Definition: adaptive streaming

A multimedia transmission technology that adapts to the changing bandwidth of the network and available CPU cycles in the receiving device. It employs video content that is encoded at high, medium and low bit rates with each stream broken into small segments. In order to maintain continuous viewing without momentary periods of no video, as conditions change, adaptive streaming switches to segments with a higher or lower encoding level.

Adaptive streaming generally starts out at the highest bit rate and its primary function is to ensure there is a sufficient number of video frames in the receiving device at all times. If the video buffer is near empty for too long, it switches to a lower bit rate, and if it fills up again quickly, it can return to a higher rate. See buffering.

Over HTTP (Via Port Number 80)
Adaptive streaming uses HTTP as the application protocol, primarily because HTTP requests, which use the #80 port identification, are accepted by all Web servers. See streaming, streaming server and streaming protocols.