| 摘要 |
A programmable data processing apparatus having a bit-plane extraction operation is described, for extracting data from a value of, for example, 32 bits containing 4 bytes, 1a to 1d. Each byte 1a to 1d comprises 8 bits, (a0 - a7, b0 - b7, c0 - c7 and d0 - d7 , respectively). The bit-plane extraction operation retrieves one bit from each of these bytes, for example the second bit (a1, b1, c1, d1), which is specified by an argument. The operation involves concatenating these bits (a1, b1, c1, d1) and returning a result value 5. Depending on the particular data processing application, the result value may be bit-reversed to provide a result value 7 (for example, if a bit-reversal is required to deal with endianness, or other reasons). The bit-plane extraction operation can be used as a pre-processing operation in data processing operations such as "sum-of-absolute-differences" in the processing of video data. |
