High-efficiency encoder and video information recording/reproducing apparatus

• US 20030133501A1
• Filed: 11/04/2002
• Published: 07/17/2003
• Est. Priority Date: 01/29/1992
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Asamura, Yoshinori, Itow, Takashi, Mishima, Hidetoshi, Onishi, Ken, Ueda, Tomohiro
• Granted Patent: US 7,376,184 B2
• Time in Patent Office: Days
• US Class Current: 375/240.13
• CPC Class Codes: G11B 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/91 Helical scan format, wherein tracks are slightly tilted with respect to tape direction, e.g. VHS, DAT, DVC, AIT or exabyte
• CPC Class Codes: G11B 27/005 Reproducing at a different information rate from the information rate of recording for television signals H04N5/783
• CPC Class Codes: G11B 27/032 on tapes G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/036 Insert-editing
• 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: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• 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 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/142 Detection of scene cut or scene change
• 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 19/179 the unit being a scene or a shot
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/46 : Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/503 : involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/577 : Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/61 : in combination with predictive coding
• CPC Class Codes: H04N 19/87 : involving scene cut or scene change detection in combination with video compression
• CPC Class Codes: H04N 5/78263 : for recording on tracks inclined relative to the direction of movement of the tape
• CPC Class Codes: H04N 5/78266 : using more than one track for the recording of one television field or frame, i.e. segmented recording
• CPC Class Codes: H04N 5/9262 : using predictive coding
• CPC Class Codes: H04N 5/9264 : using transform coding
• CPC Class Codes: H04N 5/928 : the sound signal being pulse code modulated and recorded in time division multiplex with the modulated video signal
• CPC Class Codes: H04N 7/012 : Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04N 9/8063 : using time division multiplex of the PCM audio and PCM video signals
• CPC Class Codes: H04N 9/83 : the recorded chrominance signal occupying a frequency band under the frequency band of the recorded brightness signal
• CPC Class Codes: H04N 9/8355 : the sound carriers being frequency multiplexed between the luminance carrier and the chrominance carrier

Abstract

In a high-efficiency encoder which performs motion-compensation prediction, an intra-field is set every n fields. The presence of a scene change is detected. When a scene change occurs, a reference picture of motion-compensation prediction is switched, or the field immediately after the scene change is set as an intra-field.

Claims

1. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them; and

prediction means for creating an intra-field or an intra-frame in which motion-compensation prediction is not performed, for every n fields or frames (n is an arbitrary integer not less than

     2), and for performing motion-compensation prediction with an intra-field or an intra-frame on each block for the succeeding (n−

1) fields or (n−

1) frames.

2. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

prediction means for creating an intra-field or an intra-frame in which motion-compensation prediction is not performed, for every n fields or frames (n is an arbitrary integer not less than

     2), and for performing motion-compensation prediction with an intra-field or an intra-frame on each block for the succeeding (n−

1) fields or (n−

1) frames;

means for comparing a first information amount of each block with a second information amount of each block, the first information amount being obtained in a case that motion-compensation prediction is performed, the second information amount being obtained in a case that motion-compensation prediction is not performed; and

selection means for, when said second information amount of the block is smaller than said first information amount of the block, selecting a forced intra mode as a coding mode of the block.

3. A high-efficiency encoder comprising:

encoding means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

prediction means for creating an intra-field or an intra-frame in which motion-compensation prediction is not performed, for every n fields or frames (n is an arbitrary integer not less than

     2), and for performing motion-compensation prediction with an intra-field or an intra-frame on each block for the succeeding (n−

1) fields or (n−

1) frames; and

means for comparing a first information amount of each block with a second information amount of each block, the first information amount being obtained in a case that motion-compensation prediction is performed, the second information amount being obtained in a case that motion-compensation prediction is not performed,

wherein, for a field or frame where the number of blocks in which the second information amount of the block is smaller than first information amount of the block is greater, said prediction means does not perform motion-compensation prediction, and said encoding means performs encoding as a forced intra-field or a forced intra-frame.

4. A high-efficiency encoder comprising:

encoding means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

prediction means for creating an intra-field or an intra-frame in which motion-compensation prediction is not performed, for every n fields or frames (n is an arbitrary integer not less than

     2), and for performing motion-compensation prediction with an intra-field or an intra-frame on each block for the succeeding (n−

1) fields or (n−

1) frames; and

means for comparing a first information amount of each block with a second information amount of each block, the first information amount being obtained in a case that motion-compensation prediction is performed, the second information amount being obtained in a case that motion-compensation prediction is not performed,

wherein, for a field or frame where the number of blocks in which the second information amount of the block is smaller than the first information amount of the block are greater, said prediction means does not perform motion-compensation prediction, and said encoding means performs encoding as a forced intra-field or a forced intra-frame, and, for at least (n−

1) fields or (n−

1) frames following said forced intra mode, said prediction means performs again motion-compensation prediction with a forced intra-field or a forced intra-frame.

5. A high-efficiency encoder comprising:

encoding means for segmenting a digitized video signal into blocks of a predetermined size, and for coding them;

prediction means for performing motion-compensation prediction on each block;

detection means for detecting the occurrence of a scene change in a motion-compensation prediction processing step; and

means for, when a scene change occurs, switching a field or frame in the direction along which the created code amount is reduced, the field or frame being set as a reference picture of motion-compensation prediction.

6. A high-efficiency encoder according to claim 5, wherein said detection means detects the occurrence of a scene change, using the number of blocks of a prediction mode or intra mode selected in a field or frame.

