diff --git a/README.md b/README.md
index bbf4abfb2..9a598a34e 100755
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ git clone https://code.csdn.net/winlinvip/srs-csdn.git
 报告问题(BugReport): [https://github.com/winlinvip/simple-rtmp-server/issues/new](https://github.com/winlinvip/simple-rtmp-server/issues/new)<br/>
 中文资料(Wiki): [https://github.com/winlinvip/simple-rtmp-server/wiki](https://github.com/winlinvip/simple-rtmp-server/wiki) <br/>
 使用步骤(Usage): [https://github.com/winlinvip/simple-rtmp-server#usage](#usage) <br/>
-公用机器(LiveShow): [https://github.com/winlinvip/simple-rtmp-server/wiki/LiveShow](供大家学习和使用的公用服务器) <br/>
+公用机器(LiveShow): [https://github.com/winlinvip/simple-rtmp-server/wiki/LiveShow](https://github.com/winlinvip/simple-rtmp-server/wiki/LiveShow) <br/>
 捐款(Donation): [GitHub](http://winlinvip.github.io/srs.release/donation/index.html) 
 或 [阿里云镜像](http://182.92.80.26:8085/srs/donation/index.html) ，查看
 [捐献墙(Donations)](https://github.com/winlinvip/simple-rtmp-server/blob/master/DONATIONS.txt)<br/>
diff --git a/trunk/configure b/trunk/configure
index 836c7660b..838e070f5 100755
--- a/trunk/configure
+++ b/trunk/configure
@@ -447,7 +447,7 @@ MODULE_ID="KERNEL"
 MODULE_DEPENDS=("CORE") 
 ModuleLibIncs=(${SRS_OBJS})
 MODULE_FILES=("srs_kernel_error" "srs_kernel_log" "srs_kernel_stream" "srs_kernel_buffer" 
-        "srs_kernel_utility" "srs_kernel_flv")
+        "srs_kernel_utility" "srs_kernel_flv" "srs_kernel_codec")
 KERNEL_INCS="src/kernel"; MODULE_DIR=${KERNEL_INCS} . auto/modules.sh
 KERNEL_OBJS="${MODULE_OBJS[@]}"
 #
@@ -465,7 +465,7 @@ MODULE_ID="APP"
 MODULE_DEPENDS=("CORE" "KERNEL" "RTMP") 
 ModuleLibIncs=(${LibSTRoot} ${LibHttpParserRoot} ${SRS_OBJS})
 MODULE_FILES=("srs_app_server" "srs_app_conn" "srs_app_rtmp_conn" "srs_app_socket" "srs_app_source" 
-        "srs_app_codec" "srs_app_refer" "srs_app_hls" "srs_app_forward" "srs_app_encoder" "srs_app_http" 
+        "srs_app_refer" "srs_app_hls" "srs_app_forward" "srs_app_encoder" "srs_app_http" 
         "srs_app_thread" "srs_app_bandwidth" "srs_app_st" "srs_app_log" "srs_app_config" 
         "srs_app_pithy_print" "srs_app_reload" "srs_app_http_api" "srs_app_http_conn" "srs_app_http_hooks" 
         "srs_app_json" "srs_app_ingest" "srs_app_ffmpeg" "srs_app_utility" "srs_app_dvr" "srs_app_edge"
diff --git a/trunk/research/librtmp/srs_flv_injecter.c b/trunk/research/librtmp/srs_flv_injecter.c
index 3828b62fe..445869f92 100644
--- a/trunk/research/librtmp/srs_flv_injecter.c
+++ b/trunk/research/librtmp/srs_flv_injecter.c
@@ -50,6 +50,7 @@ int main(int argc, char** argv)
     srs_flv_t oc = NULL;
     
     // temp variables.
+    int tmp_file_size = 0;
     char* tmp_file;
     
     if (argc <= 2) {
@@ -68,20 +69,30 @@ int main(int argc, char** argv)
     in_flv_file = argv[1];
     out_flv_file = argv[2];
     
-    tmp_file = (char*)malloc(strlen(out_flv_file) + strlen(".tmp") + 1);
+    tmp_file_size = strlen(out_flv_file) + strlen(".tmp") + 1;
+    tmp_file = (char*)malloc(tmp_file_size);
+    snprintf(tmp_file, tmp_file_size, "%s.tmp", out_flv_file);
     
     trace("inject flv file keyframes to metadata.");
     trace("srs(simple-rtmp-server) client librtmp library.");
     trace("version: %d.%d.%d", srs_version_major(), srs_version_minor(), srs_version_revision());
     trace("input:  %s", in_flv_file);
     trace("output:  %s", out_flv_file);
+    trace("tmp_file:  %s", tmp_file);
 
