1 /*
2 * AC-3 DSP functions
3 * Copyright (c) 2011 Justin Ruggles
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 #include <math.h>
23 #include <stdlib.h>
24 #include <string.h>
25
26 #include "config.h"
27 #include "libavutil/attributes.h"
28 #include "libavutil/common.h"
29 #include "libavutil/intmath.h"
30 #include "libavutil/mem_internal.h"
31
32 #include "ac3defs.h"
33 #include "ac3dsp.h"
34 #include "ac3tab.h"
35 #include "mathops.h"
36
ac3_exponent_min_c(uint8_t * exp,int num_reuse_blocks,int nb_coefs)37 static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
38 {
39 int blk, i;
40
41 if (!num_reuse_blocks)
42 return;
43
44 for (i = 0; i < nb_coefs; i++) {
45 uint8_t min_exp = *exp;
46 uint8_t *exp1 = exp + 256;
47 for (blk = 0; blk < num_reuse_blocks; blk++) {
48 uint8_t next_exp = *exp1;
49 if (next_exp < min_exp)
50 min_exp = next_exp;
51 exp1 += 256;
52 }
53 *exp++ = min_exp;
54 }
55 }
56
float_to_fixed24_c(int32_t * dst,const float * src,unsigned int len)57 static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
58 {
59 const float scale = 1 << 24;
60 do {
61 *dst++ = lrintf(*src++ * scale);
62 *dst++ = lrintf(*src++ * scale);
63 *dst++ = lrintf(*src++ * scale);
64 *dst++ = lrintf(*src++ * scale);
65 *dst++ = lrintf(*src++ * scale);
66 *dst++ = lrintf(*src++ * scale);
67 *dst++ = lrintf(*src++ * scale);
68 *dst++ = lrintf(*src++ * scale);
69 len -= 8;
70 } while (len > 0);
71 }
72
ac3_bit_alloc_calc_bap_c(int16_t * mask,int16_t * psd,int start,int end,int snr_offset,int floor,const uint8_t * bap_tab,uint8_t * bap)73 static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
74 int start, int end,
75 int snr_offset, int floor,
76 const uint8_t *bap_tab, uint8_t *bap)
77 {
78 int bin, band, band_end;
79
80 /* special case, if snr offset is -960, set all bap's to zero */
81 if (snr_offset == -960) {
82 memset(bap, 0, AC3_MAX_COEFS);
83 return;
84 }
85
86 bin = start;
87 band = ff_ac3_bin_to_band_tab[start];
88 do {
89 int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
90 band_end = ff_ac3_band_start_tab[++band];
91 band_end = FFMIN(band_end, end);
92
93 for (; bin < band_end; bin++) {
94 int address = av_clip_uintp2((psd[bin] - m) >> 5, 6);
95 bap[bin] = bap_tab[address];
96 }
97 } while (end > band_end);
98 }
99
ac3_update_bap_counts_c(uint16_t mant_cnt[16],uint8_t * bap,int len)100 static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap,
101 int len)
102 {
103 while (len-- > 0)
104 mant_cnt[bap[len]]++;
105 }
106
107 DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = {
108 0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
109 };
110
ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])111 static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
112 {
113 int blk, bap;
114 int bits = 0;
115
116 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
117 // bap=1 : 3 mantissas in 5 bits
118 bits += (mant_cnt[blk][1] / 3) * 5;
119 // bap=2 : 3 mantissas in 7 bits
120 // bap=4 : 2 mantissas in 7 bits
121 bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7;
122 // bap=3 : 1 mantissa in 3 bits
123 bits += mant_cnt[blk][3] * 3;
124 // bap=5 to 15 : get bits per mantissa from table
125 for (bap = 5; bap < 16; bap++)
126 bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap];
127 }
128 return bits;
129 }
130
ac3_extract_exponents_c(uint8_t * exp,int32_t * coef,int nb_coefs)131 static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
132 {
133 int i;
134
135 for (i = 0; i < nb_coefs; i++) {
136 int v = abs(coef[i]);
137 exp[i] = v ? 23 - av_log2(v) : 24;
138 }
139 }
140
ac3_sum_square_butterfly_int32_c(int64_t sum[4],const int32_t * coef0,const int32_t * coef1,int len)141 static void ac3_sum_square_butterfly_int32_c(int64_t sum[4],
142 const int32_t *coef0,
143 const int32_t *coef1,
144 int len)
