Make ff_parse_expr() and ff_parse_and_eval_expr() return an int

containing an error code.

Allow these functions to convey the reason of the failure to the
calling function, failure which is not always due to a parsing error
but it may depend for example on a memory problem.

Also fix several potential memleaks.

Originally committed as revision 23402 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -31,7 +31,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 52
 #define LIBAVCODEC_VERSION_MINOR 72
-#define LIBAVCODEC_VERSION_MICRO  0
+#define LIBAVCODEC_VERSION_MICRO  1
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \

libavcodec/eval.h

@@ -32,6 +32,8 @@ 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 error
  * @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
  * @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
  * @param const_value a zero terminated array of values for the identifers from const_name
@@ -41,9 +43,10 @@ typedef struct AVExpr AVExpr;
  * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
  * @param opaque a pointer which will be passed to all functions from func1 and func2
  * @param log_ctx parent logging context
- * @return the value of the expression
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code otherwise
  */
-double ff_parse_and_eval_expr(const char *s,
+int ff_parse_and_eval_expr(double *res, const char *s,
                               const char * const *const_name, const double *const_value,
                               const char * const *func1_name, double (* const *func1)(void *, double),
                               const char * const *func2_name, double (* const *func2)(void *, double, double),
@@ -52,6 +55,10 @@ double ff_parse_and_eval_expr(const char *s,
 /**
  * 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_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
@@ -59,10 +66,10 @@ double ff_parse_and_eval_expr(const char *s,
  * @param func2_name NULL terminated array of zero terminated strings of func2 identifers
  * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
  * @param log_ctx parent logging context
- * @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 value corresponding to an
+ * AVERROR code otherwise
  */
-AVExpr *ff_parse_expr(const char *s,
+int ff_parse_expr(AVExpr **expr, const char *s,
                       const char * const *const_name,
                       const char * const *func1_name, double (* const *func1)(void *, double),
                       const char * const *func2_name, double (* const *func2)(void *, double, double),

libavcodec/opt.c

@@ -165,10 +165,10 @@ 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 {
-                    d = ff_parse_and_eval_expr(buf, const_names, const_values, NULL, NULL, NULL, NULL, NULL, 0, obj);
-                    if (isnan(d)){
+                    int res = ff_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 AVERROR(EINVAL);
+                        return res;
                     }
                 }
             }

libavcodec/ratecontrol.c

@@ -66,7 +66,7 @@ static inline double bits2qp(RateControlEntry *rce, double bits){
 int ff_rate_control_init(MpegEncContext *s)
 {
     RateControlContext *rcc= &s->rc_context;
-    int i;
+    int i, res;
     static const char * const const_names[]={
         "PI",
         "E",
@@ -106,10 +106,10 @@ int ff_rate_control_init(MpegEncContext *s)
     };
     emms_c();
 
-    rcc->rc_eq_eval = ff_parse_expr(s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1_names, func1, NULL, NULL, 0, s->avctx);
-    if (!rcc->rc_eq_eval) {
+    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);
+    if (res < 0) {
         av_log(s->avctx, AV_LOG_ERROR, "Error parsing rc_eq \"%s\"\n", s->avctx->rc_eq);
-        return -1;
+        return res;
     }
 
     for(i=0; i<5; i++){