diff --git a/trunk/doc/CHANGELOG.md b/trunk/doc/CHANGELOG.md
index b6e8d232f..6f2437135 100644
--- a/trunk/doc/CHANGELOG.md
+++ b/trunk/doc/CHANGELOG.md
@@ -7,6 +7,7 @@ The changelog for SRS.
 <a name="v6-changes"></a>
 
 ## SRS 6.0 Changelog
+* v6.0, 2024-06-29, Merge [#4077](https://github.com/ossrs/srs/pull/4077): Fix misspelling error in app config. v6.0.133 (#4077)
 * v6.0, 2024-06-29, Merge [#4102](https://github.com/ossrs/srs/pull/4102): SmartPtr: Support detect memory leak by valgrind. v6.0.132 (#4102)
 * v6.0, 2024-06-21, Merge [#4100](https://github.com/ossrs/srs/pull/4100): Fix security scan problems. v6.0.131 (#4100)
 * v6.0, 2024-06-21, Merge [#4097](https://github.com/ossrs/srs/pull/4097): SmartPtr: Support load test for source by srs-bench. v6.0.130 (#4097)
diff --git a/trunk/src/app/srs_app_config.cpp b/trunk/src/app/srs_app_config.cpp
index 36a9007ed..07146a679 100644
--- a/trunk/src/app/srs_app_config.cpp
+++ b/trunk/src/app/srs_app_config.cpp
@@ -45,9 +45,9 @@ using namespace srs_internal;
 // @global the version to identify the core.
 const char* _srs_version = "XCORE-" RTMP_SIG_SRS_SERVER;
 
-// when user config an invalid value, macros to perfer true or false.
-#define SRS_CONF_PERFER_FALSE(conf_arg) conf_arg == "on"
-#define SRS_CONF_PERFER_TRUE(conf_arg) conf_arg != "off"
+// when user config an invalid value, macros to prefer true or false.
+#define SRS_CONF_PREFER_FALSE(conf_arg) conf_arg == "on"
+#define SRS_CONF_PREFER_TRUE(conf_arg) conf_arg != "off"
 
 // default config file.
 #define SRS_CONF_DEFAULT_COFNIG_FILE SRS_DEFAULT_CONFIG
@@ -60,8 +60,8 @@ const char* _srs_version = "XCORE-" RTMP_SIG_SRS_SERVER;
 
