diff --git a/README.md b/README.md
index 7abe0bcd6..a92d7a27e 100755
--- a/README.md
+++ b/README.md
@@ -342,6 +342,7 @@ Remark:
 
 ## History
 
+* v2.0, 2015-08-18, close [#454](https://github.com/simple-rtmp-server/srs/issues/454), support obs restart publish. 2.0.184
 * v2.0, 2015-08-14, use reduce_sequence_header for stream control.
 * v2.0, 2015-08-14, use send_min_interval for stream control. 2.0.183
 * v2.0, 2015-08-12, enable the SRS_PERF_TCP_NODELAY and add config tcp_nodelay. 2.0.182
diff --git a/trunk/configure b/trunk/configure
index d705c6ceb..f11cd25e7 100755
--- a/trunk/configure
+++ b/trunk/configure
@@ -508,10 +508,15 @@ if [ $SRS_EXPORT_LIBRTMP_PROJECT = NO ]; then
     else
         echo -e "${YELLOW}warning: without HLS support${BLACK}"
     fi
-    if [ $SRS_HDS = YES ]; then
-        echo -e "${GREEN}HDS is enabled${BLACK}"
+    if [ $SRS_STREAM_CASTER = YES ]; then
+        echo -e "${YELLOW}Experiment: StreamCaster is enabled${BLACK}"
     else
-        echo -e "${YELLOW}warning: without HDS support${BLACK}"
+        echo -e "${GREEN}note: without StreamCaster support${BLACK}"
+    fi
+    if [ $SRS_HDS = YES ]; then
+        echo -e "${YELLOW}Experiment: HDS is enabled${BLACK}"
+    else
+        echo -e "${GREEN}warning: without HDS support${BLACK}"
     fi
     if [ $SRS_NGINX = YES ]; then
         echo -e "${GREEN}Nginx http server is enabled${BLACK}"
diff --git a/trunk/src/app/srs_app_recv_thread.cpp b/trunk/src/app/srs_app_recv_thread.cpp
index e402643d4..e94b622dd 100644
--- a/trunk/src/app/srs_app_recv_thread.cpp
+++ b/trunk/src/app/srs_app_recv_thread.cpp
@@ -96,7 +96,7 @@ int SrsRecvThread::cycle()
         }
     
         if (ret != ERROR_SUCCESS) {
-            if (!srs_is_client_gracefully_close(ret)) {
+            if (!srs_is_client_gracefully_close(ret) && !srs_is_system_control_error(ret)) {
                 srs_error("thread process message failed. ret=%d", ret);
             }
     
diff --git a/trunk/src/app/srs_app_rtmp_conn.cpp b/trunk/src/app/srs_app_rtmp_conn.cpp
index f63456abb..43c3951a9 100755
--- a/trunk/src/app/srs_app_rtmp_conn.cpp
+++ b/trunk/src/app/srs_app_rtmp_conn.cpp
@@ -337,6 +337,16 @@ int SrsRtmpConn::service_cycle()
         }
     }
     
+    // set chunk size to larger.
+    // set the chunk size before any larger response greater than 128,
+    // to make OBS happy, @see https://github.com/simple-rtmp-server/srs/issues/454
+    int chunk_size = _srs_config->get_chunk_size(req->vhost);
+    if ((ret = rtmp->set_chunk_size(chunk_size)) != ERROR_SUCCESS) {
+        srs_error("set chunk_size=%d failed. ret=%d", chunk_size, ret);
+        return ret;
+    }
+    srs_info("set chunk_size=%d success", chunk_size);
+    
     // response the client connect ok.
     if ((ret = rtmp->response_connect_app(req, local_ip.c_str())) != ERROR_SUCCESS) {
         srs_error("response connect app failed. ret=%d", ret);
@@ -424,14 +434,6 @@ int SrsRtmpConn::stream_service_cycle()
     rtmp->set_recv_timeout(SRS_CONSTS_RTMP_RECV_TIMEOUT_US);
     rtmp->set_send_timeout(SRS_CONSTS_RTMP_SEND_TIMEOUT_US);
     
