Vox Populi is a command-line media transcoder written in Ruby. It’s modular, so it can theoretically support any input and output formats; at the moment, it supports only FLAC as an input format and Ogg-Vorbis as an output format.

There are several goals for it:

• Multi-threading. Yes, I realise that this really needs to wait until Ruby 2.0 with native thread support (unless you have a Ruby patched to support pthreads). Nevertheless, it’s a goal. vp will support limiting the number of decoder threads and encoder threads separately, or limiting the total number of threads.
• Metadata support. vp will support copying the metadata from the source file to the target file.
• Multiple formats with multiple backends. vp will support using a variety of backend programs to do the decoding and encoding (mplayer/mencoder, faad/faac, ogg123/oggenc, mpg321/lame, etc). It will automatically detect input formats.
• Minimal dependencies. Currently, the only dependencies are Ruby (obviously), vorbis-tools (for ogg123 and oggenc, to decode OGG Vorbis/FLAC and encode OGG Vorbis), and, optionally, flac (for metaflac, to parse the FLAC metadata).