Interleaved Time Bases in Hypermedia Synchronization

Unsolicited interleaved media content is common in digital TV systems, particularly in broadcast TV, in which advertisements are inserted into programs transmitted sequentially. Although certain existing middleware systems address this problem, their solutions have limitations. This work proposes an alternative approach that provides high-level event-based abstractions that hide or minimize the complexity of dealing with interleaved media content as part of hypermedia applications. This article discusses how multimedia languages and players can handle multiple time bases in supporting intermedia synchronization with interleaved media content. The proposal has been incorporated in the Nested Context Language (NCL) and in its player, the main component of the Ginga digital TV middleware. This approach can also be adapted to be used in other languages and engines.