VLC media player is a multimedia player, framework, streamer, and encoder. It can play inputs like files, network streams, DVDs, audio CDs, Blu-Rays, capture devices, and screens. It can play most audio and video codecs and formats (MPEG 1/2/4, H264, VC-1, DivX, WMV, Vorbis, AC3, AAC, MKV, etc.), but can also be used to convert to different formats and/or send streams through the network.
MPlayer is a movie and animation player that supports a wide range of codecs and file formats, including MPEG 1/2/4, DivX 3/4/5, Windows Media 7/8/9, RealAudio/Video up to 9, Quicktime 5/6, and Vivo 1/2. It has many MMX/SSE(2)/3Dnow(Ex) optimized native audio and video codecs, but allows using XAnim's and RealPlayer's binary codec plugins, and Win32 codec DLLs. It has basic VCD/DVD playback functionality, including DVD subtitles, but supports many text-based subtitle formats too. For video output, nearly every existing interface is supported. It's also able to convert any supported files to raw/divx/mpeg4 AVI (pcm/mp3 audio), and even video grabbing from V4L devices.
libCVD is a very portable and high performance C++ library for computer vision, image, and video processing. The emphasis is on providing simple and efficient image and video handling and high quality implementations of common low-level image processing function. The library is designed in a loosely-coupled manner, so that parts can be used easily in isolation if the whole library is not required. The video grabbing module provides a simple, uniform interface for videos from a variety of sources (live and recorded) and allows easy access to the raw pixel data. Likewise, the image loading/saving module provides simple, uniform interfaces for loading and saving images from bitmaps to 64 bit per channel RGBA images. The image processing routines can be applied easily to images and video, and accelerated versions exist for platforms supporting SSE.
Xvid (formerly XviD) is an open source MPEG-4 video codec, implementing MPEG-4 Simple Profile, Advanced Simple Profile, and Advanced Video Coding standards. It is written in C with assembler optimizations for quality and speed (including MMX, SSE, and 3Dnow! code for i386 and AltiVec for PowerPC), and is especially optimized towards offline, multi-pass compression for storage and archival purposes.
Mjpeg tools is a suite of programs which support video capture, basic editing, playback, and compression to MPEG-1/2 of MJPEG video. The capture software allows MJPEG video streams in AVI, Quicktime, and movtar format to be produced using the Iomega Buz, Miro DC10+, Matrox Marvel, and similar hardware. The editing and playback tools are hardware independent, with support for hardware accelerated playback if present. The MPEG compression tools are based on MPEG Software Simulation Group's reference encoder with enhancements to provide far faster compression and significant quality improvements.
XBMC Media Center (formerly Xbox Media Center) is a multimedia player/jukebox application for Linux, Mac OS X, Windows, and Xbox. It can be used to play or view most common video, audio, and picture formats such as MPEG-1/2/4, DivX, XviD, MP3, AAC, JPG, and GIF directly from a CD or DVD in the Xbox DVD-ROM drive or from the Xbox hard drive. XBMC can also stream files over a local network or from the Internet. Playlist and slideshow functions, a weather forecast, and many audio visualizations are also included.