Video streaming systems and methods

1. A method, comprising:

receiving a manifest associated with a video;

generating a modified manifest comprising:

i) a set of N1 URLs, where N1>1; and

ii) a corresponding set of N1 duration values, wherein

the set of N1 URLs comprises a first URL comprising a first segment identifier and a second URL comprising a second segment identifier,

each one of the N1 duration values is associated with only a single one of the URLs included in the set of N1 URls,

the set of duration values comprise a first duration value and a second duration value,

the first duration value, D1, is associated with only the first URL, and

the second duration value, D2, is associated with only the second URL;

providing the modified manifest to a player;

receiving from the player a segment request comprising the first segment identifier;

in response to receiving the segment request comprising the first segment identifier, providing to the player a first segment or a redirect message for causing the player to request the first segment;

receiving from the player a segment request comprising the second segment identifier; and

in response to receiving the segment request comprising the second segment identifier, providing to the player a second segment or a redirect message for causing the player to request the second segment, wherein

the first segment has a duration, and

the duration of the first segment is greater than D1-1 second, where D1 is in units of seconds

the second segment has a duration, and

the duration of the second segment is less than D2-1 second, where D2 is in units of seconds.

2. The method of claim 1 , wherein

generating the modified manifest comprises inserting the set of N1 URLs into the manifest at an insertion point for a first ad break.

3. The method of claim 2 , wherein

at least a first ad set can fill the first ad break,

the first ad set has a required number of segments, and

N1 is equal to the first ad set's required number of segments.

4. The method of claim 3 , wherein

a second ad set can also fill the first ad break, the second ad set having a required number of segments equal to N2, and

N1>N2.

5. The method of claim 2 , wherein

M ad sets can fill the first ad break, each one of the M ad sets having a required number of segments, and

N1=max (s1, s2, . . . , sM), where si for i=1 to M is the ith ad set's required number of segments.

6. The method of claim 2 , wherein generating the modified manifest comprises inserting into the manifest first segment grouping information for forming two or more groups of URLs.

7. The method of claim 6 , wherein

inserting into the manifest the first segment grouping information comprises inserting into the manifest a discontinuity tag such that in the modified manifest the discontinuity tag comes after the first URL but comes before the second URL.

8. The method of claim 1 , further comprising:

after providing the modified manifest to the player, submitting to an ad stitcher an ad request for triggering the ad stitcher to select a set of ads to fill a first ad break;

receiving from the ad stitcher a response responsive to the ad request, the response comprising a set of S segment URLs or a set of S ad segments, where S<N1, wherein the set f S segment URLs comprises a first ad URL or the set of S ad segments comprises a first ad segment; and

mapping the first URL included in the list of URLs with the first ad URL or the first ad segment.

9. The method of claim 1 , wherein

D1 is greater than or equal to 3, and

the duration of the second segment is less than 1 second.

10. The method of claim 2 , wherein

the manifest indicates an insertion point for a second ad break,

the manifest comprises second ad break duration information indicating a duration of the second ad break, and

generating the modified manifest further comprises inserting into the manifest at the insertion point for the second ad break a list of N2 URLs, where N2>1.