|Glossary of Audio and Video Terms
Video Container Formats
.mov .avi .mp4 .m2v .m1v .mpg .asf .vob
PCM .wav .aiff .mp3 .mp2 .m1a .m2a .wma AAC .ogg .ac3 .dts
3ivx, DivX, XviD, MPEG-1, MPEG-2, Sorenson 3, DV, Animation, MJPEG, Component Video, YV12
Video Container Formats:
Apple's QuickTime Audio/Video Container. Sports a variety of features such as multiple audio/video streams, sprite tracks, header information at the beginning of the file, Annotations, Text Tracks, and support for hundreds of codecs. This is the basis for the MP4 file format.
.avi - Audio Video Interleaved
Microsoft's first video format. Header information is placed at the end of the file. Limited codec support. Spec has been hacked too many times, and is not fully supported.
ISO MPEG-4 file format, based on the QuickTime .mov file format.
.m2v - MPEG-2 Video
Raw MPEG-2 video. Often found muxed in .vob or .mpg files
.m1v - MPEG-1 Video
Raw MPEG-1 video. Usually found muxed in .mpg files or .dat files on VCDs.
Container for MPEG-1 or MPEG-2 video. Usually muxed with an audio track. MPEG-1s can be found on VCDs.
.asf - Advanced Streaming Format
Microsoft's second video format, principally designed for streaming.
.vob - Video OBject file
The primary video container on DVDs and SVCDs. Can contain Audio, Video, Subtitles, etc. all muxed in.
PCM - Pulse Coding Modulation
General uncompressed audio. Found on CDs and DVD Audio discs. Produced by Audio digitizers.
Microsoft WAVE format, the primary audio format in Windows, normally contains uncompressed PCM audio at various depths and sampling rates, but can also use more advanced codecs (such as MP3).
.aiff - Audio Interchange File Format
Apple's Audio Interchange File Format, normally used for uncompressed PCM audio at various depths and sampling rates, or simpler audio codecs (ie MACE6:1).
MPEG-1 or 2 Layer 3 audio stream. The rage of internet music sharing; MP3 players.
.mp2 | .m1a | .m2a
MPEG-1 or 2 Layer 2 audio stream. Precursor to MP3, still found in some early PAL DVDs and muxed in MPG files and VCDs.
.wma - Windows Media Audio
Both a container and an audio format. The container is actually ASF, the audio codec is Microsoft's attempt at high compression audio. Supposedly twice as efficient as MP3.
AAC - Advanced Audio Codec
The standard Audio codec often referred to as MPEG-4 Audio. With QuickTime being the most popular encoder for AAC audio. It is frequently found in QuickTime 6 movies and MP4 files. Sounds much better than MP3 at lower bitrates, recommended for use with 3ivx Video.
.ogg | .ogm
.ogg (or sometimes .ogm) is a container (similar to ASF) for Ogg Vorbis audio which is another high compression codec.
.ac3 - Audio Codec 3
Raw Dolby Digital audio stream. Commonly 5.1 or 2.0 channel surround sound. Used in most cinemas and found on nearly all commercial DVDs muxed in .vob.
.dts - Digital Theatre Systems
Digital Theatre Systems' surround sound audio stream is similar to AC3 but supposedly less compressed, leading to greater fidelity. Used in some cinemas and found on many commercial DVDs.
There are many others, notably Qualcomm Purevoice, QDesign Music, ulaw, etc...
High Compression, High Quality, Low Bitrate. Variation of MPEG-4. Very good results, usually found in QuickTime .movs; can be in .mp4's combined usually with .mp3 or .aac audio.
High Compression, High Quality, Low Bitrate. Variation of MPEG-4. Good results, usually found in .avis combined with .mp3 or .ac3 sound.
High Compression, High Quality, Low Bitrate. Variation of MPEG-4. Very good results, usually found in .avis, .mp4s, and possibly .xvid)
Moderate compression, found on VCDs and many web downloads. Can be high quality. Usually contains MPEG-1 Audio.
Moderately Compressed. Usually high bitrate, high quality, found on DVDs and SVCDs. Usually combined with .ac3/.dts audio (DVDs) or MPEG-2 audio (SVCDs, some DVDs).
Moderate compression, can be high quality. Found in QuickTime .movs. Common for web downloads (e.g. Apple's Movie Trailer Site).
Low compression. Found on video form DV camcorders, used in iMovie.
Usually found in .movs. Nearly uncompressed, used for exporting to a high quality source (such as animation) from QuickTime.
Low compression. Usually found in QuickTime movies. Basically, just alot of JPEG pictures in a movie (Hence the name Motion JPEG).
Packed YUV4:2:2 format.
Planar YUV4:2:0 format.