Entry = pHwDevExt->StreamSRBList[StreamNumber].Flink;

    //
    // Loop through the linked list from the beginning to end,
    // trying to find the SRB to cancel
    //

    while (Entry != &pHwDevExt->StreamSRBList[StreamNumber]) {

        pIrp = (PIRP) (((PUCHAR) Entry) -
                     FIELDOFFSET(IRP, Tail.Overlay.ListEntry));

        pSrb = (PHW_STREAM_REQUEST_BLOCK) pIrp->Tail.Overlay.DriverContext[0];

        if (pSrb == pSrbToCancel) {
            RemoveEntryList(Entry);
            Found = TRUE;
            break;
        }

        Entry = Entry->Flink;
    }

    KeReleaseSpinLock (&pHwDevExt->StreamSRBSpinLock[StreamNumber], oldIrql);

    if (Found) {

        pHwDevExt->StreamSRBListSize[StreamNumber]--;

        //
        // Make the length zero, and status cancelled
        //

        pSrbToCancel->CommandData.DataBufferArray->DataUsed = 0;
        pSrbToCancel->Status = STATUS_CANCELLED;

        CompleteStreamSRB (pSrbToCancel);

        DbgLogInfo(("TestCap: VideoQueueCancelOneSRB FOUND Srb=%p, Stream=%d\n", pSrb, StreamNumber));

    }

    DbgLogInfo(("TestCap: VideoQueueCancelOneSRB Completed Stream=%d\n", StreamNumber));

    return Found;
}

/*
** VideoSetFormat()
**
**   Sets the format for a video stream.  This happens both when the
**   stream is first opened, and also when dynamically switching formats
**   on the preview pin.
**
**   It is assumed that the format has been verified for correctness before
**   this call is made.
**
** Arguments:
**
**   pSrb - Stream request block for the Video stream
**
** Returns:
**
**   TRUE if the format could be set, else FALSE
**
** Side Effects:  none
*/

BOOL
STREAMAPI
VideoSetFormat(
    IN PHW_STREAM_REQUEST_BLOCK pSrb
    )
{
    PSTREAMEX               pStrmEx = (PSTREAMEX)pSrb->StreamObject->HwStreamExtension;
    PHW_DEVICE_EXTENSION    pHwDevExt = ((PHW_DEVICE_EXTENSION)pSrb->HwDeviceExtension);
    int                     StreamNumber = pSrb->StreamObject->StreamNumber;
    UINT                    nSize;
    PKSDATAFORMAT           pKSDataFormat = pSrb->CommandData.OpenFormat;

    // -------------------------------------------------------------------
    // Specifier FORMAT_VideoInfo for VIDEOINFOHEADER
    // -------------------------------------------------------------------

    if (IsEqualGUID (&pKSDataFormat->Specifier,
                &KSDATAFORMAT_SPECIFIER_VIDEOINFO)) {

        PKS_DATAFORMAT_VIDEOINFOHEADER  pVideoInfoHeader =
                    (PKS_DATAFORMAT_VIDEOINFOHEADER) pSrb->CommandData.OpenFormat;
        PKS_VIDEOINFOHEADER     pVideoInfoHdrRequested =
                    &pVideoInfoHeader->VideoInfoHeader;

        nSize = KS_SIZE_VIDEOHEADER (pVideoInfoHdrRequested);

        DbgLogInfo(("TestCap: New Format\n"));
        DbgLogInfo(("TestCap: pVideoInfoHdrRequested=%p\n", pVideoInfoHdrRequested));
        DbgLogInfo(("TestCap: KS_VIDEOINFOHEADER size=%d\n", nSize));
        DbgLogInfo(("TestCap: Width=%d  Height=%d  BitCount=%d\n",
                    pVideoInfoHdrRequested->bmiHeader.biWidth,
                    pVideoInfoHdrRequested->bmiHeader.biHeight,
                    pVideoInfoHdrRequested->bmiHeader.biBitCount));
        DbgLogInfo(("TestCap: biSizeImage=%d\n",
                    pVideoInfoHdrRequested->bmiHeader.biSizeImage));

        //
        // If a previous format was in use, release the memory
        //
        if (pStrmEx->pVideoInfoHeader) {
            ExFreePool(pStrmEx->pVideoInfoHeader);
            pStrmEx->pVideoInfoHeader = NULL;
        }

        // Since the VIDEOINFOHEADER is of potentially variable size
        // allocate memory for it

        pStrmEx->pVideoInfoHeader = ExAllocatePool(NonPagedPool, nSize);

        if (pStrmEx->pVideoInfoHeader == NULL) {
            DbgLogError(("TestCap: ExAllocatePool failed\n"));
            pSrb->Status = STATUS_INSUFFICIENT_RESOURCES;
            return FALSE;
        }

        // Copy the VIDEOINFOHEADER requested to our storage
        RtlCopyMemory(
                pStrmEx->pVideoInfoHeader,
                pVideoInfoHdrRequested,
                nSize);

        // A renderer may be switching formats, and in this case, the AvgTimePerFrame
        // will be zero.  Don't overwrite a previously set framerate.

        if (pStrmEx->pVideoInfoHeader->AvgTimePerFrame) {
            pStrmEx->AvgTimePerFrame = pStrmEx->pVideoInfoHeader->AvgTimePerFrame;
        }
    }

    else {
        // Unknown format
        pSrb->Status = STATUS_INVALID_PARAMETER;
        return FALSE;
    }

    return TRUE;
}

/*
** VideoReceiveDataPacket()
**
**   Receives Video data packet commands on the output streams
**
** Arguments:
**
**   pSrb - Stream request block for the Video stream
**
** Returns: nothing
**
** Side Effects:  none
*/

VOID
STREAMAPI
VideoReceiveDataPacket(
    IN PHW_STREAM_REQUEST_BLOCK pSrb
    )
{
    PHW_DEVICE_EXTENSION    pHwDevExt = ((PHW_DEVICE_EXTENSION)pSrb->HwDeviceExtension);
    PSTREAMEX               pStrmEx = (PSTREAMEX)pSrb->StreamObject->HwStreamExtension;
    int                     StreamNumber = pSrb->StreamObject->StreamNumber;

    //
    // make sure we have a device extension and are at passive level
    //

    DEBUG_ASSERT(KeGetCurrentIrql() == PASSIVE_LEVEL);
    DEBUG_ASSERT(pHwDevExt!=NULL);

    DbgLogTrace(("TestCap: Receiving Stream Data    SRB %p, %x\n", pSrb, pSrb->Command));

    //
    // Default to success
    //