| 摘要 |
<p>A two-dimensional inverse discrete cosine transform (IDCT) apparatus which has a storage section for storing inverse-quantized data having a first bit-length and IDCT-transformed data having a second bit-length in allocated storage locations having the second bit-length. An IDCT processing section is provided for receiving the data stored in the storage section in a unit of a pixel, sign-extending the data having the first bit-length to the second bit-length, and then IDCT-transforming sign-extended data to produce the IDCT-transformed data having the second bit-length. An IDCT control section is provided for receiving and storing in the storage section the inverse-quantized data having the first bit-length in a unit of a packet, reading out data stored in the storage section according to a first order, and transferring read-out data to the IDCT processing section for a one-dimensional IDCT in a first direction. The IDCT control section is also provided for rewriting in the storage section first IDCT-transformed data according to a second order, reading out rewritten data, and transferring read-out data to the IDCT processing section in a second direction. The IDCT control section is also for rewriting in the storage section second IDCT-transformed data to complete two-dimensional IDCT, and reading out by a third bit-length from the storage section two-dimensional IDCT-transformed data having the second bit-length.</p> |
