ffmpeg conversion of 3gp to mp4 files

http://ffmpeg-users.933282.n4.nabble.com/3gp-to-mp4-td942632.html

ffmpeg -i test.3gp -sameq -ab 64k -ar 44100 test.mp4

-ab audio bitrage 
-ar audio resample


info from file ffmpeg -i video.avi
images to file ffmpeg -f image2 -i image%d.jpg video.mpg
file to images ffmpeg -i video.mpg image%d.jpg
sound to mp3   ffmpeg -i source_video.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 sound.mp3
 
* Source video : source_video.avi
* Audio bitrate : 192kb/s
* output format : mp3
* Generated sound : sound.mp3

avi to giff    ffmpeg -i source_video.avi animated_gif.gif

avi to ntsc    ffmpeg -i source_video.avi -target ntsc-svcd final_video.mpg 

cheatsheets:
http://www.webupd8.org/2009/08/ffmpeg-cheat-sheet-19-best-practices.html
http://rodrigopolo.com/ffmpeg/cheats.html

windows command line install:
http://www.arachneweb.co.uk/software/windows/avchdview/ffmpeg.html