Compression of video and audio signals and expansion of a compressed signal in accordance with an image hf component compression factor

A video and audio signal compressing device for compressing an original video signal and an original audio signal synchronized with each other collectively into a compressed video and audio signal comprising a compressed video signal and a compressed audio signal synchronized with each other, said original video signal comprising original images, wherein said compressing device comprises:

• table keeping means for keeping a compression data table, wherein said compression data table comprises a high frequency component compression factor and a frame rate compression factor;
• video encoding means for encoding input images into presubsampled video codes;
• audio encoding means for encoding said original audio signal into audio codes used as said compressed audio signal;
• high frequency component compressing means for compressing high frequency components of said original images into high frequency component compressed images in compliance with said high frequency compression factor;
• supply means for supplying said high frequency component compressed images to said video encoding means as said input images to produce said presubsampled video codes;
• and
• subsampling means for subsampling said presubsampled video codes in compliance with said frame rate compression factor into subsampled video codes used as said compressed video signal,
• wherein said high frequency component compressing means compresses said original images into high frequency component compressed images based on said high frequency component compression factor to ensure that said original video signal is compressed within a predetermined period of time.

A compressed video and audio signal expanding device for expanding a compressed video and audio signal separately into a video reproduction and an audio reproduction representative of original images of an original video signal and an original audio signal, said compressed video and audio signal being a succession of subsampled frames and indicating a frame rate compression factor and an indicated high frequency component compression factor, each of said subsampled frames comprising a subsampled video code and a subsampled audio code synchronized with each other with high frequency components of said original images compressed in said subsampled video code, said expanding device comprising:

• table keeping means for keeping a compression data table indicative of a plurality of high frequency component compression factors;
• frame interpolating means for interpolating additional frames in said subsampled frames in compliance with said frame rate compression factor to produce presubsampled frames comprising reproduced video codes and reproduced audio codes into which the subsampled video codes and the subsampled audio codes of said subsampled frames are expanded;
• audio decoding means for decoding said reproduced audio codes into said audio reproduction;
• video decoding means for decoding said reproduced video codes into high frequency component excluded images;
• high frequency component recovering means for recovering high frequency components of said high frequency component excluded images to produce reproduced images, wherein said high frequency component recovering means recovers said high frequency components based on one of said plurality of high frequency component compression factors of said compression data table that is selected in accordance with said indicated high frequency component compression factor, wherein said one of said plurality of high frequency component compression factors is selected by said compressed video and audio signal expanding device to ensure that said compressed video signal is expanded within a predetermined time;
• and
• video reproducing means for reproducing from said reproduced images said video reproduction with synchronism kept between said video reproduction and said audio reproduction.