 // Overwrite the config by env.
 #define SRS_OVERWRITE_BY_ENV_STRING(key) if (!srs_getenv(key).empty()) return srs_getenv(key)
-#define SRS_OVERWRITE_BY_ENV_BOOL(key) if (!srs_getenv(key).empty()) return SRS_CONF_PERFER_FALSE(srs_getenv(key))
-#define SRS_OVERWRITE_BY_ENV_BOOL2(key) if (!srs_getenv(key).empty()) return SRS_CONF_PERFER_TRUE(srs_getenv(key))
+#define SRS_OVERWRITE_BY_ENV_BOOL(key) if (!srs_getenv(key).empty()) return SRS_CONF_PREFER_FALSE(srs_getenv(key))
+#define SRS_OVERWRITE_BY_ENV_BOOL2(key) if (!srs_getenv(key).empty()) return SRS_CONF_PREFER_TRUE(srs_getenv(key))
 #define SRS_OVERWRITE_BY_ENV_INT(key) if (!srs_getenv(key).empty()) return ::atoi(srs_getenv(key).c_str())
 #define SRS_OVERWRITE_BY_ENV_FLOAT(key) if (!srs_getenv(key).empty()) return ::atof(srs_getenv(key).c_str())
 #define SRS_OVERWRITE_BY_ENV_SECONDS(key) if (!srs_getenv(key).empty()) return srs_utime_t(::atoi(srs_getenv(key).c_str()) * SRS_UTIME_SECONDS)
@@ -2908,7 +2908,7 @@ bool SrsConfig::get_daemon()
         return true;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_in_docker()
@@ -2922,7 +2922,7 @@ bool SrsConfig::get_in_docker()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::is_full_config()
@@ -2934,7 +2934,7 @@ bool SrsConfig::is_full_config()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_root()
@@ -3098,7 +3098,7 @@ bool SrsConfig::get_utc_time()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_work_dir()
@@ -3126,7 +3126,7 @@ bool SrsConfig::get_asprocess()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::whether_query_latest_version()
@@ -3140,7 +3140,7 @@ bool SrsConfig::whether_query_latest_version()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::first_wait_for_qlv()
@@ -3168,7 +3168,7 @@ bool SrsConfig::empty_ip_ok()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_grace_start_wait()
@@ -3210,7 +3210,7 @@ bool SrsConfig::is_force_grace_quit()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::disable_daemon_for_docker()
@@ -3224,7 +3224,7 @@ bool SrsConfig::disable_daemon_for_docker()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::inotify_auto_reload()
@@ -3238,7 +3238,7 @@ bool SrsConfig::inotify_auto_reload()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::auto_reload_for_docker()
@@ -3252,7 +3252,7 @@ bool SrsConfig::auto_reload_for_docker()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 // TODO: FIXME: Support reload.
@@ -3318,7 +3318,7 @@ bool SrsConfig::get_circuit_breaker()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_high_threshold()
@@ -3451,7 +3451,7 @@ bool SrsConfig::get_tencentcloud_cls_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_tencentcloud_cls_stat_heartbeat()
@@ -3470,7 +3470,7 @@ bool SrsConfig::get_tencentcloud_cls_stat_heartbeat()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_tencentcloud_cls_stat_streams()
@@ -3489,7 +3489,7 @@ bool SrsConfig::get_tencentcloud_cls_stat_streams()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_tencentcloud_cls_debug_logging()
@@ -3508,7 +3508,7 @@ bool SrsConfig::get_tencentcloud_cls_debug_logging()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 int SrsConfig::get_tencentcloud_cls_heartbeat_ratio()
@@ -3679,7 +3679,7 @@ bool SrsConfig::get_tencentcloud_apm_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_tencentcloud_apm_team()
@@ -3774,7 +3774,7 @@ bool SrsConfig::get_tencentcloud_apm_debug_logging()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_exporter_enabled()
@@ -3793,7 +3793,7 @@ bool SrsConfig::get_exporter_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_exporter_listen()
@@ -3885,7 +3885,7 @@ bool SrsConfig::get_stream_caster_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_stream_caster_engine(SrsConfDirective* conf)
@@ -3954,7 +3954,7 @@ bool SrsConfig::get_stream_caster_sip_enable(SrsConfDirective* conf)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_stream_caster_sip_listen(SrsConfDirective* conf)
@@ -4072,7 +4072,7 @@ bool SrsConfig::get_rtc_server_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 int SrsConfig::get_rtc_server_listen()
@@ -4144,7 +4144,7 @@ bool SrsConfig::get_api_as_candidates()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_resolve_api_domain()
@@ -4163,7 +4163,7 @@ bool SrsConfig::get_resolve_api_domain()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_keep_api_domain()
@@ -4182,7 +4182,7 @@ bool SrsConfig::get_keep_api_domain()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_use_auto_detect_network_ip()
@@ -4201,7 +4201,7 @@ bool SrsConfig::get_use_auto_detect_network_ip()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_server_tcp_enabled()
@@ -4225,7 +4225,7 @@ bool SrsConfig::get_rtc_server_tcp_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 int SrsConfig::get_rtc_server_tcp_listen()
@@ -4306,7 +4306,7 @@ bool SrsConfig::get_rtc_server_ecdsa()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_server_encrypt()
@@ -4325,7 +4325,7 @@ bool SrsConfig::get_rtc_server_encrypt()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_rtc_server_reuseport()
@@ -4377,7 +4377,7 @@ bool SrsConfig::get_rtc_server_merge_nalus()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_server_black_hole()
@@ -4401,7 +4401,7 @@ bool SrsConfig::get_rtc_server_black_hole()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 std::string SrsConfig::get_rtc_server_black_hole_addr()
@@ -4451,7 +4451,7 @@ bool SrsConfig::get_rtc_enabled(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_keep_bframe(string vhost)
@@ -4471,7 +4471,7 @@ bool SrsConfig::get_rtc_keep_bframe(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_keep_avc_nalu_sei(std::string vhost)
@@ -4491,7 +4491,7 @@ bool SrsConfig::get_rtc_keep_avc_nalu_sei(std::string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_from_rtmp(string vhost)
@@ -4511,7 +4511,7 @@ bool SrsConfig::get_rtc_from_rtmp(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_rtc_stun_timeout(string vhost)
@@ -4551,7 +4551,7 @@ bool SrsConfig::get_rtc_stun_strict_check(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 std::string SrsConfig::get_rtc_dtls_role(string vhost)
@@ -4629,7 +4629,7 @@ bool SrsConfig::get_rtc_to_rtmp(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_rtc_pli_for_rtmp(string vhost)
@@ -4677,7 +4677,7 @@ bool SrsConfig::get_rtc_nack_enabled(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_nack_no_copy(string vhost)
@@ -4696,7 +4696,7 @@ bool SrsConfig::get_rtc_nack_no_copy(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_rtc_twcc_enabled(string vhost)
@@ -4715,7 +4715,7 @@ bool SrsConfig::get_rtc_twcc_enabled(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_rtc_opus_bitrate(string vhost)
@@ -4840,13 +4840,13 @@ bool SrsConfig::get_vhost_enabled(SrsConfDirective* conf)
         return false;
     }
     
