Bandwidth chart

From DoWire Wiki

This is a draft bandwidth chart for Democaster.

A goal of Democaster is to provide the lowest bandwidth audio possible at a basic listening quality. Think mono voice not stereo music.

Our goal is to offer 16KB and 32KB stream and audio files in Ogg and MP3 format. Non-proprietary Ogg can sound good at low bitrates and MP3 isn't so good but is much more accessible to users.

Chart here

We need to test:

16kbps - 11.5 kHz

Sampling rates:

Telephone/VOIP Quality - 8 kHz AM Radio - 11 kHz Skype - 16 kHz FM Radio - 22 kHz CD - 44.1 kHz

Bits:

According to Nancy Price, sound quality is determined by three main factors:

• Sampling Rate: The number of times each second the computer stores information about the sound wave. Compact discs store audio that is sampled at 44.1 kilohertz (kHz). The new DVD format is capable of a maximum of 96 kHz sampling and most computer sound cards can sample at a maximum of 48 kHz. The higher the sampling rate the better the sound quality that will be heard.

• Bit Rate: Computers use a binary numbering system of “ones and zeros” which are combined into longer strings of numbers in sets, called “bits”. Compact discs are recorded with a bit length of 16. Again, the higher the bit length, the better the sound quality.

• Compression: Computers can use different schemes to eliminate repetitive information when storing data. In recorded sound, these compression schemes have many forms. Audio on a compact disc is not compressed and gives the user the highest sound quality; when working with the Internet, sound must be compressed to make a smaller file for downloading. Any form of compression will usually have some affect on the quality of the reproduced sound so users must balance the desire for high quality sound with the need to minimize the size of the recorded file.

Sources to build from: http://www.bummerhosting.com/bandwidth.htm http://www.uwm.edu/People/price/Audio_file_format_comparison.html http://www.cs.cf.ac.uk/Dave/Multimedia/node150.html http://www.digitalprosound.com/Htm/WebAudio/2000/Oct/MP3bitrates.htm http://www.audioactive.com/intro/papers/bitrate.html http://www.teamcombooks.com/mp3handbook/11.htm http://www.ukoln.ac.uk/qa-focus/documents/briefings/briefing-65/html/