A multimedia container format defined by the 3GPP (Third Generation Partnership Project) to be used on 3G mobile phones and certain mobile devices, such as the Nintendo DSi. The 3GP file format stores video streams as H.263 or H.264, and audio streams as AMR and AAC.
A multimedia container format defined by the 3GPP (Third Generation Partnership Project) to be used for 3G mobile phones. The 3G2 has some slightly enhanced storage and streaming features in comparison to the 3GP and can store the same streams of audio/video formats with some minor additions.
An open source container format for compressed files archived using the 7zip open source software. It is a popular alternative to archiving tools such as WinZip and can almost always achieve significantly better compression. All major operating systems have versions of 7zip freely available.
ASF (Advanced Systems Format)
Formerly called Advanced Streaming Format, ASF is a proprietary digital audio/video container format from Microsoft, created for streaming media as part of the Windows Media framework. ASF commonly contains Microsoft formats such as WMA and WMV. The format requires a license to be implemented and isn't compatible with open source licenses.
ASX (Advanced Stream Redirector)
A type of XML metafile configured to store a database of Windows Media files to be played during a multimedia presentation. It is usually used to handle live streaming of multiple ASF files in succession. For other Microsoft formats there are unique redirectors such as WVX for the popular WMV format.
AVI (Audio Video Interleave)
A Microsoft multimedia container format able to contain both audio and video files to allow seamless playback. While AVI's were not engineered with compression techniques in mind, the often employ different types of codec's, popular examples include MPEG-4, Xvid, and DivX.
A file which may contain virtually any type of data, it is encoded in a base-2 number system (binary code) for archiving purposes on a computer. It's use spreads across all computing and is not limited to video.
BUP (Back UP)
A backup file of the IFO file on a DVD, containing the information about the track, organization, menus, chapters, and subtitles on the disk. It is used as a redundant way to access information usually accessed by an IFO, in the event the disk is scratched or otherwise damaged.
CCD (CloneCD Control file)
A file that is a text descriptor used by CloneCD to mark the properties of a CD or DVD disk image. It is only useful when combined with an image file. CCD files can also be used with other disk mounting software such as Alcohol 120% and Daemon Tools.
Also, CISO. A compression method for the ISO image format used as an alternative to the .DAX compression method. It generally has better compression ratios, having 9 levels of compression available. It is primarily used as a way to compress PlayStation Portable (PSP) UMD disks.
DiVX (Digital Video Express)
A video codec created by DivX, Inc. created to compress large video files into small segments while maintaining good visual quality. It's popularly has waned in recent years due to it's limitations of compressing HD quality video, in favor of standards such as H.264.
The Adobe Flash animation source file that is used during development before being saved typically as an .SWF file. Flash video however, usually has the FLV of F4V extension and is considered it's own format separate from FLA.
The file extension of the Gzip utility, an open-source data compression software application created by the GNU Project. It's usage has waned in favor of newer compression packages such as 7zip, althrough it still sees use among the open-source community.
A type of DVD-video file that stores the information about chapters, subtitles, and audio tracks and basic navigational information. They work closely with other formats on DVD-videos: VOB and BUP.
A CD or DVD image file, used for digital storage. It is usually a raw dump of the contents of the disk, and often contains the exact same file structure as an ISO, to the point that the extensions are interchangeable.
ISO (International Organization for Standardization)
An archive file of an optical disc, containing all data content of every written sector. Often interchangeable with IMG files. Being a pure digital copy, no compression methods are used on ISO files.
A plain text computer file format that stores multimedia playlists, specifying the locations of one or more media files. The format was originally written for Winamp by Nullsoft, but has been used in many media programs including iTunes. In addition to pointing to a local file, many M3U files point to an online streaming location used for internet radio stations.
A binary file with a media descriptor that contains metadata about the original file and CD or DVD image. This metadata includes information on layer breaks and copy protection features. It is often used in disk imaging applications such as Alcohol 120% and Daemon Tools.
MKV (Matroska Video)
An open source multimedia container format for holding audio and video files, as well as pictures or subtitles. Intended as a universal format for multimedia storage. It is unique as the container is completely open in specification, allowing it to hold multiple audio, video, and subtitle streams in the same file. This makes it a popular choice for content with multiple audio and subtitle tracks. It had wide hardware support for many commercial media players including HDTV's and Blu-Ray players.
The multimedia container file format for QuickTime, designed to hold audio, video, and data files, usually comprised of subtitles and effects. Modern MOV files use the MPEG-4 standard. The MOV container has been approved as the basis for MPEG-4 by the International Organization for Standardization.
MP3 (MPEG-1 Audio Layer III)
Part of the MPEG-1 video encoding format, able to store good quality audio into small files, by filtering out audio that most humans cannot hear. MP3 has become one of the most popular formats for buying and sharing digital music, despite proven advancements with other lossy formats, such as AAC or OGG.
The official multimedia container format for MPEG-4 video and audio. It is a more open and generic version of the QuickTime File Format, which uses the MOV extension. A versatile container, is has support for multiple audio and video streams and is capable of being streamed over the Internet.
MPEG (Moving Pictures Experts Group)
A working group of experts formed by the ISO/IEC to develop the standards for audio and video compression and transmission. The group formed in 1988 and today has over 380 members. They are responsible for many popular standards including MP3 and MPEG-4.
A standard format for lossy compression of video and audio, designed to compress raw digital video and audio down to a 6:1 ratio without losing much quality. Having it's first public release in 1993, it has since seen huge adoption and effectively set the standard for lossy audio and video compression.
NDS (Nintendo DS)
Nintendo's handheld gaming console, released originally in 2004. It features two LCD screens, one a touchscreen, a built-in microphone, and wireless support.
