[PATCH 05/21] Change eval internal functions and ff_parse() interface.
Stefano Sabatini
stefano.sabatini-lala
Tue Apr 6 00:13:04 CEST 2010
Make them return an error code and print the error on the log rather
than set a constant error string in the Parser.
Allow ff_parse() to provide more information about the reason of the
failure, and allow the error message to be more expressive, as it is
not anymore a generic const char * string.
---
libavcodec/eval.c | 169 ++++++++++++++++++++++++++++++----------------
libavcodec/eval.h | 12 ++--
libavcodec/ratecontrol.c | 11 ++--
3 files changed, 122 insertions(+), 70 deletions(-)
diff --git a/libavcodec/eval.c b/libavcodec/eval.c
index 182bbc5..72997b4 100644
--- a/libavcodec/eval.c
+++ b/libavcodec/eval.c
@@ -47,7 +47,6 @@ typedef struct Parser{
double (**func2)(void *, double a, double b); // NULL terminated
const char **func2_name; // NULL terminated
void *opaque;
- const char **error;
#define VARS 10
double var[VARS];
} Parser;
@@ -171,7 +170,7 @@ static double eval_expr(Parser * p, AVExpr * e) {
return NAN;
}
-static AVExpr * parse_expr(Parser *p);
+static int parse_expr(AVExpr **expr, Parser *p, void *log_ctx);
void ff_free_expr(AVExpr * e) {
if (!e) return;
@@ -180,20 +179,21 @@ void ff_free_expr(AVExpr * e) {
av_freep(&e);
}
-static AVExpr * parse_primary(Parser *p) {
+static int parse_primary(AVExpr **expr, Parser *p, void *log_ctx) {
AVExpr * d = av_mallocz(sizeof(AVExpr));
char *next= p->s;
- int i;
+ int i, ret;
if (!d)
- return NULL;
+ return AVERROR(ENOMEM);
/* number */
d->value = av_strtod(p->s, &next);
if(next != p->s){
d->type = e_value;
p->s= next;
- return d;
+ *expr = d;
+ return 0;
}
d->value = 1;
@@ -203,38 +203,47 @@ static AVExpr * parse_primary(Parser *p) {
p->s+= strlen(p->const_name[i]);
d->type = e_const;
d->a.const_index = i;
- return d;
+ *expr = d;
+ return 0;
}
}
p->s= strchr(p->s, '(');
if(p->s==NULL){
- *p->error = "undefined constant or missing (";
+ av_log(log_ctx, AV_LOG_ERROR, "undefined constant or missing (\n");
p->s= next;
ff_free_expr(d);
- return NULL;
+ return AVERROR(EINVAL);
}
p->s++; // "("
if (*next == '(') { // special case do-nothing
av_freep(&d);
- d = parse_expr(p);
+ if ((ret = parse_expr(&d, p, log_ctx)) < 0)
+ return ret;
if(p->s[0] != ')'){
- *p->error = "missing )";
+ av_log(log_ctx, AV_LOG_ERROR, "missing )\n");
ff_free_expr(d);
- return NULL;
+ return AVERROR(EINVAL);
}
p->s++; // ")"
- return d;
+ *expr = d;
+ return 0;
+ }
+ if ((ret = parse_expr(&d->param[0], p, log_ctx)) < 0) {
+ ff_free_expr(d);
+ return ret;
}
- d->param[0] = parse_expr(p);
if(p->s[0]== ','){
p->s++; // ","
- d->param[1] = parse_expr(p);
+ if ((ret = parse_expr(&d->param[1], p, log_ctx)) < 0) {
+ ff_free_expr(d);
+ return ret;
+ }
}
if(p->s[0] != ')'){
- *p->error = "missing )";
+ av_log(log_ctx, AV_LOG_ERROR, "missing )\n");
ff_free_expr(d);
- return NULL;
+ return AVERROR(EINVAL);
}
p->s++; // ")"
@@ -269,7 +278,8 @@ static AVExpr * parse_primary(Parser *p) {
if(strmatch(next, p->func1_name[i])){
d->a.func1 = p->func1[i];
d->type = e_func1;
- return d;
+ *expr = d;
+ return 0;
}
}
@@ -277,16 +287,18 @@ static AVExpr * parse_primary(Parser *p) {
if(strmatch(next, p->func2_name[i])){
d->a.func2 = p->func2[i];
d->type = e_func2;
- return d;
+ *expr = d;
+ return 0;
}
}
- *p->error = "unknown function";
+ av_log(log_ctx, AV_LOG_ERROR, "unknown function\n");
ff_free_expr(d);
- return NULL;
+ return AVERROR(EINVAL);
}
- return d;
+ *expr = d;
+ return 0;
}
static AVExpr * new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1){
@@ -300,67 +312,102 @@ static AVExpr * new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1){
