ffmpeg -i [input_file (*.flv)] -vcodec [video_codec] -acodec[audio_codec] -b [video_bitrate] -ab [audio_bitrate] -ar [sampling_rate] [outout_file (*.avi)] ex) ffmpeg -i test.flv -vcodec msmpeg4v2 -acodec mp3 -b 900 -ab 96 -ar 22050 test.mpg
ffmpeg -i [input_file (*.flv)] -b [video_bitrate] -ab [audio_bitrate] -ar [sampling_rate] [outout_file (*.mpg)] ex) ffmpeg -i test.flv -b 900 -ab 96 -ar 22050 test.mpg
ffmpeg -i input.avi -vcodec copy -acodec pcm_s16le -ar 11025 output.avi