You can limit the duration of a capture operation by using the fLimitEnabled and wTimeLimit members of the CAPTUREPARMS structure. The fLimitEnabled member indicates whether the capture operation is to be timed, while wTimeLimit specifies the maximum duration of the capture operation.
You can retrieve the values for fLimitEnabled and wTimeLimit by using the WM_CAP_GET_SEQUENCE_SETUP message (or the capCaptureGetSetup macro). You can enable a timer for the capture operation by specifying TRUE as the value of fLimitEnabled, or you can set the duration of the capture operation by specifying a value, in seconds, for wTimeLimit. After you set these members, send the updated CAPTUREPARMS structure to the capture window by using the WM_CAP_SET_SEQUENCE_SETUP message (or the capCaptureSetSetup macro). The default value of fLimitEnabled is FALSE.