[FFmpeg-devel] [PATCH 2/2] Make eval API public.
Stefano Sabatini
stefano.sabatini-lala
Tue Jun 1 10:26:10 CEST 2010
---
libavcodec/Makefile | 1 -
libavcodec/avcodec.h | 2 +-
libavcodec/eval.c | 547 ----------------------------------------------
libavcodec/eval.h | 128 -----------
libavcodec/opt.c | 4 +-
libavcodec/ratecontrol.c | 8 +-
libavcodec/ratecontrol.h | 2 +-
libavutil/Makefile | 2 +
libavutil/avutil.h | 2 +-
libavutil/eval.c | 547 ++++++++++++++++++++++++++++++++++++++++++++++
libavutil/eval.h | 128 +++++++++++
11 files changed, 686 insertions(+), 685 deletions(-)
delete mode 100644 libavcodec/eval.c
delete mode 100644 libavcodec/eval.h
create mode 100644 libavutil/eval.c
create mode 100644 libavutil/eval.h
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 764555e..a5f443c 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -11,7 +11,6 @@ OBJS = allcodecs.o \
bitstream.o \
bitstream_filter.o \
dsputil.o \
- eval.o \
faanidct.o \
imgconvert.o \
jrevdct.o \
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index a07e774..9f287d5 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -31,7 +31,7 @@
#define LIBAVCODEC_VERSION_MAJOR 52
#define LIBAVCODEC_VERSION_MINOR 72
-#define LIBAVCODEC_VERSION_MICRO 1
+#define LIBAVCODEC_VERSION_MICRO 2
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \
diff --git a/libavcodec/eval.c b/libavcodec/eval.c
deleted file mode 100644
index 2a8fc44..0000000
--- a/libavcodec/eval.c
+++ /dev/null
@@ -1,547 +0,0 @@
-/*
- * Copyright (c) 2002-2006 Michael Niedermayer <michaelni at gmx.at>
- * Copyright (c) 2006 Oded Shimon <ods15 at ods15.dyndns.org>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * simple arithmetic expression evaluator.
- *
- * see http://joe.hotchkiss.com/programming/eval/eval.html
- */
-
-#include "libavutil/avutil.h"
-#include "eval.h"
-
-typedef struct Parser {
- const AVClass *class;
- int stack_index;
- char *s;
- const double *const_values;
- const char * const *const_names; // NULL terminated
- double (* const *funcs1)(void *, double a); // NULL terminated
- const char * const *func1_names; // NULL terminated
- double (* const *funcs2)(void *, double a, double b); // NULL terminated
- const char * const *func2_names; // NULL terminated
- void *opaque;
- int log_offset;
- void *log_ctx;
-#define VARS 10
- double var[VARS];
-} Parser;
-
-static const AVClass class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };
-
-static const int8_t si_prefixes['z' - 'E' + 1] = {
- ['y'-'E']= -24,
- ['z'-'E']= -21,
- ['a'-'E']= -18,
- ['f'-'E']= -15,
- ['p'-'E']= -12,
- ['n'-'E']= - 9,
- ['u'-'E']= - 6,
- ['m'-'E']= - 3,
- ['c'-'E']= - 2,
- ['d'-'E']= - 1,
- ['h'-'E']= 2,
- ['k'-'E']= 3,
- ['K'-'E']= 3,
- ['M'-'E']= 6,
- ['G'-'E']= 9,
- ['T'-'E']= 12,
- ['P'-'E']= 15,
- ['E'-'E']= 18,
- ['Z'-'E']= 21,
- ['Y'-'E']= 24,
-};
-
-double av_strtod(const char *numstr, char **tail)
-{
- double d;
- char *next;
- d = strtod(numstr, &next);
- /* if parsing succeeded, check for and interpret postfixes */
- if (next!=numstr) {
- if (*next >= 'E' && *next <= 'z') {
- int e= si_prefixes[*next - 'E'];
- if (e) {
- if (next[1] == 'i') {
- d*= pow( 2, e/0.3);
- next+=2;
- } else {
- d*= pow(10, e);
- next++;
- }
- }
- }
-
- if (*next=='B') {
- d*=8;
- next++;
- }
- }
- /* if requested, fill in tail with the position after the last parsed
- character */
- if (tail)
- *tail = next;
- return d;
-}
-
-static int strmatch(const char *s, const char *prefix)
-{
- int i;
- for (i=0; prefix[i]; i++) {
- if (prefix[i] != s[i]) return 0;
- }
- return 1;
-}
-
-struct AVExpr {
- enum {
- e_value, e_const, e_func0, e_func1, e_func2,
- e_squish, e_gauss, e_ld,
- e_mod, e_max, e_min, e_eq, e_gt, e_gte,
- e_pow, e_mul, e_div, e_add,
- e_last, e_st, e_while,
- } type;
- double value; // is sign in other types
- union {
- int const_index;
- double (*func0)(double);
- double (*func1)(void *, double);
- double (*func2)(void *, double, double);
- } a;
- struct AVExpr *param[2];
-};
-
-static double eval_expr(Parser *p, AVExpr *e)
-{
- switch (e->type) {
- case e_value: return e->value;
- case e_const: return e->value * p->const_values[e->a.const_index];
- case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0]));
- case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
- case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
- case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
- case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
- case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
- case e_while: {
- double d = NAN;
- while (eval_expr(p, e->param[0]))
- d=eval_expr(p, e->param[1]);
- return d;
- }
- default: {
- double d = eval_expr(p, e->param[0]);
- double d2 = eval_expr(p, e->param[1]);
- switch (e->type) {
- case e_mod: return e->value * (d - floor(d/d2)*d2);
