Media File Format to Support Switching Between Multiple Timeline-Altered Media Streams

• US 20080071920A1
• Filed: 11/26/2007
• Published: 03/20/2008
• Est. Priority Date: 05/03/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Omoigui, Nosakhare, He, Li-Wei, Gupta, Anoop
• Granted Patent: US 7,472,198 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04N 21/2335 involving reformatting operations of audio signals, e.g. by converting from one coding standard to another details of audio signal transcoding G10L19/173
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments
• CPC Class Codes: H04N 21/85406 involving a specific file format, e.g. MP4 format
• CPC Class Codes: H04N 21/858 Linking data to content, e.g. by linking an URL to a video object, by creating a hotspot
• CPC Class Codes: Y10S 707/99931 Database or file accessing

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.

Claims

1. A computer-readable data storage medium with computer-program instructions embedded thereon, the computer-program instructions being executable by a processor for performing operations comprising:

receiving a user selection to switch from a first timeline-altered media stream to a second timeline-altered media stream;

accessing a time-compressed stream object corresponding to a data unit, currently being rendered, of the first timeline-altered media stream;

identifying, from the time-compressed stream object, a presentation time of a primary media stream whose timeline has not been altered, the presentation time indicates when the data unit of the first timeline-altered media stream is to be rendered, the presentation time being independent of a delivery time that indicates when the data unit is to be delivered to a rendering client;

accessing an index table to identify an offset into the second timeline altered stream corresponding to the presentation time of the primary media stream; and

wherein the second timeline-altered media stream is for presentation to a user by the rendering client.

2. The computer-readable data storage medium of claim 1, wherein the computer-program instructions further comprise instructions for rendering the second timeline-altered media stream beginning at the location identified by the offset.

3. The computer-readable data storage medium of claim 1, wherein the computer-program instructions further comprise instructions for streaming the second timeline-altered media stream, beginning at the location identified by the offset, to a client computer for presentation to a user.

4. The computer-readable data storage medium of claim 1, wherein the computer-program instructions further comprise instructions for rendering the second timeline-altered media stream beginning at a location prior to the location identified by the offset.

5. The computer-readable data storage medium of claim 1, wherein the computer-program instructions further comprise instructions for streaming the second timeline-altered media stream, beginning at a location prior to the location identified by the offset, to a client computer for presentation to a user.

6. A computing device comprising:

a processor; and

a memory coupled to the processor, the memory comprising computer-program instructions executable by a processor for performing operations comprising;

receiving a user selection to switch from a first timeline-altered media stream to a second timeline-altered media stream;

accessing a time-compressed stream object corresponding to a data unit, currently being rendered, of the first timeline-altered media stream;

identifying, from the time-compressed stream object, a presentation time of a primary media stream whose timeline has not been altered, the presentation time indicates when the data unit of the first timeline-altered media stream is to be rendered, the presentation time being independent of a delivery time that indicates when the data unit is to be delivered to a rendering client;

accessing an index table to identify an offset into the second timeline altered stream corresponding to the presentation time of the primary media stream; and

wherein the second timeline-altered media stream is for presentation to a user by the rendering client.

7. The computing device of claim 6, wherein the computer-program instructions further comprise instructions for rendering the second timeline-altered media stream beginning at the location identified by the offset.

8. The computing device of claim 6, wherein the computer-program instructions further comprise instructions for streaming the second timeline-altered media stream, beginning at the location identified by the offset, to a client computer for presentation to a user.

9. The computing device of claim 6, wherein the computer-program instructions further comprise instructions for rendering the second timeline-altered media stream beginning at a location prior to the location identified by the offset.

10. The computing device of claim 6, wherein the computer-program instructions further comprise instructions for streaming the second timeline-altered media stream, beginning at a location prior to the location identified by the offset, to a client computer for presentation to a user.