How Is Information Stored in a QuickTime Movie?
QuickTime movie files store media data in separate tracks. You create a QuickTime
movie file by adding tracks that point to the media you want to use. The media may be
embedded in the file itself or in a reference movie in another file. This track architecture
is powerful and flexible, allowing you to store and synchronize multiple pieces of video
and audio media in a single file.
There are many types of tracks allowed in a QuickTime movie file. Here are a few
examples of what might be included in a QuickTime movie file used by Final Cut Pro:
Â An audio track: This track contains audio media data of a certain duration, encoded
with a particular audio codec, sample rate and bit depth. The track may be mono or
contain two (stereo) or more interleaved channels of audio samples.
Â A video track: This track contains video media data (a number of video frames) of a
certain duration (determined by the track’s frame rate), with particular horizontal and
vertical dimensions, and encoded with a particular video codec.
Â A single still image: This track contains media for a single still image. The image
data has particular horizontal and vertical dimensions and is compressed with a
Â A timecode track: A track that contains a number count and frame rate that
corresponds to the video frames in a video track. This track can be captured from a
videotape or created later in Final Cut Pro.
Â A text track: This track contains text information that changes at specified times. A
text track could contain subtitles, or marker notes about a video or audio track.