/* * Simple IDCT * * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at> * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * simpleidct in C. */ #include "libavutil/intreadwrite.h" #include "avcodec.h" #include "mathops.h" #include "simple_idct.h" #define BIT_DEPTH 8 #include "simple_idct_template.c" #undef BIT_DEPTH #define BIT_DEPTH 10 #include "simple_idct_template.c" #undef BIT_DEPTH /* 2x4x8 idct */ #define CN_SHIFT 12 #define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5)) #define C1 C_FIX(0.6532814824) #define C2 C_FIX(0.2705980501) /* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized, and the butterfly must be multiplied by 0.5 * sqrt(2.0) */ #define C_SHIFT (4+1+12) static inline void idct4col_put(uint8_t *dest, int line_size, const int16_t *col) { int c0, c1, c2, c3, a0, a1, a2, a3; a0 = col[8*0]; a1 = col[8*2]; a2 = col[8*4]; a3 = col[8*6]; c0 = ((a0 + a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1)); c2 = ((a0 - a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1)); c1 = a1 * C1 + a3 * C2; c3 = a1 * C2 - a3 * C1; dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT); dest += line_size; dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT); dest += line_size; dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT); dest += line_size; dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT); } #define BF(k) \ {\ int a0, a1;\ a0 = ptr[k];\ a1 = ptr[8 + k];\ ptr[k] = a0 + a1;\ ptr[8 + k] = a0 - a1;\ } /* only used by DV codec. The input must be interlaced. 128 is added to the pixels before clamping to avoid systematic error (1024*sqrt(2)) offset would be needed otherwise. */ /* XXX: I think a 1.0/sqrt(2) normalization should be needed to compensate the extra butterfly stage - I don't have the full DV specification */ void ff_simple_idct248_put(uint8_t *dest, int line_size, int16_t *block) { int i; int16_t *ptr; /* butterfly */ ptr = block; for(i=0;i<4;i++) { BF(0); BF(1); BF(2); BF(3); BF(4); BF(5); BF(6); BF(7); ptr += 2 * 8; } /* IDCT8 on each line */ for(i=0; i<8; i++) { idctRowCondDC_8(block + i*8, 0); } /* IDCT4 and store */ for(i=0;i<8;i++) { idct4col_put(dest + i, 2 * line_size, block + i); idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i); } } /* 8x4 & 4x8 WMV2 IDCT */ #undef CN_SHIFT #undef C_SHIFT #undef C_FIX #undef C1 #undef C2 #define CN_SHIFT 12 #define C_FIX(x) ((int)((x) * 1.414213562 * (1 << CN_SHIFT) + 0.5)) #define C1 C_FIX(0.6532814824) #define C2 C_FIX(0.2705980501) #define C3 C_FIX(0.5) #define C_SHIFT (4+1+12) static inline void idct4col_add(uint8_t *dest, int line_size, const int16_t *col) { int c0, c1, c2, c3, a0, a1, a2, a3; a0 = col[8*0]; a1 = col[8*1]; a2 = col[8*2]; a3 = col[8*3]; c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1)); c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1)); c1 = a1 * C1 + a3 * C2; c3 = a1 * C2 - a3 * C1; dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT)); dest += line_size; dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT)); dest += line_size; dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT)); dest += line_size; dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT)); } #define RN_SHIFT 15 #define R_FIX(x) ((int)((x) * 1.414213562 * (1 << RN_SHIFT) + 0.5)) #define R1 R_FIX(0.6532814824) #define R2 R_FIX(0.2705980501) #define R3 R_FIX(0.5) #define R_SHIFT 11 static inline void idct4row(int16_t *row) { int c0, c1, c2, c3, a0, a1, a2, a3; a0 = row[0]; a1 = row[1]; a2 = row[2]; a3 = row[3]; c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1)); c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1)); c1 = a1 * R1 + a3 * R2; c3 = a1 * R2 - a3 * R1; row[0]= (c0 + c1) >> R_SHIFT; row[1]= (c2 + c3) >> R_SHIFT; row[2]= (c2 - c3) >> R_SHIFT; row[3]= (c0 - c1) >> R_SHIFT; } void ff_simple_idct84_add(uint8_t *dest, int line_size, int16_t *block) { int i; /* IDCT8 on each line */ for(i=0; i<4; i++) { idctRowCondDC_8(block + i*8, 0); } /* IDCT4 and store */ for(i=0;i<8;i++) { idct4col_add(dest + i, line_size, block + i); } } void ff_simple_idct48_add(uint8_t *dest, int line_size, int16_t *block) { int i; /* IDCT4 on each line */ for(i=0; i<8; i++) { idct4row(block + i*8); } /* IDCT8 and store */ for(i=0; i<4; i++){ idctSparseColAdd_8(dest + i, line_size, block + i); } } void ff_simple_idct44_add(uint8_t *dest, int line_size, int16_t *block) { int i; /* IDCT4 on each line */ for(i=0; i<4; i++) { idct4row(block + i*8); } /* IDCT4 and store */ for(i=0; i<4; i++){ idct4col_add(dest + i, line_size, block + i); } } void ff_prores_idct(int16_t *block, const int16_t *qmat) { int i; for (i = 0; i < 64; i++) block[i] *= qmat[i]; for (i = 0; i < 8; i++) idctRowCondDC_10(block + i*8, 2); for (i = 0; i < 8; i++) idctSparseCol_10(block + i); }