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/*
* Copyright Microsoft Corporation, 1993 - 1995. All Rights Reserved. */
/*
* vcuser.h * * 32-bit Video Capture driver * User-mode support library * * define functions providing access to video capture hardware. On NT, * these functions will interface to the kernel-mode driver. * * include vcstruct.h before this. * * Geraint Davies, Feb 93 */
#ifndef _VCUSER_H_
#define _VCUSER_H_
/*
* capture device handle. This structure is opaque to the caller */typedef struct _VCUSER_HANDLE * VCUSER_HANDLE;
/*
* these are the parameters we need to issue a DriverCallback. A * pointer to one of these structs is passed on StreamInit * If the pointer is null, we don't need callbacks. */typedef struct _VCCALLBACK { DWORD dwCallback; DWORD dwFlags; HDRVR hDevice; DWORD dwUser;} VCCALLBACK, * PVCCALLBACK;
/*
* open the device and return a capture device handle that can be used * in future calls. * The device index is 0 for the first capture device up to N for the * Nth installed capture device. * * If pDriverName is non-null, then we will open the Nth device handled * by this driver. (Current implementation supports only one device per * drivername.) * * This function returns NULL if it is not able to open the device. */VCUSER_HANDLE VC_OpenDevice(PTCHAR pDriverName, int DeviceIndex);
/*
* close a capture device. This will abort any operation in progress and * render the device handle invalid. */VOID VC_CloseDevice(VCUSER_HANDLE vh);
/*
* Configuration. * * These functions perform device-dependent setup affecting the * target format, the source acquisition or the display (overlay). * * The structures passed are not interpreted by the vcuser and vckernel * libraries except that the first ulong of the struct must contain the * size in bytes of the entire structure (see vcstruct.h). It is assumed * that the structures are defined and agreed between the user-mode * hardware-specific code and the kernel-mode hardware specific code */BOOL VC_ConfigFormat(VCUSER_HANDLE, PCONFIG_INFO);BOOL VC_ConfigSource(VCUSER_HANDLE, PCONFIG_INFO);BOOL VC_ConfigDisplay(VCUSER_HANDLE, PCONFIG_INFO);
/*
* overlay and keying * * Several different methods are used by devices to locate the overlay * area on the screen: colour (either rgb or palette index) and/or * either a single rectangle, or a series of rectangles defining a complex * region. Call GetOverlayMode first to find out which type of overlay * keying is available. If this returns 0, this hardware is not capable * of overlay. */
/*
* find out the overlay keying method */ULONG VC_GetOverlayMode(VCUSER_HANDLE);
/*
* set the key colour to a specified RGB colour. This function will only * succeed if GetOverlayMode returned VCO_KEYCOLOUR and VCO_KEYCOLOUR_RGB * and not VCO_KEYCOLOUR_FIXED */BOOL VC_SetKeyColourRGB(VCUSER_HANDLE, PRGBQUAD);
/*
* set the key colour to a specified palette index. This function will only * succeed if GetOverlayMode returned VCO_KEYCOLOUR and not either * VCO_KEYCOLOUR_RGB or VCO_KEYCOLOUR_FIXED */BOOL VC_SetKeyColourPalIdx(VCUSER_HANDLE, WORD);
/*
* get the current key colour. This 32-bit value should be interpreted * as either a palette index or an RGB value according to the * VCO_KEYCOLOUR_RGB flag returned from VC_GetOverlayMode. */DWORD VC_GetKeyColour(VCUSER_HANDLE vh);
/*
* set the overlay rectangle(s). This rectangle marks the area in device * co-ordinates where the overlay video will appear. The video will be * panned so that pixel (0,0) will appear at the top-left of this rectangle, * and the video will be cropped at the bottom and right. The video * stream will not normally be scaled to fit this window: scaling is normally * determined by the destination format set by VC_ConfigFormat. * * If VCO_KEYCOLOUR was returned, the video * will only be shown at those pixels within the rectangle for which the * vga display has the key colour (VC_GetKeyColour() for this). * * Some devices may support complex regions (VCO_COMPLEX_RECT). In that case, * the first rectangle in the area must be the bounding rectangle for * the overlay area, followed by one rectangle for each region within it in * which the overlay should appear. */BOOL VC_SetOverlayRect(VCUSER_HANDLE, POVERLAY_RECTS);
