Method and apparatus for producing an information stream having still images

• US 6,324,217 B1
• Filed: 07/08/1998
• Issued: 11/27/2001
• Est. Priority Date: 07/08/1998
• Status: Expired due to Term

• Current Assignee: Cox Communications Incorporated (Cox Enterprises Incorporated)
• Original Assignee: DIVA Systems Corporation
• Inventors: Gordon, Donald F.
• Primary Examiner(s): Rao, Andy
• Application Number:
  US09/111,576
• Time in Patent Office: 1,238 Days
• Field of Search: 348/7, 348/8, 348/9, 348/10, 348/11, 348/13, 348/463, 348/464, 348/465, 348/462, 348/845.1, 348/845.2, 348/845.3, 375/240.12, 375/240.13, 375/240.14, 375/240.15, 375/240.16, 375/240.17, 375/240.26, 375/240.27, 375/240.28
• US Class Current: 375/240.28
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/177 the unit being a group of pictures [GOP]
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/234354 by altering signal-to-noise ratio parameters, e.g. requantization
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/2389 Multiplex stream processing, e.g. multiplex stream encrypting
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams

Abstract

A method and apparatus for processing an image to produce an encoded video information stream comprising a sequence of replicated group of picture (GOP) information structures, each GOP including an intra-coded frame (I-frame) and a plurality of forward predictive coded frames (P-frames), wherein the I-frame of the initial GOP is formed by intra-coding the still image. Optionally, the encoded video information stream is multiplexed with an encoded audio information stream to produce a system stream suitable for use in an MPEG-like information processing system.

Claims

1. A method for processing an image to produce a compressed information stream, said method comprising the steps of:

intra-coding said image to produce an intra-coded information frame (I-frame);

associating said intra-coded information frame with a plurality of forward predicted information frames (P-frames) to form a group of pictures (GOP); and

replicating said GOP to produce said compressed information stream.

2. The method of claim 1, wherein said plurality of forward predicted information frames comprise NULL P-frames.

3. The method of claim 1, wherein said step of replicating is terminated upon the production of a compressed information stream having a predetermined duration.

4. The method of claim 1, wherein said step of replicating further comprises the step of:

synthesizing, for at least an I-frame of each of said replicated GOPs, a time stamp parameter indicative of a temporal offset between said I-frames.

5. The method of claim 2, wherein said plurality of NULL forward predicted information frames (P-frames) are generating by forward prediction encoding said image using substantially zero motion vectors.

6. The method of claim 2, wherein said plurality of NULL P-frames are generating by forward prediction encoding said I-frame using zero motion vectors.

7. The method of claim 1, wherein said GOP comprises a predetermined number of P-frames, said predetermined number being selected to provide a predetermined duration to said GOP.

8. The method of claim 7, wherein said predetermined duration of said GOP approximates a desired presentation duration of said image.

9. The method of claim 1, wherein:

said I-frame is associated with a presentation time stamp having a first value;

each of said P-frames associated with said I-frame are associated with respective temporally sequential presentation time stamps; and

said step of replicating includes the step of updating each of said presentation time stamps such that said output information stream comprises a sequence of I-frames and associated P-frames having respective temporally sequential presentation time stamps.

10. A method for generating an information stream for providing, on a presentation device, a relatively motionless image, said method comprising the steps of:

encoding, using a preferential bit allocation determined with respect to a group of pictures (GOP) bit budget, an image to produce an intra-frame (I-frame) encoded video information frame;

associating said intra-frame encoded video information frame with a plurality of substantially zero motion vector forward predicted (P-frame) information frames; and

replicating at least one of said substantially zero motion vector P-frames to form said information stream.

11. The method of claim 10, wherein said step of replicating comprises the step of replicating said I-frame and a plurality of said P-frames, where said I-frame and said plurality of P-frames form a GOP.

12. The method of claim 10, wherein:

said I-frame is associated with a presentation time stamp having a first value;

each of said P-frames associated with said I-frame are associated with respective temporally sequential presentation time stamps; and

said step of replicating includes the step of updating each of said presentation time stamps such that said output information stream comprises a sequence of I-frames and associated P-frames having respective temporally sequential presentation time stamps.

13. Apparatus for processing an image to produce an MPEG-like information stream, comprising:

a frame encoder, for producing an intra-coded (I-frame) in response to said image, and for producing N number of forward predicted information frames (P-frames) in response to said I-frame, where N is an integer;

a memory, for storing said I-frame and said N number of P-frames; and

a controller, for causing said memory to repetitively output said I-frame and said N number of P-frames as a video elementary stream.

14. The apparatus of claim 13, wherein said I-frame and said N number of P-frames form a group of pictures (GOP) structure.

15. The apparatus of claim 13, wherein said plurality of forward predicted information frames comprise NULL P-frames.

16. The apparatus of claim 13, wherein said controller causes said memory to repetitively output said I-frame and said N number of P-frames until a video elementary stream having a predetermined duration is formed.

17. The apparatus of claim 13, wherein said controller synthesizes, for at least said replicated I-frames, a time stamp parameter indicative of a temporal offset between said I-frames.

18. The apparatus of claim 15, wherein said plurality of NULL forward predicted information frames (P-frames) are generating by forward prediction encoding said image using substantially zero motion vectors.

19. The apparatus of claim 14, wherein said predetermined duration of said GOP approximates a desired presentation duration of said image.

20. The apparatus of claim 13, wherein:

said I-frame is associated with a presentation time stamp having a first value;

each of said P-frames associated with said I-frame are associated with respective temporally sequential presentation time stamps; and

said controller updates each of said presentation time stamps such that said output elementary stream comprises a sequence of I-frames and associated P-frames having respective temporally sequential presentation time stamps.

21. The apparatus of claim 13, further comprising:

a multiplexer, for multiplexing said video elementary stream and an audio elementary stream to produce a program stream.