+ * this in order for a correct duration to be returned. If @p flags is @c NULL,
+ * special frames are considered invalid.
+ *
+ * @param s Vorbis parser context
+ * @param buf buffer containing a Vorbis frame
+ * @param buf_size size of the buffer
+ * @param flags flags for special frames
+ */
+int avpriv_vorbis_parse_frame_flags(AVVorbisParseContext *s, const uint8_t *buf,
+ int buf_size, int *flags);
+
+/**
+ * Get the duration for a Vorbis packet.
+ *
+ * avpriv_vorbis_parse_extradata() must have been successfully called prior to