--- trunk/xvidcore/src/dct/idct.c 2002/03/08 02:46:11 3 +++ trunk/xvidcore/src/dct/idct.c 2002/09/10 20:38:24 461 @@ -1,42 +1,35 @@ -/* idct.c, inverse fast discrete cosine transform */ - -/* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ - -/* - * Disclaimer of Warranty +/***************************************************************************** * - * These software programs are available to the user without any license fee or - * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims - * any and all warranties, whether express, implied, or statuary, including any - * implied warranties or merchantability or of fitness for a particular - * purpose. In no event shall the copyright-holder be liable for any - * incidental, punitive, or consequential damages of any kind whatsoever - * arising from the use of these programs. - * - * This disclaimer of warranty extends to the user of these programs and user's - * customers, employees, agents, transferees, successors, and assigns. - * - * The MPEG Software Simulation Group does not represent or warrant that the - * programs furnished hereunder are free of infringement of any third-party - * patents. - * - * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware, - * are subject to royalty fees to patent holders. Many of these patents are - * general enough such that they are unavoidable regardless of implementation - * design. - * - * MPEG2AVI - * -------- - * v0.16B33 renamed the initialization function to init_idct_int32() - * v0.16B32 removed the unused idct_row() and idct_col() functions - * v0.16B3 changed var declarations to static, to enforce data align - * 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 ) - */ + * XVID MPEG-4 VIDEO CODEC + * - inverse fast disrete cosine transformation - integer C version + * + * 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 an implementation of a part of one or more MPEG-4 + * Video tools as specified in ISO/IEC 14496-2 standard. Those intending + * to use this software module in hardware or software products are + * advised that its use may infringe existing patents or copyrights, and + * any such use would be at such party's own risk. The original + * developer of this software module and his/her company, and subsequent + * editors and their companies, will have no liability for use of this + * software or modifications or derivatives thereof. + * + * 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 + * + *************************************************************************/ /**********************************************************/ /* inverse two dimensional DCT, Chen-Wang algorithm */ @@ -52,15 +45,14 @@ /* 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) */ -#define W2 2676 /* 2048*sqrt(2)*cos(2*pi/16) */ -#define W3 2408 /* 2048*sqrt(2)*cos(3*pi/16) */ -#define W5 1609 /* 2048*sqrt(2)*cos(5*pi/16) */ -#define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */ -#define W7 565 /* 2048*sqrt(2)*cos(7*pi/16) */ +#define W1 2841 /* 2048*sqrt(2)*cos(1*pi/16) */ +#define W2 2676 /* 2048*sqrt(2)*cos(2*pi/16) */ +#define W3 2408 /* 2048*sqrt(2)*cos(3*pi/16) */ +#define W5 1609 /* 2048*sqrt(2)*cos(5*pi/16) */ +#define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */ +#define W7 565 /* 2048*sqrt(2)*cos(7*pi/16) */ /* global declarations */ @@ -68,7 +60,7 @@ //void idct_int32 (short *block); /* private data */ -static short iclip[1024]; /* clipping table */ +static short iclip[1024]; /* clipping table */ static short *iclp; /* private prototypes */ @@ -209,141 +201,150 @@ /* two dimensional inverse discrete cosine transform */ //void j_rev_dct(block) //short *block; -void idct_int32(short * const 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; + /*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);*/ - static short *blk; - static long i; - static long X0, X1, X2, X3, X4, X5, X6, X7, X8; + 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 - { - blk = block+(i<<3); - if (!