User-Mode Video Capture Driver Messages
The following table lists the messages that the DriverProc function in a user-mode video capture driver can receive, along with the operation the driver performs when it receives each message. Message definitions are contained in msviddrv.h and msvideo.h.
| Message | Operation Performed by Driver |
| DVM_CONFIGURESTORAGE | Saves or restores configuration information. |
| DVM_DIALOG | Displays a dialog box to obtain configuration information. |
| DVM_DST_RECT | Sets or retrieves destination rectangle parameters. |
| DVM_FORMAT | Sets or retrieves video-capture format parameters. |
| DVM_FRAME | Transfers data from the frame buffer. |
| DVM_GET_CHANNEL_CAPS | Returns channel capabilities. |
| DVM_GETERRORTEXT | Returns the text string associated with an error number. |
| DVM_GETVIDEOAPIVER | Returns the video API version used by the driver. |
| DVM_PALETTE | Sets or retrieves a logical palette. |
| DVM_PALETTERGB555 | Sets a logical palette and an RGB555 translation table. |
| DVM_SRC_RECT | Sets or retrieves source rectangle parameters. |
| DVM_STREAM_ADDBUFFER | Adds a data buffer to a capture stream. |
| DVM_STREAM_FINI | Terminates a capture stream. |
| DVM_STREAM_GETERROR | Returns a stream's error status. |
| DVM_STREAM_GETPOSITION | Returns the current position within a capture stream. |
| DVM_STREAM_INIT | Initializes a capture stream. |
| DVM_STREAM_PREPAREHEADER | Prepares a data buffer. |
| DVM_STREAM_RESET | Stops and resets a capture stream. |
| DVM_STREAM_START | Starts a capture stream. |
| DVM_STREAM_STOP | Stops a capture stream. |
| DVM_STREAM_UNPREPAREHEADER | Removes preparation from a data buffer. |
| DVM_UPDATE | Updates a screen overlay area. |