return e;
}
-static AVExpr * parse_pow(Parser *p, int *sign){
+static int parse_pow(AVExpr **expr, Parser *p, int *sign, void *log_ctx){
*sign= (*p->s == '+') - (*p->s == '-');
p->s += *sign&1;
- return parse_primary(p);
+ return parse_primary(expr, p, log_ctx);
}
-static AVExpr * parse_factor(Parser *p){
- int sign, sign2;
- AVExpr * e = parse_pow(p, &sign);
+static int parse_factor(AVExpr **expr, Parser *p, void *log_ctx){
+ int ret, sign, sign2;
+ AVExpr * e = NULL, * e1 = NULL;
+
+ if ((ret = parse_pow(&e, p, &sign, log_ctx)) < 0)
+ return ret;
while(p->s[0]=='^'){
p->s++;
- e= new_eval_expr(e_pow, 1, e, parse_pow(p, &sign2));
+ if ((ret = parse_pow(&e1, p, &sign2, log_ctx)) < 0) {
+ ff_free_expr(e);
+ return ret;
+ }
+ e= new_eval_expr(e_pow, 1, e, e1);
if (!e)
- return NULL;
+ return AVERROR(ENOMEM);
if (e->param[1]) e->param[1]->value *= (sign2|1);
}
if (e) e->value *= (sign|1);
- return e;
+ *expr = e;
+ return 0;
}
-static AVExpr * parse_term(Parser *p){
- AVExpr * e = parse_factor(p);
+static int parse_term(AVExpr **expr, Parser *p, void *log_ctx){
+ AVExpr * e = NULL, * e1 = NULL;
+ int ret;
+
+ if ((ret = parse_factor(&e, p, log_ctx)) < 0)
+ return ret;
+
while(p->s[0]=='*' || p->s[0]=='/'){
int c= *p->s++;
- e= new_eval_expr(c == '*' ? e_mul : e_div, 1, e, parse_factor(p));
+ if ((ret = parse_factor(&e1, p, log_ctx)) < 0) {
+ ff_free_expr(e);
+ return ret;
+ }
+ e= new_eval_expr(c == '*' ? e_mul : e_div, 1, e, e1);
if (!e)
- return NULL;
+ return AVERROR(ENOMEM);
}
- return e;
+ *expr = e;
+ return 0;
}
-static AVExpr * parse_subexpr(Parser *p) {
- AVExpr * e = parse_term(p);
+static int parse_subexpr(AVExpr **expr, Parser *p, void *log_ctx) {
+ AVExpr * e = NULL, * e1 = NULL;
+ int ret;
+
+ if ((ret = parse_term(&e, p, log_ctx)) < 0)
+ return ret;
+
while(*p->s == '+' || *p->s == '-') {
- e= new_eval_expr(e_add, 1, e, parse_term(p));
+ if ((ret = parse_term(&e1, p, log_ctx) < 0)) {
+ ff_free_expr(e);
+ return ret;
+ }
+ e= new_eval_expr(e_add, 1, e, e1);
if (!e)
- return NULL;
+ return AVERROR(ENOMEM);
};
- return e;
+ *expr = e;
+ return 0;
}
-static AVExpr * parse_expr(Parser *p) {
- AVExpr * e;
+static int parse_expr(AVExpr **expr, Parser *p, void *log_ctx) {
+ AVExpr * e = NULL, * e1 = NULL;
+ int ret;
if(p->stack_index <= 0) //protect against stack overflows
- return NULL;
+ return -1;
p->stack_index--;
- e = parse_subexpr(p);
+ if ((ret = parse_subexpr(&e, p, log_ctx)) < 0)
+ return ret;
while(*p->s == ';') {
p->s++;
- e= new_eval_expr(e_last, 1, e, parse_subexpr(p));
+ if ((ret = parse_subexpr(&e1, p, log_ctx)) < 0) {
+ ff_free_expr(e);
+ return ret;
+ }
+ e= new_eval_expr(e_last, 1, e, e1);
if (!e)
- return NULL;
+ return AVERROR(ENOMEM);
};
p->stack_index++;
- return e;
+ *expr = e;
+ return 0;
}
static int verify_expr(AVExpr * e) {
@@ -377,17 +424,17 @@ static int verify_expr(AVExpr * e) {
}
}
-AVExpr * ff_parse(const char *s, const char * const *const_name,
+int ff_parse(AVExpr **expr, const char *s, const char * const *const_name,
double (**func1)(void *, double), const char **func1_name,
double (**func2)(void *, double, double), const char **func2_name,
- const char **error){
+ void *log_ctx){
Parser p;
- AVExpr *e = NULL;
char *w = av_malloc(strlen(s) + 1);
char *wp = w;
+ int ret;
if (!w)
- goto end;
+ return AVERROR(ENOMEM);
while (*s)
if (!isspace(*s++)) *wp++ = s[-1];
@@ -400,16 +447,16 @@ AVExpr * ff_parse(const char *s, const char * const *const_name,
p.func1_name = func1_name;
p.func2 = func2;
p.func2_name = func2_name;
- p.error= error;
- e = parse_expr(&p);
- if (!verify_expr(e)) {
