XLV is a middle-level interface for Audio/Video (and generic multimedia format) playing, recording, and managing. The idea is that what you can do automatically (with one call) can also be done manually (all the decoding process can be extracted from the automate). XLV comes with a full bunch of plugins, including Vorbis, MPEG audio decoding, MPEG 1/2 video decoding, a Win32 codec interface, AVI decoder, Wave decoder, Quicktime decoder, MPEG/VOB (DVD file) decoder, and more functionalities like auto-format conversion, etc.
SDL_sound is a library that handles the decoding of several popular sound file formats such as .WAV and .MP3. Designed to make the task of sound playback easier, SDL_sound accepts files or other input through an abstraction layer and returns the decoded waveform. SDL_sound can decode a whole sound file and hand back a single pointer to the waveform, or SDL_sound can process sound data in programmer-specified blocks when resource constraints are a concern. SDL_sound can also handle sample rate, audio format, and channel conversion on-the-fly.
Scilla answers media file requests and takes conversion parameters for various media converters. Manipulated media files can be cached for future requests. Scilla is designed to take requests using the servlet API. A HttpServlet is included, and it maps path-info to a file and passes request parameters to converters.
SWFTools is a collection of code for handling Flash .SWF-files. This includes a merging tool (swfcombine), an extracting tool (swfextract), PDF/JPEG/PNG/AVI/TTF/WAV to SWF converters (pdf2swf, jpeg2swf, png2swf, avi2swf, font2swf, and wav2swf), a text parsing tool (swfstrings), an SWF parser (swfdump), and a library for writing and reading SWFs (rfxswflib).
MP3do is an "all in one" bash script. It is useful for decoding and mastering audio files. It can decode a list of MP3 or Ogg Vorbis files to WAV or CD-R, auto-convert poor quality MP3s to 44100Hz stereo, check whether all files fit on a CD, normalize all WAV files (adjust the volume to a standard volume level), and burn a CD.