- case e_max: return e->value * (d > d2 ? d : d2);
- case e_min: return e->value * (d < d2 ? d : d2);
- case e_eq: return e->value * (d == d2 ? 1.0 : 0.0);
- case e_gt: return e->value * (d > d2 ? 1.0 : 0.0);
- case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);
- case e_pow: return e->value * pow(d, d2);
- case e_mul: return e->value * (d * d2);
- case e_div: return e->value * (d / d2);
- case e_add: return e->value * (d + d2);
- case e_last:return e->value * d2;
- case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
- }
- }
- }
- return NAN;
-}
-
-static int parse_expr(AVExpr **e, Parser *p);
-
-void ff_free_expr(AVExpr *e)
-{
- if (!e) return;
- ff_free_expr(e->param[0]);
- ff_free_expr(e->param[1]);
- av_freep(&e);
-}
-
-static int parse_primary(AVExpr **e, Parser *p)
-{
- AVExpr *d = av_mallocz(sizeof(AVExpr));
- char *next= p->s;
- int ret, i;
-
- if (!d)
- return AVERROR(ENOMEM);
-
- /* number */
- d->value = av_strtod(p->s, &next);
- if (next != p->s) {
- d->type = e_value;
- p->s= next;
- *e = d;
- return 0;
- }
- d->value = 1;
-
- /* named constants */
- for (i=0; p->const_names && p->const_names[i]; i++) {
- if (strmatch(p->s, p->const_names[i])) {
- p->s+= strlen(p->const_names[i]);
- d->type = e_const;
- d->a.const_index = i;
- *e = d;
- return 0;
- }
- }
-
- p->s= strchr(p->s, '(');
- if (p->s==NULL) {
- av_log(p, AV_LOG_ERROR, "undefined constant or missing (\n");
- p->s= next;
- ff_free_expr(d);
- return AVERROR(EINVAL);
- }
- p->s++; // "("
- if (*next == '(') { // special case do-nothing
- av_freep(&d);
- if ((ret = parse_expr(&d, p)) < 0)
- return ret;
- if (p->s[0] != ')') {
- av_log(p, AV_LOG_ERROR, "missing )\n");
- ff_free_expr(d);
- return AVERROR(EINVAL);
- }
- p->s++; // ")"
- *e = d;
- return 0;
- }
- if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
- ff_free_expr(d);
- return ret;
- }
- if (p->s[0]== ',') {
- p->s++; // ","
- parse_expr(&d->param[1], p);
- }
- if (p->s[0] != ')') {
- av_log(p, AV_LOG_ERROR, "missing )\n");
- ff_free_expr(d);
- return AVERROR(EINVAL);
- }
- p->s++; // ")"
-
- d->type = e_func0;
- if (strmatch(next, "sinh" )) d->a.func0 = sinh;
- else if (strmatch(next, "cosh" )) d->a.func0 = cosh;
- else if (strmatch(next, "tanh" )) d->a.func0 = tanh;
- else if (strmatch(next, "sin" )) d->a.func0 = sin;
- else if (strmatch(next, "cos" )) d->a.func0 = cos;
- else if (strmatch(next, "tan" )) d->a.func0 = tan;
- else if (strmatch(next, "atan" )) d->a.func0 = atan;
- else if (strmatch(next, "asin" )) d->a.func0 = asin;
- else if (strmatch(next, "acos" )) d->a.func0 = acos;
- else if (strmatch(next, "exp" )) d->a.func0 = exp;
- else if (strmatch(next, "log" )) d->a.func0 = log;
- else if (strmatch(next, "abs" )) d->a.func0 = fabs;
- else if (strmatch(next, "squish")) d->type = e_squish;
- else if (strmatch(next, "gauss" )) d->type = e_gauss;
- else if (strmatch(next, "mod" )) d->type = e_mod;
- else if (strmatch(next, "max" )) d->type = e_max;
- else if (strmatch(next, "min" )) d->type = e_min;
- else if (strmatch(next, "eq" )) d->type = e_eq;
- else if (strmatch(next, "gte" )) d->type = e_gte;
- else if (strmatch(next, "gt" )) d->type = e_gt;
- else if (strmatch(next, "lte" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
- else if (strmatch(next, "lt" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
- else if (strmatch(next, "ld" )) d->type = e_ld;
- else if (strmatch(next, "st" )) d->type = e_st;
- else if (strmatch(next, "while" )) d->type = e_while;
- else {
- for (i=0; p->func1_names && p->func1_names[i]; i++) {
- if (strmatch(next, p->func1_names[i])) {
- d->a.func1 = p->funcs1[i];
- d->type = e_func1;
- *e = d;
- return 0;
- }
- }
-
- for (i=0; p->func2_names && p->func2_names[i]; i++) {
- if (strmatch(next, p->func2_names[i])) {
- d->a.func2 = p->funcs2[i];
- d->type = e_func2;
- *e = d;
- return 0;
- }
- }
-
- av_log(p, AV_LOG_ERROR, "unknown function\n");
- ff_free_expr(d);
- return AVERROR(EINVAL);
- }
-
- *e = d;
- return 0;
-}
-
-static AVExpr *new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)
-{
- AVExpr *e = av_mallocz(sizeof(AVExpr));
- if (!e)
- return NULL;
- e->type =type ;
- e->value =value ;
- e->param[0] =p0 ;
- e->param[1] =p1 ;
- return e;
-}
-
-static int parse_pow(AVExpr **e, Parser *p, int *sign)
-{
- *sign= (*p->s == '+') - (*p->s == '-');
- p->s += *sign&1;
- return parse_primary(e, p);
-}
-
-static int parse_factor(AVExpr **e, Parser *p)
-{
- int sign, sign2, ret;
- AVExpr *e0, *e1, *e2;
- if ((ret = parse_pow(&e0, p, &sign)) < 0)
- return ret;
- while(p->s[0]=='^'){
- e1 = e0;
- p->s++;
- if ((ret = parse_pow(&e2, p, &sign2)) < 0) {
- ff_free_expr(e1);
- return ret;
- }
- e0 = new_eval_expr(e_pow, 1, e1, e2);
- if (!e0) {
- ff_free_expr(e1);
- ff_free_expr(e2);
- return AVERROR(ENOMEM);
- }
