3 * Copyright (c) 2011 Justin Ruggles
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
30 if (!num_reuse_blocks)
33 for (i = 0; i < nb_coefs; i++) {
34 uint8_t min_exp = *exp;
35 uint8_t *exp1 = exp + 256;
36 for (blk = 0; blk < num_reuse_blocks; blk++) {
37 uint8_t next_exp = *exp1;
38 if (next_exp < min_exp)
46 static int ac3_max_msb_abs_int16_c(const int16_t *src, int len)
49 for (i = 0; i < len; i++)
54 static void ac3_lshift_int16_c(int16_t *src, unsigned int len,
57 uint32_t *src32 = (uint32_t *)src;
58 const uint32_t mask = ~(((1 << shift) - 1) << 16);
61 for (i = 0; i < len; i += 8) {
62 src32[i ] = (src32[i ] << shift) & mask;
63 src32[i+1] = (src32[i+1] << shift) & mask;
64 src32[i+2] = (src32[i+2] << shift) & mask;
65 src32[i+3] = (src32[i+3] << shift) & mask;
66 src32[i+4] = (src32[i+4] << shift) & mask;
67 src32[i+5] = (src32[i+5] << shift) & mask;
68 src32[i+6] = (src32[i+6] << shift) & mask;
69 src32[i+7] = (src32[i+7] << shift) & mask;
73 static void ac3_rshift_int32_c(int32_t *src, unsigned int len,
89 static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
91 const float scale = 1 << 24;
93 *dst++ = lrintf(*src++ * scale);
94 *dst++ = lrintf(*src++ * scale);
95 *dst++ = lrintf(*src++ * scale);
96 *dst++ = lrintf(*src++ * scale);
97 *dst++ = lrintf(*src++ * scale);
98 *dst++ = lrintf(*src++ * scale);
99 *dst++ = lrintf(*src++ * scale);
100 *dst++ = lrintf(*src++ * scale);
105 static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
107 int snr_offset, int floor,
108 const uint8_t *bap_tab, uint8_t *bap)
112 /* special case, if snr offset is -960, set all bap's to zero */
113 if (snr_offset == -960) {
114 memset(bap, 0, AC3_MAX_COEFS);
119 band = ff_ac3_bin_to_band_tab[start];
121 int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
122 int band_end = FFMIN(ff_ac3_band_start_tab[band+1], end);
123 for (; bin < band_end; bin++) {
124 int address = av_clip((psd[bin] - m) >> 5, 0, 63);
125 bap[bin] = bap_tab[address];
127 } while (end > ff_ac3_band_start_tab[band++]);
130 static int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap,
136 for (i = 0; i < nb_coefs; i++) {
139 // bap=1 to bap=4 will be counted in compute_mantissa_size_final
141 } else if (b <= 13) {
142 // bap=5 to bap=13 use (bap-1) bits
145 // bap=14 uses 14 bits and bap=15 uses 16 bits
146 bits += (b == 14) ? 14 : 16;
152 av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
154 c->ac3_exponent_min = ac3_exponent_min_c;
155 c->ac3_max_msb_abs_int16 = ac3_max_msb_abs_int16_c;
156 c->ac3_lshift_int16 = ac3_lshift_int16_c;
157 c->ac3_rshift_int32 = ac3_rshift_int32_c;
158 c->float_to_fixed24 = float_to_fixed24_c;
159 c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
160 c->compute_mantissa_size = ac3_compute_mantissa_size_c;
163 ff_ac3dsp_init_arm(c, bit_exact);
165 ff_ac3dsp_init_x86(c, bit_exact);