An identification file with release and general information that is packed with a software program. They contain an ASCII text file that can be read using a generic text editor. NFO files were popular with Bulletin Board Systems (BBS), which predates the World Wide Web.
A proprietary CD image file format used by Nero Burning ROM to create and burn CD images. Despite its proprietary nature, various programs can read it, including Alcohol 120%, Daemon Tools and Power ISO.
A free, open standard container format created and maintained by the Xiph.Org Foundation, designed to provide efficient streaming and editing of high-quality multimedia digital files. Influenced partly as an open-source alternative to MO3, OGG generally can generate audio files smaller than an MP3 while maintaining the same or higher level of quality. However, it isn't limited to audio, it is a complete container unrestricted by software patents.
A file format for storing multimedia playlists that can also store information about each particular song such as song title and length. It is generally more descriptive than an M3U file, and is compatible with most major media players, including iTunes, Winamp, and VLC.
RAR (Roshal Archive)
A proprietary archive file format created by Russian software engineer Eugene Roshal, supporting data compression, error recovery, and spanning. It was created for use with WinRAR, although many complression programs support it, including Winzip and 7zip.
A proprietary multimedia container format designed by RealNetworks, usually used in together with RealVideo and RealAudio for streaming content over the Internet. It uses a constant bit-rate, unlike it's newer format which supports a variable bitrate, titled RMVB.
SFV (Simple File Verification)
A file that typically arrives bundled with files downloaded off the Internet, it is a means of checking that the files downloaded are complete by matching the data with the SFV file. This is due to the possibility of file corruption in the process of downloading or hard-drive failure.
A text-based subtitle format known also as SubRip. SRT subtitles are usually found in DivX or XviD encoded AVI files. It is a plain-text file that simply queues when to display a subtitle line sequentially, down to the millisecond.
A torrent is a file that is transmitted via the BitTorrent protocol written by Bram Cohen. The torrent can be anything, usually audio, video, an application, or a game. Being completely peer-to-peer, without a central server, it is one of the most efficient P2P solutions created, rising in popularity dramatically since it's first release in 2001. As of 2009, it has been reported to account for between ¼ and ½ of all Internet traffic.
The MPEG transport stream. A standard format for transmitting and storing audio, video, and data files usually employed for use in digital television streaming. It features error correction and stream synchronization across various signal strengths.
A standard created and developed in the early '90s that made it possible for a regular CD to contain 74 minutes of both video and audio encoded in the MPEG-1 format. It is an evolution of the Laserdiscs created in the '70s and was surpassed by the DVD in the late '90s.
VOB (Video Object)
One of the core files found on a DVD, it is a container format for all the movie data layered together, containing audio, video, subtitle, menu, and navigation data. VOB files can be up to 1GB in file size to maximize compatibility, and for that reason, many DVDs are comprised of multiple VOB files.
WMV (Windows Media Video)
A video compression format for several codecs by Microsoft, designed originally for streaming applications on the Internet. It has also become adopted as a video format compatible with Blu-Ray discs. It is often compared to MPEG-4 and H.264 in terms of video quality.
A video codec that has become extremely popular for HD video due to it's great compression ratios. All Blu-Ray players can decode to this format, as it is one of it's numerous codec standards. It has seen widespread use on the web due to it's ease of encoding into Adobe's FLV video format, which has resulted in a large number of YouTube, Vimeo, and iTunes video purchaches.
A file that may be compressed, but only if it can be reconstructed to it's original state without any alteration to the source file. For this reason lossless files command a large file size with the advantage of preserving the source exactly. As such, lossless formats are not well suited for streaming.
A file that may be compressed using an approximation of the source material. This allows for file sizes many multitudes smaller than the source material while still maintaining acceptable quality. Lossy compression makes it possible to stream video over an Internet connection in real-time, as well as simply be able to store much more media using less storage capacity.
FLAC (Free Lossless Audio Codec)
An open-source lossless audio format. Has much higher file sizes than the same file encoded with a lossy format such as MP3 but is guaranteed to have the same quality as the source material. It still has compression and can reduce file sizes to 50-60% of the original source.
AAC (Advanced Audio Coding)
A standardized audio codec that was developed to be the successor to MP3, able to deliver better sound quality at similar bit rates. It has become the default audio format in the iTunes store and on many devices, including Apple's iPhone/iPod line, and several Sony and Nintendo products.
SWF (Small Web Format)
Previously standing as an abbreviation for Shockwave Flash, SWF is a file format of a compiled FLA used by Adobe Flash. A SWF may contain vector graphics and rich media including images, audio, and video. It is widely adopted plugin for many desktop Internet browsers, although availability is more limited on mobile devices. It is more common for modern Flash video to have the FLV extension, however.
AMR (Adaptive Multi-Rate audio codec)
An audio codec specially optimized for live speech. As such, it is a popular format for low-bitrate spoken-word recordings, and has become a standard for 3G-enabled mobile devices such as smartphones.
FLV (Flash Video)
One of the leading ways to deliver way through the Adobe Flash Player. The video content inside is the same as with video objects embedded within SWF files. Due to Flash's wide adoption across most modern browsers and operating systems, it has become a leading way to feature rich media such as video on the Internet. Starting with Adobe Flash 9, an alternative extension became available called F4V. This newer standard utilizes H.264 video and MP3 audio.
MP2 MPEG-1 Audio Layer II
Part of the MPEG-1 video encoding format, MP2 predates the MP3 format and is used with older containers such as Video CDs. It generally has much larger-filesizes than MP3 but requires less powerful audio decoders to play back. This allows the file format to be played on legacy equipment.