((X1 = blk[4]<<11) | (X2 = blk[6]) | (X3 = blk[2]) | - (X4 = blk[1]) | (X5 = blk[7]) | (X6 = blk[5]) | (X7 = blk[3]))) + for (i = 0; i < 8; i++) // idct rows { - blk[0]=blk[1]=blk[2]=blk[3]=blk[4]=blk[5]=blk[6]=blk[7]=blk[0]<<3; - continue; - } + blk = block + (i << 3); + if (! + ((X1 = blk[4] << 11) | (X2 = blk[6]) | (X3 = blk[2]) | (X4 = + blk[1]) | + (X5 = blk[7]) | (X6 = blk[5]) | (X7 = blk[3]))) { + blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = + blk[7] = blk[0] << 3; + continue; + } + + X0 = (blk[0] << 11) + 128; // for proper rounding in the fourth 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 + X8 = X0 + X1; + X0 -= X1; + X1 = W6 * (X3 + X2); + X2 = X1 - (W2 + W6) * X2; + X3 = X1 + (W2 - W6) * X3; + X1 = X4 + X6; + X4 -= X6; + X6 = X5 + X7; + X5 -= X7; + + // 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 + + blk[0] = (short) ((X7 + X1) >> 8); + blk[1] = (short) ((X3 + X2) >> 8); + blk[2] = (short) ((X0 + X4) >> 8); + blk[3] = (short) ((X8 + X6) >> 8); + blk[4] = (short) ((X8 - X6) >> 8); + blk[5] = (short) ((X0 - X4) >> 8); + blk[6] = (short) ((X3 - X2) >> 8); + blk[7] = (short) ((X7 - X1) >> 8); - X0 = (blk[0]<<11) + 128; // for proper rounding in the fourth stage + } // end for ( i = 0; i < 8; ++i ) IDCT-rows - // 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 - X8 = X0 + X1; - X0 -= X1; - X1 = W6*(X3+X2); - X2 = X1 - (W2+W6)*X2; - X3 = X1 + (W2-W6)*X3; - X1 = X4 + X6; - X4 -= X6; - X6 = X5 + X7; - X5 -= X7; - - // 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 - - blk[0] = (short)((X7+X1)>>8); - blk[1] = (short)((X3+X2)>>8); - blk[2] = (short)((X0+X4)>>8); - blk[3] = (short)((X8+X6)>>8); - blk[4] = (short)((X8-X6)>>8); - blk[5] = (short)((X0-X4)>>8); - blk[6] = (short)((X3-X2)>>8); - blk[7] = (short)((X7-X1)>>8); - } // end for ( i = 0; i < 8; ++i ) IDCT-rows - - - for (i=0; i<8; i++) // idct columns - { - blk = block + i; - // 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]))) + for (i = 0; i < 8; i++) // idct columns { - blk[8*0]=blk[8*1]=blk[8*2]=blk[8*3]=blk[8*4]= - blk[8*5]=blk[8*6]=blk[8*7]=iclp[(blk[8*0]+32)>>6]; - continue; + blk = block + i; + // 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]))) { + blk[8 * 0] = blk[8 * 1] = blk[8 * 2] = blk[8 * 3] = blk[8 * 4] = + blk[8 * 5] = blk[8 * 6] = blk[8 * 7] = + iclp[(blk[8 * 0] + 32) >> 6]; + continue; + } + + X0 = (blk[8 * 0] << 8) + 8192; + + // 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 + X8 = X0 + X1; + X0 -= X1; + X1 = W6 * (X3 + X2) + 4; + X2 = (X1 - (W2 + W6) * X2) >> 3; + X3 = (X1 + (W2 - W6) * X3) >> 3; + X1 = X4 + X6; + X4 -= X6; + X6 = X5 + X7; + X5 -= X7; + + // 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 + blk[8 * 0] = iclp[(X7 + X1) >> 14]; + blk[8 * 1] = iclp[(X3 + X2) >> 14]; + blk[8 * 2] = iclp[(X0 + X4) >> 14]; + blk[8 * 3] = iclp[(X8 + X6) >> 14]; + blk[8 * 4] = iclp[(X8 - X6) >> 14]; + blk[8 * 5] = iclp[(X0 - X4) >> 14]; + blk[8 * 6] = iclp[(X3 - X2) >> 14]; + blk[8 * 7] = iclp[(X7 - X1) >> 14]; } - X0 = (blk[8*0]<<8) + 8192; - - // 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 - X8 = X0 + X1; - X0 -= X1; - X1 = W6*(X3+X2) + 4; - X2 = (X1-(W2+W6)*X2)>>3; - X3 = (X1+(W2-W6)*X3)>>3; - X1 = X4 + X6; - X4 -= X6; - X6 = X5 + X7; - X5 -= X7; - - // 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 - blk[8*0] = iclp[(X7+X1)>>14]; - blk[8*1] = iclp[(X3+X2)>>14]; - blk[8*2] = iclp[(X0+X4)>>14]; - blk[8*3] = iclp[(X8+X6)>>14]; - blk[8*4] = iclp[(X8-X6)>>14]; - blk[8*5] = iclp[(X0-X4)>>14]; - blk[8*6] = iclp[(X3-X2)>>14]; - 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() +void +idct_int32_init() { - int i; + int i; - iclp = iclip+512; - for (i= -512; i<512; i++) - iclp[i] = (i<-256) ? -256 : ((i>255) ? 255 : i); + iclp = iclip + 512; + for (i = -512; i < 512; i++) + iclp[i] = (i < -256) ? -256 : ((i > 255) ? 255 : i); }