diff --git a/trunk/auto/depends.sh b/trunk/auto/depends.sh
index ca71172be..cb26c8c74 100755
--- a/trunk/auto/depends.sh
+++ b/trunk/auto/depends.sh
@@ -70,39 +70,41 @@ function Ubuntu_prepare()
         echo "install patch success"
     fi
     
-    autoconf --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
-        echo "install autoconf"
-        require_sudoer "sudo apt-get install -y --force-yes autoconf"
-        sudo apt-get install -y --force-yes autoconf; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install autoconf success"
-    fi
-    
-    libtool --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
-        echo "install libtool"
-        require_sudoer "sudo apt-get install -y --force-yes libtool"
-        sudo apt-get install -y --force-yes libtool; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install libtool success"
-    fi
-    
-    if [[ ! -f /usr/include/pcre.h ]]; then
-        echo "install libpcre3-dev"
-        require_sudoer "sudo apt-get install -y --force-yes libpcre3-dev"
-        sudo apt-get install -y --force-yes libpcre3-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install libpcre3-dev success"
-    fi
-    
-    if [[ ! -f /usr/include/zlib.h ]]; then
-        echo "install zlib1g-dev"
-        require_sudoer "sudo apt-get install -y --force-yes zlib1g-dev"
-        sudo apt-get install -y --force-yes zlib1g-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install zlib1g-dev success"
-    fi
-    
-    if [[ ! -d /usr/include/freetype2 ]]; then
-        echo "install libfreetype6-dev"
-        require_sudoer "sudo apt-get install -y --force-yes libfreetype6-dev"
-        sudo apt-get install -y --force-yes libfreetype6-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install libfreetype6-dev success"
+    if [ $SRS_FFMPEG_TOOL = YES ]; then
+        autoconf --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
+            echo "install autoconf"
+            require_sudoer "sudo apt-get install -y --force-yes autoconf"
+            sudo apt-get install -y --force-yes autoconf; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install autoconf success"
+        fi
+        
+        libtool --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
+            echo "install libtool"
+            require_sudoer "sudo apt-get install -y --force-yes libtool"
+            sudo apt-get install -y --force-yes libtool; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install libtool success"
+        fi
+        
+        if [[ ! -f /usr/include/pcre.h ]]; then
+            echo "install libpcre3-dev"
+            require_sudoer "sudo apt-get install -y --force-yes libpcre3-dev"
+            sudo apt-get install -y --force-yes libpcre3-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install libpcre3-dev success"
+        fi
+        
+        if [[ ! -f /usr/include/zlib.h ]]; then
+            echo "install zlib1g-dev"
+            require_sudoer "sudo apt-get install -y --force-yes zlib1g-dev"
+            sudo apt-get install -y --force-yes zlib1g-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install zlib1g-dev success"
+        fi
+        
+        if [[ ! -d /usr/include/freetype2 ]]; then
+            echo "install libfreetype6-dev"
+            require_sudoer "sudo apt-get install -y --force-yes libfreetype6-dev"
+            sudo apt-get install -y --force-yes libfreetype6-dev; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install libfreetype6-dev success"
+        fi
     fi
     
     # for arm, install the cross build tool chain.
@@ -168,46 +170,48 @@ function Centos_prepare()
         echo "install patch success"
     fi
     