145 {
146 int i;
147
148 sum[0] = sum[1] = sum[2] = sum[3] = 0;
149
150 for (i = 0; i < len; i++) {
151 int lt = coef0[i];
152 int rt = coef1[i];
153 int md = lt + rt;
154 int sd = lt - rt;
155 MAC64(sum[0], lt, lt);
156 MAC64(sum[1], rt, rt);
157 MAC64(sum[2], md, md);
158 MAC64(sum[3], sd, sd);
159 }
160 }
161
ac3_sum_square_butterfly_float_c(float sum[4],const float * coef0,const float * coef1,int len)162 static void ac3_sum_square_butterfly_float_c(float sum[4],
163 const float *coef0,
164 const float *coef1,
165 int len)
166 {
167 int i;
168
169 sum[0] = sum[1] = sum[2] = sum[3] = 0;
170
171 for (i = 0; i < len; i++) {
172 float lt = coef0[i];
173 float rt = coef1[i];
174 float md = lt + rt;
175 float sd = lt - rt;
176 sum[0] += lt * lt;
177 sum[1] += rt * rt;
178 sum[2] += md * md;
179 sum[3] += sd * sd;
180 }
181 }
182
ac3_downmix_5_to_2_symmetric_c(float ** samples,float ** matrix,int len)183 static void ac3_downmix_5_to_2_symmetric_c(float **samples, float **matrix,
184 int len)
185 {
186 int i;
187 float v0, v1;
188 float front_mix = matrix[0][0];
189 float center_mix = matrix[0][1];
190 float surround_mix = matrix[0][3];
191
192 for (i = 0; i < len; i++) {
193 v0 = samples[0][i] * front_mix +
194 samples[1][i] * center_mix +
195 samples[3][i] * surround_mix;
196
197 v1 = samples[1][i] * center_mix +
198 samples[2][i] * front_mix +
199 samples[4][i] * surround_mix;
200
201 samples[0][i] = v0;
202 samples[1][i] = v1;
203 }
204 }
205
ac3_downmix_5_to_1_symmetric_c(float ** samples,float ** matrix,int len)206 static void ac3_downmix_5_to_1_symmetric_c(float **samples, float **matrix,
207 int len)
208 {
209 int i;
210 float front_mix = matrix[0][0];
211 float center_mix = matrix[0][1];
212 float surround_mix = matrix[0][3];
213
214 for (i = 0; i < len; i++) {
215 samples[0][i] = samples[0][i] * front_mix +
216 samples[1][i] * center_mix +
217 samples[2][i] * front_mix +
218 samples[3][i] * surround_mix +
219 samples[4][i] * surround_mix;
220 }
221 }
222
ac3_downmix_c(float ** samples,float ** matrix,int out_ch,int in_ch,int len)223 static void ac3_downmix_c(float **samples, float **matrix,
224 int out_ch, int in_ch, int len)
225 {
226 int i, j;
227 float v0, v1;
228
229 if (out_ch == 2) {
230 for (i = 0; i < len; i++) {
231 v0 = v1 = 0.0f;
232 for (j = 0; j < in_ch; j++) {
233 v0 += samples[j][i] * matrix[0][j];
234 v1 += samples[j][i] * matrix[1][j];
235 }
236 samples[0][i] = v0;
237 samples[1][i] = v1;
238 }
239 } else if (out_ch == 1) {
240 for (i = 0; i < len; i++) {
241 v0 = 0.0f;
242 for (j = 0; j < in_ch; j++)
243 v0 += samples[j][i] * matrix[0][j];
244 samples[0][i] = v0;
245 }
246 }
247 }
248
ac3_downmix_5_to_2_symmetric_c_fixed(int32_t ** samples,int16_t ** matrix,int len)249 static void ac3_downmix_5_to_2_symmetric_c_fixed(int32_t **samples, int16_t **matrix,
250 int len)
251 {
252 int i;
253 int64_t v0, v1;
254 int16_t front_mix = matrix[0][0];
255 int16_t center_mix = matrix[0][1];
256 int16_t surround_mix = matrix[0][3];
257
258 for (i = 0; i < len; i++) {
259 v0 = (int64_t)samples[0][i] * front_mix +
260 (int64_t)samples[1][i] * center_mix +
261 (int64_t)samples[3][i] * surround_mix;
262
263 v1 = (int64_t)samples[1][i] * center_mix +
264 (int64_t)samples[2][i] * front_mix +
265 (int64_t)samples[4][i] * surround_mix;
266
267 samples[0][i] = (v0+2048)>>12;
268 samples[1][i] = (v1+2048)>>12;
269 }
270 }
271
ac3_downmix_5_to_1_symmetric_c_fixed(int32_t ** samples,int16_t ** matrix,int len)272 static void ac3_downmix_5_to_1_symmetric_c_fixed(int32_t **samples, int16_t **matrix,
273 int len)
274 {
275 int i;
276 int64_t v0;
277 int16_t front_mix = matrix[0][0];
278 int16_t center_mix = matrix[0][1];
279 int16_t surround_mix = matrix[0][3];
280
281 for (i = 0; i < len; i++) {
282 v0 = (int64_t)samples[0][i] * front_mix +
