Video coding/decoding apparatus which transmits different accuracy prediction levels

A video decoding apparatus comprising:

• receiving means for receiving upper-layer coded information and lower-layer coded information which are sent from a video coder and have been prediction-coded with a first accuracy and a second accuracy higher than the first accuracy, respectively;
• first decoding means for obtaining a prediction error signal by decoding the upper-layer coded information and lower-layer coded information;
• second decoding means for obtaining information on prediction by decoding the upper-layer coded information and the lower-layer coded information;
• deciding means for deciding whether or not the prediction error signals decoded at said first and second decoding means and the information on prediction have been decoded correctly;
• and
• picture generating means for reconstructing the video signal on the basis of said information decoded at said second decoding means, when said deciding means has decided that said first decoding means has not decoded the prediction error signal correctly.

A video coding apparatus comprising:

• means for receiving an input video signal;
• dividing means for dividing the input video signal into a plurality of first and a plurality of second regions smaller than the first regions at the respective levels;
• prediction means for predicting each of the plurality of first regions and each of the plurality of second regions at respective prediction levels ranging from a first prediction level at which motion prediction is effected with a first accuracy to a second prediction level at which motion prediction is effected with a second accuracy higher than the first accuracy, for generating prediction signals corresponding to the first and second prediction levels;
• prediction error generating means for generating a prediction error signal on the basis of the prediction signals obtained by said prediction means and the input video signal;
• first coding means for coding the prediction error signal generated by said prediction error generating means to output first coded information;
• second coding means for coding information on the prediction which is carried out at each of said prediction levels by said prediction means to output second coded information;
• and
• code string output means for outputting the first and second coded information in a hierarchical structure, and wherein
• said prediction means obtains motion vectors for the first and second regions from the input video signal and reference video signal and on the basis of the motion vectors and generates a prediction signal corresponding to each of the prediction levels from the first prediction level to the second prediction level, and
• said second coding means generates and codes the vector-quantized motion information corresponding to the motion vector as information on said prediction.

A video decoding apparatus comprising:

• receiving means for receiving upper-layer coded information and lower-layer coded information which are sent from a video coder and have been prediction-coded with a first accuracy and a second accuracy higher than the first accuracy, respectively, the upper-layer coded information and lower-layer coded information containing coded motion information indicating vector-quantized motion vectors and coded prediction error information;
• first decoding means for decoding the coded prediction error information from the upper-layer and lower-layer coded information;
• second decoding means for obtaining the vector-quantized motion vector information by decoding the motion information in said upper-layer coded information and the lower-layer coded information;
• deciding means for deciding whether or not the prediction error signals decoded at said first and second decoding means and the motion vector have been decoded correctly;
• and
• picture generating means for reconstructing the video signal on the basis of the motion vector information decoded at said second decoding means, when said deciding means has decided that said first decoding means has not decoded the prediction error signal correctly.

A video coding apparatus comprising:

• means for receiving a video signal;
• dividing means for dividing the input video signal into a plurality of blocks and further dividing the blocks into a plurality of regions in accordance with contents of pictures of the blocks;
• prediction means having means for obtaining region information indicating each of the division shapes of the regions and motion vectors of the regions, and means for vector-quantizing a combination of the region shape information and the motion vectors of said regions, to generate a prediction signal;
• prediction error generating means for generating a prediction error signal on the basis of the prediction signal and the video signal;
• first coding means for coding the prediction error signal to output first coded information;
• and
• second coding means for coding the vector-quantized motion information to output second coded information.

A video decoding apparatus comprising:

• receiving means for receiving a coded prediction error signal based on a prediction signal and a video signal, the prediction signal being obtained by vector-quantizing a combination of region shape information indicating shapes of division regions divided in accordance with contents of pictures of blocks of the video signal;
• first decoding means for decoding the coded prediction error signal;
• second decoding means for decoding motion information obtained by combining the region shape information indicating the division shape of each region with the region's motion vector for each region of the video signal and vector-quantizing the combination;
• prediction means for generating a prediction signal by performing the motion compensation prediction of the video signal using the motion information decoded by said second decoding means;
• and
• reconstructing means for reconstructing the video signal from said prediction signal and the prediction error signal decoded at said first decoding means.

A video coding apparatus which operates on an input video signal which has been divided by a dividing device into a plurality of first and a plurality of second regions smaller than the first regions, comprising:

• prediction means for predicting each of the plurality of first regions and each of the plurality of second regions smaller than the first regions at respective prediction levels ranging from a first prediction level at which motion prediction is effected with a first accuracy to a second prediction level at which motion prediction is effected with a second accuracy higher than the first accuracy, for generating prediction signals corresponding to the first and second prediction levels, the first and second regions being obtained by dividing an input video signal at the respective levels;
• prediction error generating means for generating a prediction error signal on the basis of the prediction signals obtained by said prediction means and the input video signal;
• first coding means for coding the prediction error signal generated by said prediction error generating means to output first coded information;
• second coding means for coding information on the prediction which is carried out at levels by said prediction levels by said prediction means to output second coded information;
• and
• code string output means for outputting the first and second coded information obtained by said first and second coding means in two groups.