Advertising detection in adaptive bitrate streaming
A method of handling advertisements in an adaptive bitrate stream is provided. The method includes the steps of receiving an adaptive bitrate stream playlist listing chunk identifiers pointing to a plurality of media chunks, analyzing the playlist to find one or more advertising chunks, modifying the adaptive bitrate stream playlist with a client device when the client device has been set to skip advertisements by deleting chunk identifiers associated with advertising chunks from the playlist, retrieving and playing back media chunks according to the playlist, and setting a no-trick-play flag at the client device during playback of the one or more advertising chunks when the client device has not been set to skip advertisements, such that trick-plays through and over media chunks are allowed when the no-trick-play flag is not set and are not allowed when the no-trick-play flag is set.
1. A method of preventing skipping advertisements in an adaptive bitrate stream, comprising:
receiving an adaptive bitrate stream playlist at a client device from a server, said adaptive bitrate stream playlist listing chunk identifiers pointing to a plurality of media chunks;
analyzing said adaptive bitrate stream playlist with said client device to find one or more advertising chunks within said plurality of media chunks;
retrieving and playing back at least one of said plurality of media chunks with said client device according to said adaptive bitrate stream playlist;
setting a no-trick-play flag at said client device during playback of said one or more advertising chunks;
allowing trick-plays through and over media chunks when said no-trick-play flag is not set; and
disallowing trick-plays through and over at least one media chunk when said no-trick-play flag is set, wherein disallowing trick-plays through and over at least one media chunk when said no-trick-play flag is set comprises:
receiving a set position trick-play command with a requested position at said client device;
initializing a position accumulator at said client device;
traversing through said chunk identifiers in said adaptive bitrate stream playlist, tracking positions where said no-trick-play flag is set in a record of no-trick-play positions, and
incrementing said position accumulator by the duration of the media chunks associated with each successive chunk identifier in the said adaptive bitrate stream playlist, until said position accumulator is greater than or equal to said requested position;
playing back the chunk pointed to by the chunk identifier at said requested position when said record of no-trick-play positions is empty; and
playing back an advertising chunk when said record of no-trick-play positions is not empty.
2. The method of claim 1 , wherein analyzing said adaptive bitrate stream playlist with said client device to find one or more advertising chunks within said plurality of media chunks comprises determining whether said adaptive bitrate stream playlist includes pairs of discontinuity tags, and if so identifying chunk identifiers between each pair of discontinuity tags as pointing to advertising chunks.
3. The method of claim 1 , wherein analyzing said adaptive bitrate stream playlist with said client device to find one or more advertising chunks within said plurality of media chunks comprises identifying a pattern followed by at least a preset percentage of chunk identifiers, and identifying any chunk identifiers that do not follow said pattern as pointing to advertising chunks.
4. The method of claim 1 , wherein analyzing said adaptive bitrate stream playlist with said client device to find one or more advertising chunks within said plurality of media chunks comprises identifying any chunk identifiers that have been repeated over a preset period of time at above a statistical frequency threshold as pointing to advertising chunks.
5. The method of claim 1 , wherein analyzing said adaptive bitrate stream playlist with said client device to find one or more advertising chunks within said plurality of media chunks comprises finding discontinuities in audio and/or video encoding attributes between adjacent media chunks within said plurality of media chunks that indicate transitions to or from advertising chunks, and identifying any chunk identifiers between said transitions as pointing to advertising chunks.
6. The method of claim 1 , wherein the advertising chunk played back when said record of no-trick-play positions is not empty is the advertising chunk associated with the chunk identifier at the no-trick-play position most recently added to said record of no-trick-play positions.
7. The method of claim 1 , wherein the advertising chunk played back when said record of no-trick-play positions is not empty is an advertising chunk in a first series of one or more advertising chunks when said set position trick-play command is a first set position trick-play command, and is an advertising chunk in a subsequent series of one or more advertising chunks when said set position trick-play command is a subsequent set position trick-play command.