Im trying to encode raw data(both video frame and audio sample) into .asf file, using asf writer filter in directshow. my filter graph structure: raw_send_filter - asf writer filter raw_send_filter implements CBaseFilter and CBaseOutputPin. It plays a role as source filter which get raw data, then deliver them to ASF writer filter. The process follows these steps: Get deliver buffer (return into "sample") , using the function CBaseOutputPin::GetDeliveryBuffer sample-GetPointer(&buffer); Set time stamp (with frame rate = 30 fps) deliver sample The problem is after encode some raw data, I can not deliver any more. I can encode .avi file with this way, using Avi mux filter. Can u tell me why I can not deliver samples after encoding some? Thanks.