- if (e0->param[1]) e0->param[1]->value *= (sign2|1);
- }
- if (e0) e0->value *= (sign|1);
-
- *e = e0;
- return 0;
-}
-
-static int parse_term(AVExpr **e, Parser *p)
-{
- int ret;
- AVExpr *e0, *e1, *e2;
- if ((ret = parse_factor(&e0, p)) < 0)
- return ret;
- while (p->s[0]=='*' || p->s[0]=='/') {
- int c= *p->s++;
- e1 = e0;
- if ((ret = parse_factor(&e2, p)) < 0) {
- ff_free_expr(e1);
- return ret;
- }
- e0 = new_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);
- if (!e0) {
- ff_free_expr(e1);
- ff_free_expr(e2);
- return AVERROR(ENOMEM);
- }
- }
- *e = e0;
- return 0;
-}
-
-static int parse_subexpr(AVExpr **e, Parser *p)
-{
- int ret;
- AVExpr *e0, *e1, *e2;
- if ((ret = parse_term(&e0, p)) < 0)
- return ret;
- while (*p->s == '+' || *p->s == '-') {
- e1 = e0;
- if ((ret = parse_term(&e2, p)) < 0) {
- ff_free_expr(e1);
- return ret;
- }
- e0 = new_eval_expr(e_add, 1, e1, e2);
- if (!e0) {
- ff_free_expr(e1);
- ff_free_expr(e2);
- return AVERROR(ENOMEM);
- }
- };
-
- *e = e0;
- return 0;
-}
-
-static int parse_expr(AVExpr **e, Parser *p)
-{
- int ret;
- AVExpr *e0, *e1, *e2;
- if (p->stack_index <= 0) //protect against stack overflows
- return AVERROR(EINVAL);
- p->stack_index--;
-
- if ((ret = parse_subexpr(&e0, p)) < 0)
- return ret;
- while (*p->s == ';') {
- e1 = e0;
- if ((ret = parse_subexpr(&e2, p)) < 0) {
- ff_free_expr(e1);
- return ret;
- }
- p->s++;
- e0 = new_eval_expr(e_last, 1, e1, e2);
- if (!e0) {
- ff_free_expr(e1);
- ff_free_expr(e2);
- return AVERROR(ENOMEM);
- }
- };
-
- p->stack_index++;
- *e = e0;
- return 0;
-}
-
-static int verify_expr(AVExpr *e)
-{
- if (!e) return 0;
- switch (e->type) {
- case e_value:
- case e_const: return 1;
- case e_func0:
- case e_func1:
- case e_squish:
- case e_ld:
- case e_gauss: return verify_expr(e->param[0]);
- default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
- }
-}
-
-int ff_parse_expr(AVExpr **expr, const char *s,
- const char * const *const_names,
- const char * const *func1_names, double (* const *funcs1)(void *, double),
- const char * const *func2_names, double (* const *funcs2)(void *, double, double),
- int log_offset, void *log_ctx)
-{
- Parser p;
- AVExpr *e = NULL;
- char *w = av_malloc(strlen(s) + 1);
- char *wp = w;
- int ret = 0;
-
- if (!w)
- return AVERROR(ENOMEM);
-
- while (*s)
- if (!isspace(*s++)) *wp++ = s[-1];
- *wp++ = 0;
-
- p.class = &class;
- p.stack_index=100;
- p.s= w;
- p.const_names = const_names;
- p.funcs1 = funcs1;
- p.func1_names = func1_names;
- p.funcs2 = funcs2;
- p.func2_names = func2_names;
- p.log_offset = log_offset;
- p.log_ctx = log_ctx;
-
- if ((ret = parse_expr(&e, &p)) < 0)
- goto end;
- if (!verify_expr(e)) {
- ff_free_expr(e);
- ret = AVERROR(EINVAL);
- goto end;
- }
- *expr = e;
-end:
- av_free(w);
- return ret;
-}
-
-double ff_eval_expr(AVExpr *e, const double *const_values, void *opaque)
-{
- Parser p;
-
- p.const_values = const_values;
- p.opaque = opaque;
- return eval_expr(&p, e);
-}
-
-int ff_parse_and_eval_expr(double *d, const char *s,
- const char * const *const_names, const double *const_values,
- const char * const *func1_names, double (* const *funcs1)(void *, double),
- const char * const *func2_names, double (* const *funcs2)(void *, double, double),
- void *opaque, int log_offset, void *log_ctx)
-{
- AVExpr *e = NULL;
- int ret = ff_parse_expr(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);
-
- if (ret < 0) {
- *d = NAN;
- return ret;
- }
- *d = ff_eval_expr(e, const_values, opaque);
- ff_free_expr(e);
- return isnan(*d) ? AVERROR(EINVAL) : 0;
-}
-
-#ifdef TEST
-#undef printf
-static double const_values[] = {
- M_PI,
- M_E,
- 0
-};
-
-static const char *const_names[] = {
- "PI",
- "E",
- 0
-};
-
-int main(void)
-{
- int i;
- double d;
- ff_parse_and_eval_expr(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
- const_names, const_values,
- NULL, NULL, NULL, NULL, NULL, 0, NULL);
- printf("%f == 12.7\n", d);
- ff_parse_and_eval_expr(&d, "80G/80Gi",
- const_names, const_values,
- NULL, NULL, NULL, NULL, NULL, 0, NULL);
- printf("%f == 0.931322575\n", d);
-
- for (i=0; i<1050; i++) {
- START_TIMER
- ff_parse_and_eval_expr(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
- const_names, const_values,
- NULL, NULL, NULL, NULL, NULL, 0, NULL);
- STOP_TIMER("ff_parse_and_eval_expr")
- }
- return 0;
-}
-#endif
diff --git a/libavcodec/eval.h b/libavcodec/eval.h
deleted file mode 100644
index 1db2b0c..0000000
--- a/libavcodec/eval.h
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright (c) 2002 Michael Niedermayer <michaelni at gmx.at>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * simple arithmetic expression evaluator
- */
-
-#ifndef AVCODEC_EVAL_H
-#define AVCODEC_EVAL_H
-
-typedef struct AVExpr AVExpr;
-
-/**
- * Parses and evaluates an expression.
