MP4Box

An MP4 multiplexer that can import MPEG-4 video, DivX, XviD, h264 etc, audio streams and subtitles into the .mp4 container. MP4Box is a popular MP4 multiplexer that can easily and quickly import MPEG-4 video, DivX, XviD, h264, 3ivx, etc audio streams and subtitles into the .mp4 container.

The end result will be a compliant MP4 stream.

MP4Box can also easily extract streams from a .mp4.

MP4Box is a command line utility but can be used with graphical user interfaces such as YAMB.