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.
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.
mkvtoolnix is a set of tools that allow users to display information about, extract streams from, merge several streams into, and split Matroska media files. Supported video stream types include streams from AVIs, Ogg/OGM, RealVideo, MP4 files, and MPEG program streams as well as verious elementary streams (h264/AVC, MPEG1/2, VC1, Dirac). Supported audio formats include AAC, (E)AC3, DTS/DTS-HD, FLAC, MP2, MP3, RealAudio, and Vorbis. Several subtitle formats are supported, including SRT, SSA, ASS, VobSub, and many others.
xine is a free multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet. It interprets many of the most common multimedia formats available--and some of the most uncommon formats, too. All those features come in a reusable library (xine-lib) which can easily be embedded in your applications.
GeeXboX is a standalone media player Linux distribution, similar to MoviX. It's a small bootable CD that allows you to play your favorite video (DivX, XviD, H.264, MPEG 1/2, VCD, DVD, OggMedia, Windows Media, RealMedia, etc.) and audio (MP3, Audio CD, Ogg Vorbis, FLAC, MPC, etc.) files. It also supports networking, and is able to play media from Windows/Samba share, NFS, UPnP A/V Media Servers, RTP/RTSP servers, or SHOUTcast. It supports TV-out, TV tuners, DVB cards, and WiFi cards. It is based on MPlayer, and can be used on any x86, x86_64, or PowerPC computer. It's easy to modify the source to build your own GeeXboX or use an alternative boot method.
transcode is a text console video-stream processing tool. It supports elementary video and audio frame transformations. Some example modules are included to enable import of MPEG-1/2, Digital Video, and other formats. It also includes export modules for writing to AVI files with DivX, OpenDivX, XviD, Digital Video or other codecs. Direct DVD transcoding is also supported. A set of tools is available to extract and decode the sources into raw video/audio streams for import and to enable post-processing of AVI files.
Gaupol is an editor for text-based subtitle files. It supports multiple subtitle file formats and provides means of creating subtitles, editing text, and timing subtitles to match video. The user interface is designed with attention to batch processing of multiple documents and convenience of translating.
XMovie is a multimedia player for high quality Quicktime, MPEG, and DVD movies that supports 6 channel audio. The Quicktime decoder reads OpenDivx, assorted YUV formats, JPEG photo, MJPA, RGB, DV, IMA4, ULAW, Vorbis, and PCM codecs. The MPEG decoder reads MPEG-1 video, MPEG-2 video, MPEG-1 system streams, MPEG-2 system streams, VOB files, IFO files, MP2 and MP3 audio, and AC3 audio.
Linphone is an audio and video Internet phone with GTK+ and console interfaces. It uses the SIP protocol, and is compatible with most SIP clients and gateways. It can use various audio and video codecs such as Speex, GSM, G711, G722, ilbc, amr, Theora, H263-1998, MPEG4, H264, VP8, and snow.