FLV

Convert FLV to MP4
]Convert flv to mp4, by changing container without re-encoding: ffmpeg -i input.flv -codec copy output.mp4

Convert flv to mp4: ffmpeg -i filename.flv -c:v libx264 -crf 19 -strict experimental filename.mp4 ffmpeg -i input.flv -codec copy output.mp4 ffmpeg -i filename.flv -ab 56 -ar 22050 -b 500 -s 320x240 filename.mpg

avconv -i inputfile.flv -map 0 -c:v libx264 -c:a copy outputfile.mp4 ffmpeg -i filename.flv -vcodec libvpx -acodec libvorbis
 * 1) same as:

avconv -i inputfile.flv -map 0 -c:v libx264 -c:a copy outputfile.mp4

ffmpeg -i $1 -sameq -ar 22050 -vcodec libx264 $1.mp4

guide ffmpeg -i input.flv -c copy -copyts output.mp4