FFmpeg
nellymoser.c
Go to the documentation of this file.
1 /*
2  * Common code between Nellymoser encoder and decoder
3  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
4  * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
5  * 520e17cd55896441042b14df2566a6eb610ed444
6  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
7  * Benjamin Larsson
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25  * DEALINGS IN THE SOFTWARE.
26  */
27 
28 /**
29  * @file
30  * The 3 alphanumeric copyright notices are md5summed they are from the original
31  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
32  */
33 
34 #include <stdlib.h>
35 
36 #include "libavutil/intmath.h"
37 #include "libavutil/common.h"
38 
39 #include "nellymoser.h"
40 
41 const float ff_nelly_dequantization_table[127] = {
42  0.0000000000,
43 
44 -0.8472560048, 0.7224709988,
45 
46 -1.5247479677,-0.4531480074, 0.3753609955, 1.4717899561,
47 
48 -1.9822579622,-1.1929379702,-0.5829370022,-0.0693780035, 0.3909569979, 0.9069200158, 1.4862740040, 2.2215409279,
49 
50 -2.3887870312,-1.8067539930,-1.4105420113,-1.0773609877,-0.7995010018,-0.5558109879,-0.3334020078,-0.1324490011,
51  0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398, 1.3954459429, 1.8098750114, 2.3918759823,
52 
53 -2.3893830776,-1.9884680510,-1.7514040470,-1.5643119812,-1.3922129869,-1.2164649963,-1.0469499826,-0.8905100226,
54 -0.7645580173,-0.6454579830,-0.5259280205,-0.4059549868,-0.3029719889,-0.2096900046,-0.1239869967,-0.0479229987,
55  0.0257730000, 0.1001340002, 0.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119,
56  0.8425520062, 1.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354,
57 
58 -2.5756309032,-2.0573320389,-1.8984919786,-1.7727810144,-1.6662600040,-1.5742180347,-1.4993319511,-1.4316639900,
59 -1.3652280569,-1.3000990152,-1.2280930281,-1.1588579416,-1.0921250582,-1.0135740042,-0.9202849865,-0.8287050128,
60 -0.7374889851,-0.6447759867,-0.5590940118,-0.4857139885,-0.4110319912,-0.3459700048,-0.2851159871,-0.2341620028,
61 -0.1870580018,-0.1442500055,-0.1107169986,-0.0739680007,-0.0365610011,-0.0073290002, 0.0203610007, 0.0479039997,
62  0.0751969963, 0.0980999991, 0.1220389977, 0.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984,
63  0.2870100141, 0.3197099864, 0.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058,
64  0.6122040153, 0.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075,
65  1.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547, 2.2903931141
66 };
67 
69 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15
70 };
71 
72 const uint16_t ff_nelly_init_table[64] = {
73 3134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770,
74 12116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824,
75 16157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078,
76 19381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453,
77 22756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730,
78 26120, 26497, 26895, 27344, 27877, 28463, 29426, 31355
79 };
80 
81 const int16_t ff_nelly_delta_table[32] = {
82 -11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596,
83 -2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433,
84 2968, 3569, 4314, 5279, 6622, 8154, 10076, 12975
85 };
86 
87 static inline int signed_shift(int i, int shift) {
88  if (shift > 0)
89  return (unsigned)i << shift;
90  return i >> -shift;
91 }
92 
93 static int sum_bits(short *buf, short shift, short off)
94 {
95  int i, ret = 0;
96 
97  for (i = 0; i < NELLY_FILL_LEN; i++) {
98  int b = buf[i]-off;
99  b = ((b>>(shift-1))+1)>>1;
100  ret += av_clip(b, 0, NELLY_BIT_CAP);
101  }
102 
103  return ret;
104 }
105 
106 static int headroom(int *la)
107 {
108  int l;
109  if (*la == 0) {
110  return 31;
111  }
112  l = 30 - av_log2(FFABS(*la));
113  *la *= 1<<l;
114  return l;
115 }
116 
117 
118 void ff_nelly_get_sample_bits(const float *buf, int *bits)
119 {
120  int i, j;
121  short sbuf[128];
122  int bitsum = 0, last_bitsum, small_bitsum, big_bitsum;
123  short shift, shift_saved;
124  int max, sum, last_off, tmp;
125  int big_off, small_off;
126  int off;
127 
128  max = 0;
