diff --git a/fec_manager.cpp b/fec_manager.cpp
index f301661..5dc851c 100644
--- a/fec_manager.cpp
+++ b/fec_manager.cpp
@@ -189,6 +189,7 @@ int fec_encode_manager_t::input(char *s,int len/*,int &is_first_packet*/)
 {
 	int about_to_fec=0;
 	int delayed_append=0;
+	//int counter_back=counter;
 	if(type==0&& s!=0 &&counter==0&&blob_encode.get_shard_len(fec_data_num,len)>=fec_mtu)
 	{
 		mylog(log_warn,"message too long len=%d,ignored\n",len);
@@ -302,6 +303,9 @@ int fec_encode_manager_t::input(char *s,int len/*,int &is_first_packet*/)
 
 		mylog(log_info,"!!! s= %d\n");
 
+    	ready_for_output=1;
+    	seq++;
+    	counter=0;
     	output_n=actual_data_num+actual_redundant_num;
     	blob_encode.clear();
 
@@ -309,19 +313,18 @@ int fec_encode_manager_t::input(char *s,int len/*,int &is_first_packet*/)
 		memset(&its,0,sizeof(its));
 		timerfd_settime(timer_fd,TFD_TIMER_ABSTIME,&its,0);
 
-    	if(encode_fast_send&&s!=0&&type==1)
+    	if(encode_fast_send&&type==1)
     	{
 			int packet_to_send[max_fec_packet_num+5]={0};
 			int packet_to_send_counter=0;
 
-			assert(counter!=0);
+			//assert(counter!=0);
 			if(s!=0)
-				packet_to_send[packet_to_send_counter++]=counter-1;
+				packet_to_send[packet_to_send_counter++]=actual_data_num-1;
 			for(int i=actual_data_num;i<actual_data_num+actual_redundant_num;i++)
 			{
-				{
+
 					packet_to_send[packet_to_send_counter++]=i;
-				}
 			}
 			output_n=packet_to_send_counter;//re write
 			for(int i=0;i<packet_to_send_counter;i++)
@@ -331,11 +334,6 @@ int fec_encode_manager_t::input(char *s,int len/*,int &is_first_packet*/)
 			}
 
     	}
-
-    	ready_for_output=1;
-    	seq++;
-    	counter=0;
-
 	}
     else
     {
@@ -351,10 +349,11 @@ int fec_encode_manager_t::input(char *s,int len/*,int &is_first_packet*/)
     		int tmp_idx=0;
     		write_u32(buf[buf_idx]+tmp_idx,seq);
     		tmp_idx+=sizeof(u32_t);
+
     		buf[buf_idx][tmp_idx++]=(unsigned char)type;
     		buf[buf_idx][tmp_idx++]=(unsigned char)0;
     		buf[buf_idx][tmp_idx++]=(unsigned char)0;
-    		buf[buf_idx][tmp_idx++]=(unsigned char)((u32_t)counter);
+    		buf[buf_idx][tmp_idx++]=(unsigned char)((u32_t)buf_idx);
 
     		output_len[0]=buf_s_len[buf_idx]+tmp_idx;
     		output_buf[0]=buf[buf_idx];
@@ -440,10 +439,16 @@ int fec_decode_manager_t::input(char *s,int len)
 	}
 	if(!anti_replay.is_vaild(seq))
 	{
-		mylog(log_info,"failed here2\n");
+		//mylog(log_info,"failed here2\n");
 		return 0;
 	}
 
+	if(mp[seq].group_mp.find(inner_index)!=mp[seq].group_mp.end() )
+	{
+		mylog(log_info,"dup inner_index\n");
+		return -1;
+	}
+
 	int ok=1;
 	if(mp[seq].type==-1)
 		mp[seq].type=type;
@@ -452,7 +457,12 @@ int fec_decode_manager_t::input(char *s,int len)
 		if(mp[seq].type!=type) ok=0;
 	}
 
-	if(type==0) assert(data_num!=0);
+	if(type==0&&data_num==0)
+	{
+		mylog(log_warn,"unexpected here,data_num=0\n");
+		return -1;
+	}
+
 
 	if(data_num!=0)
 	{
@@ -467,18 +477,21 @@ int fec_decode_manager_t::input(char *s,int len)
 		else
 		{
 			if(mp[seq].data_num!=data_num||mp[seq].redundant_num!=redundant_num||mp[seq].len!=len)
+			{
+				mylog(log_warn,"unexpected here\n");
 				ok=0;
+			}
 		}
 	}
 
 	if(ok==0)
 	{
-		mylog(log_info,"ok=0\n");
+		//mylog(log_info,"ok=0\n");
 		return -1;
 	}
 	else
 	{
-		mylog(log_info,"ok=1\n");
+		//mylog(log_info,"ok=1\n");
 	}
 
 	if(fec_data[index].used!=0)
@@ -519,43 +532,58 @@ int fec_decode_manager_t::input(char *s,int len)
 	{
 		if(mp[seq].data_num!=-1)
 		{
-			data_num=mp[seq].data_num;
-			redundant_num=mp[seq].redundant_num;
+			//int old_data_num=data_num;
+			//int old_redundant_num=redundant_num;
 
