Extract mp3 from flash:


mplayer -dumpaudio  myflash.flv -dumpfile mydump.mp3

or

ffmpeg -i myflash.flv -ab 128 -ar 44100 mydump.mp3


Extract mp3 from stream:

mplayer -dumpstream http://xxx.xxx.xxx.xxx:80/stream/1005 -dumpfile mydump.mp3

or

ffmpeg -i http://xxx.xxx.xxx.xxx:80/stream/1005 -ab 128 -ar 44100 mydump.mp3


Crop video

mplayer myvideo.avi -vf crop=640:360:0:70


# crop[[=w:h:x:y]]
#  w,h  Cropped width and height, defaults to original width and height.
#  x,y  Position of the cropped picture, defaults to center.


Running mplayer and enable taking screenshots wiht "s".  Screenshots are put in current directory and named shot0001.png  and auto incremented.

mplayer -vf screenshot   /pat/to/video.avi