| /* |
| * Xvid MPEG-4 IDCT |
| * |
| * Copyright (C) 2006-2011 Xvid Solutions GmbH |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Walken IDCT |
| * Alternative IDCT implementation for decoding compatibility. |
| * |
| * @author Skal |
| * @note This C version is not the original IDCT, but a modified one that |
| * yields the same error profile as the MMX/MMXEXT/SSE2 versions. |
| */ |
| |
| #include "config.h" |
| #include "libavutil/attributes.h" |
| #include "avcodec.h" |
| #include "idctdsp.h" |
| #include "xvididct.h" |
| |
| #define ROW_SHIFT 11 |
| #define COL_SHIFT 6 |
| |
| // #define FIX(x) (int)((x) * (1 << ROW_SHIFT)) |
| #define RND0 65536 // 1 << (COL_SHIFT + ROW_SHIFT - 1); |
| #define RND1 3597 // FIX (1.75683487303); |
| #define RND2 2260 // FIX (1.10355339059); |
| #define RND3 1203 // FIX (0.587788325588); |
| #define RND4 0 |
| #define RND5 120 // FIX (0.058658283817); |
| #define RND6 512 // FIX (0.25); |
| #define RND7 512 // FIX (0.25); |
| |
| static const int TAB04[] = { 22725, 21407, 19266, 16384, 12873, 8867, 4520 }; |
| static const int TAB17[] = { 31521, 29692, 26722, 22725, 17855, 12299, 6270 }; |
| static const int TAB26[] = { 29692, 27969, 25172, 21407, 16819, 11585, 5906 }; |
| static const int TAB35[] = { 26722, 25172, 22654, 19266, 15137, 10426, 5315 }; |
| |
| static int idct_row(short *in, const int *const tab, int rnd) |
| { |
| const int c1 = tab[0]; |
| const int c2 = tab[1]; |
| const int c3 = tab[2]; |
| const int c4 = tab[3]; |
| const int c5 = tab[4]; |
| const int c6 = tab[5]; |
| const int c7 = tab[6]; |
| |
| const int right = in[5] | in[6] | in[7]; |
| const int left = in[1] | in[2] | in[3]; |
| if (!(right | in[4])) { |
| const int k = c4 * in[0] + rnd; |
| if (left) { |
| const int a0 = k + c2 * in[2]; |
| const int a1 = k + c6 * in[2]; |
| const int a2 = k - c6 * in[2]; |
| const int a3 = k - c2 * in[2]; |
| |
| const int b0 = c1 * in[1] + c3 * in[3]; |
| const int b1 = c3 * in[1] - c7 * in[3]; |
| const int b2 = c5 * in[1] - c1 * in[3]; |
| const int b3 = c7 * in[1] - c5 * in[3]; |
| |
| in[0] = (a0 + b0) >> ROW_SHIFT; |
| in[1] = (a1 + b1) >> ROW_SHIFT; |
| in[2] = (a2 + b2) >> ROW_SHIFT; |
| in[3] = (a3 + b3) >> ROW_SHIFT; |
| in[4] = (a3 - b3) >> ROW_SHIFT; |
| in[5] = (a2 - b2) >> ROW_SHIFT; |
| in[6] = (a1 - b1) >> ROW_SHIFT; |
| in[7] = (a0 - b0) >> ROW_SHIFT; |
| } else { |
| const int a0 = k >> ROW_SHIFT; |
| if (a0) { |
| in[0] = |
| in[1] = |
| in[2] = |
| in[3] = |
| in[4] = |
| in[5] = |
| in[6] = |
| in[7] = a0; |
| } else |
| return 0; |
| } |
| } else if (!(left | right)) { |
| const int a0 = (rnd + c4 * (in[0] + in[4])) >> ROW_SHIFT; |
| const int a1 = (rnd + c4 * (in[0] - in[4])) >> ROW_SHIFT; |
| |
| in[0] = a0; |
| in[3] = a0; |
| in[4] = a0; |
| in[7] = a0; |
| in[1] = a1; |
| in[2] = a1; |
| in[5] = a1; |
| in[6] = a1; |
| } else { |
| const int k = c4 * in[0] + rnd; |
| const int a0 = k + c2 * in[2] + c4 * in[4] + c6 * in[6]; |
| const int a1 = k + c6 * in[2] - c4 * in[4] - c2 * in[6]; |
| const int a2 = k - c6 * in[2] - c4 * in[4] + c2 * in[6]; |
| const int a3 = k - c2 * in[2] + c4 * in[4] - c6 * in[6]; |
| |
| const int b0 = c1 * in[1] + c3 * in[3] + c5 * in[5] + c7 * in[7]; |
| const int b1 = c3 * in[1] - c7 * in[3] - c1 * in[5] - c5 * in[7]; |
| const int b2 = c5 * in[1] - c1 * in[3] + c7 * in[5] + c3 * in[7]; |
