Multimedia Fundamentals: Audio and Video Technology

1. Scope of Multimedia

The term multimedia applies to both software and hardware. Programs are used for creating and editing sound, images, graphics, videos, and multimedia content in general.

2. Multimedia Software

Multimedia software is capable of handling and processing visual information.

3. Digital Sound

Digital sound is a sequence of binary numbers stored in a computer or device (e.g., MP3), created through a sampling process of analog sound or vibration.

• Sampling: The process of capturing and digitizing an analog sound.

4. Sound Quality Factors

The quality of a sound depends on the sampling rate and resolution (bit rate).

• Sampling Frequency: The number of samples taken per second (e.g., 44,100 samples per second).
• Bit Rate (Resolution): The number of bits used for each sample.

5. Common Audio Formats

• WAV: Uncompressed format with large file size.
• MP3: Compressed format that reduces file size to 1/12.
• CDA: Compressed disk format (1 minute = 10 Mbits).
• AAC: Compressed format, 30% more efficient than MP3.
• WMA: Windows format with compression similar to MP3.

6. Audio Conversion

Tools like Sound Juicer and Audacity can convert audio files into other formats:

• Ogg: Lossy quality format.
• FLAC: Lossless quality format.

7. What is Ripping?

Ripping is the process of extracting data from a CD or DVD and saving it to a hard disk drive (HDD).

8. Movies, Analog, and Digital Video

9. Frame Rate

A movie is a sequence of 18 or more images or frames per second.

10. Frame Size

The physical dimensions of the images or frames.

11. Video Codecs

A video codec is a program that compresses and decompresses video using mathematical formulas. Examples include DV, MPEG, and DivX.

12. Video Formats

The manner in which data is saved in a file. Common formats include AVI, MOV, MPG, and WMV.

13. Video Editing Software

Kino is a video editor similar to Cinelerra, Avidemux, or Windows Movie Maker.

Features of Kino:

• Capturing video from a DV camera to a PC via Firewire (1394) cable.
• Timeline: The workspace for arranging sequences of digital video.