-    automake --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
-        echo "install automake"
-        require_sudoer "sudo yum install -y automake"
-        sudo yum install -y automake; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install automake success"
-    fi
-    
-    autoconf --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
-        echo "install autoconf"
-        require_sudoer "sudo yum install -y autoconf"
-        sudo yum install -y autoconf; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install autoconf success"
-    fi
-    
-    libtool --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
-        echo "install libtool"
-        require_sudoer "sudo yum install -y libtool"
-        sudo yum install -y libtool; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install libtool success"
-    fi
-    
-    if [[ ! -f /usr/include/pcre.h ]]; then
-        echo "install pcre-devel"
-        require_sudoer "sudo yum install -y pcre-devel"
-        sudo yum install -y pcre-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install pcre-devel success"
-    fi
-    
-    if [[ ! -f /usr/include/zlib.h ]]; then
-        echo "install zlib-devel"
-        require_sudoer "sudo yum install -y zlib-devel"
-        sudo yum install -y zlib-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install zlib-devel success"
-    fi
-    
-    if [[ ! -d /usr/include/freetype2 ]]; then
-        echo "install freetype-devel"
-        require_sudoer "sudo yum install -y freetype-devel"
-        sudo yum install -y freetype-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
-        echo "install freetype-devel success"
+    if [ $SRS_FFMPEG_TOOL = YES ]; then
+        automake --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
+            echo "install automake"
+            require_sudoer "sudo yum install -y automake"
+            sudo yum install -y automake; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install automake success"
+        fi
+        
+        autoconf --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
+            echo "install autoconf"
+            require_sudoer "sudo yum install -y autoconf"
+            sudo yum install -y autoconf; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install autoconf success"
+        fi
+        
+        libtool --help >/dev/null 2>&1; ret=$?; if [[ 0 -ne $ret ]]; then
+            echo "install libtool"
+            require_sudoer "sudo yum install -y libtool"
+            sudo yum install -y libtool; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install libtool success"
+        fi
+        
+        if [[ ! -f /usr/include/pcre.h ]]; then
+            echo "install pcre-devel"
+            require_sudoer "sudo yum install -y pcre-devel"
+            sudo yum install -y pcre-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install pcre-devel success"
+        fi
+        
+        if [[ ! -f /usr/include/zlib.h ]]; then
+            echo "install zlib-devel"
+            require_sudoer "sudo yum install -y zlib-devel"
+            sudo yum install -y zlib-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install zlib-devel success"
+        fi
+        
+        if [[ ! -d /usr/include/freetype2 ]]; then
+            echo "install freetype-devel"
+            require_sudoer "sudo yum install -y freetype-devel"
+            sudo yum install -y freetype-devel; ret=$?; if [[ 0 -ne $ret ]]; then return $ret; fi
+            echo "install freetype-devel success"
+        fi
     fi
     
     # for arm, install the cross build tool chain.
diff --git a/trunk/research/librtmp/srs_ingest_flv.c b/trunk/research/librtmp/srs_ingest_flv.c
index 1b2437c18..d0aa1d797 100644
--- a/trunk/research/librtmp/srs_ingest_flv.c
+++ b/trunk/research/librtmp/srs_ingest_flv.c
@@ -43,13 +43,18 @@ void close_flv_file(int flv_fd);
 int flv_open_ic(int flv_fd);
 int flv_read_packet(int flv_fd, int* type, u_int32_t* timestamp, char** data, int* size);
 
+#define RE_PULSE_MS 300
 int64_t re_create();
-int64_t re_update(int64_t re, u_int32_t time);
+void re_update(int64_t re, u_int32_t time);
 
+int64_t tools_main_entrance_startup_time;
 int main(int argc, char** argv)
 {
     int ret = 0;
     
+    // main function
+    tools_main_entrance_startup_time = srs_get_time_ms();
+    
     // user option parse index.
     int opt = 0;
     // user options.
@@ -118,8 +123,6 @@ int proxy(int flv_fd, srs_rtmp_t ortmp)
     int type, size;
     u_int32_t timestamp = 0;
     char* data = NULL;
-    // re
-    int64_t re = re_create();
     
     if ((ret = flv_open_ic(flv_fd)) != 0) {
         return ret;
@@ -128,6 +131,9 @@ int proxy(int flv_fd, srs_rtmp_t ortmp)
         return ret;
     }
     