7. A high-efficiency encoder according to claim 5, wherein said detection means detects the occurrence of a scene change, using a ratio of the number of blocks, among a predetermined number of blocks, which have been processed in a prediction mode or in an intra mode, to the predetermined number.

8. A high-efficiency encoder comprising:

encoding means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

means for switching between a prediction mode in which motion-compensation prediction is performed on each block and an intra mode in which motion-compensation prediction is not performed; and

means for, when a scene change occurs in a motion-compensation prediction processing step, detecting the scene change according to a signal which is generated from the prediction mode and the intra mode, and for switching a field or frame in the direction along which the created code amount is reduced, the field or frame being set as a reference picture of motion-compensation prediction.

9. A high-efficiency encoder according to claim 8, wherein the occurrence of a scene change is detected, using the number of blocks of a prediction mode or intra mode selected in a field or frame.

10. A high-efficiency encoder according to claim 8, wherein the occurrence of a scene change is detected, using a ratio of the number of blocks, among a predetermined number of blocks, which have been processed in a prediction mode or in an intra mode, to the predetermined number.

11. A high-efficiency encoder comprising:

encoding means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

prediction means for performing motion-compensation prediction on each block;

detection means for detecting the occurrence of a scene change in a motion-compensation prediction processing step; and

means for switching a reference picture in such a manner that the field or frame immediately after the detected scene change is surely set as a reference picture of motion-compensation prediction.

12. A high-efficiency encoder according to claim 11, wherein said detection means detects the occurrence of a scene change, using the number of blocks of a prediction mode or intra mode selected in a field or frame.

13. A high-efficiency encoder according to claim 11, wherein said detection means detects the occurrence of a scene change, using a ratio of the number of blocks, among a predetermined number of blocks, which have been processed in a prediction mode or in an intra mode, to the predetermined number.

14. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

prediction means for performing motion-compensation prediction on each block;

detection means for detecting the occurrence of a scene change in a motion-compensation prediction processing step; and

means for switching a reference picture in such a manner that a field or frame before the detected scene change is not surely used as a reference picture of motion-compensation prediction.

15. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

means for setting n fields or frames (n is an arbitrary integer not less than

     2) as one process unit, and for performing a motion-compensation prediction process in such a manner that an intra-field or intra-frame of one field is in the process unit; and

detection means for detecting the occurrence of a scene change in the motion-compensation prediction process unit,

wherein a field or frame in which a scene change is detected is set as an intra-field or intra-frame, and a plurality of intra-fields or intra-frames are in the motion-compensation prediction process unit.

16. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for encoding them;

means for setting n fields or frames (n is an arbitrary integer not less than

     2) as one process unit, and for performing a motion-compensation prediction process in such a manner that an intra-field or intra-frame of one field is in the process unit; and

detection means for detecting the occurrence of a scene change in the motion-compensation prediction process unit,

wherein a field or frame in which a scene change is detected is set as an intra-field or intra-frame, and as the first field or frame of a new motion-compensation prediction process unit.

17. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for coding them;

means for setting n fields or frames (n is an arbitrary integer not less than

     2) as one process unit, and for performing a motion-compensation prediction process in such a manner that an intra-field or intra-frame of one field is in the process unit; and

detection means for detecting the occurrence of a scene change in the motion-compensation prediction process unit,

wherein a series of fields or frames from a field or frame in which a scene change is detected to the last field or frame of the motion-compensation prediction process unit are combined with the next motion-compensation prediction process unit, the motion-compensation prediction process unit is longer than n fields or frames of a usual motion-compensation prediction process unit, and motion-compensation prediction is performed while an intra-field or intra-frame belonging to the next motion-compensation prediction process unit is set as a reference picture.

18. A high-efficiency encoder comprising:

means for segmenting a digitized video signal into blocks of a predetermined size, and for coding them;

means for setting n fields or frames (n is an arbitrary integer not less than

     2) as one process unit, and for performing a motion-compensation prediction process in such a manner that an intra-field or intra-frame of one field is in the process unit; and

detection means for detecting the occurrence of a scene change in the motion-compensation prediction process unit,

wherein motion-compensation prediction is performed while a field or frame in which a scene change is detected is set as an intra-field or intra-frame, and n fields or frames from the field or frame in which a scene change is detected are set for the next motion-compensation prediction process unit.

19. A video information recording/reproducing apparatus for recording video information with helical scanning recording, wherein signals of a plurality of fields or frames are collected in one recording unit and recorded in a predetermined number of tracks.

20. A video information recording/reproducing apparatus according to claim 19, wherein an information amount of one field or frame in the case of collecting signals in one recording unit is not necessarily an integral multiple of an information amount which can be recorded in one track.

21. A video information recording/reproducing apparatus according to claim 20, wherein, in the signals of a plurality of fields or frames to be recorded, an intra-field or intra-frame in which interplane prediction is not used and a prediction-field or prediction frame in which interplane prediction is used are mixedly present.

22. A video information recording/reproducing apparatus for recording video information with helical scanning recording, wherein signals of a plurality of fields or frames are collected in one recording unit, and recorded in one or more tracks which are selected from a predetermined number of tracks in accordance with an information amount to be recorded.

23. A video information recording/reproducing apparatus according to claim 22, wherein an information amount of one field or frame in the case of collecting signals in one recording unit is not necessarily an integral multiple of an information amount which can be recorded in one track.

24. A video information recording/reproducing apparatus according to claim 23, wherein, in the signals of a plurality of fields or frames to be recorded, an intra-field or intra-frame in which interplane prediction is not used and a prediction-field or prediction frame in which interplane prediction is used are mixedly present.