| const int b3 = c7 * in[1] - c5 * in[3] + c3 * in[5] - c1 * in[7]; |
| |
| in[0] = (a0 + b0) >> ROW_SHIFT; |
| in[1] = (a1 + b1) >> ROW_SHIFT; |
| in[2] = (a2 + b2) >> ROW_SHIFT; |
| in[3] = (a3 + b3) >> ROW_SHIFT; |
| in[4] = (a3 - b3) >> ROW_SHIFT; |
| in[5] = (a2 - b2) >> ROW_SHIFT; |
| in[6] = (a1 - b1) >> ROW_SHIFT; |
| in[7] = (a0 - b0) >> ROW_SHIFT; |
| } |
| return 1; |
| } |
| |
| #define TAN1 0x32EC |
| #define TAN2 0x6A0A |
| #define TAN3 0xAB0E |
| #define SQRT2 0x5A82 |
| |
| #define MULT(c, x, n) (((c) * (x)) >> (n)) |
| // 12b version => #define MULT(c,x, n) ((((c) >> 3) * (x)) >> ((n) - 3)) |
| // 12b zero-testing version: |
| |
| #define BUTTERFLY(a, b, tmp) \ |
| (tmp) = (a) + (b); \ |
| (b) = (a) - (b); \ |
| (a) = (tmp) |
| |
| #define LOAD_BUTTERFLY(m1, m2, a, b, tmp, s) \ |
| (m1) = (s)[(a)] + (s)[(b)]; \ |
| (m2) = (s)[(a)] - (s)[(b)] |
| |
| static void idct_col_8(short *const in) |
| { |
| int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill; |
| |
| // odd |
| |
| mm4 = (int) in[7 * 8]; |
| mm5 = (int) in[5 * 8]; |
| mm6 = (int) in[3 * 8]; |
| mm7 = (int) in[1 * 8]; |
| |
| mm0 = MULT(TAN1, mm4, 16) + mm7; |
| mm1 = MULT(TAN1, mm7, 16) - mm4; |
| mm2 = MULT(TAN3, mm5, 16) + mm6; |
| mm3 = MULT(TAN3, mm6, 16) - mm5; |
| |
| mm7 = mm0 + mm2; |
| mm4 = mm1 - mm3; |
| mm0 = mm0 - mm2; |
| mm1 = mm1 + mm3; |
| mm6 = mm0 + mm1; |
| mm5 = mm0 - mm1; |
| mm5 = 2 * MULT(SQRT2, mm5, 16); // 2*sqrt2 |
| mm6 = 2 * MULT(SQRT2, mm6, 16); // Watch out: precision loss but done to match |
| // the pmulhw used in MMX/MMXEXT/SSE2 versions |
| |
| // even |
| |
| mm1 = (int) in[2 * 8]; |
| mm2 = (int) in[6 * 8]; |
| mm3 = MULT(TAN2, mm2, 16) + mm1; |
| mm2 = MULT(TAN2, mm1, 16) - mm2; |
| |
| LOAD_BUTTERFLY(mm0, mm1, 0 * 8, 4 * 8, spill, in); |
| |
| BUTTERFLY(mm0, mm3, spill); |
| BUTTERFLY(mm0, mm7, spill); |
| in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT); |
| in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT); |
| BUTTERFLY(mm3, mm4, mm0); |
| in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT); |
| in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT); |
| |
| BUTTERFLY(mm1, mm2, mm0); |
| BUTTERFLY(mm1, mm6, mm0); |
| in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT); |
| in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT); |
| BUTTERFLY(mm2, mm5, mm0); |
| in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT); |
| in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT); |
| } |
| |
| static void idct_col_4(short *const in) |
| { |
| int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill; |
| |
| // odd |
| |
| mm0 = (int) in[1 * 8]; |
| mm2 = (int) in[3 * 8]; |
| |
| mm1 = MULT(TAN1, mm0, 16); |
| mm3 = MULT(TAN3, mm2, 16); |
| |
| mm7 = mm0 + mm2; |
| mm4 = mm1 - mm3; |
| mm0 = mm0 - mm2; |
| mm1 = mm1 + mm3; |
| mm6 = mm0 + mm1; |
| mm5 = mm0 - mm1; |
| mm6 = 2 * MULT(SQRT2, mm6, 16); // 2*sqrt2 |
| mm5 = 2 * MULT(SQRT2, mm5, 16); |
| |
| // even |
| |
| mm0 = mm1 = (int) in[0 * 8]; |
| mm3 = (int) in[2 * 8]; |
| mm2 = MULT(TAN2, mm3, 16); |
| |
| BUTTERFLY(mm0, mm3, spill); |
| BUTTERFLY(mm0, mm7, spill); |
| in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT); |
| in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT); |
| BUTTERFLY(mm3, mm4, mm0); |
| in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT); |