+    // re
+    int64_t re = re_create();
+    
     trace("start ingest flv to RTMP stream");
     for (;;) {
         if ((ret = flv_read_packet(flv_fd, &type, &timestamp, &data, &size)) != 0) {
@@ -144,7 +150,7 @@ int proxy(int flv_fd, srs_rtmp_t ortmp)
         verbose("ortmp sent packet: type=%s, time=%d, size=%d", 
             srs_type2string(type), timestamp, size);
         
-        re = re_update(re, timestamp);
+        re_update(re, timestamp);
     }
     
     return ret;
@@ -177,17 +183,35 @@ int connect_oc(srs_rtmp_t ortmp)
 
 int64_t re_create()
 {
-    return 0;
-}
-int64_t re_update(int64_t re, u_int32_t time)
-{
-    if (time - re > 500) {
-        usleep((time - re) * 1000);
-        return time;
+    // if not very precise, we can directly use this as re.
+    int64_t re = srs_get_time_ms();
+    
+    // use the starttime to get the deviation
+    int64_t deviation = re - tools_main_entrance_startup_time;
+    trace("deviation is %d ms, pulse is %d ms", (int)(deviation), (int)(RE_PULSE_MS));
+    
+    // so, we adjust time to max(0, deviation - pulse/4)
+    // because the last pulse, we never sleep, so we use pulse/4,
+    // for example, when EOF at the 120ms of last pulse, 
+    // these bytes is additional data and to fill the deviation.
+    int adjust = (int)(deviation - (RE_PULSE_MS / 4));
+    if (adjust > 0) {
+        trace("adjust re time, sub %d ms", adjust);
+        re -= adjust;
+    } else {
+        trace("no need to adjust re time");
     }
     
     return re;
 }
+void re_update(int64_t re, u_int32_t time)
+{
+    int64_t now = srs_get_time_ms();
+    int64_t diff = time - (now -re);
+    if (diff > RE_PULSE_MS) {
+        usleep(diff * 1000);
+    }
+}
 
 int open_flv_file(char* in_flv_file)
 {
diff --git a/trunk/src/core/srs_core.hpp b/trunk/src/core/srs_core.hpp
index 48f91b210..24f6ed5d9 100644
--- a/trunk/src/core/srs_core.hpp
+++ b/trunk/src/core/srs_core.hpp
@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR "0"
 #define VERSION_MINOR "9"
-#define VERSION_REVISION "107"
+#define VERSION_REVISION "108"
 #define RTMP_SIG_SRS_VERSION VERSION_MAJOR"."VERSION_MINOR"."VERSION_REVISION
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"
diff --git a/trunk/src/libs/srs_librtmp.cpp b/trunk/src/libs/srs_librtmp.cpp
index ea099d3c9..ddd9c9e7f 100644
--- a/trunk/src/libs/srs_librtmp.cpp
+++ b/trunk/src/libs/srs_librtmp.cpp
@@ -35,6 +35,7 @@ using namespace std;
 #include <srs_protocol_utility.hpp>
 #include <srs_core_autofree.hpp>
 #include <srs_protocol_rtmp_stack.hpp>
+#include <srs_kernel_utility.hpp>
 
 // if user want to define log, define the folowing macro.
 #ifndef SRS_RTMP_USER_DEFINED_LOG
@@ -399,6 +400,12 @@ int srs_version_revision()
     return ::atoi(VERSION_REVISION);
 }
 
+int64_t srs_get_time_ms()
+{
+    srs_update_system_time_ms();
+    return srs_get_system_time_ms();
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/trunk/src/libs/srs_librtmp.hpp b/trunk/src/libs/srs_librtmp.hpp
index 4fdfc9b73..4254e64b8 100644
--- a/trunk/src/libs/srs_librtmp.hpp
+++ b/trunk/src/libs/srs_librtmp.hpp
@@ -154,6 +154,11 @@ int srs_version_major();
 int srs_version_minor();
 int srs_version_revision();
 
+/**
+* utilities
+*/
+extern int64_t srs_get_time_ms();
+
 #ifdef __cplusplus
 }
 #endif