ffmpeg -i Fashion.divx -acodec aac -vcodec libx264 out.mp4


Codecs:
D..... = Decoding supported
.E.... = Encoding supported
..V... = Video codec
..A... = Audio codec
..S... = Subtitle codec
...I.. = Intra frame-only codec
....L. = Lossy compression
.....S = Lossless compression

ffmpeg -i InputFile.mpg -ab 128 -b 5000 OutputFile.mp4