FFmpeg  4.4.6
ac3dsp.c
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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 "libavutil/mem_internal.h"
23 
24 #include "avcodec.h"
25 #include "ac3.h"
26 #include "ac3dsp.h"
27 #include "mathops.h"
28 
29 static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
30 {
31  int blk, i;
32 
33  if (!num_reuse_blocks)
34  return;
35 
36  for (i = 0; i < nb_coefs; i++) {
37  uint8_t min_exp = *exp;
38  uint8_t *exp1 = exp + 256;
39  for (blk = 0; blk < num_reuse_blocks; blk++) {
40  uint8_t next_exp = *exp1;
41  if (next_exp < min_exp)
42  min_exp = next_exp;
43  exp1 += 256;
44  }
45  *exp++ = min_exp;
46  }
47 }
48 
49 static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
50 {
51  const float scale = 1 << 24;
52  do {
53  *dst++ = lrintf(*src++ * scale);
54  *dst++ = lrintf(*src++ * scale);
55  *dst++ = lrintf(*src++ * scale);
56  *dst++ = lrintf(*src++ * scale);
57  *dst++ = lrintf(*src++ * scale);
58  *dst++ = lrintf(*src++ * scale);
59  *dst++ = lrintf(*src++ * scale);
60  *dst++ = lrintf(*src++ * scale);
61  len -= 8;
62  } while (len > 0);
63 }
64 
65 static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
66  int start, int end,
67  int snr_offset, int floor,
68  const uint8_t *bap_tab, uint8_t *bap)
69 {
70  int bin, band, band_end;
71 
72  /* special case, if snr offset is -960, set all bap's to zero */
73  if (snr_offset == -960) {
74  memset(bap, 0, AC3_MAX_COEFS);
75  return;
76  }
77 
78  bin = start;
79  band = ff_ac3_bin_to_band_tab[start];
80  do {
81  int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
82  band_end = ff_ac3_band_start_tab[++band];
83  band_end = FFMIN(band_end, end);
84 
85  for (; bin < band_end; bin++) {
86  int address = av_clip_uintp2((psd[bin] - m) >> 5, 6);
87  bap[bin] = bap_tab[address];
88  }
89  } while (end > band_end);
90 }
91 
92 static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap,
93  int len)
94 {
95  while (len-- > 0)
96  mant_cnt[bap[len]]++;
97 }
98 
99 DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = {
100  0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
101 };
102 
103 static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
104 {
105  int blk, bap;
106  int bits = 0;
107 
108  for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
109  // bap=1 : 3 mantissas in 5 bits
110  bits += (mant_cnt[blk][1] / 3) * 5;
111  // bap=2 : 3 mantissas in 7 bits
112  // bap=4 : 2 mantissas in 7 bits
113  bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7;
114  // bap=3 : 1 mantissa in 3 bits
115  bits += mant_cnt[blk][3] * 3;
116  // bap=5 to 15 : get bits per mantissa from table
117  for (bap = 5; bap < 16; bap++)
118  bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap];
119  }
120  return bits;
121 }
122 
123 static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
124 {
125  int i;
126 
127  for (i = 0; i < nb_coefs; i++) {
128  int v = abs(coef[i]);
129  exp[i] = v ? 23 - av_log2(v) : 24;
130  }
131 }
132 
134  const int32_t *coef0,
135  const int32_t *coef1,
136  int len)
137 {
138  int i;
139 
140  sum[0] = sum[1] = sum[2] = sum[3] = 0;
141 
142  for (i = 0; i < len; i++) {
143  int lt = coef0[i];
144  int rt = coef1[i];
145  int md = lt + rt;
146  int sd = lt - rt;
147  MAC64(sum[0], lt, lt);
148  MAC64(sum[1], rt, rt);
149  MAC64(sum[2], md, md);
