/* * ALAC (Apple Lossless Audio Codec) decoder * Copyright (c) 2005 David Hammerton * * 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 "libavutil/attributes.h"#include "alacdsp.h"#include "config.h" static void decorrelate_stereo(int32_t *buffer[2], int nb_samples,                               int decorr_shift, int decorr_left_weight){    int i;     for (i = 0; i < nb_samples; i++) {        uint32_t a, b;         a = buffer[0][i];        b = buffer[1][i];         a -= (int)(b * decorr_left_weight) >> decorr_shift;        b += a;         buffer[0][i] = b;        buffer[1][i] = a;    }} static void append_extra_bits(int32_t *buffer[2], int32_t *extra_bits_buffer[2],                              int extra_bits, int channels, int nb_samples){    int i, ch;     for (ch = 0; ch < channels; ch++)        for (i = 0; i < nb_samples; i++)            buffer[ch][i] = ((unsigned)buffer[ch][i] << extra_bits) | extra_bits_buffer[ch][i];} av_cold void ff_alacdsp_init(ALACDSPContext *c){    c->decorrelate_stereo   = decorrelate_stereo;    c->append_extra_bits[0] =    c->append_extra_bits[1] = append_extra_bits; #if ARCH_RISCV    ff_alacdsp_init_riscv(c);#elif ARCH_X86    ff_alacdsp_init_x86(c);#endif}