CPC H04N 21/23892 (2013.01) [H04N 21/23418 (2013.01); H04N 21/23424 (2013.01); H04N 21/23614 (2013.01); H04N 21/4305 (2013.01); H04N 21/8545 (2013.01); H04N 21/8547 (2013.01)] | 20 Claims |
1. A method comprising:
receiving, into a computing system, a packet-based transport stream carrying a media stream that defines media content and carrying metadata that is not watermarked in the media stream, wherein the metadata specifies a content-revision time point in the media stream as a time-offset value measured from a point in the media stream where the metadata is carried;
obtaining, by the computing system, from the transport stream, the metadata that is not watermarked in the media stream, wherein obtaining the metadata from the transport stream comprises obtaining the specified content-revision time point from the transport stream;
computing, by the computing system, an absolute time point in the media stream, based on the obtained content-revision time point;
modifying, by the computing system, the media stream by at least (i) encoding in a watermark in the media stream the computed absolute time point and a code that directs a downstream entity to obtain, from local storage at the downstream entity, replacement content to be inserted into the media stream at the absolute time point and (ii) encoding at a specific time point in the media stream a timestamp of the specific time point, whereby the timestamp is usable by the downstream entity as a basis to establish synchronous lock in order to map the absolute time point to a time point according to a clock of the downstream entity; and
outputting from the computing system, for transmission to the downstream entity, at least the modified media stream.
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