-    // perfer true for exists one.
+    // prefer true for exists one.
     conf = conf->get("enabled");
     if (!conf || conf->arg0().empty()) {
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_gop_cache(string vhost)
@@ -4868,7 +4868,7 @@ bool SrsConfig::get_gop_cache(string vhost)
         return SRS_PERF_GOP_CACHE;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 
@@ -4916,7 +4916,7 @@ bool SrsConfig::get_debug_srs_upnode(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_atc(string vhost)
@@ -4940,7 +4940,7 @@ bool SrsConfig::get_atc(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_atc_auto(string vhost)
@@ -4964,7 +4964,7 @@ bool SrsConfig::get_atc_auto(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 int SrsConfig::get_time_jitter(string vhost)
@@ -5014,7 +5014,7 @@ bool SrsConfig::get_mix_correct(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_queue_length(string vhost)
@@ -5060,7 +5060,7 @@ bool SrsConfig::get_refer_enabled(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_refer_all(string vhost)
@@ -5199,7 +5199,7 @@ bool SrsConfig::get_parse_sps(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::try_annexb_first(string vhost)
@@ -5224,7 +5224,7 @@ bool SrsConfig::try_annexb_first(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_mr_enabled(string vhost)
@@ -5246,7 +5246,7 @@ bool SrsConfig::get_mr_enabled(string vhost)
         return SRS_PERF_MR_ENABLED;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_mr_sleep(string vhost)
@@ -5382,9 +5382,9 @@ bool SrsConfig::get_realtime_enabled(string vhost, bool is_rtc)
     }
 
     if (is_rtc) {
-        return SRS_CONF_PERFER_TRUE(conf->arg0());
+        return SRS_CONF_PREFER_TRUE(conf->arg0());
     } else {
-        return SRS_CONF_PERFER_FALSE(conf->arg0());
+        return SRS_CONF_PREFER_FALSE(conf->arg0());
     }
 }
 
