EFFICIENT CODING AND DECODING CONVERSION UNITS Russian patent published in 2011 - IPC H03M7/46 H03M7/40 H04N7/12 

FIELD: information technology.

SUBSTANCE: codec encodes conversion coefficients through composite coding of nonzero coefficients with subsequent series of coefficients with zero values (dwg. 14). When nonzero coefficients are last in their unit, the last indicator is replaced for the value of the series in the symbol of that coefficient (1435). Initial nonzero coefficients are indicated in a special symbol which jointly codes the nonzero coefficient together with initial and subsequent series of zeroes (1440). The codec enables several coding contexts by detecting interruptions in the series of nonzero coefficients and coding nonzero coefficients on any side of that interruption separately (1460). The codec also reduces the size of the code table by indicating in each symbol whether a nonzero coefficient has an absolute value greater than 1, and whether the series of zeroes have positive values (1475), and separately codes the level of coefficients and the length of the series outside the symbols (1490).

EFFECT: high efficiency of compressing conversion coefficients and rate of coding and decoding.

25 cl, 28 dwg