- * Note, this is significantly slower than ff_eval_expr().
- *
- * @param res a pointer to a double where is put the result value of
- * the expression, or NAN in case of invalid expression
- * @param s expression as a zero terminated string, for example
- * "1+2^3+5*5+sin(2/3)"
- * @param const_names NULL terminated array of zero terminated strings
- * of constant identifers, for example {"PI", "E", 0}
- * @param const_values a zero terminated array of values for the
- * identifers from const_names
- * @param func1_names NULL terminated array of zero terminated strings
- * of funcs1 identifers
- * @param funcs1 NULL terminated array of function pointers for
- * functions which take 1 argument
- * @param func2_names NULL terminated array of zero terminated strings
- * of funcs2 identifers
- * @param funcs2 NULL terminated array of function pointers for
- * functions which take 2 arguments
- * @param opaque a pointer which will be passed to all functions from
- * funcs1 and funcs2
- * @param log_ctx parent logging context
- * @return 0 in case of success, a negative value corresponding to an
- * AVERROR code otherwise
- */
-int ff_parse_and_eval_expr(double *res, const char *s,
- const char * const *const_names, const double *const_values,
- const char * const *func1_names, double (* const *funcs1)(void *, double),
- const char * const *func2_names, double (* const *funcs2)(void *, double, double),
- void *opaque, int log_offset, void *log_ctx);
-
-/**
- * Parses an expression.
- *
- * @param expr a pointer where is put an AVExpr containing the parsed
- * value in case of successfull parsing, or NULL otherwise.
- * The pointed to AVExpr must be freed with ff_free_expr() by
- * the user when it is not needed anymore.
- * @param s expression as a zero terminated string, for example
- * "1+2^3+5*5+sin(2/3)"
- * @param const_names NULL terminated array of zero terminated strings
- * of constant identifers, for example {"PI", "E", 0}
- * @param func1_names NULL terminated array of zero terminated strings
- * of funcs1 identifers
- * @param funcs1 NULL terminated array of function pointers for
- * functions which take 1 argument
- * @param func2_names NULL terminated array of zero terminated strings
- * of funcs2 identifers
- * @param funcs2 NULL terminated array of function pointers for
- * functions which take 2 arguments
- * @param log_ctx parent logging context
- * @return 0 in case of success, a negative value corresponding to an
- * AVERROR code otherwise
- */
-int ff_parse_expr(AVExpr **expr, const char *s,
- const char * const *const_names,
- const char * const *func1_names, double (* const *funcs1)(void *, double),
- const char * const *func2_names, double (* const *funcs2)(void *, double, double),
- int log_offset, void *log_ctx);
-
-/**
- * Evaluates a previously parsed expression.
- *
- * @param const_values a zero terminated array of values for the
- * identifers from ff_parse() const_names
- * @param opaque a pointer which will be passed to all functions from
- * funcs1 and funcs2
- * @return the value of the expression
- */
-double ff_eval_expr(AVExpr *e, const double *const_values, void *opaque);
-
-/**
- * Frees a parsed expression previously created with ff_parse_expr().
- */
-void ff_free_expr(AVExpr *e);
-
-/**
- * Parses the string in numstr and returns its value as a double. If
- * the string is empty, contains only whitespaces, or does not contain
- * an initial substring that has the expected syntax for a
- * floating-point number, no conversion is performed. In this case,
- * returns a value of zero and the value returned in tail is the value
- * of numstr.
- *
- * @param numstr a string representing a number, may contain one of
- * the International System number postfixes, for example 'K',
- * 'M', 'G'. If 'i' is appended after the postfix, powers of 2
- * are used instead of powers of 10. The 'B' postfix multiplies
- * the value for 8, and can be appended after another postfix
- * or used alone. This allows using for example 'KB', 'MiB',
- * 'G' and 'B' as postfix.
- * @param tail if non-NULL puts here the pointer to the char next
- * after the last parsed character
- */
-double av_strtod(const char *numstr, char **tail);
-
-#endif /* AVCODEC_EVAL_H */
diff --git a/libavcodec/opt.c b/libavcodec/opt.c
index 8473d90..128d95d 100644
--- a/libavcodec/opt.c
+++ b/libavcodec/opt.c
@@ -27,7 +27,7 @@
#include "avcodec.h"
#include "opt.h"
-#include "eval.h"
+#include "libavutil/eval.h"
//FIXME order them and do a bin search
const AVOption *av_find_opt(void *v, const char *name, const char *unit, int mask, int flags){
@@ -165,7 +165,7 @@ int av_set_string3(void *obj, const char *name, const char *val, int alloc, cons
else if(!strcmp(buf, "none" )) d= 0;
else if(!strcmp(buf, "all" )) d= ~0;
else {
- int res = ff_parse_and_eval_expr(&d, buf, const_names, const_values, NULL, NULL, NULL, NULL, NULL, 0, obj);
+ int res = av_parse_and_eval_expr(&d, buf, const_names, const_values, NULL, NULL, NULL, NULL, NULL, 0, obj);
if (res < 0) {
av_log(obj, AV_LOG_ERROR, "Unable to parse option value \"%s\"\n", val);
return res;
diff --git a/libavcodec/ratecontrol.c b/libavcodec/ratecontrol.c
index 375815a..69ed0c9 100644
--- a/libavcodec/ratecontrol.c
+++ b/libavcodec/ratecontrol.c
@@ -30,7 +30,7 @@
#include "dsputil.h"
#include "ratecontrol.h"
#include "mpegvideo.h"
-#include "eval.h"
+#include "libavutil/eval.h"
#undef NDEBUG // Always check asserts, the speed effect is far too small to disable them.
