System and method for media stream indexing and synchronization

• US 8,015,480 B2
• Filed: 05/15/2007
• Issued: 09/06/2011
• Est. Priority Date: 03/31/1997
• Status: Expired due to Fees

• Current Assignee: Espial Incorporated (Enghouse Systems Limited)
• Original Assignee: Espial Incorporated (Enghouse Systems Limited)
• Inventors: Abbott, Michael J., Close, Paul, Smith, Kevin P.
• Primary Examiner(s): Hong; Stephen S
• Assistant Examiner(s): Ludwig; Matthew J
• Application Number:
  US11/803,930
• Publication Number:
  US 20080010658A1
• Time in Patent Office: 1,575 Days
• Field of Search: 715/201, 715/202, 715/203, 715/204
• US Class Current: 715/201
• 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 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• 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 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/812 involving advertisement data advertising per se G06Q30/02
• CPC Class Codes: H04N 21/8146 involving graphical data, e.g. 3D object, 2D graphics
• CPC Class Codes: H04N 21/8455 involving pointers to the content, e.g. pointers to the I-frames of the video stream
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

An indexing system and method for allowing a viewer to control the mode of delivery of program material. By mapping from time to data position, data delivery can begin at any selected time in the program material. The indexing method also provides for controlling data delivery to begin at the beginning of a frame of data. A synchronizing method is provided to minimize a time offset between audio and video data, particularly in environments using groups of pictures.

Claims

1. A method for locating program material at a specified time T, comprising:

converting the specified time T to a time T_rel, relative to media data representing the program material;

determining an index number from said time T_rel using an index duration;

converting said index number to a data position, thereby locating media data representing the program material at the specified time T; and

converting a specified-segment relative time T_seg to a specified-atom relative time T_atom by adding a specified segment'"'"'s offset to T_seg, and computing an index number from T_atom using an index duration.

2. The method of claim 1, wherein said index duration is a duration of one frame of media data.

3. The method of claim 1, further comprising:

rounding said index number to locate an index boundary.

4. The method of claim 3, wherein said index boundary is a beginning of a frame of media data.

5. The method of claim 3, wherein said index boundary is a beginning of a group of pictures of media data.

6. A method as in claim 1, wherein the method for locating program material comprises locating the program material so that delivery of the program material to a viewer via media delivery on demand begins at the specified time T in the program material.

7. A method as in claim 1, further comprising accessing a group having one or more series, each series having one or more segments that references a corresponding atom containing the media data representing the program material.

8. A method as in claim 7, further comprising determining in which specified segment of which specified atom of media data the specified time T occurs.

9. A method as in claim 8, further comprising converting the specified time T to the specified-segment relative time T_seg by calculating an elapsed time into the specified segment at which the specified time occurs.

10. A method as in claim 1, wherein an index file is used to correlate index number with a corresponding data position.

11. A method as in claim 10, wherein the corresponding data positions are the beginning of a frame of media data, or the beginning of a group of media items of media data.

12. A method as in claim 11, wherein the media items include pictures.

13. A computer program product stored on a computer readable medium for use with a computer system and a content on demand media delivery system including computer readable program code for enabling a computer system to carry out the locating of program material so that delivery of the program material to a viewer via media delivery on demand begins at the specified time T in the program material;

the computer program product including instructions for;

converting the specified time T to a time T_rel relative to media data representing the program material;

determining an index number from said time T_rel using an index duration;

converting said index number to a data position, thereby locating media data representing the program material at the specified time T; and

converting a specified-segment relative time T_seg to a specified-atom relative time T_atom by adding a specified segment'"'"'s offset to T_seg, and computing an index number from T_atom using an index duration.