129  for (i = 0; i < NELLY_FILL_LEN; i++) {
130  max = FFMAX(max, buf[i]);
131  }
132  shift = -16;
133  shift += headroom(&max);
134 
135  sum = 0;
136  for (i = 0; i < NELLY_FILL_LEN; i++) {
137  sbuf[i] = signed_shift(buf[i], shift);
138  sbuf[i] = (3*sbuf[i])>>2;
139  sum += sbuf[i];
140  }
141 
142  shift += 11;
143  shift_saved = shift;
144  sum -= NELLY_DETAIL_BITS << shift;
145  shift += headroom(&sum);
146  small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15;
147  shift = shift_saved - (NELLY_BASE_SHIFT+shift-31);
148 
149  small_off = signed_shift(small_off, shift);
150 
151  bitsum = sum_bits(sbuf, shift_saved, small_off);
152 
153  if (bitsum != NELLY_DETAIL_BITS) {
154  off = bitsum - NELLY_DETAIL_BITS;
155 
156  for(shift=0; FFABS(off) <= 16383; shift++)
157  off *= 2;
158 
159  off = (off * NELLY_BASE_OFF) >> 15;
160  shift = shift_saved-(NELLY_BASE_SHIFT+shift-15);
161 
162  off = signed_shift(off, shift);
163 
164  for (j = 1; j < 20; j++) {
165  last_off = small_off;
166  small_off += off;
167  last_bitsum = bitsum;
168 
169  bitsum = sum_bits(sbuf, shift_saved, small_off);
170 
171  if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0)
172  break;
173  }
174 
175  if (bitsum > NELLY_DETAIL_BITS) {
176  big_off = small_off;
177  small_off = last_off;
178  big_bitsum=bitsum;
179  small_bitsum=last_bitsum;
180  } else {
181  big_off = last_off;
182  big_bitsum=last_bitsum;
183  small_bitsum=bitsum;
184  }
185 
186  while (bitsum != NELLY_DETAIL_BITS && j <= 19) {
187  off = (big_off+small_off)>>1;
188  bitsum = sum_bits(sbuf, shift_saved, off);
189  if (bitsum > NELLY_DETAIL_BITS) {
190  big_off=off;
191  big_bitsum=bitsum;
192  } else {
193  small_off = off;
194  small_bitsum=bitsum;
195  }
196  j++;
197  }
198 
199  if (abs(big_bitsum-NELLY_DETAIL_BITS) >=
200  abs(small_bitsum-NELLY_DETAIL_BITS)) {
201  bitsum = small_bitsum;
202  } else {
203  small_off = big_off;
204  bitsum = big_bitsum;
205  }
206  }
207 
208  for (i = 0; i < NELLY_FILL_LEN; i++) {
209  tmp = sbuf[i]-small_off;
210  tmp = ((tmp>>(shift_saved-1))+1)>>1;
211  bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP);
212  }
213 
214  if (bitsum > NELLY_DETAIL_BITS) {
215  tmp = i = 0;
216  while (tmp < NELLY_DETAIL_BITS) {
217  tmp += bits[i];
218  i++;
219  }
220 
221  bits[i-1] -= tmp - NELLY_DETAIL_BITS;
222  for(; i < NELLY_FILL_LEN; i++)
223  bits[i] = 0;
224  }
225 }
av_clip
#define av_clip
Definition: common.h:96
nellymoser.h
NELLY_FILL_LEN
#define NELLY_FILL_LEN
Definition: nellymoser.h:44
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:26
b
#define b
Definition: input.c:40
max
#define max(a, b)
Definition: cuda_runtime.h:33
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
ff_nelly_band_sizes_table
const uint8_t ff_nelly_band_sizes_table[NELLY_BANDS]
Definition: nellymoser.c:68
ff_nelly_dequantization_table
const float ff_nelly_dequantization_table[127]
Definition: nellymoser.c:41
NELLY_BANDS
#define NELLY_BANDS
Definition: nellymoser.h:39
NELLY_BASE_OFF
#define NELLY_BASE_OFF
Definition: nellymoser.h:46
signed_shift
static int signed_shift(int i, int shift)
Definition: nellymoser.c:87
bits
uint8_t bits
Definition: vp3data.h:141
NELLY_BASE_SHIFT
#define NELLY_BASE_SHIFT
Definition: nellymoser.h:47
ff_nelly_init_table
const uint16_t ff_nelly_init_table[64]
Definition: nellymoser.c:72
ff_nelly_delta_table
const int16_t ff_nelly_delta_table[32]
Definition: nellymoser.c:81
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:65
NELLY_DETAIL_BITS
#define NELLY_DETAIL_BITS
Definition: nellymoser.h:42
abs
#define abs(x)
Definition: cuda_runtime.h:35
NELLY_BIT_CAP
#define NELLY_BIT_CAP
Definition: nellymoser.h:45
sum_bits
static int sum_bits(short *buf, short shift, short off)
Definition: nellymoser.c:93
i
int i
Definition: input.c:406
common.h
headroom
static int headroom(int *la)
Definition: nellymoser.c:106
ret
ret
Definition: filter_design.txt:187
shift
static int shift(int a, int b)
Definition: sonic.c:83
av_log2
int av_log2(unsigned v)
Definition: intmath.c:26
ff_nelly_get_sample_bits
void ff_nelly_get_sample_bits(const float *buf, int *bits)
Definition: nellymoser.c:118
intmath.h