Decoding and presentation time stamps for MPEG-4 advanced video coding

• US 7,787,539 B2
• Filed: 01/09/2003
• Issued: 08/31/2010
• Est. Priority Date: 07/17/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Chen, Sherman (Xuemin)
• Primary Examiner(s): Dastouri; Mehrdad
• Assistant Examiner(s): Huber; Jeremaiah C
• Application Number:
  US10/340,061
• Publication Number:
  US 20040012510A1
• Time in Patent Office: 2,791 Days
• Field of Search: 375/240.12, 375/340.15, 375/240.15
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/68 involving the insertion of resynchronisation markers into the bitstream
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• 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 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/4344 Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/8451 using Advanced Video Coding [AVC]
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content

Abstract

A system, method, and apparatus for time stamping compressed video data is disclosed. A delay parameter is generated and can be encoded with the compressed video, representing the number of picture delay between the decoded sequence and the presented sequence. The presentation time stamp is associated with each of the pictures. The presentation time stamp is a function of the delay parameter and other parameters associated with picture associated therewith.

Claims

1. A method for time stamping a plurality of frames, wherein the plurality of frames comprises a first anchor frame and a second anchor frame, said method comprising:

encoding said plurality of frames, wherein one of the encoded frames is predicted from another one of the encoded frames with a circuit; and

encoding a delay parameter in a sequence header of an MPEG-4 AVC multilayered bitstream, said multilayered bitstream comprising the sequence header and a sequence payload, said sequence payload comprising a Group of Pictures Header and a plurality of Groups of Pictures, wherein each Group of Pictures further comprise a plurality of pictures and picture headers, wherein the delay parameter is a variable re-ordering buffer delay;

encoding a presentation time stamp with each of said plurality of encoded frames, wherein the presentation time stamp is a function of the delay parameter, a decode time stamp, and the number of frames between the first anchor frame and the second anchor frame; and

transmitting the MPEG-4 AVC multilayered bitstream over a communication medium.

2. The method of claim 1, wherein encoding a delay parameter further comprises:

encoding the delay parameter with a variable length code.

3. The method of claim 1, further comprising:

encoding the decoding time stamp with each of said plurality of frames.

4. The method of claim 1, wherein encoding the presentation time stamp further comprises:

encoding the presentation time stamp with each of said plurality of frames, wherein the presentation time stamp is also a function of the type of frame encoding with the presentation time stamp.

5. The method of claim 1, wherein the decode time stamp is calculated prior to the presentation time stamp, and wherein the presentation time stamp is calculated from the decode time stamp by adding a product of the frame period and the number of frames between the first encoded anchor frame and the second anchor frame plus one to the decode time stamp.

6. The method of claim 1, wherein each frame comprises two fields and wherein the decode time stamp is calculated prior to the presentation time stamp, and wherein the presentation time stamp is calculated from the decode time stamp by adding a product of the field period and the number of fields between the first encoded anchor frame and the second encoded anchor frame plus one to the decode time stamp.

7. An encoder for time stamping a plurality of frames, said plurality of frames comprising a first encoded anchor frame and a second encoded anchor frame, said encoder comprising:

a video compression engine for encoding said plurality of frames, wherein one of the encoded frames is predicted from another one of the encoded frames; and

a header generation unit for encoding a delay parameter in a sequence header of a multilayered bitstream, said multilayered bitstream comprising the sequence header and a sequence payload, said sequence payload comprising a Group of Pictures Header and a plurality of Groups of Pictures, wherein each Group of Pictures further comprise a plurality of pictures and picture headers, wherein the delay parameter is a variable re-ordering buffer delay;

a program multiplexer for encoding a presentation time stamp with each of the plurality of pictures, wherein the presentation time stamp is a function of the delay parameter, a decode time stamp and a number of frames between the first encoded anchor frame and the second encoded anchor frame, and packetizing the multilayered bitstream into payloads of a plurality of transport packets.

8. The encoder of claim 7, wherein the header generation unit encodes the delay parameter with a variable length code.

9. The encoder of claim 7, further comprising:

a program multiplexer for encoding a decoding time stamp with each of said plurality of encoded frames.

10. The encoder of claim 7, wherein the presentation time stamp is a function of the type of frame encoded with the presentation time stamp.