/*
* set the offset of the overlay. This changes the panning - ie which * source co-ordinate appears as the top left pixel in the overlay rectangle. * Initially after a call to VC_SetOverlayRect, the source image will be panned * so that the top-left of the source image is aligned with the top-left of the * overlay rectangle. This call aligns the top-left of the source image * with the top-left of this offset rectangle. */BOOL VC_SetOverlayOffset(VCUSER_HANDLE, PRECT);
/* enable or disable overlay. if the BOOL bOverlay is TRUE, and the overlay
* key colour and rectangle have been set, overlay will be enabled. */BOOL VC_Overlay(VCUSER_HANDLE, BOOL);
/*
* enable or disable acquisition. * If acquisition is disabled, the overlay image will be frozen. * * this function will have no effect during capture since the acquisition * flag is toggled at each frame capture. */BOOL VC_Capture(VCUSER_HANDLE, BOOL);
/*
* capture a single frame, synchronously. the video header must point * to a data buffer large enough to hold one frame of the format set by * VC_ConfigFormat. */// BOOL VC_Frame(VCUSER_HANDLE, LPVIDEOHDR);
/*
* data streaming. * * Call VC_StreamInit to prepare for streaming. * Call VC_StreamStart to initiate capture. * Call VC_AddBuffer to add a capture buffer to the list. As each * frame capture completes, the callback function specified in * VC_StreamInit will be called with the buffer that has completed. * * If there is no buffer ready when it is time to capture a frame, * a callback will occur. In addition, VC_StreamGetError will return * a count of the frames missed this session. VC_StreamGetPos will return * the position (in millisecs) reached so far. * * Call VC_StreamStop to terminate streaming. Any buffer currently in * progress may still complete. Uncompleted buffers will remain in the * queue. Call VC_Reset to release all buffers from the queue. * * Finally call VC_StreamFini to tidy up. */
/*
* prepare to start capturing frames */BOOL VC_StreamInit(VCUSER_HANDLE, PVCCALLBACK, // pointer to callback function
ULONG // desired capture rate: microseconds per frame
);
/*
* clean up after capturing. You must have stopped capturing first. */BOOL VC_StreamFini(VCUSER_HANDLE);
/*
* initiate capturing of frames. Must have called VC_StreamInit first. */BOOL VC_StreamStart(VCUSER_HANDLE);
/*
* stop capturing frames. Current frame may still complete. All other buffers * will remain in the queue until capture is re-started, or they are released * by VC_StreamReset. */BOOL VC_StreamStop(VCUSER_HANDLE);
/*
* cancel all buffers that have been 'add-buffered' but have not * completed. This will also force VC_StreamStop if it hasn't already been * called. */BOOL VC_StreamReset(VCUSER_HANDLE);
/*
* get the count of frames that have been skipped since the last call * to VC_StreamInit. */ULONG VC_GetStreamError(VCUSER_HANDLE);
/*
* get the current position within the capture stream (ie time * in millisecs since capture began) */BOOL VC_GetStreamPos(VCUSER_HANDLE, LPMMTIME);
/*
* add a buffer to the queue. The buffer should be large enough * to hold one frame of the format specified by VC_ConfigFormat. */// BOOL VC_StreamAddBuffer(VCUSER_HANDLE, LPVIDEOHDR);
/*
* playback * * Call VC_DrawFrame to draw a frame into the frame buffer. You should * call VC_Overlay functions to arrange for the frame buffer to appear * on screen. */BOOL VC_DrawFrame(VCUSER_HANDLE, PDRAWBUFFER);
/*
* installation/configuration * * on NT, the following functions will start and stop the * kernel driver. The callback function can write profile information * to the registry between stopping the driver (if already running) and * re-starting the driver. The kernel driver DriverEntry routine is responsible * for reading these values from the registry before calling VC_Init(). * * The win-16 implementation will (?) call the callback to write * values to the profile, and then call the HW_Startup function. This function * is responsible for calling VC_Init, initialising the callback table and * initialising the hardware. */
