Method of and apparatus for recording motion picture, which generate encoded data with higher compression efficiency using a motion vector similarity

A motion picture recording method which performs coding processing of an input picture through inter prediction to record a motion picture, the method comprising:

• performing a block-based motion search for the input picture to calculate a motion vector of each block;
• setting up blocks having a similar motion vector as a similar motion area, by comparing the motion vector of a previously coded block with the motion vector of a block to be subjected to coding, the similar motion vector included in each motion vector calculated in the block-based motion search;
• calculating a representative motion vector by use of a motion vector provided by each block included in the similar motion area set up in the similar motion area;
• selecting either the representative motion vector or the motion vector provided by each block, so as to reduce the amount of generated codes regarding the motion vector, as a selected motion vector which is to be used for each block in the similar motion area;
• generating encoded data by use of the selected motion vector and a prediction picture of each block generated using the selected motion vector, for each block in the similar motion area;
• and
• calculating, as a block-based cost calculation, a coding cost for each block when the motion vector calculated in the block-based motion search step is used;
• calculating, as a similar motion area cost calculation, a coding cost for each similar motion area when the representative motion vector is used;
• wherein, based on the result of a comparison of a sum total of coding costs of the plurality of blocks calculated in the block-based cost calculation with the coding cost of the similar motion area calculated in the similar motion area cost calculation, for a plurality of blocks included in the similar motion area, the selecting determines which of the respective motion vector calculated in the representative motion vector calculation and the motion vector provided by each block is to be used, for each block in the similar motion area;
• if the coding cost for the similar motion area is smaller than the sum total of the coding costs of the plurality of blocks, the selecting replaces the motion vector of each block in the similar motion area with the representative motion vector.

A motion picture recording apparatus which codes and records an input, the apparatus comprising:

• an input unit constructed of at least one of at least part of a hardware processor and circuitry, and configured to input the input picture;
• an encoder constructed of at least one of at least part of a hardware processor and circuitry, and configured to input picture inputted from the input unit;
• and
• an accumulation unit constructed of at least one of at least part of a hardware processor and circuitry, and configured to accumulate an image signal coded by the encoder;
• wherein the encoder is further configured to:
• perform a block-based motion search for the input picture, to calculate a motion vector of each block;
• set up blocks having a similar motion vector as a similar motion area, by comparing a motion vector of a previously coded block with a motion vector of a block to be subjected to coding;
• calculate a representative motion vector by use of the motion vector provided by each block included in the similar motion area;
• and
• select, as a selected motion vector, either the representative motion vector or the motion vector provided by each block, so as to reduce the amount of generated codes regarding the motion vector, which is to be used for each block in the similar motion area;
• wherein the selected motion vector and a prediction picture of each block generated using the selected motion vector are outputted, and coding processing is performed using the selected motion vector and the prediction picture, for each block in the similar motion area;
• the perform the block-based motion search calculates a coding cost of each block when a moving vector further calculated is used;
• the calculate the representative motion vector calculates a coding cost of each similar motion area when the representative motion vector is used;
• and
• the selection unit determines whether or not the representative motion vector is to be used based on a result of a comparison of a sum total of the coding cost of each block calculated by the block-based motion search, with the coding cost of the similar motion area, for a plurality of blocks included in the similar motion area.