Need help with RTMPDump and RTMPDumpHelper and downloading CSPAN vids

[Nomorecocktails]

I am using RTMP Dump and RTMP Dump helper to DL Cspan vids. The problem is that when the video is HD - I always get 1 hour and 8 seconds of video and it is not always what I want. The portion I am interested in may only be small part out of the 1 hour of video. This never happens with the low quality video.

As an example - http://www.c-spanvideo.org/program/CainonI
The resulting downloaded video has House Appropriations Hearings at the start and later the 2014 Defense Budget hearing. The actual McCain Schumer presser starts at about 47 min 45 seconds.

So how can i get just the part that i want and not all this extra?