Method and apparatus for transitions and other special effects in digital motion video

• US 5,959,690 A
• Filed: 02/19/1997
• Issued: 09/28/1999
• Est. Priority Date: 02/20/1996
• Status: Expired due to Fees

• Current Assignee: Research Triangle Institute
• Original Assignee: SAS Institute Incorporated
• Inventors: Walker, Douglas J., Toebes, VIII, John A.
• Primary Examiner(s): LEE, RICHARD J
• Application Number:
  US08/801,254
• Time in Patent Office: 951 Days
• Field of Search: 348/12, 348/13, 348/402, 348/407, 348/409-413, 348/416, 348/578, 348/584, 348/588, 348/589, 348/699, 348/714, 348/715, 348/718, 364/725.03, 386/109-112, 434/118
• US Class Current: 348/578
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• CPC Class Codes: G11B 27/329 on a disc [VTOC]
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 5/262 Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

A method and apparatus for transition effects in digitally compressed motion video, such video complying with the MPEG-1 standard. Transitions between two frames of video are effectuated by selecting a FROM frame and a TO frame, generating a stream of bidirectionally dependent duplicator frames which vary in their motion vector references to the FROM frame and the TO frame according to a predefined pattern, placing the FROM frame in the past buffer of a decoder, placing the TO frame in the future frame of a decoder, feeding the stream of duplicator frames to the decoder, causing the duplicator frames to be displayed, and beginning normal playback of the video stream containing the TO frame at the TO frame position.

Claims

1. A computer-implemented method of generating transition effects between two frames of digitally compressed video by manipulating the output of a digital video decoder which said decoder comprises a past buffer and a future buffer, said method comprising the steps of:

a. selecting a FROM frame in a video stream and a TO frame in a video stream;

b. placing the FROM frame in the past buffer of said decoder;

c. placing the TO frame in the future buffer of said decoder;

d. generating a stream of bidirectionally dependent duplicator frames having motion vector references to a past reference frame and a future reference frame wherein the constituent frames of said stream of bidirectionally dependent duplicator frames vary in their motion vector references to said FROM frame and said TO frame according to a predefined pattern;

e. feeding said stream of bidirectionally dependent duplicator frames to said decoder, causing said duplicator frames to be displayed; and

f. beginning normal playback of the video stream containing the TO frame at the TO frame position.

2. A computer-based system for generating transition effects between two frames of digitally compressed video by manipulating the output of a digital video decoder which decoder comprises a past buffer and a future buffer, comprising:

a. means for selecting a FROM frame in a video stream and a TO frame in a video stream;

b. means for placing the FROM frame in the past buffer of said decoder;

c. means for placing the TO frame in the future buffer of said decoder;

d. means for generating a stream of bidirectionally dependent duplicator frames having motion vector references to a past reference frame and a future reference frame constituent wherein the frames of said stream of bidirectionally dependent duplicator frames vary in their motion vector references to said FROM frame and said TO frame according to a predefined pattern;

e. means for feeding said stream of directionally dependent duplicator frames to said decoder, causing said duplicator frames to be displayed; and

f. means for beginning normal playback of the video stream containing the TO frame at the TO frame position.

3. A system according to claim 2 wherein said selecting means comprises identification of permitted FROM and TO frames during an edit process.

4. A system according to claim 2 wherein said generating means comprises creation of said stream of bidirectionally dependent duplicator frame during an edit process.

5. A system according to claim 2 wherein said generating means comprises creation of said stream of bidirectionally dependent duplicator frames on-the-fly during playback.

6. A system according to claim 2 wherein the transition effects are used to mask the time required to prepare said decoder to play back the video stream containing the TO frame at the TO frame position.

7. A system according to claim 2 wherein said generating means, said TO frame placing means, said FROM frame placing means, said feeding means and said means for beginning normal playback comprise use of a streamer means wherein said decoder is fed a digital video stream from a streamer buffer in which various video frames from various sources are sent to said streamer buffer where they are combined into a virtual video stream.

8. A system for generating transition effects between a FROM frame in a stream of digitally compressed video and a TO frame in a stream of digitally compressed video by manipulating the output of a digital video decoder which said decoder comprises a past buffer and a future buffer, comprising:

a. a computer;

b. said computer being programmed to;

i. place the FROM frame in the past buffer of said decoder,

ii. place the TO frame in the future buffer of said decoder,

iii. generate a stream of bidirectionally dependent duplicator frames wherein the constituent frames of said stream of bidirectionally dependent duplicator frames vary in their motion vector references to said past buffer and said future buffer according to a predefined pattern,

iv. feed said stream of duplicator frames bidirectionally dependent to said decoder, causing said duplicator frames to be displayed, and

v. begin normal playback of the video stream containing the TO frame at the TO frame position.

9. A computer-readable medium for causing a computer to generate transition effects between a FROM frame in a stream of digitally compressed video and a TO frame in a stream of digitally compressed video by manipulating the output of a digital video decoder which said decoder comprises a past buffer and a future buffer, comprising:

a. a computer-readable storage medium; and

b. a computer program stored on said storage medium;

c. said computer program comprising;

i. means for placing the FROM frame in the past buffer of said decoder;

ii. means for placing the TO frame in the future buffer of said decoder;

iii. means for generating a stream of bidirectionally dependent duplicator frames wherein the constituent frames of said stream of bidirectionally dependent duplicator frames vary in their motion vector references to said past buffer and said future buffer according to a predefined pattern;

iv. means for feeding said stream of bidirectionally dependent duplicator frames to said decoder, causing said duplicator frames to be displayed; and

v. means for beginning normal playback of the video stream containing the TO frame at the TO frame position.

10. A computer-readable medium according to claim 9 wherein:

a. the FROM frame is a non-reference frame; and

b. said means for placing the FROM frame in the past buffer of said decoder comprises means for copying the decoded data of the FROM frame directly into the past buffer of the decoder.

11. A computer-readable medium according to claim 9 wherein:

a. the TO frame is a non-reference frame; and

b. said means for placing the TO frame in the future buffer of the decoder comprises means for copying the decoded data of the TO frame directly into the future buffer of the decoder.

12. A computer-readable medium according to claim 9 wherein said transition effects are generated in response to user input or program signal.

13. A computer-readable medium according to claim 9 wherein said means for placing said TO frame in said future buffer comprises:

a. means for storing at least one possible TO frame in at least one TO frame buffer; and

b. means for sending the appropriate TO frame to said decoder after said decoder receives said FROM frame.

14. A computer-readable medium according to claim 9 further comprising upgrading means whereby said FROM frame and said TO frame if originally encoded as reference frames are upgraded to reference frames.

15. A computer-readable medium according to claim 14 wherein said TO frame is upgraded to a reference frame with no dependencies on other frames.

16. A computer-readable medium according to claim 14 wherein said FROM frame and said TO frame are upgraded by reencoding the video streams where an encoder is instructed to encode said FROM frame and said TO frame as the required frame type.