@@ -5404,7 +5404,7 @@ bool SrsConfig::get_tcp_nodelay(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_send_min_interval(string vhost)
@@ -5452,7 +5452,7 @@ bool SrsConfig::get_reduce_sequence_header(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_publish_1stpkt_timeout(string vhost)
@@ -5573,7 +5573,7 @@ bool SrsConfig::get_forward_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_forwards(string vhost)
@@ -5646,7 +5646,7 @@ bool SrsConfig::get_vhost_http_hooks_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_vhost_on_connect(string vhost)
@@ -5841,7 +5841,7 @@ bool SrsConfig::get_vhost_edge_follow_client(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_vhost_edge_token_traverse(string vhost)
@@ -5863,7 +5863,7 @@ bool SrsConfig::get_vhost_edge_token_traverse(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_vhost_edge_transform_vhost(string vhost)
@@ -5913,7 +5913,7 @@ bool SrsConfig::get_vhost_origin_cluster(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 vector<string> SrsConfig::get_vhost_coworkers(string vhost)
@@ -5967,7 +5967,7 @@ bool SrsConfig::get_security_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_security_rules(string vhost)
@@ -6008,7 +6008,7 @@ bool SrsConfig::get_transcode_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_transcode_ffmpeg(SrsConfDirective* conf)
@@ -6059,7 +6059,7 @@ bool SrsConfig::get_engine_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string srs_prefix_underscores_ifno(string name)
@@ -6459,7 +6459,7 @@ bool SrsConfig::get_exec_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 vector<SrsConfDirective*> SrsConfig::get_exec_publishs(string vhost)
@@ -6524,7 +6524,7 @@ bool SrsConfig::get_ingest_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_ingest_ffmpeg(SrsConfDirective* conf)
@@ -6723,7 +6723,7 @@ bool SrsConfig::get_dash_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_dash_fragment(string vhost)
@@ -6856,7 +6856,7 @@ bool SrsConfig::get_dash_cleanup(std::string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_dash_dispose(std::string vhost)
@@ -6915,7 +6915,7 @@ bool SrsConfig::get_hls_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_hls_entry_prefix(string vhost)
@@ -7010,7 +7010,7 @@ bool SrsConfig::get_hls_ts_floor(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_hls_fragment(string vhost)
@@ -7182,7 +7182,7 @@ bool SrsConfig::get_vhost_hls_dts_directly(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_hls_ctx_enabled(std::string vhost)
@@ -7201,7 +7201,7 @@ bool SrsConfig::get_hls_ctx_enabled(std::string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_hls_ts_ctx_enabled(std::string vhost)
@@ -7220,7 +7220,7 @@ bool SrsConfig::get_hls_ts_ctx_enabled(std::string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_hls_cleanup(string vhost)
@@ -7239,7 +7239,7 @@ bool SrsConfig::get_hls_cleanup(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_hls_dispose(string vhost)
@@ -7277,7 +7277,7 @@ bool SrsConfig::get_hls_wait_keyframe(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_hls_keys(string vhost)
@@ -7296,7 +7296,7 @@ bool SrsConfig::get_hls_keys(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_hls_fragments_per_key(string vhost)
@@ -7418,7 +7418,7 @@ bool SrsConfig::get_hds_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_hds_path(const string &vhost)
@@ -7518,7 +7518,7 @@ bool SrsConfig::get_dvr_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_dvr_apply(string vhost)
@@ -7609,7 +7609,7 @@ bool SrsConfig::get_dvr_wait_keyframe(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_dvr_time_jitter(string vhost)
@@ -7655,7 +7655,7 @@ bool SrsConfig::get_http_api_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_http_api_listen()
@@ -7694,7 +7694,7 @@ bool SrsConfig::get_http_api_crossdomain()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_raw_api()
@@ -7718,7 +7718,7 @@ bool SrsConfig::get_raw_api()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_raw_api_allow_reload()
@@ -7742,7 +7742,7 @@ bool SrsConfig::get_raw_api_allow_reload()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_raw_api_allow_query()
@@ -7778,7 +7778,7 @@ bool SrsConfig::get_http_api_auth_enabled()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 std::string SrsConfig::get_http_api_auth_username()
@@ -7855,7 +7855,7 @@ bool SrsConfig::get_https_api_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_https_api_listen()
@@ -7936,7 +7936,7 @@ bool SrsConfig::get_srt_enabled()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 unsigned short SrsConfig::get_srt_listen_port()
@@ -8004,7 +8004,7 @@ bool SrsConfig::get_srto_tsbpdmode()
     if (!conf || conf->arg0().empty()) {
         return DEFAULT;
     }
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_srto_latency()
@@ -8072,7 +8072,7 @@ bool SrsConfig::get_srt_sei_filter()
     if (!conf || conf->arg0().empty()) {
         return DEFAULT;
     }
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_srto_tlpktdrop()
@@ -8089,7 +8089,7 @@ bool SrsConfig::get_srto_tlpktdrop()
     if (!conf || conf->arg0().empty()) {
         return DEFAULT;
     }
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_srto_conntimeout()
@@ -8251,7 +8251,7 @@ bool SrsConfig::get_srt_enabled(std::string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_srt_to_rtmp(std::string vhost)
@@ -8271,7 +8271,7 @@ bool SrsConfig::get_srt_to_rtmp(std::string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 bool SrsConfig::get_http_stream_enabled()
@@ -8295,7 +8295,7 @@ bool SrsConfig::get_http_stream_enabled(SrsConfDirective* conf)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_http_stream_listen()
@@ -8352,7 +8352,7 @@ bool SrsConfig::get_http_stream_crossdomain()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_https_stream()
@@ -8381,7 +8381,7 @@ bool SrsConfig::get_https_stream_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_https_stream_listen()
@@ -8462,7 +8462,7 @@ bool SrsConfig::get_vhost_http_enabled(string vhost)
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 string SrsConfig::get_vhost_http_mount(string vhost)
@@ -8543,7 +8543,7 @@ bool SrsConfig::get_vhost_http_remux_enabled(SrsConfDirective* vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_vhost_http_remux_fast_cache(string vhost)
@@ -8591,7 +8591,7 @@ bool SrsConfig::get_vhost_http_remux_drop_if_not_match(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_vhost_http_remux_has_audio(string vhost)
@@ -8615,7 +8615,7 @@ bool SrsConfig::get_vhost_http_remux_has_audio(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_vhost_http_remux_has_video(string vhost)
@@ -8639,7 +8639,7 @@ bool SrsConfig::get_vhost_http_remux_has_video(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 bool SrsConfig::get_vhost_http_remux_guess_has_av(string vhost)
@@ -8663,7 +8663,7 @@ bool SrsConfig::get_vhost_http_remux_guess_has_av(string vhost)
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 string SrsConfig::get_vhost_http_remux_mount(string vhost)
@@ -8711,7 +8711,7 @@ bool SrsConfig::get_heartbeat_enabled()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 srs_utime_t SrsConfig::get_heartbeat_interval()
@@ -8787,7 +8787,7 @@ bool SrsConfig::get_heartbeat_summaries()
         return DEFAULT;
     }
     
-    return SRS_CONF_PERFER_FALSE(conf->arg0());
+    return SRS_CONF_PREFER_FALSE(conf->arg0());
 }
 
 SrsConfDirective* SrsConfig::get_stats()
@@ -8809,7 +8809,7 @@ bool SrsConfig::get_stats_enabled()
         return DEFAULT;
     }
 
-    return SRS_CONF_PERFER_TRUE(conf->arg0());
+    return SRS_CONF_PREFER_TRUE(conf->arg0());
 }
 
 int SrsConfig::get_stats_network()
diff --git a/trunk/src/app/srs_app_rtc_source.cpp b/trunk/src/app/srs_app_rtc_source.cpp
index 21e53c175..c3b8ddfe4 100644
--- a/trunk/src/app/srs_app_rtc_source.cpp
+++ b/trunk/src/app/srs_app_rtc_source.cpp
@@ -1140,7 +1140,7 @@ srs_error_t SrsRtcRtpBuilder::filter(SrsSharedPtrMessage* msg, SrsFormat* format
         
