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libavcodec/binkidct.c

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00001 /*
00002  * Bink IDCT algorithm
00003  * Copyright (c) 2009 Kostya Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "dsputil.h"
00028 
00029 #define A1  2896 /* (1/sqrt(2))<<12 */
00030 #define A2  2217
00031 #define A3  3784
00032 #define A4 -5352
00033 
00034 #define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\
00035     const int a0 = (src)[s0] + (src)[s4]; \
00036     const int a1 = (src)[s0] - (src)[s4]; \
00037     const int a2 = (src)[s2] + (src)[s6]; \
00038     const int a3 = (A1*((src)[s2] - (src)[s6])) >> 11; \
00039     const int a4 = (src)[s5] + (src)[s3]; \
00040     const int a5 = (src)[s5] - (src)[s3]; \
00041     const int a6 = (src)[s1] + (src)[s7]; \
00042     const int a7 = (src)[s1] - (src)[s7]; \
00043     const int b0 = a4 + a6; \
00044     const int b1 = (A3*(a5 + a7)) >> 11; \
00045     const int b2 = ((A4*a5) >> 11) - b0 + b1; \
00046     const int b3 = (A1*(a6 - a4) >> 11) - b2; \
00047     const int b4 = ((A2*a7) >> 11) + b3 - b1; \
00048     (dest)[d0] = munge(a0+a2   +b0); \
00049     (dest)[d1] = munge(a1+a3-a2+b2); \
00050     (dest)[d2] = munge(a1-a3+a2+b3); \
00051     (dest)[d3] = munge(a0-a2   -b4); \
00052     (dest)[d4] = munge(a0-a2   +b4); \
00053     (dest)[d5] = munge(a1-a3+a2-b3); \
00054     (dest)[d6] = munge(a1+a3-a2-b2); \
00055     (dest)[d7] = munge(a0+a2   -b0); \
00056 }
00057 /* end IDCT_TRANSFORM macro */
00058 
00059 #define MUNGE_NONE(x) (x)
00060 #define IDCT_COL(dest,src) IDCT_TRANSFORM(dest,0,8,16,24,32,40,48,56,0,8,16,24,32,40,48,56,MUNGE_NONE,src)
00061 
00062 #define MUNGE_ROW(x) (((x) + 0x7F)>>8)
00063 #define IDCT_ROW(dest,src) IDCT_TRANSFORM(dest,0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,MUNGE_ROW,src)
00064 
00065 static inline void bink_idct_col(DCTELEM *dest, const DCTELEM *src)
00066 {
00067     if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) {
00068         dest[0]  =
00069         dest[8]  =
00070         dest[16] =
00071         dest[24] =
00072         dest[32] =
00073         dest[40] =
00074         dest[48] =
00075         dest[56] = src[0];
00076     } else {
00077         IDCT_COL(dest, src);
00078     }
00079 }
00080 
00081 void ff_bink_idct_c(DCTELEM *block)
00082 {
00083     int i;
00084     DCTELEM temp[64];
00085 
00086     for (i = 0; i < 8; i++)
00087         bink_idct_col(&temp[i], &block[i]);
00088     for (i = 0; i < 8; i++) {
00089         IDCT_ROW( (&block[8*i]), (&temp[8*i]) );
00090     }
00091 }
00092 
00093 void ff_bink_idct_add_c(uint8_t *dest, int linesize, DCTELEM *block)
00094 {
00095     int i, j;
00096 
00097     ff_bink_idct_c(block);
00098     for (i = 0; i < 8; i++, dest += linesize, block += 8)
00099         for (j = 0; j < 8; j++)
00100              dest[j] += block[j];
00101 }
00102 
00103 void ff_bink_idct_put_c(uint8_t *dest, int linesize, DCTELEM *block)
00104 {
00105     int i;
00106     DCTELEM temp[64];
00107     for (i = 0; i < 8; i++)
00108         bink_idct_col(&temp[i], &block[i]);
00109     for (i = 0; i < 8; i++) {
00110         IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) );
00111     }
00112 }

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