This document discusses various multimedia elements including sound, animation, and video. It provides details on:
- How sound waves are converted from analog to digital format through sampling. Common sampling rates and sizes are discussed.
- Popular sound file formats like WAV, AIFF, RealAudio and MP3. Considerations for using sound on the internet like file size.
- Types of 2D and 3D animation. Steps involved in 3D animation like modeling, animation and rendering. Special effects like morphing and warping.
- Design considerations for animation on websites like giving user control.
- How analog video is digitized. Factors that determine video file size like frame rate, image size
➢ Video is a collection of bit-mapped still images (called frames) that are taken one after the other.
➢ When the file is played, these pictures are shown in quick succession to give the impression of a moving image.
➢ The number of frames is called the frame rate and this is measured in FPS (Frames per Second). The standard rate is 25 FPS.
➢ Video is a collection of bit-mapped still images (called frames) that are taken one after the other.
➢ When the file is played, these pictures are shown in quick succession to give the impression of a moving image.
➢ The number of frames is called the frame rate and this is measured in FPS (Frames per Second). The standard rate is 25 FPS.
This slide gives a brief discussion of the multimedia. This is based on Anita Goel's Computers Fundamentals.
You can have a clear vision of the devices, video, audio and animations.
What is Video Compression?, Introduction of Video Compression. Motivation, Working Methodology of Video Compression., Example, Applications, Needs of Video Compression, Advantages & Disadvantages
Multimedia: is a form of communication that combines different
content forms such as text, audio, images, animations, or video into a
single presentation, in contrast to traditional mass media, such as
printed material or audio recordings.
Intro to Compression: Audio and Video Optimization for LearningNick Floro
Learn how to compress audio and video for delivery to desktop and mobile devices today. Learn how to use HTML5 and Flash as well as best practices from editing, compression and delivery of content.
This slide gives a brief discussion of the multimedia. This is based on Anita Goel's Computers Fundamentals.
You can have a clear vision of the devices, video, audio and animations.
What is Video Compression?, Introduction of Video Compression. Motivation, Working Methodology of Video Compression., Example, Applications, Needs of Video Compression, Advantages & Disadvantages
Multimedia: is a form of communication that combines different
content forms such as text, audio, images, animations, or video into a
single presentation, in contrast to traditional mass media, such as
printed material or audio recordings.
Intro to Compression: Audio and Video Optimization for LearningNick Floro
Learn how to compress audio and video for delivery to desktop and mobile devices today. Learn how to use HTML5 and Flash as well as best practices from editing, compression and delivery of content.
Esoft Metro Campus - Diploma in Web Engineering - (Module II) Multimedia Technologies
(Template - Virtusa Corporate)
Contents:
What are Graphics ?
Digital Image Concepts
Pixel
Resolution of Images
Resolution of Devices
Color Depth
Color Palette
Dithering
Bitmap and Vector Graphics
Bitmap Graphics
Vector Graphics
Comparison
Graphics File Formats
Bit Map
Tagged Image File Format
Graphical Interchange Format
Join Picture Expert Group
Portable Network Graphics
Multi-image Network Graphics
Multimedia on Web
Animations
Rollovers
Animated GIF
Flash Files
Audio
Audio on Web Sites
Audio File Formats
MIDI
WAVE
MP3
AU
AIFF
Video
Video File Formats
AVI
ASF
MPEG
QuickTime
RealVideo
Copyrights of Web Content
2. Sound
Analog wave patterns – these wave
patterns have two attributes
Volume – the height of each peak in the sound
wave
Frequency – (sometimes referred to as pitch)
the distance between the peaks. The greater
the distance, the lower the sound.
Image: scanned from Multimedia Concepts – James Schuman
3. Sampling
To include sound in a multimedia
application, the sound waves must be
converted from analog to digital form
This conversion is called sampling – every
fraction of a second a sample the of sound
is recorded in digital bits
4. Sampling
Two factors affect the quality of digitized
sound
1) Sample rate – the number of times the sample
is taken
Most common sampling rates are: 11.025, 22.05,
and 44.1 kHz
1) Sample size – the amount of information
stored about the sample
Most common sampling sizes are: 8 and 16 bit
5. Sampling
Image: scanned from Multimedia Concepts – James Schuman
7. Sound on the Internet
Your first consideration when using sound
on the Internet is file size
Uncompressed files can be very large
A 10 second recording of an audio CD can be
as large as 2MB
8. Sound Tips for the Internet
Appropriate Consider the appropriateness of using sound. Some
Use sounds are content-related, such as hearing a foreign
phrase pronounced. Other sounds are for effect, such
as creating a mood or setting a scene. Avoid using
sound when there is no compelling benefit.
