Digital multimedia elements
Audio 
Video
Bit resolution
Sampling rate
Is the number of bits used to represent the amplitude of an audio signal.
The higher the number of bits used, the more precise the amplitude of the audio signal will be
The higher of sampling ratw, the better the quality of the digital audio will show
Is the number of samples taken each second during the conversion process
Is measured in Hz
Stereo audio contains two steams of audio signals, known as lee sound track and right sound track
Mono audio contains only one sound track
Audio data can be stored either in uncompressed or compressed format
Uncompressed
Compressed
WAV
WMA
MP3
The file size of it can be very large
Factors affecting the size of a video file
Is a sequence of full-motion images together with sound tracks
Frame rate
Duration
Compression
Colour depth
Frame size
The higher the frame size and frame rate, the better the video quality and the larger the file size
A particular compression method has its own specification of compression ratio, frame sizes and frame rates
Different video file formats require different media players and plug-ins
Video files can be compressed into different video file formats for different playback media
AVI is the most popular standard of uncompressed video
MPEG-1, MPEG-2 and WMV are examples of compressed video file format