lavu/opt: introduce av_opt_serialize()

Function allows to create string containing object's serialized options.
Such string may be passed back to av_set_options_string() in order to restore options.

Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/libavutil/opt.h b/libavutil/opt.h
index 1b458e1860..7338e78368 100644
--- a/libavutil/opt.h
+++ b/libavutil/opt.h
@@ -869,6 +869,27 @@ int av_opt_is_set_to_default(void *obj, const AVOption *o);
  */
 int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags);
 
+
+#define AV_OPT_SERIALIZE_SKIP_DEFAULTS              0x00000001  ///< Serialize options that are not set to default values only.
+#define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT            0x00000002  ///< Serialize options that exactly match opt_flags only.
+
+/**
+ * Serialize object's options.
+ *
+ * Create a string containing object's serialized options.
+ * Such string may be passed back to av_opt_set_from_string() in order to restore option values.
+ *
+ * @param[in]  obj           AVClass object to serialize
+ * @param[in]  opt_flags     serialize options with all the specified flags set (AV_OPT_FLAG)
+ * @param[in]  flags         combination of AV_OPT_SERIALIZE_* flags
+ * @param[out] buffer        Pointer to buffer that will be allocated with string containg serialized options.
+ *                           Buffer must be freed by the caller when is no longer needed.
+ * @param[in]  key_val_sep   character used to separate key from value
+ * @param[in]  pairs_sep     character used to separate two pairs from each other
+ * @return                   >= 0 on success, negative on error
+ */
+int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer,
+                     const char key_val_sep, const char pairs_sep);
 /**
  * @}
  */