150  MAC64(sum[3], sd, sd);
151  }
152 }
153 
154 static void ac3_sum_square_butterfly_float_c(float sum[4],
155  const float *coef0,
156  const float *coef1,
157  int len)
158 {
159  int i;
160 
161  sum[0] = sum[1] = sum[2] = sum[3] = 0;
162 
163  for (i = 0; i < len; i++) {
164  float lt = coef0[i];
165  float rt = coef1[i];
166  float md = lt + rt;
167  float sd = lt - rt;
168  sum[0] += lt * lt;
169  sum[1] += rt * rt;
170  sum[2] += md * md;
171  sum[3] += sd * sd;
172  }
173 }
174 
175 static void ac3_downmix_5_to_2_symmetric_c(float **samples, float **matrix,
176  int len)
177 {
178  int i;
179  float v0, v1;
180  float front_mix = matrix[0][0];
181  float center_mix = matrix[0][1];
182  float surround_mix = matrix[0][3];
183 
184  for (i = 0; i < len; i++) {
185  v0 = samples[0][i] * front_mix +
186  samples[1][i] * center_mix +
187  samples[3][i] * surround_mix;
188 
189  v1 = samples[1][i] * center_mix +
190  samples[2][i] * front_mix +
191  samples[4][i] * surround_mix;
192 
193  samples[0][i] = v0;
194  samples[1][i] = v1;
195  }
196 }
197 
198 static void ac3_downmix_5_to_1_symmetric_c(float **samples, float **matrix,
199  int len)
200 {
201  int i;
202  float front_mix = matrix[0][0];
203  float center_mix = matrix[0][1];
204  float surround_mix = matrix[0][3];
205 
206  for (i = 0; i < len; i++) {
207  samples[0][i] = samples[0][i] * front_mix +
208  samples[1][i] * center_mix +
209  samples[2][i] * front_mix +
210  samples[3][i] * surround_mix +
211  samples[4][i] * surround_mix;
212  }
213 }
214 
215 static void ac3_downmix_c(float **samples, float **matrix,
216  int out_ch, int in_ch, int len)
217 {
218  int i, j;
219  float v0, v1;
220 
221  if (out_ch == 2) {
222  for (i = 0; i < len; i++) {
223  v0 = v1 = 0.0f;
224  for (j = 0; j < in_ch; j++) {
225  v0 += samples[j][i] * matrix[0][j];
226  v1 += samples[j][i] * matrix[1][j];
227  }
228  samples[0][i] = v0;
229  samples[1][i] = v1;
230  }
231  } else if (out_ch == 1) {
232  for (i = 0; i < len; i++) {
233  v0 = 0.0f;
234  for (j = 0; j < in_ch; j++)
235  v0 += samples[j][i] * matrix[0][j];
236  samples[0][i] = v0;
237  }
238  }
239 }
240 
241 static void ac3_downmix_5_to_2_symmetric_c_fixed(int32_t **samples, int16_t **matrix,
242  int len)
243 {
244  int i;
245  int64_t v0, v1;
246  int16_t front_mix = matrix[0][0];
247  int16_t center_mix = matrix[0][1];
248  int16_t surround_mix = matrix[0][3];
249 
250  for (i = 0; i < len; i++) {
251  v0 = (int64_t)samples[0][i] * front_mix +
252  (int64_t)samples[1][i] * center_mix +
253  (int64_t)samples[3][i] * surround_mix;
254 
255  v1 = (int64_t)samples[1][i] * center_mix +
256  (int64_t)samples[2][i] * front_mix +
257  (int64_t)samples[4][i] * surround_mix;
258 
259  samples[0][i] = (v0+2048)>>12;
260  samples[1][i] = (v1+2048)>>12;
261  }
262 }
263 
264 static void ac3_downmix_5_to_1_symmetric_c_fixed(int32_t **samples, int16_t **matrix,
265  int len)
266 {
267  int i;
268  int64_t v0;
269  int16_t front_mix = matrix[0][0];
270  int16_t center_mix = matrix[0][1];
271  int16_t surround_mix = matrix[0][3];
272 
273  for (i = 0; i < len; i++) {
274  v0 = (int64_t)samples[0][i] * front_mix +
275  (int64_t)samples[1][i] * center_mix +
276  (int64_t)samples[2][i] * front_mix +
277  (int64_t)samples[3][i] * surround_mix +
278  (int64_t)samples[4][i] * surround_mix;
279 
