| 摘要 |
<p>The elementary transformation or reverse transformation unit is contained in a coding or decoding device, and is incorporated in a data processing apparatus. The elementary transformation unit comprises an advance (AV2), first and second decimators by two (D1,D2), filters (P1, U1), approximation units (A1, A2), and subtraction and addition operators (OP1, OP2). The input signal includes samples (xi). The first and second output signals include samples (y2i+1, y2i) of odd and even ranking, respectively, each equal to the input sample (x2i) of the same ranking decreased by an approximation to the sum of input samples of even and odd ranking, and multiplied by the first and second filtering coefficients (pk,uk), respectively. The reverse transformation unit comprises two inputs, first and second filters, approximation units, subtraction and addition operators, interpolators by two, a delay, and an addition operator to output reconstructed samples. The elementary analysis and synthesis units with preferred combinations for the filter P1 are 9/7, 13/7 and 17/11 (low-pass/high-pass length) filters. In another embodiment, the transformation unit comprises an additional parallel branch with a third filter, a third approximation unit, and a second subtraction operator. In another embodiment, the reverse transformation unit comprises an additional parallel branch, with a third filter, a third approximation unit, and a third addition operator. The elementary analysis and synthesis units with preferred combinations for two filters are 6/10, 6/14 and 10/18 filters.</p> |
