Abstract: Media content is streamed from a server computer to a client computer. A media file format is used to store data for multiple timeline-altered streams that provides support for switching between the different timeline-altered streams during their presentation. In one aspect, a user can switch between different timeline-altered streams. Upon receiving a user request to switch to a particular timeline-altered stream (the target stream), the client computer accesses a time code stream data object corresponding to the current data unit being presented. The time code stream data object identifies a primary stream presentation time corresponding to the data unit. The client then uses the primary stream presentation time to index into a table of mappings to byte offsets. The table provides a mapping of the primary stream presentation time to a corresponding byte offset of the target stream.

Abstract: Meta data associated with multiple pieces of content (e.g., songs, movies, other audio/video clips, etc.) stored on multiple pieces of media (e.g., CDs, DVDs, etc.) is maintained in a meta data store. The meta data store also includes meta data associated with other pieces of content stored elsewhere, such as songs stored in files on a local hard drive that have been ripped from a CD or DVD. These other pieces of content are associated with the content on the pieces of media, such as being ripped versions of the same song tracks. This association is maintained in the meta data store, so that whenever a change is made to meta data for one piece of content (e.g., for a track on a CD), then the meta data for the associated piece(s) is also changed (e.g., the ripped version stored in a file on the hard drive).

Abstract: A skimmed or preview version of multimedia content is provided to a client computer by a server computer using playlists. The skimmed version of multimedia content can be presented to a user of a client computer in less time than presenting the entire multimedia content would require. The server computer maintains skimming information that identifies particular segments of the multimedia content corresponding to the skimmed version. The server computer uses the skimming information to generate a playlist, which in turn is used by the server computer to access the appropriate segments of the multimedia content and provide the segments to the client computer.

Abstract: A skimmed or preview version of multimedia content is provided to a client computer by a server computer using playlists. The skimmed version of multimedia content can be presented to a user of a client computer in less time than presenting the entire multimedia content would require. The server computer maintains skimming information that identifies particular segments of the multimedia content corresponding to the skimmed version. The server computer uses the skimming information to generate a playlist, which in turn is used by the server computer to access the appropriate segments of the multimedia content and provide the segments to the client computer.

Abstract: Systems for enabling users to register for notifications pertaining to electronic presentations of interest are described. In one embodiment, a notification system is configured to receive source information from at least one source of an electronic presentation. The source information describes one or more aspects of the electronic presentation as it is being or is about to be broadcast by the source. The system evaluates the source information against user information that gives an indication of electronic presentations that might be of particular interest to a particular user. The system generates a notification to one or more users if, as a result of an evaluation of the source information against the user information, it appears that the one or more users would be interested in an electronic presentation.

Abstract: Meta data associated with multiple pieces of content (e.g., songs, movies, other audio/video clips, etc.) stored on multiple pieces of media (e.g., CDs, DVDs, etc.) is maintained in a meta data store. The meta data store also includes meta data associated with other pieces of content stored elsewhere, such as songs stored in files on a local hard drive that have been ripped from a CD or DVD. These other pieces of content are associated with the content on the pieces of media, such as being ripped versions of the same song tracks. This association is maintained in the meta data store, so that whenever a change is made to meta data for one piece of content (e.g., for a track on a CD), then the meta data for the associated piece(s) is also changed (e.g., the ripped version stored in a file on the hard drive).

Abstract: Viewing management methods and systems for managing viewing of multiple live electronic presentations are described. In one described embodiment, viewers are given an opportunity to register their preferences for viewing certain events that can occur within a plurality of different electronic presentations. The selected electronic presentations are simultaneously monitored, during their broadcast, while a viewer might be watching only one of the electronic presentations. When one or more of the viewer-defined events is detected, the viewer is notified that the event is taking place.

Abstract: Viewing management systems for managing viewing of multiple live electronic presentations are described. In one described embodiment, viewers are given an opportunity to register their preferences for viewing certain events that can occur within a plurality of different electronic presentations. The selected electronic presentations are simultaneously monitored, during their broadcast, while a viewer might be watching only one of the electronic presentations. When one or more of the viewer-defined events is detected, the viewer is notified that the event is taking place.

Abstract: In a networked client/server system, live presentations can be streamed from an encoder or other server to a client computer. Additionally, information describing the presentation is registered with a search server. This information is made available for user searches only for as long as the information properly describes the live presentation. When the information no longer describes a current live presentation, the information is no longer available for searching.

Abstract: In a networked client/server system, live presentations can be streamed from an encoder or other server to a client computer. Additionally, information describing the presentation is registered with a search server. This information is made available for user searches only for as long as the information properly describes the live presentation. When the information no longer describes a current live presentation, the information is no longer available for searching.

Abstract: A skimmed or preview version of multimedia content is provided to a client computer by a server computer using playlists. The skimmed version of multimedia content can be presented to a user of a client computer in less time than presenting the entire multimedia content would require. The server computer maintains skimming information that identifies particular segments of the multimedia content corresponding to the skimmed version. The server computer uses the skimming information to generate a playlist, which in turn is used by the server computer to access the appropriate segments of the multimedia content and provide the segments to the client computer.