Remove unused variables and the corresponding warnings along with them.
[libav.git] / libavcodec / eval.c
1 /*
2 * simple arithmetic expression evaluator
3 *
4 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 */
21
22 /**
23 * @file eval.c
24 * simple arithmetic expression evaluator.
25 *
26 * see http://joe.hotchkiss.com/programming/eval/eval.html
27 */
28
29 #include "avcodec.h"
30 #include "mpegvideo.h"
31
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <math.h>
36
37 #ifndef NAN
38 #define NAN 0.0/0.0
39 #endif
40
41 #ifndef M_PI
42 #define M_PI 3.14159265358979323846
43 #endif
44
45 typedef struct Parser{
46 int stack_index;
47 char *s;
48 double *const_value;
49 const char **const_name; // NULL terminated
50 double (**func1)(void *, double a); // NULL terminated
51 const char **func1_name; // NULL terminated
52 double (**func2)(void *, double a, double b); // NULL terminated
53 char **func2_name; // NULL terminated
54 void *opaque;
55 char **error;
56 } Parser;
57
58 static double evalExpression(Parser *p);
59
60 static int8_t si_prefixes['z' - 'E' + 1]={
61 ['y'-'E']= -24,
62 ['z'-'E']= -21,
63 ['a'-'E']= -18,
64 ['f'-'E']= -15,
65 ['p'-'E']= -12,
66 ['n'-'E']= - 9,
67 ['u'-'E']= - 6,
68 ['m'-'E']= - 3,
69 ['c'-'E']= - 2,
70 ['d'-'E']= - 1,
71 ['h'-'E']= 2,
72 ['k'-'E']= 3,
73 ['K'-'E']= 3,
74 ['M'-'E']= 6,
75 ['G'-'E']= 9,
76 ['T'-'E']= 12,
77 ['P'-'E']= 15,
78 ['E'-'E']= 18,
79 ['Z'-'E']= 21,
80 ['Y'-'E']= 24,
81 };
82
83 /** strtod() function extended with 'k', 'M', 'G', 'ki', 'Mi', 'Gi' and 'B'
84 * postfixes. This allows using f.e. kB, MiB, G and B as a postfix. This
85 * function assumes that the unit of numbers is bits not bytes.
86 */
87 static double av_strtod(const char *name, char **tail) {
88 double d;
89 char *next;
90 d = strtod(name, &next);
91 /* if parsing succeeded, check for and interpret postfixes */
92 if (next!=name) {
93
94 if(*next >= 'E' && *next <= 'z'){
95 int e= si_prefixes[*next - 'E'];
96 if(e){
97 if(next[1] == 'i'){
98 d*= pow( 2, e/0.3);
99 next+=2;
100 }else{
101 d*= pow(10, e);
102 next++;
103 }
104 }
105 }
106
107 if(*next=='B') {
108 d*=8;
109 *next++;
110 }
111 }
112 /* if requested, fill in tail with the position after the last parsed
113 character */
114 if (tail)
115 *tail = next;
116 return d;
117 }
118
119 static int strmatch(const char *s, const char *prefix){
120 int i;
121 for(i=0; prefix[i]; i++){
122 if(prefix[i] != s[i]) return 0;
123 }
124 return 1;
125 }
126
127 static double evalPrimary(Parser *p){
128 double d, d2=NAN;
129 char *next= p->s;
130 int i;
131
132 /* number */
133 d= av_strtod(p->s, &next);
134 if(next != p->s){
135 p->s= next;
136 return d;
137 }
138
139 /* named constants */
140 for(i=0; p->const_name && p->const_name[i]; i++){
141 if(strmatch(p->s, p->const_name[i])){
142 p->s+= strlen(p->const_name[i]);
143 return p->const_value[i];
144 }
145 }
146
147 p->s= strchr(p->s, '(');
148 if(p->s==NULL){
149 *p->error = "missing (";
150 p->s= next;
151 return NAN;
152 }
153 p->s++; // "("
154 d= evalExpression(p);
155 if(p->s[0]== ','){
156 p->s++; // ","
157 d2= evalExpression(p);
158 }
159 if(p->s[0] != ')'){
160 *p->error = "missing )";
161 return NAN;
162 }
163 p->s++; // ")"
164
165 if( strmatch(next, "sinh" ) ) d= sinh(d);
166 else if( strmatch(next, "cosh" ) ) d= cosh(d);
167 else if( strmatch(next, "tanh" ) ) d= tanh(d);
168 else if( strmatch(next, "sin" ) ) d= sin(d);
169 else if( strmatch(next, "cos" ) ) d= cos(d);
170 else if( strmatch(next, "tan" ) ) d= tan(d);
171 else if( strmatch(next, "exp" ) ) d= exp(d);
172 else if( strmatch(next, "log" ) ) d= log(d);
173 else if( strmatch(next, "squish") ) d= 1/(1+exp(4*d));