         if (!keep_avc_nalu_sei && format->vcodec->id == SrsVideoCodecIdAVC) {
             SrsAvcNaluType avc_nalu_type;
-            // TODO: FIXME use static method to parse avc nalu type.
+
             if ((err = SrsVideoFrame::parse_avc_nalu_type(sample, avc_nalu_type)) != srs_success) {
                 return srs_error_wrap(err, "parse avc nalu_type");
             }
diff --git a/trunk/src/app/srs_app_source.cpp b/trunk/src/app/srs_app_source.cpp
index 603296bf6..3a47ebdf3 100755
--- a/trunk/src/app/srs_app_source.cpp
+++ b/trunk/src/app/srs_app_source.cpp
@@ -2533,7 +2533,7 @@ srs_error_t SrsLiveSource::on_aggregate(SrsCommonMessage* msg)
         o.header.timestamp_delta = timestamp;
         o.header.timestamp = timestamp;
         o.header.stream_id = stream_id;
-        o.header.perfer_cid = msg->header.perfer_cid;
+        o.header.prefer_cid = msg->header.prefer_cid;
         
         if (data_size > 0) {
             o.size = data_size;
diff --git a/trunk/src/core/srs_core_version6.hpp b/trunk/src/core/srs_core_version6.hpp
index 29249711b..775c9d359 100644
--- a/trunk/src/core/srs_core_version6.hpp
+++ b/trunk/src/core/srs_core_version6.hpp
@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       6
 #define VERSION_MINOR       0
-#define VERSION_REVISION    132
+#define VERSION_REVISION    133
 
 #endif
diff --git a/trunk/src/kernel/srs_kernel_flv.cpp b/trunk/src/kernel/srs_kernel_flv.cpp
index 20111e839..86ef2b3c3 100644
--- a/trunk/src/kernel/srs_kernel_flv.cpp
+++ b/trunk/src/kernel/srs_kernel_flv.cpp
@@ -37,7 +37,7 @@ SrsMessageHeader::SrsMessageHeader()
     
     timestamp = 0;
     // we always use the connection chunk-id
-    perfer_cid = RTMP_CID_OverConnection;
+    prefer_cid = RTMP_CID_OverConnection;
 }
 
 SrsMessageHeader::~SrsMessageHeader()
@@ -113,7 +113,7 @@ void SrsMessageHeader::initialize_amf0_script(int size, int stream)
     stream_id = (int32_t)stream;
     
     // amf0 script use connection2 chunk-id
-    perfer_cid = RTMP_CID_OverConnection2;
+    prefer_cid = RTMP_CID_OverConnection2;
 }
 
 void SrsMessageHeader::initialize_audio(int size, uint32_t time, int stream)
@@ -125,7 +125,7 @@ void SrsMessageHeader::initialize_audio(int size, uint32_t time, int stream)
     stream_id = (int32_t)stream;
     
     // audio chunk-id
-    perfer_cid = RTMP_CID_Audio;
+    prefer_cid = RTMP_CID_Audio;
 }
 
 void SrsMessageHeader::initialize_video(int size, uint32_t time, int stream)
@@ -137,7 +137,7 @@ void SrsMessageHeader::initialize_video(int size, uint32_t time, int stream)
     stream_id = (int32_t)stream;
     
     // video chunk-id
-    perfer_cid = RTMP_CID_Video;
+    prefer_cid = RTMP_CID_Video;
 }
 
 SrsCommonMessage::SrsCommonMessage()
@@ -175,7 +175,7 @@ SrsSharedMessageHeader::SrsSharedMessageHeader()
 {
     payload_length = 0;
     message_type = 0;
-    perfer_cid = 0;
+    prefer_cid = 0;
 }
 
 SrsSharedMessageHeader::~SrsSharedMessageHeader()
@@ -244,7 +244,7 @@ srs_error_t SrsSharedPtrMessage::create(SrsMessageHeader* pheader, char* payload
     if (pheader) {
         ptr->header.message_type = pheader->message_type;
         ptr->header.payload_length = size;
-        ptr->header.perfer_cid = pheader->perfer_cid;
+        ptr->header.prefer_cid = pheader->prefer_cid;
         this->timestamp = pheader->timestamp;
         this->stream_id = pheader->stream_id;
     }
@@ -284,9 +284,9 @@ bool SrsSharedPtrMessage::check(int stream_id)
 
     // we donot use the complex basic header,
     // ensure the basic header is 1bytes.
-    if (ptr->header.perfer_cid < 2 || ptr->header.perfer_cid > 63) {
-        srs_info("change the chunk_id=%d to default=%d", ptr->header.perfer_cid, RTMP_CID_ProtocolControl);
-        ptr->header.perfer_cid = RTMP_CID_ProtocolControl;
+    if (ptr->header.prefer_cid < 2 || ptr->header.prefer_cid > 63) {
+        srs_info("change the chunk_id=%d to default=%d", ptr->header.prefer_cid, RTMP_CID_ProtocolControl);
+        ptr->header.prefer_cid = RTMP_CID_ProtocolControl;
     }
     