#include <assert.h>
@@ -106,7 +106,7 @@ int ff_rate_control_init(MpegEncContext *s)
};
emms_c();
- res = ff_parse_expr(&rcc->rc_eq_eval, s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1_names, func1, NULL, NULL, 0, s->avctx);
+ res = av_parse_expr(&rcc->rc_eq_eval, s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1_names, func1, NULL, NULL, 0, s->avctx);
if (res < 0) {
av_log(s->avctx, AV_LOG_ERROR, "Error parsing rc_eq \"%s\"\n", s->avctx->rc_eq);
return res;
@@ -254,7 +254,7 @@ void ff_rate_control_uninit(MpegEncContext *s)
RateControlContext *rcc= &s->rc_context;
emms_c();
- ff_free_expr(rcc->rc_eq_eval);
+ av_free_expr(rcc->rc_eq_eval);
av_freep(&rcc->entry);
#if CONFIG_LIBXVID
@@ -338,7 +338,7 @@ static double get_qscale(MpegEncContext *s, RateControlEntry *rce, double rate_f
0
};
- bits= ff_eval_expr(rcc->rc_eq_eval, const_values, rce);
+ bits= av_eval_expr(rcc->rc_eq_eval, const_values, rce);
if (isnan(bits)) {
av_log(s->avctx, AV_LOG_ERROR, "Error evaluating rc_eq \"%s\"\n", s->avctx->rc_eq);
return -1;
diff --git a/libavcodec/ratecontrol.h b/libavcodec/ratecontrol.h
index d5fe2bc..32efe01 100644
--- a/libavcodec/ratecontrol.h
+++ b/libavcodec/ratecontrol.h
@@ -30,7 +30,7 @@
#include <stdio.h>
#include <stdint.h>
-#include "eval.h"
+#include "libavutil/eval.h"
typedef struct Predictor{
double coeff;
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 6035ba6..5a9acd2 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -9,6 +9,7 @@ HEADERS = adler32.h \
base64.h \
common.h \
crc.h \
+ eval.h \
error.h \
fifo.h \
intfloat_readwrite.h \
@@ -31,6 +32,7 @@ OBJS = adler32.o \
base64.o \
crc.o \
des.o \
+ eval.o \
error.o \
fifo.o \
intfloat_readwrite.o \
diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index 72bd2c5..b23f42f 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -40,7 +40,7 @@
#define AV_VERSION(a, b, c) AV_VERSION_DOT(a, b, c)
#define LIBAVUTIL_VERSION_MAJOR 50
-#define LIBAVUTIL_VERSION_MINOR 16
+#define LIBAVUTIL_VERSION_MINOR 17
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
diff --git a/libavutil/eval.c b/libavutil/eval.c
new file mode 100644
index 0000000..59ebd94
--- /dev/null
+++ b/libavutil/eval.c
@@ -0,0 +1,547 @@
+/*
+ * Copyright (c) 2002-2006 Michael Niedermayer <michaelni at gmx.at>
+ * Copyright (c) 2006 Oded Shimon <ods15 at ods15.dyndns.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * simple arithmetic expression evaluator.
+ *
+ * see http://joe.hotchkiss.com/programming/eval/eval.html
+ */
+
+#include "libavutil/avutil.h"
+#include "eval.h"
+
+typedef struct Parser {
+ const AVClass *class;
+ int stack_index;
+ char *s;
+ const double *const_values;
+ const char * const *const_names; // NULL terminated
+ double (* const *funcs1)(void *, double a); // NULL terminated
+ const char * const *func1_names; // NULL terminated
+ double (* const *funcs2)(void *, double a, double b); // NULL terminated
+ const char * const *func2_names; // NULL terminated
+ void *opaque;
+ int log_offset;
+ void *log_ctx;
+#define VARS 10
+ double var[VARS];
+} Parser;
+
+static const AVClass class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };
+
+static const int8_t si_prefixes['z' - 'E' + 1] = {
+ ['y'-'E']= -24,
+ ['z'-'E']= -21,
+ ['a'-'E']= -18,
+ ['f'-'E']= -15,
+ ['p'-'E']= -12,
+ ['n'-'E']= - 9,
+ ['u'-'E']= - 6,
+ ['m'-'E']= - 3,
+ ['c'-'E']= - 2,
+ ['d'-'E']= - 1,
+ ['h'-'E']= 2,
+ ['k'-'E']= 3,
+ ['K'-'E']= 3,
+ ['M'-'E']= 6,
+ ['G'-'E']= 9,
+ ['T'-'E']= 12,
+ ['P'-'E']= 15,
+ ['E'-'E']= 18,
+ ['Z'-'E']= 21,
+ ['Y'-'E']= 24,
+};
+
+double av_strtod(const char *numstr, char **tail)
+{
+ double d;
+ char *next;
+ d = strtod(numstr, &next);
+ /* if parsing succeeded, check for and interpret postfixes */
+ if (next!=numstr) {
+ if (*next >= 'E' && *next <= 'z') {
+ int e= si_prefixes[*next - 'E'];
+ if (e) {
+ if (next[1] == 'i') {
+ d*= pow( 2, e/0.3);
+ next+=2;
+ } else {
+ d*= pow(10, e);
+ next++;
+ }
+ }
+ }
+
+ if (*next=='B') {
+ d*=8;
+ next++;
+ }
+ }
+ /* if requested, fill in tail with the position after the last parsed
+ character */
+ if (tail)
+ *tail = next;
+ return d;
+}
+
+static int strmatch(const char *s, const char *prefix)
+{
+ int i;
+ for (i=0; prefix[i]; i++) {
+ if (prefix[i] != s[i]) return 0;
+ }
+ return 1;
+}
+
+struct AVExpr {
+ enum {
+ e_value, e_const, e_func0, e_func1, e_func2,
+ e_squish, e_gauss, e_ld,
+ e_mod, e_max, e_min, e_eq, e_gt, e_gte,
+ e_pow, e_mul, e_div, e_add,
+ e_last, e_st, e_while,
+ } type;
+ double value; // is sign in other types
+ union {
+ int const_index;
+ double (*func0)(double);
+ double (*func1)(void *, double);
+ double (*func2)(void *, double, double);
+ } a;
+ struct AVExpr *param[2];
+};
+
+static double eval_expr(Parser *p, AVExpr *e)
+{
+ switch (e->type) {
+ case e_value: return e->value;
+ case e_const: return e->value * p->const_values[e->a.const_index];
