Question

Consider a DASH system for which there are N video versions (at N different rates and qualities) and N audio versions (at N different rates and qualities). Suppose we want to allow the player to choose at any time any of the N video versions and any of the N audio version. (a) (4 points) If we create files so that the audio is mixed in with the video, so server sends only one media stream at a given time, how many files will and server need to store (each a different URL)? (b) (4 points) If the server instead sends the audio and video streams separately and has the client synchronize the streams, how many files will the server need to store?

Answer 1

Answer: a) N² files. b) 2 N files.

Step-by-step explanation:

a) If the user can select at any time, any of the N video versions, along with any of the N audio versions, and the files are created mixing audio and video in one stream, it will be needed to store one audio file for each of the N video files, this means that there will be N files for each video file, so, the server must store N x N= N² files.

b) If the server sends the audio and video streams separately, so the user must synchronize the streams, this means that the user can access to any of the N video files and to any of the N audio files, as separate entities, so it will needed to store only N video files and N audio files, i.e., 2N files.