-    // set chunk size to larger.
-    int chunk_size = _srs_config->get_chunk_size(req->vhost);
-    if ((ret = rtmp->set_chunk_size(chunk_size)) != ERROR_SUCCESS) {
-        srs_error("set chunk_size=%d failed. ret=%d", chunk_size, ret);
-        return ret;
-    }
-    srs_info("set chunk_size=%d success", chunk_size);
-    
     // find a source to serve.
     SrsSource* source = SrsSource::fetch(req);
     if (!source) {
@@ -637,7 +639,7 @@ int SrsRtmpConn::do_playing(SrsSource* source, SrsConsumer* consumer, SrsQueueRe
         
         // quit when recv thread error.
         if ((ret = trd->error_code()) != ERROR_SUCCESS) {
-            if (!srs_is_client_gracefully_close(ret)) {
+            if (!srs_is_client_gracefully_close(ret) && !srs_is_system_control_error(ret)) {
                 srs_error("recv thread failed. ret=%d", ret);
             }
             return ret;
@@ -824,7 +826,7 @@ int SrsRtmpConn::do_publishing(SrsSource* source, SrsPublishRecvThread* trd)
 
         // check the thread error code.
         if ((ret = trd->error_code()) != ERROR_SUCCESS) {
-            if (!srs_is_client_gracefully_close(ret)) {
+            if (!srs_is_system_control_error(ret) && !srs_is_client_gracefully_close(ret)) {
                 srs_error("recv thread failed. ret=%d", ret);
             }
             return ret;
diff --git a/trunk/src/app/srs_app_source.cpp b/trunk/src/app/srs_app_source.cpp
index 35661bd9c..e8063b85e 100755
--- a/trunk/src/app/srs_app_source.cpp
+++ b/trunk/src/app/srs_app_source.cpp
@@ -1463,7 +1463,11 @@ int SrsSource::on_meta_data(SrsCommonMessage* msg, SrsOnMetaDataPacket* metadata
     srs_verbose("initialize shared ptr metadata success.");
     
     // copy to all consumer
-    if (true) {
+    bool drop_for_reduce = false;
+    if (cache_metadata && _srs_config->get_reduce_sequence_header(_req->vhost)) {
+        drop_for_reduce = true;
+    }
+    if (!drop_for_reduce) {
         std::vector<SrsConsumer*>::iterator it;
         for (it = consumers.begin(); it != consumers.end(); ++it) {
             SrsConsumer* consumer = *it;
@@ -2084,10 +2088,10 @@ void SrsSource::on_unpublish()
     hds->on_unpublish();
 #endif
 
-    // only clear the gop cache metadata,
-    // donot clear the sequence header, for it maybe not changed.
+    // only clear the gop cache,
+    // donot clear the sequence header, for it maybe not changed,
+    // when drop dup sequence header, drop the metadata also.
     gop_cache->clear();
-    srs_freep(cache_metadata);
     
     srs_info("clear cache/metadata when unpublish.");
     srs_trace("cleanup when unpublish");
diff --git a/trunk/src/app/srs_app_thread.cpp b/trunk/src/app/srs_app_thread.cpp
index 0007df3ea..097758563 100644
--- a/trunk/src/app/srs_app_thread.cpp
+++ b/trunk/src/app/srs_app_thread.cpp
@@ -187,7 +187,7 @@ namespace internal {
             srs_info("thread %s on before cycle success");
             
             if ((ret = handler->cycle()) != ERROR_SUCCESS) {
-                if (!srs_is_client_gracefully_close(ret)) {
+                if (!srs_is_client_gracefully_close(ret) && !srs_is_system_control_error(ret)) {
                     srs_warn("thread %s cycle failed, ignored and retry, ret=%d", _name, ret);
                 }
                 goto failed;
diff --git a/trunk/src/protocol/srs_rtmp_stack.cpp b/trunk/src/protocol/srs_rtmp_stack.cpp
index d3658999f..0a169d64a 100644
--- a/trunk/src/protocol/srs_rtmp_stack.cpp
+++ b/trunk/src/protocol/srs_rtmp_stack.cpp
@@ -2924,7 +2924,9 @@ int SrsRtmpServer::fmle_unpublish(int stream_id, double unpublish_tid)
         pkt->data->set(StatusDescription, SrsAmf0Any::str("Stop publishing stream."));
         