Quality Start with the highest-quality sound available and
reduce the file size by converting the audio file to a
compressed format. When possible, avoid using free
sound clips available from the Internet. These are often
of poor quality and overused.
Cost When recording audio files, it may be cost-prohibitive to
considerations contract with a recording studio and hire professional
talent. Investing in reasonably high-end equipment
(such as a sound card, microphone, and recording and
editing software), however, will prove worthwhile.
9. Sound Tips for the Internet
Alternative Consider using sound and still images as an alternative to
Methods video to reduce file sizes. It may be just as effective to
show a photograph of a speaker and play the sound file
of the speech as it is to show a video of a “talking head.”
Streaming Consider streaming the audio, especially for large files.
User If appropriate, provide a way to give the user some
Control control over the audio. Consider allowing the user to skip
a sound clip or adjust the volume. This issue is especially
important if a musical introduction is played when the
user first enters a Web site. The second time visiting the
site, the user may not want to hear the musical
introduction.
10. Animation on the Internet
Animation is an excellent way to provide
appeal on a web site, choose from the
following
Animated text
Animated GIF’s
Marcomedia Director applications
3-D environments
11. 2-D Animation
Two types of animation exist
Cel animation – based on changes that occur
form one frame to the next
Path animation – moves an object along a
predetermined path on the screen
12. 3-D Animation
3-D Animation involves three steps
1) Modeling – creating the broad contours and
structure of 3-D objects and scenes
2) Animation – defining the object’s motion
3) Rendering – giving objects attributes such as
color, surface textures, and amounts of
transparency
13. 3-D Animation
Image: scanned from Multimedia Concepts – James Schuman
14. 3-D Animation Special Effects
Morphing – blending together two images
into a series of images
Warping – distorts a single image
Virtual Reality – creates an environment
that surrounds the user so that he or she
becomes part of the experience
15. Animation
Animated text – using the HTML <blink>
command causes text to flash on and off
Animated gif – using a software program
to create a series of gif files such as GIF
Builder
Director movie – animation played using
Shockwave plug-in
3-D environments – a computer language
used to create 3-D images
16. Design Considerations
Give the user control over whether or not
to display or enlarge graphic images
Allow the user to be active while graphic
images are being displayed
Provide feedback to the user by
displaying the amount of time a file will
take to download
17. Video
Video, like sound, is recorded and played
an as analog signal
Analog video must be digitized in order for
it to put into a multimedia file
Digital video has many advantages, but
file size is important
18. Video
Several elements determine file size:
Frame rate
Image size
Color depth
To determine file size use the following
formula:
Frames per second X image size X color
depth / 8 = file size
19. Video Compression and Editing
There are two types of video compression
Lossless – preserves the exact image
throughout the compression
Lossy – eliminates some of the data in the
image (provides greater compression ratios
than lossless)
Remember – there is always a trade off, file
size versus image quality
20. Video on the Internet
There are two types of video transfer over
the Internet
HTTP (Hypertext Transfer Protocol) –
downloads the entire video to the hard drive on
the user’s computer
RTSP (Real-Time Streaming Protocol) – is a
continuous-playing, streaming technology in
which the user’s computer is in constant contact
with the server playing the video
21. Video Tips
Color Reducing the color depth to less than 256 colors
depth gives a markedly poorer-quality image.
Frame Reducing the frame rate to less than 15 frames
rate per second causes a noticeable and distracting
jerkiness that is usually unacceptable.
File size A technique for reducing file size is to minimize
the use of video in the image that appears on
the screen – that is, to create video only for the
parts of an object that are changing, such as a
flickering candle. The video could be played over
and over to create the motion of a flickering
candle.
22. Video Tips
Display size In most multimedia titles, you do not need
to show full-screen video. The video can
be played in a window that can be as
small as one-fourth or even one-sixteenth
the size of the screen.
Conclusion: Changing the image size and compressing
the file become the primary ways of reducing file size. In
most cases, a one-quarter screen image (320 X 240), an 8-
bit (256 colors) color depth, and a 15 frames per second
frame rate are acceptable in a multimedia title.