+ case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0]));
+ case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
+ case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
+ case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
+ case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
+ case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
+ case e_while: {
+ double d = NAN;
+ while (eval_expr(p, e->param[0]))
+ d=eval_expr(p, e->param[1]);
+ return d;
+ }
+ default: {
+ double d = eval_expr(p, e->param[0]);
+ double d2 = eval_expr(p, e->param[1]);
+ switch (e->type) {
+ case e_mod: return e->value * (d - floor(d/d2)*d2);
+ case e_max: return e->value * (d > d2 ? d : d2);
+ case e_min: return e->value * (d < d2 ? d : d2);
+ case e_eq: return e->value * (d == d2 ? 1.0 : 0.0);
+ case e_gt: return e->value * (d > d2 ? 1.0 : 0.0);
+ case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);
+ case e_pow: return e->value * pow(d, d2);
+ case e_mul: return e->value * (d * d2);
+ case e_div: return e->value * (d / d2);
+ case e_add: return e->value * (d + d2);
+ case e_last:return e->value * d2;
+ case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
+ }
+ }
+ }
+ return NAN;
+}
+
+static int parse_expr(AVExpr **e, Parser *p);
+
+void av_free_expr(AVExpr *e)
+{
+ if (!e) return;
+ av_free_expr(e->param[0]);
+ av_free_expr(e->param[1]);
+ av_freep(&e);
+}
+
+static int parse_primary(AVExpr **e, Parser *p)
+{
+ AVExpr *d = av_mallocz(sizeof(AVExpr));
+ char *next= p->s;
+ int ret, i;
+
+ if (!d)
+ return AVERROR(ENOMEM);
+
+ /* number */
+ d->value = av_strtod(p->s, &next);
+ if (next != p->s) {
+ d->type = e_value;
+ p->s= next;
+ *e = d;
+ return 0;
+ }
+ d->value = 1;
+
+ /* named constants */
+ for (i=0; p->const_names && p->const_names[i]; i++) {
+ if (strmatch(p->s, p->const_names[i])) {
+ p->s+= strlen(p->const_names[i]);
+ d->type = e_const;
+ d->a.const_index = i;
+ *e = d;
+ return 0;
+ }
+ }
+
+ p->s= strchr(p->s, '(');
+ if (p->s==NULL) {
+ av_log(p, AV_LOG_ERROR, "undefined constant or missing (\n");
+ p->s= next;
+ av_free_expr(d);
+ return AVERROR(EINVAL);
+ }
+ p->s++; // "("
+ if (*next == '(') { // special case do-nothing
+ av_freep(&d);
+ if ((ret = parse_expr(&d, p)) < 0)
+ return ret;
+ if (p->s[0] != ')') {
+ av_log(p, AV_LOG_ERROR, "missing )\n");
+ av_free_expr(d);
+ return AVERROR(EINVAL);
+ }
+ p->s++; // ")"
+ *e = d;
+ return 0;
+ }
+ if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
+ av_free_expr(d);
+ return ret;
+ }
+ if (p->s[0]== ',') {
+ p->s++; // ","
+ parse_expr(&d->param[1], p);
+ }
+ if (p->s[0] != ')') {
+ av_log(p, AV_LOG_ERROR, "missing )\n");
+ av_free_expr(d);
+ return AVERROR(EINVAL);
+ }
+ p->s++; // ")"
+
+ d->type = e_func0;
+ if (strmatch(next, "sinh" )) d->a.func0 = sinh;
+ else if (strmatch(next, "cosh" )) d->a.func0 = cosh;
+ else if (strmatch(next, "tanh" )) d->a.func0 = tanh;
+ else if (strmatch(next, "sin" )) d->a.func0 = sin;
+ else if (strmatch(next, "cos" )) d->a.func0 = cos;
+ else if (strmatch(next, "tan" )) d->a.func0 = tan;
+ else if (strmatch(next, "atan" )) d->a.func0 = atan;
+ else if (strmatch(next, "asin" )) d->a.func0 = asin;
+ else if (strmatch(next, "acos" )) d->a.func0 = acos;
+ else if (strmatch(next, "exp" )) d->a.func0 = exp;
+ else if (strmatch(next, "log" )) d->a.func0 = log;
+ else if (strmatch(next, "abs" )) d->a.func0 = fabs;
+ else if (strmatch(next, "squish")) d->type = e_squish;
+ else if (strmatch(next, "gauss" )) d->type = e_gauss;
+ else if (strmatch(next, "mod" )) d->type = e_mod;
+ else if (strmatch(next, "max" )) d->type = e_max;
+ else if (strmatch(next, "min" )) d->type = e_min;
+ else if (strmatch(next, "eq" )) d->type = e_eq;
+ else if (strmatch(next, "gte" )) d->type = e_gte;
+ else if (strmatch(next, "gt" )) d->type = e_gt;
+ else if (strmatch(next, "lte" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
+ else if (strmatch(next, "lt" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
+ else if (strmatch(next, "ld" )) d->type = e_ld;
+ else if (strmatch(next, "st" )) d->type = e_st;
+ else if (strmatch(next, "while" )) d->type = e_while;
+ else {
+ for (i=0; p->func1_names && p->func1_names[i]; i++) {
+ if (strmatch(next, p->func1_names[i])) {
+ d->a.func1 = p->funcs1[i];
+ d->type = e_func1;
+ *e = d;
+ return 0;
+ }
+ }
+
+ for (i=0; p->func2_names && p->func2_names[i]; i++) {
+ if (strmatch(next, p->func2_names[i])) {
+ d->a.func2 = p->funcs2[i];
+ d->type = e_func2;
+ *e = d;
+ return 0;
+ }
+ }
+
+ av_log(p, AV_LOG_ERROR, "unknown function\n");
+ av_free_expr(d);
+ return AVERROR(EINVAL);
+ }
+
+ *e = d;
+ return 0;
+}
+
+static AVExpr *new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)
+{
+ AVExpr *e = av_mallocz(sizeof(AVExpr));
+ if (!e)
+ return NULL;
+ e->type =type ;