/*
* opaque pointer to the information we need to access the registry/profile. */typedef struct _VC_PROFILE_INFO * PVC_PROFILE_INFO;
/*
* open a handle to whatever functions are needed to access the registry, * service controller or profile. Must call this function before * calls to the other VC_ configuration routines. * * The argument is the name of the driver. This should be the name of * the kernel driver file (without path or extension). It will also be used * as the registry key name or profile section name. */PVC_PROFILE_INFO VC_OpenProfileAccess(PTCHAR DriverName);
/*
* close a profile access handle */VOID VC_CloseProfileAccess(PVC_PROFILE_INFO);
/*
* takes a PVC_PROFILE_INFO returned from VC_OpenProfileAccess, and * returns TRUE if we currently have sufficient privilege to perform * driver configuration operations. */BOOL VC_ConfigAccess(PVC_PROFILE_INFO);
/*
* This function is called once the driver has definitely been unloaded, and * the profile entry created, but before the driver is re-loaded. It can write * any configuration information to the registry. It should return TRUE if * it is ok to load and start the kernel-mode driver, or false if some * error has occured. */typedef BOOL (*PPROFILE_CALLBACK)(PVOID);
/*
* start the hardware-access portion of the driver. Call the callback * function at a moment when it is possible to write configuration information * to the profile using VC_WriteProfile. * Returns DRVCNF_OK if all is ok, DRVCNF_CANCEL for failure, or DRVCNF_RESTART if * all is ok but a system-restart is needed before the driver will load correctly. */LRESULT VC_InstallDriver( PVC_PROFILE_INFO pProfile, // access info returned by OpenProfileAccess
PPROFILE_CALLBACK pCallback, // callback function
PVOID pContext // context info for callback
);
/*
* Write a single string keyword and DWORD value to the registry or profile * for this driver. * This can be re-read from the h/w driver using VC_ReadProfile (in either * the kernel-mode vckernel.lib version or user mode in the vcuser version). * * return TRUE for success or FALSE for failure. */BOOL VC_WriteProfile(PVC_PROFILE_INFO pProfile, PTCHAR ValueName, DWORD Value);
/*
* Write a single string keyword and DWORD value to the registry or profile * for this driver. * This writes to HKEY_CURRENT_USER and is typically used to store user defaults. * * return TRUE for success or FALSE for failure. */BOOL VC_WriteProfileUser(PVC_PROFILE_INFO pProfile, PTCHAR ValueName, DWORD Value);
/*
* read back a driver-specific DWORD profile parameter that was written with * VC_WriteProfile. If the valuename cannot be found, the default is returned. */DWORD VC_ReadProfile(PVC_PROFILE_INFO pProfile, PTCHAR ValueName, DWORD dwDefault);
/*
* read back a driver-specific DWORD profile parameter that was written with * VC_WriteProfileUser. If the valuename cannot be found, the default is returned. * This reads from HKEY_CURRENT_USER and is typically used to store user defaults. */DWORD VC_ReadProfileUser(PVC_PROFILE_INFO pProfile, PTCHAR ValueName, DWORD dwDefault);
/*
* read a string parameter from the device's profile. returns FALSE * if it fails to read the string. */BOOL VC_ReadProfileString( PVC_PROFILE_INFO pProfile, // access info from OpenProfile
PTCHAR ValueName, // name of value to read
PTCHAR ValueString, // put value here
DWORD ValueLength // size of ValueString in bytes
);
/*
* unload a driver. On NT, this stops and removes the kernel-mode driver. * On win-16, this calls the Cleanup callback. * * return DRVCNF_OK if the unload was successful, DRVCNF_CANCEL if it failed, and * DRVCNF_RESTART if a system-restart is needed before the removal takes effect. * * note that after this operation, the PVC_PROFILE_INFO information is still held * open. A call to VC_CloseProfileAccess is still needed before exiting. */LRESULT VC_RemoveDriver(PVC_PROFILE_INFO pProfile);
#endif //_VCUSER_H_
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