Audio and Video Terminology

Aspect Ratio
The aspect ratio of a video or photo is the proportional relationship between the width and height of the image. This ratio is typically expressed as two numbers separated by a colon, where the number on the left of the colon is the width and the number on the right is the height. The aspect ratio people are likely most familiar with is the 16:9 aspect ratio of HDTV content. When referring to landscape aspect ratios, the width is always a larger number than the height. Portrait aspect ratios typically have a height that is great than the width.

AVCHD is a digital video camera recording format created in a partnership between Sony and Panasonic. The format supports both 1080i and 720p high definition resolutions. The MPEG-4 AVC codec is used for video with 7.1PCM uncompressed audio or 5.1 AC-3 compressed audio. Maximum bit rate for AVCHD files is 25 Mbps.Typically camcorders using this format either record to DVD, hard disk or SD memory.

Abbreviation for Audio Video Interleaved, this is the standard Windows format for delivering uncompressed video.

Short for binary digit, this is the smallest unit of data recognized by a PC.

Bit Rate
The number of bits transferred per second.

Using an application like the freeware tool Aspect, you can calculate the approximate file size of video content using the built-in bit rate calculator.

Recording audio, video, or still images as digital information in a movie project file.

Capture Device
Hardware used in transferring audio and video from an external source, such aslike a camcorder or VCR, to a computer.

In the context of audio or video editing, a clip is a segment of video or audio extracted from a larger file.

Software or hardware used to compress and decompress digital media. Some of the more common Codecs in use today include H.264, Windows Media 9 Video, Windows Media 9 Audio, MPEG-4, MPEG-2 and MPEG-1.

The process of reducing a file in size by removing redundant information from the file and creating a logical way of reconstructing the file through references to non-redundant components.

A video transition method where the frames in the current clip fade out as frames in the new clip fade in.

An uncompressed audio/video format used to encode camcorder data into a format recognizable by both digital video cameras and standard video editing applications.

Digital Artifacts
Distorted areas in a video or image file often appearing as square shapes within the picture.

Digital Video
Video and sound stored in a digital format.

Digital Video Camera
A device for recording video in a digital format. Common Digital camcorders capture video in MiniDV, Digital8, and DVD MPEG-2 formats.

Sony's proprietary digital video format, which is backward compatible with Hi8. This format uses standard 8mm tape to record and store video data.

A special effect applied to video footage in movie editing applications like Windows Movie Maker, Adobe Premiere, iMovie and Final Cut Pro.

A transitional effect designed to bring the video from or two black by gradually decreasing or increasing light in the picture.

(See also iLink and IEEE-1394) A high-speed data serial transfer standard providing connectivity for a wide range of devices, including camcoderscamcorders, external hard drives, and portable media devices. Data transfer rates for FireWire are typically 400 mbps, although a newer standard IEEE-1394b supports speeds up to 800 mbps.

One single image in the series of images making up a video. A frame is the smallest component of video. Digital video is typically made up of 29.97 frames per second. Newer HD digital video is recorded at 24 frames per second to match the film standard of 24 frames per second.

Frame Rate
The number of video frames displayed per second. Most DV camcorders record video at 29.97 frames per second. In general, the higher the frame rate the smoother the picture. New High Definition digital video cameras record at 24 frames per second to match the standard set by film.

(See also FireWire and iLINK) A high-speed data serial transfer standard providing connectivity for a wide range of devices, including camcoderscamcorders, external hard drives, and portable media devices. Data transfer rates for FireWire are typically 400 mbps, although a newer standard IEEE-1394b supports speeds up to 800 mbps.

Line Noise
Unwanted noise in an audio track caused by electrical currents interfering with the transmission of audio data through a cable.

Microphone Noise
Unwanted sound captured when a microphone is bumped during recording.

The format common to most digital video camcorders, which uses 6.35mm tape to record and store video data.

National Television Standards Committee. This is most commonly referenced in terms of the technical standard for video formatting in the United States.

Ogg Media (OGM) is a container format for video, audio and subtitles. It's similar to the AVI container, with a few additional features. OGM supports mutliple subtitle tracks, multiple audio files in different formats, chapter support and native support for the Vorbis OGG audio file format.

Phase Alternative Line. A competing standards body to NTSC. Most of the world outside the U.S. conforms to video standards based on PAL.

Real Media Variable Bitrate files are created either with the RealVideo 9 or RealVideo 10 codecs from RealNetworks. They are increasingly popular for video distributions from Asian countries including China and Korea because of smaller file sizes and better quality at lower bitrates than DivX.

Sometimes referred to as S-VHS, this video transmission format separates black-and-white video information from color data into two signals. Traditional composite video sends this information as one signal.

A layout of your video project in video editing software displaying video clips, transitions, and effects sequentially in a simplified workspace. Typically the story board displays the first frame from each individual clip in a linear scene-by-scene progression.

Super 8
A film format introduced by Kodak in 1965, which uses 8mm cartridge-loaded film reels for recording movies.

A detailed workspace view of your video editing project showing relative lengths of each video and audio clip used within the project and how they overlap.

A transition is a special kind of effect placed betweem two movie clips to enhance the progression of the movie's story as it moves to the next scene.

A non-destructive way of hiding parts of an audio or video clip in your video editing application without permanently removing those parts from the source file. Audio and video clips can be trimmed by adjusting the start or end trim points, which alters playback within the project, while leaving the original file intact.

Trim Points
Markers on the timeline of a project file designating the starting and ending points for a particular media clip.

Windows Media file
A file containing audio, video, or script data stored in Windows Media Format. Depending on content and purpose, Windows Media files use a variety of file name extensions, including: .wma, .wme, .wms, .wmv, .wmx, .wmz, or .wvx.

Magnifying or shrinking the image viewed by a camera lens, making the object appear closer or farther than it actually is in physical space.

The Sony implementation of IEEE-1394.