280  samples[0][i] = (v0+2048)>>12;
281  }
282 }
283 
284 static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix,
285  int out_ch, int in_ch, int len)
286 {
287  int i, j;
288  int64_t v0, v1;
289  if (out_ch == 2) {
290  for (i = 0; i < len; i++) {
291  v0 = v1 = 0;
292  for (j = 0; j < in_ch; j++) {
293  v0 += (int64_t)samples[j][i] * matrix[0][j];
294  v1 += (int64_t)samples[j][i] * matrix[1][j];
295  }
296  samples[0][i] = (v0+2048)>>12;
297  samples[1][i] = (v1+2048)>>12;
298  }
299  } else if (out_ch == 1) {
300  for (i = 0; i < len; i++) {
301  v0 = 0;
302  for (j = 0; j < in_ch; j++)
303  v0 += (int64_t)samples[j][i] * matrix[0][j];
304  samples[0][i] = (v0+2048)>>12;
305  }
306  }
307 }
308 
309 void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix,
310  int out_ch, int in_ch, int len)
311 {
312  if (c->in_channels != in_ch || c->out_channels != out_ch) {
313  c->in_channels = in_ch;
314  c->out_channels = out_ch;
315  c->downmix_fixed = NULL;
316 
317  if (in_ch == 5 && out_ch == 2 &&
318  !(matrix[1][0] | matrix[0][2] |
319  matrix[1][3] | matrix[0][4] |
320  (matrix[0][1] ^ matrix[1][1]) |
321  (matrix[0][0] ^ matrix[1][2]))) {
322  c->downmix_fixed = ac3_downmix_5_to_2_symmetric_c_fixed;
323  } else if (in_ch == 5 && out_ch == 1 &&
324  matrix[0][0] == matrix[0][2] &&
325  matrix[0][3] == matrix[0][4]) {
326  c->downmix_fixed = ac3_downmix_5_to_1_symmetric_c_fixed;
327  }
328  }
329 
330  if (c->downmix_fixed)
331  c->downmix_fixed(samples, matrix, len);
332  else
333  ac3_downmix_c_fixed(samples, matrix, out_ch, in_ch, len);
334 }
335 
336 void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
337  int out_ch, int in_ch, int len)
338 {
339  if (c->in_channels != in_ch || c->out_channels != out_ch) {
340  int **matrix_cmp = (int **)matrix;
341 
342  c->in_channels = in_ch;
343  c->out_channels = out_ch;
344  c->downmix = NULL;
345 
346  if (in_ch == 5 && out_ch == 2 &&
347  !(matrix_cmp[1][0] | matrix_cmp[0][2] |
348  matrix_cmp[1][3] | matrix_cmp[0][4] |
349  (matrix_cmp[0][1] ^ matrix_cmp[1][1]) |
350  (matrix_cmp[0][0] ^ matrix_cmp[1][2]))) {
352  } else if (in_ch == 5 && out_ch == 1 &&
353  matrix_cmp[0][0] == matrix_cmp[0][2] &&
354  matrix_cmp[0][3] == matrix_cmp[0][4]) {
356  }
357 
358  if (ARCH_X86)
360  }
361 
362  if (c->downmix)
363  c->downmix(samples, matrix, len);
364  else
365  ac3_downmix_c(samples, matrix, out_ch, in_ch, len);
366 }
367 
368 av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
369 {
370  c->ac3_exponent_min = ac3_exponent_min_c;
371  c->float_to_fixed24 = float_to_fixed24_c;
372  c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
373  c->update_bap_counts = ac3_update_bap_counts_c;
374  c->compute_mantissa_size = ac3_compute_mantissa_size_c;
375  c->extract_exponents = ac3_extract_exponents_c;
376  c->sum_square_butterfly_int32 = ac3_sum_square_butterfly_int32_c;
377  c->sum_square_butterfly_float = ac3_sum_square_butterfly_float_c;
378  c->in_channels = 0;
379  c->out_channels = 0;
380  c->downmix = NULL;
381  c->downmix_fixed = NULL;
382 
383  if (ARCH_ARM)
384  ff_ac3dsp_init_arm(c, bit_exact);
385  if (ARCH_X86)
386  ff_ac3dsp_init_x86(c, bit_exact);
387  if (ARCH_MIPS)
388  ff_ac3dsp_init_mips(c, bit_exact);
389 }
const uint8_t ff_ac3_bin_to_band_tab[253]
Map each frequency coefficient bin to the critical band that contains it.