- ff_free_expr(e);
- e = NULL;
+ ret = parse_expr(expr, &p, log_ctx);
+ if (ret < 0)
+ goto end;
+ if (!verify_expr(*expr)) {
+ ff_free_expr(*expr);
}
end:
av_free(w);
- return e;
+ return ret;
}
double ff_parse_eval(AVExpr * e, const double *const_value, void *opaque) {
@@ -424,9 +471,13 @@ double ff_eval2(const char *s, const double *const_value, const char * const *co
double (**func1)(void *, double), const char **func1_name,
double (**func2)(void *, double, double), const char **func2_name,
void *opaque, const char **error){
- AVExpr * e = ff_parse(s, const_name, func1, func1_name, func2, func2_name, error);
+ AVExpr * e;
double d;
- if (!e) return NAN;
+ int ret = ff_parse(&e, s, const_name, func1, func1_name, func2, func2_name, NULL);
+ if (ret < 0) {
+ *error = "Error occurred during parsing, check log";
+ return NAN;
+ }
d = ff_parse_eval(e, const_value, opaque);
ff_free_expr(e);
return d;
diff --git a/libavcodec/eval.h b/libavcodec/eval.h
index c3c9942..be96a7d 100644
--- a/libavcodec/eval.h
+++ b/libavcodec/eval.h
@@ -51,20 +51,22 @@ double ff_eval2(const char *s, const double *const_value, const char * const *co
/**
* Parses a expression.
+ * @param expr in case of successfull parsing puts here an AVExpr
+ * which 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 func1 NULL terminated array of function pointers for functions which take 1 argument
* @param func2 NULL terminated array of function pointers for functions which take 2 arguments
* @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
* @param func1_name NULL terminated array of zero terminated strings of func1 identifers
* @param func2_name NULL terminated array of zero terminated strings of func2 identifers
- * @param error pointer to a char* which is set to an error message if something goes wrong
- * @return AVExpr which must be freed with ff_free_expr() by the user when it is not needed anymore
- * NULL if anything went wrong
+ * @return 0 in case of success, a negative error corresponding to an
+ * AVERROR code in case of failure
*/
-AVExpr * ff_parse(const char *s, const char * const *const_name,
+int ff_parse(AVExpr **expr, const char *s, const char * const *const_name,
double (**func1)(void *, double), const char **func1_name,
double (**func2)(void *, double, double), const char **func2_name,
- const char **error);
+ void *log_ctx);
/**
* Evaluates a previously parsed expression.
* @param const_value a zero terminated array of values for the identifers from ff_parse const_name
diff --git a/libavcodec/ratecontrol.c b/libavcodec/ratecontrol.c
index f1f9c06..dd05668 100644
--- a/libavcodec/ratecontrol.c
+++ b/libavcodec/ratecontrol.c
@@ -66,8 +66,7 @@ static inline double bits2qp(RateControlEntry *rce, double bits){
int ff_rate_control_init(MpegEncContext *s)
{
RateControlContext *rcc= &s->rc_context;
- int i;
- const char *error = NULL;
+ int i, ret;
static const char * const const_names[]={
"PI",
"E",
@@ -107,10 +106,10 @@ int ff_rate_control_init(MpegEncContext *s)
};
emms_c();
- rcc->rc_eq_eval = ff_parse(s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1, func1_names, NULL, NULL, &error);
- if (!rcc->rc_eq_eval) {
- av_log(s->avctx, AV_LOG_ERROR, "Error parsing rc_eq \"%s\": %s\n", s->avctx->rc_eq, error? error : "");
- return -1;
+ ret = ff_parse(&rcc->rc_eq_eval, s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1, func1_names, NULL, NULL, s->avctx);
+ if (ret < 0) {
+ av_log(s->avctx, AV_LOG_ERROR, "Error parsing rc_eq \"%s\"\n", s->avctx->rc_eq);
+ return ret;
}
for(i=0; i<5; i++){
--
1.7.0
--zYM0uCDKw75PZbzx--
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