2005 version of FFMPEG Each conversions locks the command line into a 
loop:  "frame decodeinf failed."  A workable copy is still generated and 
this error indicates that there is data that a later version of ffmpeg 
will be able to process.  Download and install the latest version of 
ffmpeg to avoid this error.

SIMPLE CHANGE FILE FORMAT -same size frame 
ffmpeg.exe -i GOPR0090.MP4 gp.avi 

RESIZE FRAME -s 
ffmpeg.exe -i GOPR0090.MP4 -s 320X240 GP320x240.avi EXTRACT first ten seconds of video 
-t 10 ffmpeg.exe -i GOPR0090.MP4 -t 10 gp.avi (looks like -ss is start time) 

EXTRACT TIME SEGMENT -ss -t ffmpeg -ss 7 -i GOPR0090.MP4 -t 3 
gpr.mpg [Starts seven seconds in and records three seconds.] 

DISABLE SOUND -an 
ffmpeg -i GOPR0090.MP4 -an gpr.mov 

CROPPING [2005 version] 
ffmpeg -i inputfile.avi -croptop 88 -cropbottom 88 -cropleft 360 -cropright 360 
outputfile.avi [Later versions my have changed 'crop'] 

CROPPING LATEr 2014 VERSION of ffmpeg 
ffmpeg -i GOPR0088.MP4 -vf "crop=852:480" gpr88.mpg Also ffmpeg -i 
GOPR0088.MP$ -vf "crop=852:480:50:25"  may work
  This crops image to 852 x 480 starting at x = 50 and y = 25.
  
  
FILE DATA -i 
ffmpeg -i fileName.MP4 
without an output file will print frame size, audio hertz, bit rate etc.



FPS (frames per second) -r 
ffmpeg -i abc.mp4 -r 24 xyz.mpg