Variable picture rate coding/decoding method and apparatus
View Patent ↗First pictures are coded by a variable picture rate coding, the first pictures being set at a predetermined interval, to be used as reference pictures for inter-picture prediction of an incoming moving picture and second pictures different from the first pictures are coded. The first pictures are coded by intra-picture coding or unidirectional inter-picture predictive coding, thus obtaining a first bitstream. A coding picture rate is set in accordance with motion activity of the incoming moving picture. Pictures that have remained after decimation of the second pictures are coded in accordance with the picture rate by bidirectional inter-picture predictive coding using the first pictures or locally-decoded pictures of the first pictures as the reference pictures, thus obtaining a second bitstream. The first and the second bitstreams and data indicating the picture rate are multiplexed.
1. A moving-picture scanning-type conversion apparatus comprising:
a scanning-type setter to set a scanning type for each frame of an interlaced moving picture incoming at a given frame rate, in accordance with motion activity of the incoming moving picture, wherein the scanning rate is set to interlaced scanning when an average value of the motion activity for each frame is equal to or larger than a predetermined value whereas the scanning type is set to progressive scanning when the average value is smaller than the predetermined value;
a converter to convert the incoming interlaced moving picture into a progressive moving picture at a frame rate that is equal to the given frame rate; and
a switch to switch the incoming interlaced moving picture and the progressive moving picture for each frame in accordance with the set scanning type.
2. A moving-picture scanning-type conversion method comprising the steps of:
setting a scanning type for each frame of an interlaced moving picture incoming at a given frame rate, in accordance with motion activity of the incoming moving picture, wherein the scanning type is set to interlaced scanning when an average value of the motion activity for each frame is equal to or larger than a predetermined value whereas the scanning type is set to progressive scanning when the average value is smaller than the predetermined value;
converting the incoming interlaced moving picture into a progressive moving picture at a frame rate that is equal to the given frame rate; and
switching the incoming interlaced moving picture and the progressive moving picture for each frame in accordance with the set scanning type.