Distinguishing Between File Formats and Codecs
A file’s format specifies the unique way data is stored and organized in a file,
regardless of what the content of that data represents. A codec is an algorithm that
transforms image or sound data into a more compact, albeit temporarily
unintelligible form for the purpose of compression (reducing data size for
transmission or storage). The codec must be reversed in order to see the original
content of the media data.
A file format determines consistent guidelines for where information is stored and
found in a file. For example, a Microsoft Word file will always store the name of the
creator in a particular location in the file’s structure. On the other hand, a codec is
specific to media-intensive data, such as video or audio, and is used simply to reduce
the data size.
Learning About QuickTime
Â QuickTime: This refers to the QuickTime movie file format, which can contain multiple
media tracks, each containing data encoding with a number of possible codecs.
QuickTime is not a codec, but rather has the ability to present images and sound
stored with a number of codecs.
Â AIFF and WAVE: These are audio file formats that contain uncompressed audio data.
Â DV: There are several DV codecs available for NTSC, PAL, and other varieties such as
DVCPRO HD. A DV camcorder uses a DV codec to turn full-resolution image data into
compressed media, which is then stored on tape. The raw data stream from tape can
be captured to your hard disk in a file format called a DV stream. Applications such as
iMovie can capture and edit DV stream files, while applications like Final Cut Pro
capture media into tracks within a QuickTime media file, allowing for more flexibility
such as adding and manipulating timecode tracks.