This section is a reference to the messages and data structures provided by Windows for use by video capture device drivers. There are separate sections for messages and data structures.
Windows communicates with video capture device drivers through messages sent to the driver. The driver processes these messages with its DriverProc entry-point function. Each message name contains a prefix, identifying the type of the message. A message consists of three parts: a message number and two DWORD parameters. Message numbers are identified by predefined message names. The two DWORD parameters contain message-dependent values.
| To | See these messages and data structures |
|---|---|
| Handle the DRV_OPEN message. | VIDEO_OPEN_PARMS |
| Configure the channels of a video capture driver. | DVM_DIALOG |
| Set and obtain video capture formats. | DVM_FORMAT |
| Set and obtain video source and destination rectangles. | DVM_DST_RECT
DVM_SRC_RECT DVM_UPDATE VIDEO_CONFIGURE_GET |
| Determine channel capabilities. | DVM_GET_CHANNEL_CAPS
CHANNEL_CAPS |
| Set and obtain a video capture palette. | DVM_PALETTE
DVM_PALETTERGB555 VIDEOCONFIGPARMS |
| Obtain the device driver version. | DVM_GETVIDEOAPIVER |
| Transfer data from the frame buffer. | DVM_FRAME |
| Allocate and free capture buffers on the capture device | DVM_STREAM_ALLOCBUFFER
DVM_STREAM_FREEBUFFER |
| Prepare and unprepare buffers for streaming video capture. | DVM_STREAM_PREPAREHEADER
DVM_STREAM_ADDBUFFER DVM_STREAM_UNPREPAREHEADER |
| Initialize and terminate streaming video capture. | DVM_STREAM_FINI
DVM_STREAM_INIT VIDEO_STREAM_INIT_PARMS |
| Start and stop video streaming capture. | DVM_STREAM_START
DVM_STREAM_STOP |
| Reset, get error information, or get the current stream position. | DVM_STREAM_RESET
DVM_STREAM_GETERROR DVM_GETERRORTEXT VIDEO_GETERRORTEXT_PARMS DVM_STREAM_GETPOSITION |
| Send messages to the video capture callback function. | MM_DRVM_CLOSE
MM_DRVM_DATA MM_DRVM_ERROR MM_DRVM_OPEN |