Television – Bandwidth reduction system – Data rate reduction
Patent
1996-07-08
1997-12-09
Britton, Howard W.
Television
Bandwidth reduction system
Data rate reduction
348314, 386111, H04N 5915
Patent
active
056965575
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a video signal editing apparatus which connects a plurality of coded video signals, compressed and coded by inter-frame compression and coding, and edits the same.
BACKGROUND ART
Video signal compression and coding apparatuses are being developed which take note of the correlation of the video data among a plurality of frames contained in a video signal and use the video compression technology of, for example, the MPEG (Motion Picture Expert Group) method to perform inter-frame compression and coding of the video signal so as to establish correlation among the plurality of frames and thereby generate a coded video signal. The coded video signal obtained by compression and coding by such a video signal compression and coding apparatus is divided into groups of a plurality of frames serving as the units at the time of decoding. Editing is sometimes performed by connecting (combining) a plurality of coded video signals subjected to inter-frame predictive coding (inter-frame compression and coding) in this way. When expanding and decoding coded video signals edited in this way; the image is sometimes disturbed at the points where the coded video signals were connected (edited) depending upon the nature of the coded signals.
Below, such a disturbance of video signals will be explained taking as an example a case of decoding two coded video signals a and b wherein bi-directional frames (B-frames) requiring video data of the two adjoining frames and intra-frames (I-frames) which are complete by the video data of those frames themselves and do not require the video data of other frames when decoding the video data of those frames are arranged in that order and two frames of a B-frame and an I-frame comprise a group.
Where connecting two coded video signals a and b by an alternate arrangement of B-frames and I-frames, first it is necessary to divide the coded video signals a and b at the connection timing and connect the two signals from there. When the timing of connection of the two signals corresponds to the B-frames of both or either of the coded video signals a and b, if the coded video signals a and b are simply connected, at the time of decoding, it is necessary to decode the video data of the B-frame existing at the editing position by using the video data of another frame. Explaining this in more detail, when there is a B-frame at the editing position of the coded video signal a, the video data of the B-frame of the coded video signal a is decoded by using the video data of the I-frame or B-frame of the coded video signal b. The coded video signals a and b generally do not have any inter-relationship, so the video data at the editing position cannot be normally decoded and therefore a disturbance occurs in the obtained image.
DISCLOSURE OF THE INVENTION
The present invention was made in consideration of the problems of the related art and has as an object thereof to provide a video signal editing apparatus with which no disturbance is generated in the image either when connecting and editing video signals coded by inter-frame coding or when decoding video signals obtained as a result of editing to reproduce an image.
According to the present invention, there is provided a video signal editing apparatus for connecting a plurality of coded video signals, wherein each of the coded video signals is divided into groups each comprised by a plurality of frames containing at least one intra-frame; the intra-frames are coded so that original video data can be decoded from only the video data contained in those frames; the video data of the frames other than the intra-frames of the groups require the video data of other frames when decoded to the original video data; and provision is made of a signal processing means for dividing each of the plurality of coded video signals at a timing of connection of the coded video signals so that the boundaries of the groups become ends of the coded video signals and a video signal superimposing means for superimposing the
REFERENCES:
patent: 4931879 (1990-06-01), Koga et al.
patent: 5168356 (1992-12-01), Acampora et al.
patent: 5191436 (1993-03-01), Yonemitsu
patent: 5367341 (1994-11-01), Schnorf
patent: 5543847 (1996-08-01), Kato
patent: 5631742 (1997-05-01), Shimoda
Eto Toru
Kamiyama Kazuo
Yamashita Yoshiharu
Britton Howard W.
Frommer William S.
Sinderbrand Alvin
Snow Frank
Sony Corporation
LandOfFree
Video signal editing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Video signal editing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Video signal editing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1611495