What is a bit stream?
A bit stream is a continuous flow of bits over a communication path. This path can be within the computer itself, across computer networks from a source computer (usually some sort of server) to a destination computer. We will be focusing on network bit streams and two ways in which they can be handled.
Real-Time Bit Streaming
Real time bit streaming
Real time bit streaming is where is data is retrieved live from the source as it is being created. Real time streaming cannot be paused or re-winded, as any data that is not immediately used (e.g. video data outputted to the screen) is discarded.
Low latency(delay) is prioritised over quality – packets that don’t arrive in time are discarded.
If the data cannot be reliably streamed at the current bit-rate(quality) then a lower bit-rate and quality will be used.
- Live sports television broadcasts
- Online Gaming
- Some financial data
- Some weather data
- Live streaming services (e.g. Twitch)
- Controlling UAVs and other autonomous devices.
On-Demand Bit Streaming
On Demand bit streaming
On demand bit streaming is used to transmit data that has been pre-recorded. The player buffers (waits and saves up packets) until the data can be streamed in the bit-rate selected before starting playback
Data integrity is prioritised over latency.
If there is insufficient bandwidth to handle the bit stream then buffering will occur and the output will pause or drop frames until the bandwidth increases or a lower bit rate stream is selected.
- Movie playback
- Music streaming (not live radio)
- Video streaming sites such as YouTube