| in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT); |
| |
| BUTTERFLY(mm1, mm2, mm0); |
| BUTTERFLY(mm1, mm6, mm0); |
| in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT); |
| in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT); |
| BUTTERFLY(mm2, mm5, mm0); |
| in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT); |
| in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT); |
| } |
| |
| static void idct_col_3(short *const in) |
| { |
| int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill; |
| |
| // odd |
| |
| mm7 = (int) in[1 * 8]; |
| mm4 = MULT(TAN1, mm7, 16); |
| |
| mm6 = mm7 + mm4; |
| mm5 = mm7 - mm4; |
| mm6 = 2 * MULT(SQRT2, mm6, 16); // 2*sqrt2 |
| mm5 = 2 * MULT(SQRT2, mm5, 16); |
| |
| // even |
| |
| mm0 = mm1 = (int) in[0 * 8]; |
| mm3 = (int) in[2 * 8]; |
| mm2 = MULT(TAN2, mm3, 16); |
| |
| BUTTERFLY(mm0, mm3, spill); |
| BUTTERFLY(mm0, mm7, spill); |
| in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT); |
| in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT); |
| BUTTERFLY(mm3, mm4, mm0); |
| in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT); |
| in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT); |
| |
| BUTTERFLY(mm1, mm2, mm0); |
| BUTTERFLY(mm1, mm6, mm0); |
| in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT); |
| in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT); |
| BUTTERFLY(mm2, mm5, mm0); |
| in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT); |
| in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT); |
| } |
| |
| void ff_xvid_idct(int16_t *const in) |
| { |
| int i, rows = 0x07; |
| |
| idct_row(in + 0 * 8, TAB04, RND0); |
| idct_row(in + 1 * 8, TAB17, RND1); |
| idct_row(in + 2 * 8, TAB26, RND2); |
| if (idct_row(in + 3 * 8, TAB35, RND3)) |
| rows |= 0x08; |
| if (idct_row(in + 4 * 8, TAB04, RND4)) |
| rows |= 0x10; |
| if (idct_row(in + 5 * 8, TAB35, RND5)) |
| rows |= 0x20; |
| if (idct_row(in + 6 * 8, TAB26, RND6)) |
| rows |= 0x40; |
| if (idct_row(in + 7 * 8, TAB17, RND7)) |
| rows |= 0x80; |
| |
| if (rows & 0xF0) { |
| for (i = 0; i < 8; i++) |
| idct_col_8(in + i); |
| } else if (rows & 0x08) { |
| for (i = 0; i < 8; i++) |
| idct_col_4(in + i); |
| } else { |
| for (i = 0; i < 8; i++) |
| idct_col_3(in + i); |
| } |
| } |
| |
| static void xvid_idct_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block) |
| { |
| ff_xvid_idct(block); |
| ff_put_pixels_clamped_c(block, dest, line_size); |
| } |
| |
| static void xvid_idct_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block) |
| { |
| ff_xvid_idct(block); |
| ff_add_pixels_clamped_c(block, dest, line_size); |
| } |
| |
| av_cold void ff_xvid_idct_init(IDCTDSPContext *c, AVCodecContext *avctx) |
| { |
| const unsigned high_bit_depth = avctx->bits_per_raw_sample > 8; |
| |
| if (high_bit_depth || avctx->lowres || |
| !(avctx->idct_algo == FF_IDCT_AUTO || |
| avctx->idct_algo == FF_IDCT_XVID)) |
| return; |
| |
| if (avctx->idct_algo == FF_IDCT_XVID) { |
| c->idct_put = xvid_idct_put; |
| c->idct_add = xvid_idct_add; |
| c->idct = ff_xvid_idct; |
| c->perm_type = FF_IDCT_PERM_NONE; |
| } |
| |
| if (ARCH_X86) |
| ff_xvid_idct_init_x86(c, avctx, high_bit_depth); |
| if (ARCH_MIPS) |
| ff_xvid_idct_init_mips(c, avctx, high_bit_depth); |
| |
| ff_init_scantable_permutation(c->idct_permutation, c->perm_type); |
| } |
