--- idct.c 2003/02/15 15:22:18 1.6 +++ idct.c 2004/03/22 22:36:23 1.7 @@ -1,4 +1,28 @@ -/* idct.c, inverse fast discrete cosine transform */ +/***************************************************************************** + * + * XVID MPEG-4 VIDEO CODEC + * - Inverse DCT - + * + * These routines are from Independent JPEG Group's free JPEG software + * Copyright (C) 1991-1998, Thomas G. Lane (see the file README.IJG) + * + * This program is free software ; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation ; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY ; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program ; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * $Id: idct.c,v 1.7 2004/03/22 22:36:23 edgomez Exp $ + * + ****************************************************************************/ /* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ @@ -33,7 +57,7 @@ * v0.16B22 idct_FAST() renamed to idct_int32() * also merged idct_FAST() into a single function, to help VC++ * optimize it. - * + * * v0.14 changed int to long, to avoid confusion when compiling on x86 * platform ( in VC++ "int" -> 32bits ) */ @@ -52,7 +76,6 @@ /* this code assumes >> to be a two's-complement arithmetic */ /* right shift: (-2)>>1 == -1 , (-3)>>1 == -2 */ -//#include #include "idct.h" #define W1 2841 /* 2048*sqrt(2)*cos(1*pi/16) */ @@ -62,18 +85,11 @@ #define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */ #define W7 565 /* 2048*sqrt(2)*cos(7*pi/16) */ - -/* global declarations */ -//void init_idct_int32 (void); -//void idct_int32 (short *block); - /* private data */ static short iclip[1024]; /* clipping table */ static short *iclp; /* private prototypes */ -//static void idctrow _ANSI_ARGS_((short *blk)); -//static void idctcol _ANSI_ARGS_((short *blk)); /* row (horizontal) IDCT * @@ -85,13 +101,13 @@ * c[1..7] = 128*sqrt(2) */ -/* +#if 0 static void idctrow(blk) short *blk; { int X0, X1, X2, X3, X4, X5, X6, X7, X8; - // shortcut + /* shortcut */ if (!((X1 = blk[4]<<11) | (X2 = blk[6]) | (X3 = blk[2]) | (X4 = blk[1]) | (X5 = blk[7]) | (X6 = blk[5]) | (X7 = blk[3]))) { @@ -99,17 +115,17 @@ return; } - X0 = (blk[0]<<11) + 128; // for proper rounding in the fourth stage + X0 = (blk[0]<<11) + 128; /* for proper rounding in the fourth stage */ - // first stage + /* first stage */ X8 = W7*(X4+X5); X4 = X8 + (W1-W7)*X4; X5 = X8 - (W1+W7)*X5; X8 = W3*(X6+X7); X6 = X8 - (W3-W5)*X6; X7 = X8 - (W3+W5)*X7; - - // second stage + + /* second stage */ X8 = X0 + X1; X0 -= X1; X1 = W6*(X3+X2); @@ -119,16 +135,16 @@ X4 -= X6; X6 = X5 + X7; X5 -= X7; - - // third stage + + /* third stage */ X7 = X8 + X3; X8 -= X3; X3 = X0 + X2; X0 -= X2; X2 = (181*(X4+X5)+128)>>8; X4 = (181*(X4-X5)+128)>>8; - - // fourth stage + + /* fourth stage */ blk[0] = (X7+X1)>>8; blk[1] = (X3+X2)>>8; blk[2] = (X0+X4)>>8; @@ -137,7 +153,8 @@ blk[5] = (X0-X4)>>8; blk[6] = (X3-X2)>>8; blk[7] = (X7-X1)>>8; -}*/ +} +#endif /* column (vertical) IDCT * @@ -148,13 +165,14 @@ * where: c[0] = 1/1024 * c[1..7] = (1/1024)*sqrt(2) */ -/* + +#if 0 static void idctcol(blk) short *blk; { int X0, X1, X2, X3, X4, X5, X6, X7, X8; - // shortcut + /* shortcut */ if (!