283 (int64_t)samples[1][i] * center_mix +
284 (int64_t)samples[2][i] * front_mix +
285 (int64_t)samples[3][i] * surround_mix +
286 (int64_t)samples[4][i] * surround_mix;
287
288 samples[0][i] = (v0+2048)>>12;
289 }
290 }
291
ac3_downmix_c_fixed(int32_t ** samples,int16_t ** matrix,int out_ch,int in_ch,int len)292 static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix,
293 int out_ch, int in_ch, int len)
294 {
295 int i, j;
296 int64_t v0, v1;
297 if (out_ch == 2) {
298 for (i = 0; i < len; i++) {
299 v0 = v1 = 0;
300 for (j = 0; j < in_ch; j++) {
301 v0 += (int64_t)samples[j][i] * matrix[0][j];
302 v1 += (int64_t)samples[j][i] * matrix[1][j];
303 }
304 samples[0][i] = (v0+2048)>>12;
305 samples[1][i] = (v1+2048)>>12;
306 }
307 } else if (out_ch == 1) {
308 for (i = 0; i < len; i++) {
309 v0 = 0;
310 for (j = 0; j < in_ch; j++)
311 v0 += (int64_t)samples[j][i] * matrix[0][j];
312 samples[0][i] = (v0+2048)>>12;
313 }
314 }
315 }
316
ff_ac3dsp_downmix_fixed(AC3DSPContext * c,int32_t ** samples,int16_t ** matrix,int out_ch,int in_ch,int len)317 void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix,
318 int out_ch, int in_ch, int len)
319 {
320 if (c->in_channels != in_ch || c->out_channels != out_ch) {
321 c->in_channels = in_ch;
322 c->out_channels = out_ch;
323 c->downmix_fixed = NULL;
324
325 if (in_ch == 5 && out_ch == 2 &&
326 !(matrix[1][0] | matrix[0][2] |
327 matrix[1][3] | matrix[0][4] |
328 (matrix[0][1] ^ matrix[1][1]) |
329 (matrix[0][0] ^ matrix[1][2]))) {
330 c->downmix_fixed = ac3_downmix_5_to_2_symmetric_c_fixed;
331 } else if (in_ch == 5 && out_ch == 1 &&
332 matrix[0][0] == matrix[0][2] &&
333 matrix[0][3] == matrix[0][4]) {
334 c->downmix_fixed = ac3_downmix_5_to_1_symmetric_c_fixed;
335 }
336 }
337
338 if (c->downmix_fixed)
339 c->downmix_fixed(samples, matrix, len);
340 else
341 ac3_downmix_c_fixed(samples, matrix, out_ch, in_ch, len);
342 }
343
ff_ac3dsp_downmix(AC3DSPContext * c,float ** samples,float ** matrix,int out_ch,int in_ch,int len)344 void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
345 int out_ch, int in_ch, int len)
346 {
347 if (c->in_channels != in_ch || c->out_channels != out_ch) {
348 int **matrix_cmp = (int **)matrix;
349
350 c->in_channels = in_ch;
351 c->out_channels = out_ch;
352 c->downmix = NULL;
353
354 if (in_ch == 5 && out_ch == 2 &&
355 !(matrix_cmp[1][0] | matrix_cmp[0][2] |
356 matrix_cmp[1][3] | matrix_cmp[0][4] |
357 (matrix_cmp[0][1] ^ matrix_cmp[1][1]) |
358 (matrix_cmp[0][0] ^ matrix_cmp[1][2]))) {
359 c->downmix = ac3_downmix_5_to_2_symmetric_c;
360 } else if (in_ch == 5 && out_ch == 1 &&
361 matrix_cmp[0][0] == matrix_cmp[0][2] &&
362 matrix_cmp[0][3] == matrix_cmp[0][4]) {
363 c->downmix = ac3_downmix_5_to_1_symmetric_c;
364 }
365
366 #if ARCH_X86
367 ff_ac3dsp_set_downmix_x86(c);
368 #endif
369 }
370
371 if (c->downmix)
372 c->downmix(samples, matrix, len);
373 else
374 ac3_downmix_c(samples, matrix, out_ch, in_ch, len);
375 }
376
ff_ac3dsp_init(AC3DSPContext * c,int bit_exact)377 av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
378 {
379 c->ac3_exponent_min = ac3_exponent_min_c;
380 c->float_to_fixed24 = float_to_fixed24_c;
381 c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
382 c->update_bap_counts = ac3_update_bap_counts_c;
383 c->compute_mantissa_size = ac3_compute_mantissa_size_c;
384 c->extract_exponents = ac3_extract_exponents_c;
385 c->sum_square_butterfly_int32 = ac3_sum_square_butterfly_int32_c;
386 c->sum_square_butterfly_float = ac3_sum_square_butterfly_float_c;
387 c->in_channels = 0;
388 c->out_channels = 0;
389 c->downmix = NULL;
390 c->downmix_fixed = NULL;
391
392 #if ARCH_ARM
393 ff_ac3dsp_init_arm(c, bit_exact);
394 #elif ARCH_X86
395 ff_ac3dsp_init_x86(c, bit_exact);
396 #elif ARCH_MIPS
397 ff_ac3dsp_init_mips(c, bit_exact);
398 #endif
399 }
400