Add a simple capture feature (-capture)
If a specified key is pressed during playback, the current stream is
captured to a file, similar to what -dumpstream achieves.
original patch by Pásztor Szilárd, don tricon hu
Taken from the following svn commits, but with several fixes and
modifications (one obvious user-visible difference is that the default
key binding is 'C', not 'c'):
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32524 b3059339-0415-0410-9bf9-f77b7e298cf2
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32529 b3059339-0415-0410-9bf9-f77b7e298cf2
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32530 b3059339-0415-0410-9bf9-f77b7e298cf2