     // we assume that the stream_id in a group must be the same.
@@ -317,10 +317,10 @@ bool SrsSharedPtrMessage::is_video()
 int SrsSharedPtrMessage::chunk_header(char* cache, int nb_cache, bool c0)
 {
     if (c0) {
-        return srs_chunk_header_c0(ptr->header.perfer_cid, (uint32_t)timestamp,
+        return srs_chunk_header_c0(ptr->header.prefer_cid, (uint32_t)timestamp,
             ptr->header.payload_length, ptr->header.message_type, stream_id, cache, nb_cache);
     } else {
-        return srs_chunk_header_c3(ptr->header.perfer_cid, (uint32_t)timestamp,
+        return srs_chunk_header_c3(ptr->header.prefer_cid, (uint32_t)timestamp,
             cache, nb_cache);
     }
 }
diff --git a/trunk/src/kernel/srs_kernel_flv.hpp b/trunk/src/kernel/srs_kernel_flv.hpp
index 349c4c579..72347d817 100644
--- a/trunk/src/kernel/srs_kernel_flv.hpp
+++ b/trunk/src/kernel/srs_kernel_flv.hpp
@@ -153,10 +153,10 @@ public:
     // @remark, we use 64bits for large time for jitter detect and hls.
     int64_t timestamp;
 public:
-    // Get the perfered cid(chunk stream id) which sendout over.
+    // Get the prefered cid(chunk stream id) which sendout over.
     // set at decoding, and canbe used for directly send message,
     // For example, dispatch to all connections.
-    int perfer_cid;
+    int prefer_cid;
 public:
     SrsMessageHeader();
     virtual ~SrsMessageHeader();
@@ -230,10 +230,10 @@ public:
     // (1-7) are reserved for protocol control messages.
     // For example, RTMP_MSG_AudioMessage or RTMP_MSG_VideoMessage.
     int8_t message_type;
-    // Get the perfered cid(chunk stream id) which sendout over.
+    // Get the prefered cid(chunk stream id) which sendout over.
     // set at decoding, and canbe used for directly send message,
     // For example, dispatch to all connections.
-    int perfer_cid;
+    int prefer_cid;
 public:
     SrsSharedMessageHeader();
     virtual ~SrsSharedMessageHeader();
@@ -313,7 +313,7 @@ public:
     // if this or copy deleted, free payload when count is 0, or count--.
     // @remark, assert object is created.
     virtual int count();
-    // check perfer cid and stream id.
+    // check prefer cid and stream id.
     // @return whether stream id already set.
     virtual bool check(int stream_id);
 public:
diff --git a/trunk/src/kernel/srs_kernel_utility.cpp b/trunk/src/kernel/srs_kernel_utility.cpp
index 204b8f145..356515bdd 100644
--- a/trunk/src/kernel/srs_kernel_utility.cpp
+++ b/trunk/src/kernel/srs_kernel_utility.cpp
@@ -1180,7 +1180,7 @@ int srs_hex_to_data(uint8_t* data, const char* p, int size)
     return size / 2;
 }
 
-int srs_chunk_header_c0(int perfer_cid, uint32_t timestamp, int32_t payload_length, int8_t message_type, int32_t stream_id, char* cache, int nb_cache)
+int srs_chunk_header_c0(int prefer_cid, uint32_t timestamp, int32_t payload_length, int8_t message_type, int32_t stream_id, char* cache, int nb_cache)
 {
     // to directly set the field.
     char* pp = NULL;
@@ -1194,7 +1194,7 @@ int srs_chunk_header_c0(int perfer_cid, uint32_t timestamp, int32_t payload_leng
     }
     
     // write new chunk stream header, fmt is 0
-    *p++ = 0x00 | (perfer_cid & 0x3F);
+    *p++ = 0x00 | (prefer_cid & 0x3F);
     
     // chunk message header, 11 bytes
     // timestamp, 3bytes, big-endian
@@ -1255,7 +1255,7 @@ int srs_chunk_header_c0(int perfer_cid, uint32_t timestamp, int32_t payload_leng
     return (int)(p - cache);
 }
 
-int srs_chunk_header_c3(int perfer_cid, uint32_t timestamp, char* cache, int nb_cache)
+int srs_chunk_header_c3(int prefer_cid, uint32_t timestamp, char* cache, int nb_cache)
 {
     // to directly set the field.
     char* pp = NULL;
@@ -1269,9 +1269,9 @@ int srs_chunk_header_c3(int perfer_cid, uint32_t timestamp, char* cache, int nb_
     }
     
     // write no message header chunk stream, fmt is 3
-    // @remark, if perfer_cid > 0x3F, that is, use 2B/3B chunk header,
+    // @remark, if prefer_cid > 0x3F, that is, use 2B/3B chunk header,
     // SRS will rollback to 1B chunk header.
-    *p++ = 0xC0 | (perfer_cid & 0x3F);
+    *p++ = 0xC0 | (prefer_cid & 0x3F);
     