((X1 = (blk[8*4]<<8)) | (X2 = blk[8*6]) | (X3 = blk[8*2]) | (X4 = blk[8*1]) | (X5 = blk[8*7]) | (X6 = blk[8*5]) | (X7 = blk[8*3]))) { @@ -165,15 +183,15 @@ X0 = (blk[8*0]<<8) + 8192; - // first stage + /* first stage */ X8 = W7*(X4+X5) + 4; X4 = (X8+(W1-W7)*X4)>>3; X5 = (X8-(W1+W7)*X5)>>3; X8 = W3*(X6+X7) + 4; X6 = (X8-(W3-W5)*X6)>>3; X7 = (X8-(W3+W5)*X7)>>3; - - // second stage + + /* second stage */ X8 = X0 + X1; X0 -= X1; X1 = W6*(X3+X2) + 4; @@ -183,16 +201,16 @@ X4 -= X6; X6 = X5 + X7; X5 -= X7; - - // third stage + + /* third stage */ X7 = X8 + X3; X8 -= X3; X3 = X0 + X2; X0 -= X2; X2 = (181*(X4+X5)+128)>>8; X4 = (181*(X4-X5)+128)>>8; - - // fourth stage + + /* fourth stage */ blk[8*0] = iclp[(X7+X1)>>14]; blk[8*1] = iclp[(X3+X2)>>14]; blk[8*2] = iclp[(X0+X4)>>14]; @@ -201,35 +219,40 @@ blk[8*5] = iclp[(X0-X4)>>14]; blk[8*6] = iclp[(X3-X2)>>14]; blk[8*7] = iclp[(X7-X1)>>14]; -}*/ +} +#endif -// function pointer +/* function pointer */ idctFuncPtr idct; /* two dimensional inverse discrete cosine transform */ -//void j_rev_dct(block) -//short *block; void idct_int32(short *const block) { - // idct_int32_init() must be called before the first call to this function! + /* + * idct_int32_init() must be called before the first call to this + * function! + */ - /*int i; - long i; +#if 0 + int i; + long i; + + for (i=0; i<8; i++) + idctrow(block+8*i); - for (i=0; i<8; i++) - idctrow(block+8*i); + for (i=0; i<8; i++) + idctcol(block+i); +#endif - for (i=0; i<8; i++) - idctcol(block+i); */ static short *blk; static long i; static long X0, X1, X2, X3, X4, X5, X6, X7, X8; - for (i = 0; i < 8; i++) // idct rows + for (i = 0; i < 8; i++) /* idct rows */ { blk = block + (i << 3); if (! @@ -241,9 +264,9 @@ continue; } - X0 = (blk[0] << 11) + 128; // for proper rounding in the fourth stage + X0 = (blk[0] << 11) + 128; /* for proper rounding in the fourth stage */ - // first stage + /* first stage */ X8 = W7 * (X4 + X5); X4 = X8 + (W1 - W7) * X4; X5 = X8 - (W1 + W7) * X5; @@ -251,7 +274,7 @@ X6 = X8 - (W3 - W5) * X6; X7 = X8 - (W3 + W5) * X7; - // second stage + /* second stage */ X8 = X0 + X1; X0 -= X1; X1 = W6 * (X3 + X2); @@ -262,7 +285,7 @@ X6 = X5 + X7; X5 -= X7; - // third stage + /* third stage */ X7 = X8 + X3; X8 -= X3; X3 = X0 + X2; @@ -270,7 +293,7 @@ X2 = (181 * (X4 + X5) + 128) >> 8; X4 = (181 * (X4 - X5) + 128) >> 8; - // fourth stage + /* fourth stage */ blk[0] = (short) ((X7 + X1) >> 8); blk[1] = (short) ((X3 + X2) >> 8); @@ -281,14 +304,14 @@ blk[6] = (short) ((X3 - X2) >> 8); blk[7] = (short) ((X7 - X1) >> 8); - } // end for ( i = 0; i < 8; ++i ) IDCT-rows + } /* end for ( i = 0; i < 8; ++i ) IDCT-rows */ - for (i = 0; i < 8; i++) // idct columns + for (i = 0; i < 8; i++) /* idct columns */ { blk = block + i; - // shortcut + /* shortcut */ if (! ((X1 = (blk[8 * 4] << 8)) | (X2 = blk[8 * 6]) | (X3 = blk[8 * @@ -304,7 +327,7 @@ X0 = (blk[8 * 0] << 8) + 8192; - // first stage + /* first stage */ X8 = W7 * (X4 + X5) + 4; X4 = (X8 + (W1 - W7) * X4) >> 3; X5 = (X8 - (W1 + W7) * X5) >> 3; @@ -312,7 +335,7 @@ X6 = (X8 - (W3 - W5) * X6) >> 3; X7 = (X8 - (W3 + W5) * X7) >> 3; - // second stage + /* second stage */ X8 = X0 + X1; X0 -= X1; X1 = W6 * (X3 + X2) + 4; @@ -323,7 +346,7 @@ X6 = X5 + X7; X5 -= X7; - // third stage + /* third stage */ X7 = X8 + X3; X8 -= X3; X3 = X0 + X2; @@ -331,7 +354,7 @@ X2 = (181 * (X4 + X5) + 128) >> 8; X4 = (181 * (X4 - X5) + 128) >> 8; - // fourth stage + /* fourth stage */ blk[8 * 0] = iclp[(X7 + X1) >> 14]; blk[8 * 1] = iclp[(X3 + X2) >> 14]; blk[8 * 2] = iclp[(X0 + X4) >> 14]; @@ -342,11 +365,9 @@ blk[8 * 7] = iclp[(X7 - X1) >> 14]; } -} // end function idct_int32(block) +} /* end function idct_int32(block) */ -//void -//idct_int32_init() void idct_int32_init() {