20. Graphics Data Translation Accelerator (GDTA)
Rev.1.00 Jan. 10, 2008 Page 1026 of 1658
REJ09B0261-0100
No. Operation
Description
(6) Half-pixel
correction
processing
Half-pixel correction processing is performed for the data read in (5).
(For the Y pointer: 16 to the right and 16 downward in 4 pixel units, for a total
of 256 processed)
*
The Recon_down value is used to perform half-pixel correction even/odd
decisions. Decision results are as follows.
(The Recon_right value is similarly used to perform half-pixel correction
even/odd decisions.)
Recon_down
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Y even/odd even odd even odd even odd even
odd even
odd even
odd even
U/V
even/odd
odd even even odd odd even
even even odd odd even
even
odd
Formulae for each correction case at "Input data for one macroblock" in figure
20.6 are as follows.
Correction case 1: right = even, down = even
-> (A + A + 1)/2 = A (digits below the decimal point are discarded (no
change))
Correction case 2: right = even, down = odd
-> (A + C + 1)/2 = A' (digits below the decimal point are discarded)
Correction case 3: right = odd, down = even
-> (A + B + 1)/2 = A' (digits below the decimal point are discarded)
Correction case 4: right = odd, down = odd
-> (A + D + B + C + 2)/4 = A' (digits below the decimal point are discarded)
In bidirectional macroblock processing, the result of computation of the
following formula using past data after half-pixel correction and future data
after half-pixel correction is taken to be the half-pixel correction result, and
computation processing with IDCT data is performed.
(past data after half-pixel corr future data after half-pixel correction
+1)/2 = half-pixel correction result
There are cases in which, due to the settings, input macroblock data is not
within the padding area and the data exceeds the screen height (invalid
image data), but the hardware performs processing without modification.
Содержание SH7781
Страница 4: ...Rev 1 00 Jan 10 2008 Page iv of xxx REJ09B0261 0100 ...
Страница 74: ...2 Programming Model Rev 1 00 Jan 10 2008 Page 44 of 1658 REJ09B0261 0100 ...
Страница 272: ...8 Caches Rev 1 00 Jan 10 2008 Page 242 of 1658 REJ09B0261 0100 ...
Страница 376: ...10 Interrupt Controller INTC Rev 1 00 Jan 10 2008 Page 346 of 1658 REJ09B0261 0100 ...
Страница 694: ...13 PCI Controller PCIC Rev 1 00 Jan 10 2008 Page 664 of 1658 REJ09B0261 0100 ...
Страница 762: ...14 Direct Memory Access Controller DMAC Rev 1 00 Jan 10 2008 Page 732 of 1658 REJ09B0261 0100 ...
Страница 788: ...15 Clock Pulse Generator CPG Rev 1 00 Jan 10 2008 Page 758 of 1658 REJ09B0261 0100 ...
Страница 828: ...17 Power Down Mode Rev 1 00 Jan 10 2008 Page 798 of 1658 REJ09B0261 0100 ...
Страница 846: ...18 Timer Unit TMU Rev 1 00 Jan 10 2008 Page 816 of 1658 REJ09B0261 0100 ...
Страница 1292: ...24 Multimedia Card Interface MMCIF Rev 1 00 Jan 10 2008 Page 1262 of 1658 REJ09B0261 0100 ...
Страница 1326: ...25 Audio Codec Interface HAC Rev 1 00 Jan 10 2008 Page 1296 of 1658 REJ09B0261 0100 ...
Страница 1482: ...28 General Purpose I O Ports GPIO Rev 1 00 Jan 10 2008 Page 1452 of 1658 REJ09B0261 0100 ...
Страница 1538: ...30 User Debugging Interface H UDI Rev 1 00 Jan 10 2008 Page 1508 of 1658 REJ09B0261 0100 ...
Страница 1688: ...Appendix Rev 1 00 Jan 10 2008 Page 1658 of 1658 REJ09B0261 0100 ...
Страница 1691: ......
Страница 1692: ...SH7785 Hardware Manual ...