         if ((ret = protocol->send_and_free_packet(pkt, stream_id)) != ERROR_SUCCESS) {
-            srs_error("send onFCUnpublish(NetStream.unpublish.Success) message failed. ret=%d", ret);
+            if (!srs_is_system_control_error(ret) && !srs_is_client_gracefully_close(ret)) {
+                srs_error("send onFCUnpublish(NetStream.unpublish.Success) message failed. ret=%d", ret);
+            }
             return ret;
         }
         srs_info("send onFCUnpublish(NetStream.unpublish.Success) message success.");
@@ -2933,7 +2935,9 @@ int SrsRtmpServer::fmle_unpublish(int stream_id, double unpublish_tid)
     if (true) {
         SrsFMLEStartResPacket* pkt = new SrsFMLEStartResPacket(unpublish_tid);
         if ((ret = protocol->send_and_free_packet(pkt, stream_id)) != ERROR_SUCCESS) {
-            srs_error("send FCUnpublish response message failed. ret=%d", ret);
+            if (!srs_is_system_control_error(ret) && !srs_is_client_gracefully_close(ret)) {
+                srs_error("send FCUnpublish response message failed. ret=%d", ret);
+            }
             return ret;
         }
         srs_info("send FCUnpublish response message success.");
@@ -2948,7 +2952,9 @@ int SrsRtmpServer::fmle_unpublish(int stream_id, double unpublish_tid)
         pkt->data->set(StatusClientId, SrsAmf0Any::str(RTMP_SIG_CLIENT_ID));
         
         if ((ret = protocol->send_and_free_packet(pkt, stream_id)) != ERROR_SUCCESS) {
-            srs_error("send onStatus(NetStream.Unpublish.Success) message failed. ret=%d", ret);
+            if (!srs_is_system_control_error(ret) && !srs_is_client_gracefully_close(ret)) {
+                srs_error("send onStatus(NetStream.Unpublish.Success) message failed. ret=%d", ret);
+            }
             return ret;
         }
         srs_info("send onStatus(NetStream.Unpublish.Success) message success.");
@@ -4234,10 +4240,22 @@ int SrsPlayPacket::get_message_type()
 
 int SrsPlayPacket::get_size()
 {
-    return SrsAmf0Size::str(command_name) + SrsAmf0Size::number()
-        + SrsAmf0Size::null() + SrsAmf0Size::str(stream_name)
-        + SrsAmf0Size::number() + SrsAmf0Size::number()
-        + SrsAmf0Size::boolean();
+    int size = SrsAmf0Size::str(command_name) + SrsAmf0Size::number()
+        + SrsAmf0Size::null() + SrsAmf0Size::str(stream_name);
+    
+    if (start != -2 || duration != -1 || !reset) {
+        size += SrsAmf0Size::number();
+    }
+    
+    if (duration != -1 || !reset) {
+        size += SrsAmf0Size::number();
+    }
+    
+    if (!reset) {
+        size += SrsAmf0Size::boolean();
+    }
+    
+    return size;
 }
 
 int SrsPlayPacket::encode_packet(SrsStream* stream)
@@ -4268,19 +4286,19 @@ int SrsPlayPacket::encode_packet(SrsStream* stream)
     }
     srs_verbose("encode stream_name success.");
     
-    if ((ret = srs_amf0_write_number(stream, start)) != ERROR_SUCCESS) {
+    if ((start != -2 || duration != -1 || !reset) && (ret = srs_amf0_write_number(stream, start)) != ERROR_SUCCESS) {
         srs_error("encode start failed. ret=%d", ret);
         return ret;
     }
     srs_verbose("encode start success.");
     
