stop video preview using directshow in vc++

hai.. just i wrote application for show preview to user 开发者_StackOverflow中文版and capture image.am using sample grapher filter for capture image from CAPTURE PIN.PREVIEW PIN user for just preview video.its running nice but when i stop preview its affect the CAPTURE.cant capture image

am using CONTROL STREAM for stop preview..

pl kindly help

One solution is to use GMFBridge, which allows you to connect several graphs together and control them independently. That way you can have 3 graphs, one which connects your source to two sinks:

Source -- (capture pin) --> capture sink
       -- (preview pin) --> preview sink

one for the preview:

Preview source --> renderer

and another for the capture:

Capture source --> sample grabber

Using GMFBridge you can then hook up the capture sink to the capture source and the preview sink to the preview source. Once that's done you can start or stop the preview graph without affecting the capture graph, and vice versa. Hope that helps