format_cap: Perform codec lookups by pointer instead of name

ASTERISK-28416 #close

Change-Id: I069420875ebdbcaada52d92599a5f7de3cb2cdf4

include/asterisk/format_cache.h

@@ -306,4 +306,17 @@ struct ast_format *ast_format_cache_get_slin_by_rate(unsigned int rate);
  */
 int ast_format_cache_is_slinear(struct ast_format *format);
 
+/*!
+ * \brief Retrieve a format from the cache by its codec
+ *
+ * \param codec The codec to search by
+ *
+ * \retval non-NULL if found
+ * \retval NULL if not found
+ *
+ * \note The returned format has its reference count incremented. It must be
+ * dropped using ao2_ref or ao2_cleanup.
+ */
+struct ast_format *ast_format_cache_get_by_codec(const struct ast_codec *codec);
+
 #endif /* _AST_FORMAT_CACHE_H */

main/format_cache.c

@@ -541,3 +541,24 @@ int ast_format_cache_is_slinear(struct ast_format *format)
 
 	return 0;
 }
+
+struct ast_format *ast_format_cache_get_by_codec(const struct ast_codec *codec)
+{
+	struct ast_format *format;
+	struct ao2_iterator it;
+
+	for (it = ao2_iterator_init(formats, 0);
+		 (format = ao2_iterator_next(&it));
+		 ao2_ref(format, -1)) {
+		struct ast_codec *candidate = ast_format_get_codec(format);
+		if (codec == candidate) {
+			ao2_cleanup(candidate);
+			ao2_iterator_destroy(&it);
+			return format;
+		}
+		ao2_cleanup(candidate);
+	}
+
+	ao2_iterator_destroy(&it);
+	return NULL;
+}

main/format_cap.c

@@ -268,7 +268,7 @@ int ast_format_cap_append_by_type(struct ast_format_cap *cap, enum ast_media_typ
 			continue;
 		}
 
-		format = ast_format_cache_get(codec->name);
+		format = ast_format_cache_get_by_codec(codec);
 
 		if (format == ast_format_none) {
 			ao2_ref(format, -1);