AVOptions: add av_opt_set_dict() mapping a dictionary struct to a context.

This way the caller can pass all the options in one nice package.

libavutil/opt.c

@@ -29,6 +29,7 @@
 #include "avstring.h"
 #include "opt.h"
 #include "eval.h"
+#include "dict.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)
@@ -538,6 +539,27 @@ void av_opt_free(void *obj)
             av_freep((uint8_t *)obj + o->offset);
 }
 
+int av_opt_set_dict(void *obj, AVDictionary **options)
+{
+    AVDictionaryEntry *t = NULL;
+    AVDictionary    *tmp = NULL;
+    int ret = 0;
+
+    while ((t = av_dict_get(*options, "", t, AV_DICT_IGNORE_SUFFIX))) {
+        ret = av_set_string3(obj, t->key, t->value, 1, NULL);
+        if (ret == AVERROR_OPTION_NOT_FOUND)
+            av_dict_set(&tmp, t->key, t->value, 0);
+        else if (ret < 0) {
+            av_log(obj, AV_LOG_ERROR, "Error setting option %s to value %s.\n", t->key, t->value);
+            break;
+        }
+        ret = 0;
+    }
+    av_dict_free(options);
+    *options = tmp;
+    return ret;
+}
+
 #ifdef TEST
 
 #undef printf

libavutil/opt.h

@@ -29,6 +29,7 @@
 
 #include "rational.h"
 #include "avutil.h"
+#include "dict.h"
 
 enum AVOptionType{
     FF_OPT_TYPE_FLAGS,
@@ -191,4 +192,20 @@ void av_opt_free(void *obj);
  */
 int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
 
+/*
+ * Set all the options from a given dictionary on an object.
+ *
+ * @param obj a struct whose first element is a pointer to AVClass
+ * @param options options to process. This dictionary will be freed and replaced
+ *                by a new one containing all options not found in obj.
+ *                Of course this new dictionary needs to be freed by caller
+ *                with av_dict_free().
+ *
+ * @return 0 on success, a negative AVERROR if some option was found in obj,
+ *         but could not be set.
+ *
+ * @see av_dict_copy()
+ */
+int av_opt_set_dict(void *obj, struct AVDictionary **options);
+
 #endif /* AVUTIL_OPT_H */