+ e->value =value ;
+ e->param[0] =p0 ;
+ e->param[1] =p1 ;
+ return e;
+}
+
+static int parse_pow(AVExpr **e, Parser *p, int *sign)
+{
+ *sign= (*p->s == '+') - (*p->s == '-');
+ p->s += *sign&1;
+ return parse_primary(e, p);
+}
+
+static int parse_factor(AVExpr **e, Parser *p)
+{
+ int sign, sign2, ret;
+ AVExpr *e0, *e1, *e2;
+ if ((ret = parse_pow(&e0, p, &sign)) < 0)
+ return ret;
+ while(p->s[0]=='^'){
+ e1 = e0;
+ p->s++;
+ if ((ret = parse_pow(&e2, p, &sign2)) < 0) {
+ av_free_expr(e1);
+ return ret;
+ }
+ e0 = new_eval_expr(e_pow, 1, e1, e2);
+ if (!e0) {
+ av_free_expr(e1);
+ av_free_expr(e2);
+ return AVERROR(ENOMEM);
+ }
+ if (e0->param[1]) e0->param[1]->value *= (sign2|1);
+ }
+ if (e0) e0->value *= (sign|1);
+
+ *e = e0;
+ return 0;
+}
+
+static int parse_term(AVExpr **e, Parser *p)
+{
+ int ret;
+ AVExpr *e0, *e1, *e2;
+ if ((ret = parse_factor(&e0, p)) < 0)
+ return ret;
+ while (p->s[0]=='*' || p->s[0]=='/') {
+ int c= *p->s++;
+ e1 = e0;
+ if ((ret = parse_factor(&e2, p)) < 0) {
+ av_free_expr(e1);
+ return ret;
+ }
+ e0 = new_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);
+ if (!e0) {
+ av_free_expr(e1);
+ av_free_expr(e2);
+ return AVERROR(ENOMEM);
+ }
+ }
+ *e = e0;
+ return 0;
+}
+
+static int parse_subexpr(AVExpr **e, Parser *p)
+{
+ int ret;
+ AVExpr *e0, *e1, *e2;
+ if ((ret = parse_term(&e0, p)) < 0)
+ return ret;
+ while (*p->s == '+' || *p->s == '-') {
+ e1 = e0;
+ if ((ret = parse_term(&e2, p)) < 0) {
+ av_free_expr(e1);
+ return ret;
+ }
+ e0 = new_eval_expr(e_add, 1, e1, e2);
+ if (!e0) {
+ av_free_expr(e1);
+ av_free_expr(e2);
+ return AVERROR(ENOMEM);
+ }
+ };
+
+ *e = e0;
+ return 0;
+}
+
+static int parse_expr(AVExpr **e, Parser *p)
+{
+ int ret;
+ AVExpr *e0, *e1, *e2;
+ if (p->stack_index <= 0) //protect against stack overflows
+ return AVERROR(EINVAL);
+ p->stack_index--;
+
+ if ((ret = parse_subexpr(&e0, p)) < 0)
+ return ret;
+ while (*p->s == ';') {
+ e1 = e0;
+ if ((ret = parse_subexpr(&e2, p)) < 0) {
+ av_free_expr(e1);
+ return ret;
+ }
+ p->s++;
+ e0 = new_eval_expr(e_last, 1, e1, e2);
+ if (!e0) {
+ av_free_expr(e1);
+ av_free_expr(e2);
+ return AVERROR(ENOMEM);
+ }
+ };
+
+ p->stack_index++;
+ *e = e0;
+ return 0;
+}
+
+static int verify_expr(AVExpr *e)
+{
+ if (!e) return 0;
+ switch (e->type) {
+ case e_value:
+ case e_const: return 1;
+ case e_func0:
+ case e_func1:
+ case e_squish:
+ case e_ld:
+ case e_gauss: return verify_expr(e->param[0]);
+ default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
+ }
+}
+
+int av_parse_expr(AVExpr **expr, const char *s,
+ const char * const *const_names,
+ const char * const *func1_names, double (* const *funcs1)(void *, double),
+ const char * const *func2_names, double (* const *funcs2)(void *, double, double),
+ int log_offset, void *log_ctx)
+{
+ Parser p;
+ AVExpr *e = NULL;
+ char *w = av_malloc(strlen(s) + 1);
+ char *wp = w;
+ int ret = 0;
+
+ if (!w)
+ return AVERROR(ENOMEM);
+
+ while (*s)
+ if (!isspace(*s++)) *wp++ = s[-1];
+ *wp++ = 0;
+
+ p.class = &class;
+ p.stack_index=100;
+ p.s= w;
+ p.const_names = const_names;
+ p.funcs1 = funcs1;
+ p.func1_names = func1_names;
+ p.funcs2 = funcs2;
+ p.func2_names = func2_names;
+ p.log_offset = log_offset;
+ p.log_ctx = log_ctx;
+
+ if ((ret = parse_expr(&e, &p)) < 0)
+ goto end;
+ if (!verify_expr(e)) {
+ av_free_expr(e);
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+ *expr = e;
+end:
+ av_free(w);
+ return ret;
+}
+
+double av_eval_expr(AVExpr *e, const double *const_values, void *opaque)
+{
+ Parser p;
+
+ p.const_values = const_values;
+ p.opaque = opaque;
+ return eval_expr(&p, e);
+}
+
+int av_parse_and_eval_expr(double *d, const char *s,
+ const char * const *const_names, const double *const_values,
+ const char * const *func1_names, double (* const *funcs1)(void *, double),
+ const char * const *func2_names, double (* const *funcs2)(void *, double, double),
+ void *opaque, int log_offset, void *log_ctx)
+{
+ AVExpr *e = NULL;
+ int ret = av_parse_expr(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);
+
+ if (ret < 0) {
+ *d = NAN;
+ return ret;
+ }
+ *d = av_eval_expr(e, const_values, opaque);
+ av_free_expr(e);
+ return isnan(*d) ? AVERROR(EINVAL) : 0;
+}
+
+#ifdef TEST
+#undef printf
+static double const_values[] = {
+ M_PI,
+ M_E,
+ 0
+};
+
+static const char *const_names[] = {
+ "PI",
+ "E",
+ 0
+};
+
+int main(void)
+{
+ int i;
+ double d;
+ av_parse_and_eval_expr(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
+ const_names, const_values,
+ NULL, NULL, NULL, NULL, NULL, 0, NULL);
+ printf("%f == 12.7\n", d);
+ av_parse_and_eval_expr(&d, "80G/80Gi",
+ const_names, const_values,
+ NULL, NULL, NULL, NULL, NULL, 0, NULL);
+ printf("%f == 0.931322575\n", d);
+
+ for (i=0; i<1050; i++) {
+ START_TIMER
+ av_parse_and_eval_expr(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