-			if(mp[seq].data_counter>data_num)
+			//data_num=mp[seq].data_num;
+			//redundant_num=mp[seq].redundant_num;
+
+			/*if(mp[seq].data_counter>data_num)  //invaild
 			{
 				mylog(log_warn,"unexpected mp[seq].data_counter>mp[seq].data_num\n");
 				anti_replay.set_invaild(seq);
 				return -1;
+			}*/
+			//assert((int)inner_mp.size()<=data_num);
+			if((int)inner_mp.size()>=mp[seq].data_num)
+			{
+				about_to_fec=1;
 			}
-			else if(mp[seq].data_counter==data_num)
+
+
+			/*
+			else if(mp[seq].data_counter==data_num)   //no need to fec . (received first redundant packet ,or received a data packet after redunant packet)
 			{
 				anti_replay.set_invaild(seq);// dont do fec,but  still set invaild
 			}
 			else //mp[seq].data_counter < mp[seq].data_num
 			{
-				if((int)inner_mp.size()>data_num+1)
+				if((int)inner_mp.size()>data_num)
 				{
 					mylog(log_warn,"unexpected (int)inner_mp.size()>data_num+1\n");
 					anti_replay.set_invaild(seq);
 					return -1;
-				}
+				}*/
 
+				//if((int)inner_mp.size()==data_num)
+					//about_to_fec=1;
+
+				/*
 				if((int)inner_mp.size()==data_num+1)
 				{
 					anti_replay.set_invaild(seq);
-					if(data_num==0)
+
+					if(old_data_num==0)
 						return 0;
 					else
 					{
-						//mylog(log_warn,"data_num!=0\n"); //this is possible
+						mylog(log_warn,"data_num=0\n");
 						return -1;
 					}
-				}
+				}*/
 
-				if((int)inner_mp.size()==data_num)
-					about_to_fec=1;
-			}
+
+			//}
 		}
 		else
 		{
@@ -564,9 +592,13 @@ int fec_decode_manager_t::input(char *s,int len)
 		//for()
 	}
 
+
 	if(about_to_fec)
 	{
-		mylog(log_error,"fec here!\n");
+		int group_data_num=mp[seq].data_num;
+		int group_redundant_num=mp[seq].redundant_num;
+
+		//mylog(log_error,"fec here!\n");
 		if(type==0)
 		{
 			char *fec_tmp_arr[max_fec_packet_num+5]={0};
@@ -574,9 +606,9 @@ int fec_decode_manager_t::input(char *s,int len)
 			{
 				fec_tmp_arr[it->first]=fec_data[it->second].buf;
 			}
-			rs_decode2(data_num,data_num+redundant_num,fec_tmp_arr,len); //the input data has been modified in-place
+			rs_decode2(group_data_num,group_data_num+group_redundant_num,fec_tmp_arr,len); //the input data has been modified in-place
 			blob_decode.clear();
-			for(int i=0;i<data_num;i++)
+			for(int i=0;i<group_data_num;i++)
 			{
 				blob_decode.input(fec_tmp_arr[i],len);
 			}
@@ -587,6 +619,8 @@ int fec_decode_manager_t::input(char *s,int len)
 		}
 		else
 		{
+
+
 			int max_len=-1;
 			int fec_ok=1;
 			int debug_num=inner_mp.size();
@@ -594,7 +628,7 @@ int fec_decode_manager_t::input(char *s,int len)
 
 			//memset(output_s_arr_buf,0,sizeof(output_s_arr_buf));//in efficient
 
-			for(int i=0;i<data_num+redundant_num;i++)
+			for(int i=0;i<group_data_num+group_redundant_num;i++)
 			{
 				output_s_arr_buf[i]=0;
 			}
@@ -613,7 +647,7 @@ int fec_decode_manager_t::input(char *s,int len)
 			int missed_packet[max_fec_packet_num+5];
 			int missed_packet_counter=0;
 
-			for(int i=0;i<data_num;i++)
+			for(int i=0;i<group_data_num;i++)
 			{
 				if(output_s_arr_buf[i]==0 ||i==inner_index) //only missed packet +current packet
 				{
@@ -621,14 +655,14 @@ int fec_decode_manager_t::input(char *s,int len)
 				}
 			}
 
-			rs_decode2(data_num,data_num+redundant_num,output_s_arr_buf,max_len);
-			for(int i=0;i<data_num;i++)
+			rs_decode2(group_data_num,group_data_num+group_redundant_num,output_s_arr_buf,max_len);
+			for(int i=0;i<group_data_num;i++)
 			{
 				output_len_arr_buf[i]=read_u16(output_s_arr_buf[i]);
 				output_s_arr_buf[i]+=sizeof(u16_t);
 				if(output_len_arr_buf[i]>max_data_len)
 				{
-					mylog(log_warn,"invaild len %d,seq= %u,data_num= %d r_num= %d,i= %d\n",output_len_arr_buf[i],seq,data_num,redundant_num,i);
+					mylog(log_warn,"invaild len %d,seq= %u,data_num= %d r_num= %d,i= %d\n",output_len_arr_buf[i],seq,group_data_num,group_redundant_num,i);
 					fec_ok=0;
 					for(int i=0;i<missed_packet_counter;i++)
 					{
@@ -641,7 +675,7 @@ int fec_decode_manager_t::input(char *s,int len)
 			if(fec_ok)
 			{
 
-				output_n=data_num;
+				output_n=group_data_num;
 
 				if(decode_fast_send)
 				{