System and method of processing MPEG streams for file index insertion

• US 20020048450A1
• Filed: 05/18/2001
• Published: 04/25/2002
• Est. Priority Date: 09/15/2000
• Status: Active Grant

• Current Assignee: Hulu LLC (The Walt Disney Company)
• Original Assignee: International Business Machines Corporation
• Inventors: Zetts, John Mark
• Granted Patent: US 7,212,726 B2
• Time in Patent Office: Days
• US Class Current: 386/95
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/032 on tapes G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/11 by using information not detectable on the record carrier
• CPC Class Codes: G11B 27/34 Indicating arrangements indicating means incorporated in magazine or cassette G11B23/046 and G11B23/0875; indicating measured values in general G01D
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/23611 Insertion of stuffing data into a multiplex stream, e.g. to obtain a constant bitrate synchronisation arrangements in time-division multiplex systems using bit stuffing for systems with different or fluctuating information rates H04J3/073
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/4346 involving stuffing data, e.g. packets or bytes synchronisation arrangements in time-division multiplex systems with different or fluctuating information rates H04J3/073
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/84 Generation or processing of descriptive data, e.g. content descriptors systems specially adapted for using meta-information in broadcast systems H04H60/73
• 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 21/8547 involving timestamps for synchronizing content

Abstract

A method, apparatus and article of manufacture is provided for automatic insertion of a compressed GOP offset table within a previously encoded MPEG video file, for frame accurate random access of each individual video frame in play-from-offset mode. The method creates a compressed GOP offset table having an entry for each GOP header of every video packet of the MPEG video file, and modifies the MPEG video file by inserting the compressed GOP offset table before the MPEG video file as at least one padding packet, thereby preserving the MPEG compliance and compressed audio/video data of the MPEG video file. The method further has a step for estimating a number of padding packets needed for the GOP offset table, thereby limiting the MPEG video file reading to a single read.

Claims

1. A method for automatic insertion of a compressed GOP offset table within a previously encoded MPEG video file, for frame accurate random access of each individual video frame by an MPEG player/decoder in play-from-offset mode, comprising the following steps:

(a) creating a compressed GOP offset table having an entry for each GOP header of every video packet of the MPEG video file, for obtaining accurate GOP header SMPTE timecode and address offsets; and

(b) modifying the MPEG video file by inserting the compressed GOP offset table before the MPEG video file as at least one padding packet, while maintaining the MPEG video file'"'"'s original frame presentation,

thereby preserving the MPEG compliance and compressed audio/video data of the MPEG video file.

2. The method according to claim 1, further comprising a step for estimating a number of padding packets needed for the GOP offset table, thereby limiting the MPEG video file reading to a single read.

3. The method according to claim 1, wherein at least one compressed GOP offset table padding packet being preceded by a pack header having a system clock reference (SCR), and further comprising:

a standard PES header, an offset table signature, a starting timecode field, and a starting GOP address field.

4. The method according to claim 3, wherein each said GOP header entry further comprises:

a field for number of frames within a prior GOP, and a field for a GOP address offset having an offset address of the pack header corresponding to the GOP header, for re-synchronizing an MPEG player/decoder clock prior to decoding of the GOP offset table, and for reconstructing the timecode and address offset of each GOP header during decompression and decoding by the MPEG player/decoder, by adding the number of frames and address offset of each GOP header entry to the starting timecode and starting GOP address, respectively, and for allowing random access of each individual video frame in play-from-offset mode.

5. The method according to claim 3, further comprising a step for adjusting the SCR backwards in time, after the GOP offset table insertion, for maintaining proper system timing.

6. A system for automatic insertion of a compressed GOP offset table within a previously encoded MPEG video file, for frame accurate random access of each individual video frame by an MPEG player/decoder in play-from-offset mode, comprising:

a computer coupled to an electronic storage device for storing the MPEG video file;

programming means, performed by the computer, for creating a compressed GOP offset table having an entry for each GOP header of every video packet of the MPEG video file, for obtaining accurate GOP header SMPTE timecode and address offsets; and

programming means, performed by the computer, for modifying the MPEG video file by inserting the compressed GOP offset table before the MPEG video file as at least one padding packet, while maintaining the MPEG video file'"'"'s original frame presentation,

thereby preserving the MPEG compliance and compressed audio/video data of the MPEG video file.

7. The system according to claim 6, further comprising a means for estimating a number of padding packets needed for the GOP offset table, thereby limiting the MPEG video file reading to a single read.

8. The system according to claim 6, wherein at least one compressed GOP offset table padding packet being preceded by a pack header having a system clock reference (SCR), and further comprising:

a standard PES header, an offset table signature, a starting timecode field, and a starting GOP address field.

9. The system according to claim 8, wherein each said GOP header entry further comprises:

a field for number of frames within a prior GOP, and a field for a GOP address offset having an offset address of the pack header corresponding to the GOP header, for re-synchronizing an MPEG player/decoder clock prior to decoding of the GOP offset table, and for reconstructing the timecode and address offset of each GOP header during decompression and decoding by the MPEG player/decoder, by adding the number of frames and address offset of each GOP header entry to the starting timecode and starting GOP address, respectively, and for allowing random access of each individual video frame in play-from-offset mode.

10. The system according to claim 8, further comprising a means for adjusting the SCR backwards in time, after the GOP offset table insertion, for maintaining proper system timing.

11. A program storage device readable by a computer tangibly embodying a program of instructions executable by the computer to perform method steps for automatic insertion of a compressed GOP offset table within a previously encoded MPEG video file, for frame accurate random access of each individual video frame by an MPEG player/decoder in play-from-offset mode, the MPEG video file stored in an electronic storage device coupled to the computer, the method comprising the following steps:

(a) creating a compressed GOP offset table having an entry for each GOP header of every video packet of the MPEG video file, for obtaining accurate GOP header SMPTE timecode and address offsets; and

(b) modifying the MPEG video file by inserting the compressed GOP offset table before the MPEG video file as at least one padding packet, while maintaining the MPEG video file'"'"'s original frame presentation,

thereby preserving the MPEG compliance and compressed audio/video data of the MPEG video file.

12. The method according to claim 11, further comprising a step for estimating a number of padding packets needed for the GOP offset table, thereby limiting the MPEG video file reading to a single read.

13. The method according to claim 11, wherein at least one compressed GOP offset table padding packet being preceded by a pack header having a system clock reference (SCR), and further comprising:

a standard PES header, an offset table signature, a starting timecode field, and a starting GOP address field.

14. The method according to claim 13, wherein each said GOP header entry further comprises:

a field for number of frames within a prior GOP, and a field for a GOP address offset having an offset address of the pack header corresponding to the GOP header, for re-synchronizing an MPEG player/decoder clock prior to decoding of the GOP offset table, and for reconstructing the timecode and address offset of each GOP header during decompression and decoding by the MPEG player/decoder, by adding the number of frames and address offset of each GOP header entry to the starting timecode and starting GOP address, respectively, and for allowing random access of each individual video frame in play-from-offset mode.

15. The method according to claim 13, further comprising a step for adjusting the SCR backwards in time, after the GOP offset table insertion, for maintaining proper system timing.