Definition: ac3.c:46
const uint8_t ff_ac3_band_start_tab[AC3_CRITICAL_BANDS+1]
Starting frequency coefficient bin for each critical band.
Definition: ac3.c:35
Common code between the AC-3 encoder and decoder.
#define AC3_MAX_BLOCKS
Definition: ac3.h:36
#define AC3_MAX_COEFS
Definition: ac3.h:34
static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
Definition: ac3dsp.c:49
av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp.c:368
static void ac3_sum_square_butterfly_int32_c(int64_t sum[4], const int32_t *coef0, const int32_t *coef1, int len)
Definition: ac3dsp.c:133
static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len)
Definition: ac3dsp.c:284
static void 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)
Definition: ac3dsp.c:65
static void ac3_sum_square_butterfly_float_c(float sum[4], const float *coef0, const float *coef1, int len)
Definition: ac3dsp.c:154
static void ac3_downmix_c(float **samples, float **matrix, int out_ch, int in_ch, int len)
Definition: ac3dsp.c:215
static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
Definition: ac3dsp.c:29
void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len)
Definition: ac3dsp.c:309
static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
Definition: ac3dsp.c:123
static void ac3_downmix_5_to_2_symmetric_c(float **samples, float **matrix, int len)
Definition: ac3dsp.c:175
void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix, int out_ch, int in_ch, int len)
Definition: ac3dsp.c:336
static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap, int len)
Definition: ac3dsp.c:92
const uint16_t ff_ac3_bap_bits[16]
Number of mantissa bits written for each bap value.
Definition: ac3dsp.c:99
static void ac3_downmix_5_to_1_symmetric_c_fixed(int32_t **samples, int16_t **matrix, int len)
Definition: ac3dsp.c:264
static void ac3_downmix_5_to_1_symmetric_c(float **samples, float **matrix, int len)
Definition: ac3dsp.c:198
static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
Definition: ac3dsp.c:103
static void ac3_downmix_5_to_2_symmetric_c_fixed(int32_t **samples, int16_t **matrix, int len)
Definition: ac3dsp.c:241
void ff_ac3dsp_set_downmix_x86(AC3DSPContext *c)
Definition: ac3dsp_init.c:89
void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact)
void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp_mips.c:403
void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp_init.c:42
#define av_cold
Definition: attributes.h:88
uint8_t
int32_t
Libavcodec external API header.
#define FFMIN(a, b)
Definition: common.h:105
#define FFMAX(a, b)
Definition: common.h:103
#define av_clip_uintp2
Definition: common.h:146
#define ARCH_X86
Definition: config.h:39
#define ARCH_ARM
Definition: config.h:20
#define ARCH_MIPS
Definition: config.h:27
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
#define abs(x)
Definition: cuda_runtime.h:35
static __device__ float floor(float a)
Definition: cuda_runtime.h:173
static const uint8_t bap_tab[64]
Definition: dolby_e.c:589
int8_t exp
Definition: eval.c:72
#define DECLARE_ALIGNED(n, t, v)
Declare a variable that is aligned in memory.
Definition: mem.h:117
int i
Definition: input.c:407
#define av_log2
Definition: intmath.h:83
#define lrintf(x)
Definition: libm_mips.h:70
static const uint16_t mask[17]
Definition: lzw.c:38
#define MAC64(d, a, b)
Definition: mathops.h:74
#define v0
Definition: regdef.h:26
#define blk(i)
Definition: sha.c:185
#define src
Definition: vp8dsp.c:255
#define md
int len
uint8_t bits
Definition: vp3data.h:141
static double c[64]