libav is a hyper fast realtime audio/video encoder, a streaming server and a generic audio and video file converter.
It can grab from a standard Video4Linux video source and convert it into several file formats based on DCT/motion compensation encoding. Sound is compressed in MPEG audio layer 2 or using an AC3 compatible stream.
The library is available as 32-bit and 64-bit:
Note: libav is a fork of ffmpeg so can have only one installed.
Even older version