| /* |
| * Copyright (c) 2011 Mans Rullgard |
| * |
| * 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 |
| */ |
| |
| #include "config.h" |
| #include "libavutil/attributes.h" |
| #include "libavutil/thread.h" |
| #include "mpegaudio.h" |
| #include "mpegaudiodsp.h" |
| #include "dct.h" |
| #include "dct32.h" |
| |
| static AVOnce mpadsp_table_init = AV_ONCE_INIT; |
| |
| static av_cold void mpadsp_init_tabs(void) |
| { |
| int i, j; |
| /* compute mdct windows */ |
| for (i = 0; i < 36; i++) { |
| for (j = 0; j < 4; j++) { |
| double d; |
| |
| if (j == 2 && i % 3 != 1) |
| continue; |
| |
| d = sin(M_PI * (i + 0.5) / 36.0); |
| if (j == 1) { |
| if (i >= 30) d = 0; |
| else if (i >= 24) d = sin(M_PI * (i - 18 + 0.5) / 12.0); |
| else if (i >= 18) d = 1; |
| } else if (j == 3) { |
| if (i < 6) d = 0; |
| else if (i < 12) d = sin(M_PI * (i - 6 + 0.5) / 12.0); |
| else if (i < 18) d = 1; |
| } |
| //merge last stage of imdct into the window coefficients |
| d *= 0.5 * IMDCT_SCALAR / cos(M_PI * (2 * i + 19) / 72); |
| |
| if (j == 2) { |
| ff_mdct_win_float[j][i/3] = d / (1 << 5); |
| ff_mdct_win_fixed[j][i/3] = d / (1 << 5) * (1LL << 32) + 0.5; |
| } else { |
| int idx = i < 18 ? i : i + (MDCT_BUF_SIZE/2 - 18); |
| ff_mdct_win_float[j][idx] = d / (1 << 5); |
| ff_mdct_win_fixed[j][idx] = d / (1 << 5) * (1LL << 32) + 0.5; |
| } |
| } |
| } |
| |
| /* NOTE: we do frequency inversion after the MDCT by changing |
| the sign of the right window coefs */ |
| for (j = 0; j < 4; j++) { |
| for (i = 0; i < MDCT_BUF_SIZE; i += 2) { |
| ff_mdct_win_float[j + 4][i ] = ff_mdct_win_float[j][i ]; |
| ff_mdct_win_float[j + 4][i + 1] = -ff_mdct_win_float[j][i + 1]; |
| ff_mdct_win_fixed[j + 4][i ] = ff_mdct_win_fixed[j][i ]; |
| ff_mdct_win_fixed[j + 4][i + 1] = -ff_mdct_win_fixed[j][i + 1]; |
| } |
| } |
| |
| if (ARCH_X86) |
| ff_mpadsp_init_x86_tabs(); |
| } |
| |
| av_cold void ff_mpadsp_init(MPADSPContext *s) |
| { |
| DCTContext dct; |
| |
| ff_dct_init(&dct, 5, DCT_II); |
| ff_thread_once(&mpadsp_table_init, &mpadsp_init_tabs); |
| |
| s->apply_window_float = ff_mpadsp_apply_window_float; |
| s->apply_window_fixed = ff_mpadsp_apply_window_fixed; |
| |
| s->dct32_float = dct.dct32; |
| s->dct32_fixed = ff_dct32_fixed; |
| |
| s->imdct36_blocks_float = ff_imdct36_blocks_float; |
| s->imdct36_blocks_fixed = ff_imdct36_blocks_fixed; |
| |
| if (ARCH_AARCH64) ff_mpadsp_init_aarch64(s); |
| if (ARCH_ARM) ff_mpadsp_init_arm(s); |
| if (ARCH_PPC) ff_mpadsp_init_ppc(s); |
| if (ARCH_X86) ff_mpadsp_init_x86(s); |
| if (HAVE_MIPSFPU) ff_mpadsp_init_mipsfpu(s); |
| if (HAVE_MIPSDSP) ff_mpadsp_init_mipsdsp(s); |
| } |