     // for c0
     // chunk extended timestamp header, 0 or 4 bytes, big-endian
diff --git a/trunk/src/kernel/srs_kernel_utility.hpp b/trunk/src/kernel/srs_kernel_utility.hpp
index 603f4d2f6..400ca6122 100644
--- a/trunk/src/kernel/srs_kernel_utility.hpp
+++ b/trunk/src/kernel/srs_kernel_utility.hpp
@@ -151,13 +151,13 @@ extern char* srs_data_to_hex_lowercase(char* des, const uint8_t* src, int len);
 // @param cache, the cache to write header.
 // @param nb_cache, the size of cache.
 // @return The size of header. 0 if cache not enough.
-extern int srs_chunk_header_c0(int perfer_cid, uint32_t timestamp, int32_t payload_length, int8_t message_type, int32_t stream_id, char* cache, int nb_cache);
+extern int srs_chunk_header_c0(int prefer_cid, uint32_t timestamp, int32_t payload_length, int8_t message_type, int32_t stream_id, char* cache, int nb_cache);
 
 // Generate the c3 chunk header for msg.
 // @param cache, the cache to write header.
 // @param nb_cache, the size of cache.
 // @return the size of header. 0 if cache not enough.
-extern int srs_chunk_header_c3(int perfer_cid, uint32_t timestamp, char* cache, int nb_cache);
+extern int srs_chunk_header_c3(int prefer_cid, uint32_t timestamp, char* cache, int nb_cache);
 
 // For utest to mock it.
 #include <sys/time.h>
diff --git a/trunk/src/protocol/srs_protocol_rtmp_stack.cpp b/trunk/src/protocol/srs_protocol_rtmp_stack.cpp
index 98ba57566..4a250114a 100644
--- a/trunk/src/protocol/srs_protocol_rtmp_stack.cpp
+++ b/trunk/src/protocol/srs_protocol_rtmp_stack.cpp
@@ -110,7 +110,7 @@ srs_error_t SrsPacket::to_msg(SrsCommonMessage* msg, int stream_id)
     header.payload_length = size;
     header.message_type = get_message_type();
     header.stream_id = stream_id;
-    header.perfer_cid = get_prefer_cid();
+    header.prefer_cid = get_prefer_cid();
 
     if ((err = msg->create(&header, payload, size)) != srs_success) {
         return srs_error_wrap(err, "create %dB message", size);
@@ -200,9 +200,9 @@ SrsProtocol::SrsProtocol(ISrsProtocolReadWriter* io)
     }
     for (int cid = 0; cid < SRS_PERF_CHUNK_STREAM_CACHE; cid++) {
         SrsChunkStream* cs = new SrsChunkStream(cid);
-        // set the perfer cid of chunk,
+        // set the prefer cid of chunk,
         // which will copy to the message received.
-        cs->header.perfer_cid = cid;
+        cs->header.prefer_cid = cid;
         
         cs_cache[cid] = cs;
     }
@@ -740,7 +740,7 @@ srs_error_t SrsProtocol::send_and_free_messages(SrsSharedPtrMessage** msgs, int
             continue;
         }
         
-        // check perfer cid and stream,
+        // check prefer cid and stream,
         // when one msg stream id is ok, ignore left.
         if (msg->check(stream_id)) {
             break;
@@ -812,9 +812,9 @@ srs_error_t SrsProtocol::recv_interlaced_message(SrsCommonMessage** pmsg)
         // chunk stream cache miss, use map.
         if (chunk_streams.find(cid) == chunk_streams.end()) {
             chunk = chunk_streams[cid] = new SrsChunkStream(cid);
-            // set the perfer cid of chunk,
+            // set the prefer cid of chunk,
             // which will copy to the message received.
-            chunk->header.perfer_cid = cid;
+            chunk->header.prefer_cid = cid;
         } else {
             chunk = chunk_streams[cid];
         }
diff --git a/trunk/src/protocol/srs_protocol_rtmp_stack.hpp b/trunk/src/protocol/srs_protocol_rtmp_stack.hpp
index 6364e3b63..f76136ed3 100644
--- a/trunk/src/protocol/srs_protocol_rtmp_stack.hpp
+++ b/trunk/src/protocol/srs_protocol_rtmp_stack.hpp
@@ -114,8 +114,8 @@ public:
 // Encode functions for concrete packet to override.
 public:
     // The cid(chunk id) specifies the chunk to send data over.
-    // Generally, each message perfer some cid, for example,
-    // all protocol control messages perfer RTMP_CID_ProtocolControl,
+    // Generally, each message prefer some cid, for example,
+    // all protocol control messages prefer RTMP_CID_ProtocolControl,
     // SrsSetWindowAckSizePacket is protocol control message.
     virtual int get_prefer_cid();
     // The subpacket must override to provide the right message type.
diff --git a/trunk/src/utest/srs_utest_kernel.cpp b/trunk/src/utest/srs_utest_kernel.cpp
index 9be30ef11..7525963bc 100644
--- a/trunk/src/utest/srs_utest_kernel.cpp
+++ b/trunk/src/utest/srs_utest_kernel.cpp
@@ -4867,7 +4867,7 @@ VOID TEST(KernelFLVTest, CoverSharedPtrMessage)
 
 	if (true) {
 		SrsMessageHeader h;
-		h.perfer_cid = 1;
+		h.prefer_cid = 1;
 
