Summary

DASH

DASH, which stands for Dynamic Adaptive Streaming over HTTP, is a video streaming technology designed to handle the challenges of varying network conditions and different device capabilities. It allows video to be streamed smoothly by adjusting the quality in real-time based on the available bandwidth.

Server:

• divides video file into multiple chunk
• each chunks encoded at multiple different rates
• each file has different coding rates (e.g., 300Kbps, 700Kbps, 1Mbps, etc.)
• Files replicated in various Content Distribution Network (CDN)
• manifest file: provides URLs for different chunks

Client:

3W

client intelligently determines

• when to request chunk (buffer optimize)
• what encoding rate to request (bandwidth optimize)
• where to request chunk (CDN optimize)

• estimates server-to-client bandidth
• request chunk with the highest rate that is less than estimated bandwidth
• if bandwidth changes, client can request different rate chunk for next chunk