Multimedia Elements Sound, Animation, and Video : Multimedia Elements Sound, Animation, and Video
Sound : 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
Sampling : 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
Sampling : Sampling Two factors affect the quality of digitized sound
Sample rate – the number of times the sample is taken
Most common sampling rates are: 11.025, 22.05, and 44.1 kHz
Sample size – the amount of information stored about the sample
Most common sampling sizes are: 8 and 16 bit
Sampling : Sampling Image: scanned from Multimedia Concepts – James Schuman
Sound File Formats : Sound File Formats WAV format – filename.wav
AIFF (Audio Interchange File Format)
AIFFC (compressed)
RealAudio – filename.ra
MP3 (mpeg layer 3)
Sound on the Internet : 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
Sound Tips for the Internet : Sound Tips for the Internet
Sound Tips for the Internet : Sound Tips for the Internet
Animation on the Internet : 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
2-D Animation : 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
3-D Animation : 3-D Animation 3-D Animation involves three steps
Modeling – creating the broad contours and structure of 3-D objects and scenes
Animation – defining the object’s motion
Rendering – giving objects attributes such as color, surface textures, and amounts of transparency
3-D Animation : 3-D Animation Image: scanned from Multimedia Concepts – James Schuman
3-D Animation Special Effects : 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
Slide15 : Animation Animated text – using the HTML
Slide16 : 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
Video : 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
Video : 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
Video Compression and Editing : 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
Video on the Internet : 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
Video Tips : Video Tips
Video Tips : Video Tips
The End : The End