 		SrsSharedPtrMessage m;
 		HELPER_EXPECT_SUCCESS(m.create(&h, NULL, 0));
diff --git a/trunk/src/utest/srs_utest_protocol.cpp b/trunk/src/utest/srs_utest_protocol.cpp
index 8ac6a79d4..09590c697 100644
--- a/trunk/src/utest/srs_utest_protocol.cpp
+++ b/trunk/src/utest/srs_utest_protocol.cpp
@@ -2097,7 +2097,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid1BNormal)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 1B cid(6bits), cid in 2-63
-    EXPECT_EQ(0x09, msg->header.perfer_cid);
+    EXPECT_EQ(0x09, msg->header.prefer_cid);
 }
 
 /**
@@ -2150,7 +2150,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid1BMax)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 1B cid(6bits), max is 63
-    EXPECT_EQ(0x3F, msg->header.perfer_cid);
+    EXPECT_EQ(0x3F, msg->header.prefer_cid);
 }
 
 /**
@@ -2203,7 +2203,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid2BMin)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 2B cid(8bits), min is 64
-    EXPECT_EQ(64, msg->header.perfer_cid);
+    EXPECT_EQ(64, msg->header.prefer_cid);
 }
 
 /**
@@ -2256,7 +2256,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid2BNormal)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 2B cid(8bits), cid in 64-319
-    EXPECT_EQ(0x10+64, msg->header.perfer_cid);
+    EXPECT_EQ(0x10+64, msg->header.prefer_cid);
 }
 
 /**
@@ -2309,7 +2309,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid2BNormal2)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 2B cid(8bits), cid in 64-319
-    EXPECT_EQ(0x11+64, msg->header.perfer_cid);
+    EXPECT_EQ(0x11+64, msg->header.prefer_cid);
 }
 
 /**
@@ -2362,7 +2362,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid2BMax)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 2B cid(68bits), max is 319
-    EXPECT_EQ(319, msg->header.perfer_cid);
+    EXPECT_EQ(319, msg->header.prefer_cid);
 }
 
 /**
@@ -2415,7 +2415,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BMin)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 3B cid(16bits), min is 64
-    EXPECT_EQ(64, msg->header.perfer_cid);
+    EXPECT_EQ(64, msg->header.prefer_cid);
 }
 
 /**
@@ -2468,7 +2468,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BNormal)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 3B cid(16bits), cid in 64-65599
-    EXPECT_EQ(0x10*256+64, msg->header.perfer_cid);
+    EXPECT_EQ(0x10*256+64, msg->header.prefer_cid);
 }
 
 /**
@@ -2521,7 +2521,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BNormal2)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 3B cid(16bits), cid in 64-65599
-    EXPECT_EQ(0x01 + (0x10*256) + 64, msg->header.perfer_cid);
+    EXPECT_EQ(0x01 + (0x10*256) + 64, msg->header.prefer_cid);
 }
 
 /**
@@ -2574,7 +2574,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BNormal3)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 3B cid(16bits), cid in 64-65599
-    EXPECT_EQ(0xFF + (0x10*256) + 64, msg->header.perfer_cid);
+    EXPECT_EQ(0xFF + (0x10*256) + 64, msg->header.prefer_cid);
 }
 
 /**
@@ -2627,7 +2627,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BNormal4)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 3B cid(16bits), cid in 64-65599
-    EXPECT_EQ(0x02 + (0x10*256) + 64, msg->header.perfer_cid);
+    EXPECT_EQ(0x02 + (0x10*256) + 64, msg->header.prefer_cid);
 }
 
 /**
@@ -2680,7 +2680,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid3BMax)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 2B cid(16bits), max is 65599
-    EXPECT_EQ(65599, msg->header.perfer_cid);
+    EXPECT_EQ(65599, msg->header.prefer_cid);
 }
 
 /**
diff --git a/trunk/src/utest/srs_utest_protocol2.cpp b/trunk/src/utest/srs_utest_protocol2.cpp
index e3444727e..b24529db9 100644
--- a/trunk/src/utest/srs_utest_protocol2.cpp
+++ b/trunk/src/utest/srs_utest_protocol2.cpp
@@ -1228,7 +1228,7 @@ VOID TEST(ProtocolStackTest, ProtocolRecvVCid1BMin)
     SrsAutoFree(SrsCommonMessage, msg);
     EXPECT_TRUE(msg->header.is_video());
     // 1B cid(6bits), min is 2
-    EXPECT_EQ(0x02, msg->header.perfer_cid);
+    EXPECT_EQ(0x02, msg->header.prefer_cid);
 }
 
 VOID TEST(ProtocolKbpsTest, Connections)