Video streaming systems and methods

A method comprising:

• providing a manifest to a player, wherein
• the manifest comprises first segment locator information and content segment locator information, and
• the first segment locator information comprises:
• i) a set of N segment URLs comprising a first segment URL comprising a first segment identifier or ii) URL template information that can be used by the player to generate the N segment URLs;
• submitting to an ad stitcher an ad request;
• receiving from the ad stitcher a response responsive to the ad request, the response comprising a set of M ad segment URLs, where M≤N, wherein the set of M ad segment URLs comprises a first ad segment URL comprising a first ad segment identifier for use in identifying a first ad segment;
• creating a mapping that maps the first segment identifier to the first ad segment identifier;
• receiving from the player a first segment request comprising the first segment identifier;
• in response to receiving the first segment request comprising the first segment identifier, using the mapping to obtain the first ad segment URL;
• and
• after obtaining the first ad segment URL:
• using the first ad segment URL to retrieve the first ad segment and then providing to the player the first ad segment, or
• providing to the player a redirect message comprising the first ad segment URL for causing the player to request the first ad segment.