+static const AVOption options[]={
+{"iblock", "Sets the impulse block bias", offsetof(OggVorbisContext, iblock), FF_OPT_TYPE_DOUBLE, 0, -15, 0, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_ENCODING_PARAM},
+{NULL}
+};
+static const AVClass class = { "libvorbis", av_default_item_name, options, LIBAVUTIL_VERSION_INT };