+ const_names, const_values,
+ NULL, NULL, NULL, NULL, NULL, 0, NULL);
+ STOP_TIMER("av_parse_and_eval_expr")
+ }
+ return 0;
+}
+#endif
diff --git a/libavutil/eval.h b/libavutil/eval.h
new file mode 100644
index 0000000..3559323
--- /dev/null
+++ b/libavutil/eval.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2002 Michael Niedermayer <michaelni at gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * simple arithmetic expression evaluator
+ */
+
+#ifndef AVUTIL_EVAL_H
+#define AVUTIL_EVAL_H
+
+typedef struct AVExpr AVExpr;
+
+/**
+ * Parses and evaluates an expression.
+ * Note, this is significantly slower than av_eval_expr().
+ *
+ * @param res a pointer to a double where is put the result value of
+ * the expression, or NAN in case of invalid expression
+ * @param s expression as a zero terminated string, for example
+ * "1+2^3+5*5+sin(2/3)"
+ * @param const_names NULL terminated array of zero terminated strings
+ * of constant identifers, for example {"PI", "E", 0}
+ * @param const_values a zero terminated array of values for the
+ * identifers from const_names
+ * @param func1_names NULL terminated array of zero terminated strings
+ * of funcs1 identifers
+ * @param funcs1 NULL terminated array of function pointers for
+ * functions which take 1 argument
+ * @param func2_names NULL terminated array of zero terminated strings
+ * of funcs2 identifers
+ * @param funcs2 NULL terminated array of function pointers for
+ * functions which take 2 arguments
+ * @param opaque a pointer which will be passed to all functions from
+ * funcs1 and funcs2
+ * @param log_ctx parent logging context
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code otherwise
+ */
+int av_parse_and_eval_expr(double *res, const char *s,
+ const char * const *const_names, const double *const_values,
+ const char * const *func1_names, double (* const *funcs1)(void *, double),
+ const char * const *func2_names, double (* const *funcs2)(void *, double, double),
+ void *opaque, int log_offset, void *log_ctx);
+
+/**
+ * Parses an expression.
+ *
+ * @param expr a pointer where is put an AVExpr containing the parsed
+ * value in case of successfull parsing, or NULL otherwise.
+ * The pointed to AVExpr must be freed with av_free_expr() by
+ * the user when it is not needed anymore.
+ * @param s expression as a zero terminated string, for example
+ * "1+2^3+5*5+sin(2/3)"
+ * @param const_names NULL terminated array of zero terminated strings
+ * of constant identifers, for example {"PI", "E", 0}
+ * @param func1_names NULL terminated array of zero terminated strings
+ * of funcs1 identifers
+ * @param funcs1 NULL terminated array of function pointers for
+ * functions which take 1 argument
+ * @param func2_names NULL terminated array of zero terminated strings
+ * of funcs2 identifers
+ * @param funcs2 NULL terminated array of function pointers for
+ * functions which take 2 arguments
+ * @param log_ctx parent logging context
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code otherwise
+ */
+int av_parse_expr(AVExpr **expr, const char *s,
+ const char * const *const_names,
+ const char * const *func1_names, double (* const *funcs1)(void *, double),
+ const char * const *func2_names, double (* const *funcs2)(void *, double, double),
+ int log_offset, void *log_ctx);
+
+/**
+ * Evaluates a previously parsed expression.
+ *
+ * @param const_values a zero terminated array of values for the
+ * identifers from ff_parse() const_names
+ * @param opaque a pointer which will be passed to all functions from
+ * funcs1 and funcs2
+ * @return the value of the expression
+ */
+double av_eval_expr(AVExpr *e, const double *const_values, void *opaque);
+
+/**
+ * Frees a parsed expression previously created with av_parse_expr().
+ */
+void av_free_expr(AVExpr *e);
+
+/**
+ * Parses the string in numstr and returns its value as a double. If
+ * the string is empty, contains only whitespaces, or does not contain
+ * an initial substring that has the expected syntax for a
+ * floating-point number, no conversion is performed. In this case,
+ * returns a value of zero and the value returned in tail is the value
+ * of numstr.
+ *
+ * @param numstr a string representing a number, may contain one of
+ * the International System number postfixes, for example 'K',
+ * 'M', 'G'. If 'i' is appended after the postfix, powers of 2
+ * are used instead of powers of 10. The 'B' postfix multiplies
+ * the value for 8, and can be appended after another postfix
+ * or used alone. This allows using for example 'KB', 'MiB',
+ * 'G' and 'B' as postfix.
+ * @param tail if non-NULL puts here the pointer to the char next
+ * after the last parsed character
+ */
+double av_strtod(const char *numstr, char **tail);
+
+#endif /* AVUTIL_EVAL_H */
--
1.7.1
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