/* * AC-3 DSP utils * Copyright (c) 2011 Justin Ruggles * * 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 "avcodec.h" #include "ac3dsp.h" static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs) { int blk, i; if (!num_reuse_blocks) return; for (i = 0; i < nb_coefs; i++) { uint8_t min_exp = *exp; uint8_t *exp1 = exp + 256; for (blk = 0; blk < num_reuse_blocks; blk++) { uint8_t next_exp = *exp1; if (next_exp < min_exp) min_exp = next_exp; exp1 += 256; } *exp++ = min_exp; } } static int ac3_max_msb_abs_int16_c(const int16_t *src, int len) { int i, v = 0; for (i = 0; i < len; i++) v |= abs(src[i]); return v; } av_cold void ff_ac3dsp_init(AC3DSPContext *c) { c->ac3_exponent_min = ac3_exponent_min_c; c->ac3_max_msb_abs_int16 = ac3_max_msb_abs_int16_c; if (HAVE_MMX) ff_ac3dsp_init_x86(c); }