OBJECTIVE 3.01 - Understand Principles of Audio and Video

UNIT 3 NOTES

OBJECTIVE 3.01 - Understand principles of audio and video

1)  Introduction to Sound

a)  Sound wave – an audible vibration that travels through air or water.

i)  Frequency - Number of waves to pass a point in one second.

ii)  Amplitude - Distance from rest to crest or rest to trough.

iii)  Wavelength - Distance from crest to crest.

iv)  Crest - Point that exhibits maximum amount of upward displacement from the rest position.

v)  Trough - Point that exhibits maximum amount of downward displacement from the rest position.

vi)  Pitch – The quality of the sound determined by the rate of vibration.

b)  Digitizing Sound

i)  Sampling – process used to convert analog sound waves into digital data to be used by computers.

ii)  Sample rate – the number of samples taken per second, often measured in Kilohertz (kHz).

iii)  Bit rate (Depth) – the number of computer bits process per unit of time.

iv)  Sample size – the number of bits used to save one sample.

v)  Channel-single audio stream consisting of a sequence of samples.

i)  Mono - one channel; audio is a single channel, where sound comes from a single direction.

ii)  Stereo - two channels; creates the impression of sound being heard from various directions, as in human hearing.

vi)  Audio file size – determined by the sample rate, sample size and number of channels used.

vii)  File Formats

i)  MP3 – MPEG-1 Audio Layer 3

ii)  WAV – Waveform file

iii)  OGG – Ogg Vorbis

iv)  AIFF- Audio Interchange File Format

2)  Introduction to Analog Video and Digital Video

a)  Terminology

i)  Analog video - video uses a continuous electrical signal to capture footage on a magnetic tape.

ii)  Digital video - videos that are made up of 1’s and 0’s, binary format, that represent the video image which computers can read.

iii)  Capture - to record audio, video, or still images as digital data in a file.

iv)  Frame - a single picture or still shot in a video.

v)  Frame rate - the number of video frames played per second.

(a)  NTSC Television- 24 fps (23.967)

vi)  Resolution- number of pixels that can be displayed on a screen.

(a)  480p (720 x 480) – standard definition.

(b)  720p (1280 x 720) – high definition.

(c)  1080p (1920 x 1080) – high definition.

b)  Stages of Video Production

i)  Preproduction – tasks undertaken before production begins.

(a)  Brainstorming – producing ideas through spontaneous group discussion.

(b)  Script writing – the written text for your movie.

(c)  Storyboarding - a sequence of drawings, with directions and sometimes dialog, that represents planned shots for a movie.

(d)  Casting- finding appropriate people to play the roles of the video.

ii)  Production- Filming the video

(a)  Field of view – the extent of what can be seen in a still or video shot.

1.  Shot Types - Wide, medium, tight.

2.  Panning - sweeping movement of a camera horizontally across a scene.

3.  Zooming - gradually changing from a longer to shorter shot or vice versa.

(b)  Framing – the process of creating composition in your shots. Follow the Rule of Thirds

iii)  Postproduction

(a)  Capturing Video- importing video from the original recording device.

(b)  Video Editing

(i)  Trimming and Editing Video

1.  Clips - Small segments of a larger video.

2.  Trim - To hide parts of a file or clip without deleting them from the original source.

3.  Sequence - A variety of wide, medium, and tight video shots edited together.

4.  Timeline - Shows the components of the movie such as photos, video, audio clips and titles in the order and timing that they will appear in movie.

(c)  Adding Titles and Graphics (Still Images, Logos, etc…)

(i)  Rolling credits- Include cast and credits for sources.

(d)  Adding/Editing Audio

(i)  Soundtracks – a musical recording that accompanies and is frequently synchronized with a video.

(ii)  Sound Effects - Artificially created or enhanced sounds to emphasize content or enhance a creative point in a video.

(iii) Narration - audio of one or more people that has been recorded to enhance or assist in telling the story for your video.

(e)  Adding Effects

(i)  Transitions - The visual movements as one picture, video clip, or title changes to another.

(ii)  Video Effects - Enable you to add special effects to your movie, such as a vintage look or changing a video to black and white.

(f)  Exporting

(i)  Video File Formats

1.  AVI – Audio Video Interleave

2.  MOV - Movie

3.  MPEG – Moving Picture Experts Group

4.  FLV – Flash

OBJECTIVE 3.02 - Understand basic motion graphic programming

1)  Animation Introduction

a)  Simulation of movement created by rapidly displaying images or frames.

b)  Relies on persistence of vision- the way our eyes retain images for a split second longer than they actually appear which makes quick flashes of images appear as one continuous motion. Example: Flipbooks

2)  Uses of Animation

a)  Advertising – used to catch attention, such as banners on websites.

b)  Entertainment – films, games, virtual reality

c)  Selling – showcasing products, services or instructions

d)  Teaching – illustrating concepts or processes

e)  Training – simulations, presentations, etc.

3)  Animation Considerations

a)  Is it appropriate for the target audience?

b)  Does it help deliver the message?

c)  Does it enhance or detract from message?

4)  Animation types

a)  Frame by Frame Animation - the rapid display of a sequence of still images that create the optical illusion of movement.

b)  Stop Motion Animation – manipulating real-world objects and photographing them one frame at a time. Example: Claymation

c)  Morphing – transforming one object into another.

d)  Path Based Animation – also called vector animation where the computer tweens, or creates the frames, to move the object along the path.

5)  Creating computer animations with animation software

a)  Stage – part of program where the content is created and manipulated.

b)  Library – used to store frequently used assets such as graphics and audio.

c)  Timeline – used to organize the content over time.

d)  Frame – one individual image in an animation.

e)  Keyframe – indicates where an action is to occur.

f)  Layers – the timeline can be divided into different layers to give the author more control over different elements such as sound and text.

g)  Playhead – the marker in the timeline that shows which frame is the current frame as the animation plays.

h)  Scrubbing – dragging the playhead across the timeline in order to preview the animation.

6)  Publishing Animations

a)  Identify end user and device

b)  Optimize the Animation- compression and file size

c)  Identify appropriate animation File Types