Time-dependent or Time-independent Digital Video and Audio are time-dependent Time-dependent media stress the system Sampling or Sequencing Raster (Bit-map) or Vector Digitized Sound or MIDI Digital Video or Animation
Digital Video and Audio are time-dependent
Time-dependent media stress the system
Raster (Bit-map) or Vector
Digitized Sound or MIDI
Digital Video or Animation
Compression and Rarefaction of Air Digitized Audio vs Sequences MP3 = digitized audio MIDI = sequenced audio
MP3 = digitized audio
MIDI = sequenced audio
Sampling rate (how many samples a second) Resolution of each sample – amount of information Quantization CD Quality = 44.1 kHz with 16 bit resolution (stereo) 10.5 Megabytes to store 1 minute
Quantization
CD Quality = 44.1 kHz with 16 bit resolution (stereo)
10.5 Megabytes to store 1 minute
.snd – Macintosh sound format (sound file) .wav – Microsoft sound format (wave file) Real Audio format for WWW .mp3 - MP 3 files (Motion Picture Experts Group) Uses compression to get audio files down in size MPEG 1 Audio Layer-3
Uses compression to get audio files down in size
MPEG 1 Audio Layer-3
Records performance information Sequence of notes or actions Can be used to control other things Much more efficient than waveform audio recordings Use MIDI Sequencers, Synthesizers
Sequence of notes or actions
The eye sees motion when shown over 24 images a second A digital video clip is a sequence of images Animated or Digitized Quality is a matter of Frames (samples) per second Resolution of images Size of files makes it hard to use digital video Bandwidth problems within computer
Animated or Digitized
Frames (samples) per second
Resolution of images
Sampling and Quantizing DV = sequence of digitized images
NTSC – National Television Standards Committee 1953 Standard for television signal (PAL, SECAM) QuickTime – Apple format (for both PC and Mac) Allows different types of compression .qt or .mov MPEG – different formats Do not confuse with MP3 files – audio files DVD – (Digital Video Disk or Digital Versatile Disk – uses MPEG-2 for video) 4.3 Gigabytes (other standards coming) AVI – Microsoft (Audio Video Interleave) Flash (SWF) - Animation format for Web
1953 Standard for television signal (PAL, SECAM)
Allows different types of compression
.qt or .mov
Do not confuse with MP3 files – audio files
4.3 Gigabytes (other standards coming)
Created by Geoffrey Rockwell, October, 2003