174 else if( strmatch(next, "gauss" ) ) d= exp(-d*d/2)/sqrt(2*M_PI);
175 else if( strmatch(next, "abs" ) ) d= fabs(d);
176 else if( strmatch(next, "max" ) ) d= d > d2 ? d : d2;
177 else if( strmatch(next, "min" ) ) d= d < d2 ? d : d2;
178 else if( strmatch(next, "gt" ) ) d= d > d2 ? 1.0 : 0.0;
179 else if( strmatch(next, "gte" ) ) d= d >= d2 ? 1.0 : 0.0;
180 else if( strmatch(next, "lt" ) ) d= d > d2 ? 0.0 : 1.0;
181 else if( strmatch(next, "lte" ) ) d= d >= d2 ? 0.0 : 1.0;
182 else if( strmatch(next, "eq" ) ) d= d == d2 ? 1.0 : 0.0;
183 else if( strmatch(next, "(" ) ) d= d;
184 // else if( strmatch(next, "l1" ) ) d= 1 + d2*(d - 1);
185 // else if( strmatch(next, "sq01" ) ) d= (d >= 0.0 && d <=1.0) ? 1.0 : 0.0;
186 else{
187 for(i=0; p->func1_name && p->func1_name[i]; i++){
188 if(strmatch(next, p->func1_name[i])){
189 return p->func1[i](p->opaque, d);
190 }
191 }
192
193 for(i=0; p->func2_name && p->func2_name[i]; i++){
194 if(strmatch(next, p->func2_name[i])){
195 return p->func2[i](p->opaque, d, d2);
196 }
197 }
198
199 *p->error = "unknown function";
200 return NAN;
201 }
202
203 return d;
204 }
205
206 static double evalPow(Parser *p){
207 int sign= (*p->s == '+') - (*p->s == '-');
208 p->s += sign&1;
209 return (sign|1) * evalPrimary(p);
210 }
211
212 static double evalFactor(Parser *p){
213 double ret= evalPow(p);
214 while(p->s[0]=='^'){
215 p->s++;
216 ret= pow(ret, evalPow(p));
217 }
218 return ret;
219 }
220
221 static double evalTerm(Parser *p){
222 double ret= evalFactor(p);
223 while(p->s[0]=='*' || p->s[0]=='/'){
224 if(*p->s++ == '*') ret*= evalFactor(p);
225 else ret/= evalFactor(p);
226 }
227 return ret;
228 }
229
230 static double evalExpression(Parser *p){
231 double ret= 0;
232
233 if(p->stack_index <= 0) //protect against stack overflows
234 return NAN;
235 p->stack_index--;
236
237 do{
238 ret += evalTerm(p);
239 }while(*p->s == '+' || *p->s == '-');
240
241 p->stack_index++;
242
243 return ret;
244 }
245
246 double ff_eval2(char *s, double *const_value, const char **const_name,
247 double (**func1)(void *, double), const char **func1_name,
248 double (**func2)(void *, double, double), char **func2_name,
249 void *opaque, char **error){
250 Parser p;
251
252 p.stack_index=100;
253 p.s= s;
254 p.const_value= const_value;
255 p.const_name = const_name;
256 p.func1 = func1;
257 p.func1_name = func1_name;
258 p.func2 = func2;
259 p.func2_name = func2_name;
260 p.opaque = opaque;
261 p.error= error;
262
263 return evalExpression(&p);
264 }
265
266 #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
267 attribute_deprecated double ff_eval(char *s, double *const_value, const char **const_name,
268 double (**func1)(void *, double), const char **func1_name,
269 double (**func2)(void *, double, double), char **func2_name,
270 void *opaque){
271 char *error=NULL;
272 double ret;
273 ret = ff_eval2(s, const_value, const_name, func1, func1_name, func2, func2_name, opaque, &error);
274 if (error)
275 av_log(NULL, AV_LOG_ERROR, "Error evaluating \"%s\": %s\n", s, error);
276 return ret;
277 }
278 #endif
279
280 #ifdef TEST
281 #undef printf
282 static double const_values[]={
283 M_PI,
284 M_E,
285 0
286 };
287 static const char *const_names[]={
288 "PI",
289 "E",
290 0
291 };
292 main(){
293 int i;
294 printf("%f == 12.7\n", ff_eval("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL));
295 printf("%f == 0.931322575\n", ff_eval("80G/80Gi", const_values, const_names, NULL, NULL, NULL, NULL, NULL));
296
297 for(i=0; i<1050; i++){
298 START_TIMER
299 ff_eval("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL);
300 STOP_TIMER("ff_eval")
301 }
302 }
303 #endif