METHODS AND ARCHITECTURE FOR INDEXING AND EDITING COMPRESSED VIDEO OVER THE WORLD WIDE WEB

• US 20110064136A1
• Filed: 09/02/2010
• Published: 03/17/2011
• Est. Priority Date: 05/16/1997
• Status: Abandoned Application

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Meng, Horace J., Chang, Shih-Fu
• Application Number:
  US12/874,337
• Publication Number:
  US 20110064136A1
• Time in Patent Office: Days
• US Class Current: 375/240.13
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence

Abstract

A system and method is provided for editing and parsing compressed digital information. The compressed digital information may include visual information which is edited and parsed in the compressed domain. In a preferred embodiment, the present invention provides a method for detecting moving objects in a compressed digital bitstream which represents a sequence of fields or frames of video information for one or more captured scenes of video.

Claims

1-18. -18. (canceled)

19. A method for masking a region of a compressed frame of digital video information, comprising the steps of:

a. determining whether said frame to be masked is intra-coded, predictive-coded or bi-directionally predictive-coded;

b. if said frame is intra-coded;

i. extracting DCT coefficients for all blocks within said frame;

ii. examining block_n to determine where in said frame said block is located;

iii. setting said DCT coefficients for said block to zero if said block is outside said mask region;

iv. applying a DCT cropping algorithm to said DCT coefficients if said block is on the boundary of said mask region; and

v. repeating steps (b)(ii)-(b)(iv) for each block in said frame;

c. If said frame is predictive-coded or bi-directionally predictive-coded;

i. examining motion vectors associated with block_n to determine whether they point to blocks outside or on said mask region;

ii. reencoding said block if a motion vector points to blocks outside or on said mask region; and

iii. repeating steps (c)(i)-(c)(ii) for all blocks in said frame.

20. A method for generating a reduced speed sequence of frames of video information from a sequence of frames of compressed video information, comprising the steps of:

a. selecting a frame of compressed video information to be repeated;

b. determining whether said frame to be repeated is intra-coded, predictive-coded or bi-directionally predictive-coded;

c. converting said frame into an intra-coded frame if said frame is a predictive-coded or bi-directionally predictive-coded frame;

d. creating duplicate predictive-coded frames; and

e. arranging said determined frame and said duplicate predictive-coded frames into a sequence of compressed frames of video information.

21. The method of claim 20, wherein said reduced speed sequence of frames generates a frozen frame effect.

22. The method of claim 20, further comprising the step of converting said frame into an intra-coded frame if said frame is a predictive-coded or bi-directionally predictive-coded frame.

24. The system of claim 21, wherein said editing means includes means for dissolving an incoming scene of video information which includes a sequence of fields or frame of compressed video information and an outgoing scene of video information which includes a sequence of fields or frame of compressed video information, said dissolving means comprising:

a. outgoing motion compensation means for applying DCT domain motion compensation to a last frame of said outgoing video scene to obtain DCT coefficients for all blocks of video information which make up said last frame of said outgoing video scene;

b. incoming motion compensation means, for applying DCT domain motion compensation to a first frame of said incoming video scene to obtain the DCT coefficients for all blocks of video information which make up said first frame of said incoming video scene; and

c. dissolve region creating means, coupled to said incoming motion compensation means and to said outgoing motion compensation means, for creating a first frame in a dissolve region from said DCT coefficients of said last outgoing frame and said first incoming frame.

25. The system of claim 21, wherein said editing means includes means for masking a region of a compressed frame of digital video information, said masking means comprising:

a. means for determining whether said frame to be masked is intra-coded, predictive-coded or bi-directionally predictive-coded;

b. means for processing intra-coded frames including;

i. means for receiving DCT coefficients and for extracting DCT coefficients for all blocks within said frame;

ii. means, coupled to said receiving means, for examining blocks of compressed video information in said frame to determine where in said frame said block is located;

iii. means, coupled to said examining means, for setting said DCT coefficients for said block to zero if said block is outside said mask region; and

iv. means, coupled to said setting means, for applying a DCT translation algorithm to said DCT coefficients if said block is on the boundary of said mask region; and

c. means for processing predictive-coded and bi-directionally predictive-coded frames, including;

i. means for receiving and examining motion vectors associated with blocks of video information to determine whether they point to blocks outside or on said mask region; and

ii. means, coupled to said receiving means, for reencoding said block if a motion vector points to blocks outside or on said mask region.

23. A system for editing compressed video information over a distributed network, comprising:

a. a client computer;

b. a network link, coupled to said client computer, for permitting said client computer to search for and locate compressed video information on said distributed network; and

c. means for editing a compressed bitstream of video information over said distributed network.

27. A method for converting a full resolution compressed domain bitstream into a reduced resolution compressed bitstream, comprising the steps of:

a. examining a frame of compressed video information from said full resolution bitstream;

b. determining whether said examined frame is intra-coded, predictive-coded or bi-directionally predictive-coded;

c. extracting DCT DC coefficients for said determined frame if said determined frame is intra-coded

d. applying DCT domain inverse motion compensation to said frame to extract DCT DC coefficients if said frame is predictive-coded or bi-directionally predictive-coded; and

e. converting said extracted DCT DC coefficients into DCT DC coefficients for a reduced size intra-coded frame of video.