-    if ((ret = srs_amf0_write_number(stream, duration)) != ERROR_SUCCESS) {
+    if ((duration != -1 || !reset) && (ret = srs_amf0_write_number(stream, duration)) != ERROR_SUCCESS) {
         srs_error("encode duration failed. ret=%d", ret);
         return ret;
     }
     srs_verbose("encode duration success.");
     
-    if ((ret = srs_amf0_write_boolean(stream, reset)) != ERROR_SUCCESS) {
+    if (!reset && (ret = srs_amf0_write_boolean(stream, reset)) != ERROR_SUCCESS) {
         srs_error("encode reset failed. ret=%d", ret);
         return ret;
     }
@@ -5111,14 +5129,29 @@ int SrsUserControlPacket::decode(SrsStream* stream)
 {
     int ret = ERROR_SUCCESS;
     
-    if (!stream->require(6)) {
+    if (!stream->require(2)) {
         ret = ERROR_RTMP_MESSAGE_DECODE;
         srs_error("decode user control failed. ret=%d", ret);
         return ret;
     }
     
     event_type = stream->read_2bytes();
-    event_data = stream->read_4bytes();
+    
+    if (event_type == SrsPCUCFmsEvent0) {
+        if (!stream->require(1)) {
+            ret = ERROR_RTMP_MESSAGE_DECODE;
+            srs_error("decode user control failed. ret=%d", ret);
+            return ret;
+        }
+        event_data = stream->read_1bytes();
+    } else {
+        if (!stream->require(4)) {
+            ret = ERROR_RTMP_MESSAGE_DECODE;
+            srs_error("decode user control failed. ret=%d", ret);
+            return ret;
+        }
+        event_data = stream->read_4bytes();
+    }
     
     if (event_type == SrcPCUCSetBufferLength) {
         if (!stream->require(4)) {
@@ -5148,11 +5181,19 @@ int SrsUserControlPacket::get_message_type()
 
 int SrsUserControlPacket::get_size()
 {
-    if (event_type == SrcPCUCSetBufferLength) {
-        return 2 + 4 + 4;
+    int size = 2;
+    
+    if (event_type == SrsPCUCFmsEvent0) {
+        size += 1;
     } else {
-        return 2 + 4;
+        size += 4;
     }
+    
+    if (event_type == SrcPCUCSetBufferLength) {
+        size += 4;
+    }
+    
+    return size;
 }
 
 int SrsUserControlPacket::encode_packet(SrsStream* stream)
@@ -5166,7 +5207,12 @@ int SrsUserControlPacket::encode_packet(SrsStream* stream)
     }
     
     stream->write_2bytes(event_type);
-    stream->write_4bytes(event_data);
+    
+    if (event_type == SrsPCUCFmsEvent0) {
+        stream->write_1bytes(event_data);
+    } else {
+        stream->write_4bytes(event_data);
+    }
 
     // when event type is set buffer length,
     // write the extra buffer length.
diff --git a/trunk/src/protocol/srs_rtmp_stack.hpp b/trunk/src/protocol/srs_rtmp_stack.hpp
index db6d76f46..f2c837fc8 100644
--- a/trunk/src/protocol/srs_rtmp_stack.hpp
+++ b/trunk/src/protocol/srs_rtmp_stack.hpp
@@ -1991,6 +1991,13 @@ enum SrcPCUCEventType
     * kMsgPingRequest request.
     */
     SrcPCUCPingResponse             = 0x07,
+    
+    /**
+     * for PCUC size=3, the payload is "00 1A 01",
+     * where we think the event is 0x001a, fms defined msg,
+     * which has only 1bytes event data.
+     */
+    SrsPCUCFmsEvent0                = 0x1a,
 };
 
 /**
@@ -2019,6 +2026,11 @@ public:
     * @see: SrcPCUCEventType
     */
     int16_t event_type;
+    /**
+     * the event data generally in 4bytes.
+     * @remark for event type is 0x001a, only 1bytes.
+     * @see SrsPCUCFmsEvent0
+     */
     int32_t event_data;
     /**
     * 4bytes if event_type is SetBufferLength; otherwise 0.