Streaming Bandwidth and Storage
A broadband speed of 2.5 Mbit/s or more is recommended for streaming movies, for example to an Apple TV, Google TV or a Sony TV Blu-ray Disc Player, 10 Mbit/s for High Definition content.
Streaming media storage size is calculated from the streaming bandwidth and length of the media using the following formula (for a single user and file):
- storage size (in megabytes) = length (in seconds) × bit rate (in bit/s) / (8 × 1024 × 1024)
Real world example:
One hour of video encoded at 300 kbit/s (this is a typical broadband video as of 2005 and it is usually encoded in a 320 × 240 pixels window size) will be:
- (3,600 s × 300,000 bit/s) / (8×1024×1024) requires around 128 MB of storage.
If the file is stored on a server for on-demand streaming and this stream is viewed by 1,000 people at the same time using a Unicast protocol, the requirement is:
- 300 kbit/s × 1,000 = 300,000 kbit/s = 300 Mbit/s of bandwidth
This is equivalent to around 135 GB per hour. Using a multicast protocol the server sends out only a single stream that is common to all users. Therefore such a stream would only use 300 kbit/s of serving bandwidth. See below for more information on these protocols.
The calculation for live streaming is similar.
Assumptions: speed at the encoder, is 500 kbit/s.
If the show lasts for 3 hours with 3,000 viewers, then the calculation is:
- Number of MBs transferred = encoder speed (in bit/s) × number of seconds × number of viewers / (8*1024*1024)
- Number of MBs transferred = 500,000 (bit/s) × 3 × 3,600 ( = 3 hours) × 3,000 (nbr of viewers) / (8*1024*1024) = 1,931,190 MB
Read more about this topic: Streaming Media
Famous quotes containing the words streaming and/or storage:
“The mob is man voluntarily descending to the nature of the beast. Its fit hour of activity is night. Its actions are insane like its whole constitution. It persecutes a principle; it would whip a right; it would tar and feather justice, by inflicting fire and outrage upon the houses and persons of those who have these. It resembles the prank of boys, who run with fire-engines to put out the ruddy aurora streaming to the stars.”
—Ralph Waldo Emerson (1803–1882)
“Many of our houses, both public and private, with their almost innumerable apartments, their huge halls and their cellars for the storage of wines and other munitions of peace, appear to me extravagantly large for their inhabitants. They are so vast and magnificent that the latter seem to be only vermin which infest them.”
—Henry David Thoreau (1817–1862)