-    if ((ret = process(in_flv_file, out_flv_file, &ic, &oc)) != 0) {
-        return ret;
-    }
+    ret = process(in_flv_file, tmp_file, &ic, &oc);
     
     srs_flv_close(ic);
     srs_flv_close(oc);
+    
+    if (ret != 0) {
+        unlink(tmp_file);
+        trace("error, remove tmp file.");
+    } else {
+        rename(tmp_file, out_flv_file);
+        trace("completed, rename to %s", out_flv_file);
+    }
+    
     free(tmp_file);
     
     return ret;
@@ -110,9 +121,86 @@ int process(const char* in_flv_file, const char* out_flv_file, srs_flv_t* pic, s
     return ret;
 }
 
+int parse_metadata(char* data, int size, srs_amf0_t* pname, srs_amf0_t* pdata)
+{
+    int ret = 0;
+    
+    int nparsed = 0;
+    *pname = srs_amf0_parse(data, size, &nparsed);
+    
+    if (*pname == NULL || nparsed >= size) {
+        trace("invalid amf0 name data.");
+        return -1;
+    }
+    
+    *pdata = srs_amf0_parse(data + nparsed, size - nparsed, &nparsed);
+    if (*pdata == NULL || nparsed > size) {
+        trace("invalid amf0 value data");
+        return -1;
+    }
+    
+    return ret;
+}
+
 int inject_flv(srs_flv_t ic, srs_flv_t oc)
 {
     int ret = 0;
     
+    // flv header
+    char header[13];
+    // packet data
+    char type;
+    u_int32_t timestamp = 0;
+    char* data = NULL;
+    int32_t size;
+    
+    // metadata
+    srs_amf0_t amf0_name = NULL;
+    srs_amf0_t amf0_data = NULL;
+    
+    // reset to generate metadata
+    srs_flv_lseek(ic, 0);
+    
+    if ((ret = srs_flv_read_header(oc, header)) != 0) {
+        return ret;
+    }
+    
+    trace("start inject flv");
+    for (;;) {
+        // tag header
+        if ((ret = srs_flv_read_tag_header(oc, &type, &size, &timestamp)) != 0) {
+            if (srs_flv_is_eof(ret)) {
+                trace("parse completed.");
+                return 0;
+            }
+            trace("flv get packet failed. ret=%d", ret);
+            return ret;
+        }
+        
+        if (size <= 0) {
+            trace("invalid size=%d", size);
+            break;
+        }
+        
+        // TODO: FIXME: mem leak when error.
+        data = (char*)malloc(size);
+        if ((ret = srs_flv_read_tag_data(oc, data, size)) != 0) {
+            return ret;
+        }
+        
+        // data tag
+        if (type == SRS_RTMP_TYPE_VIDEO) {
+        } else if (type == SRS_RTMP_TYPE_SCRIPT) {
+            if ((ret = parse_metadata(data, size, &amf0_name, &amf0_data)) != 0) {
+                return ret;
+            }
+        }
+        
+        free(data);
+    }
+    
+    srs_amf0_free(amf0_name);
+    srs_amf0_free(amf0_data);
+    
     return ret;
 }
diff --git a/trunk/research/librtmp/srs_flv_parser.c b/trunk/research/librtmp/srs_flv_parser.c
index ec0fbdad0..fd8c2de97 100644
--- a/trunk/research/librtmp/srs_flv_parser.c
+++ b/trunk/research/librtmp/srs_flv_parser.c
@@ -233,7 +233,7 @@ int parse_flv(srs_flv_t flv)
                 trace("parse completed.");
                 return 0;
             }
-            trace("irtmp get packet failed. ret=%d", ret);
+            trace("flv get packet failed. ret=%d", ret);
             return ret;
         }
         
diff --git a/trunk/src/app/srs_app_dvr.cpp b/trunk/src/app/srs_app_dvr.cpp
index e0a397165..e6d7fde05 100644
--- a/trunk/src/app/srs_app_dvr.cpp
+++ b/trunk/src/app/srs_app_dvr.cpp
@@ -38,7 +38,7 @@ using namespace std;
 #include <srs_kernel_stream.hpp>
 #include <srs_kernel_utility.hpp>
 #include <srs_app_http_hooks.hpp>
-#include <srs_app_codec.hpp>
+#include <srs_kernel_codec.hpp>
 #include <srs_kernel_flv.hpp>
 
 SrsFlvSegment::SrsFlvSegment()
diff --git a/trunk/src/app/srs_app_hls.cpp b/trunk/src/app/srs_app_hls.cpp
index 921ca4080..24bb26603 100644
--- a/trunk/src/app/srs_app_hls.cpp
+++ b/trunk/src/app/srs_app_hls.cpp
@@ -35,7 +35,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 using namespace std;
 
 #include <srs_kernel_error.hpp>
-#include <srs_app_codec.hpp>
+#include <srs_kernel_codec.hpp>
 #include <srs_protocol_amf0.hpp>
 #include <srs_protocol_rtmp_stack.hpp>
 #include <srs_app_config.hpp>
diff --git a/trunk/src/app/srs_app_source.cpp b/trunk/src/app/srs_app_source.cpp
index e8e50a5c4..7b685f093 100644
--- a/trunk/src/app/srs_app_source.cpp
+++ b/trunk/src/app/srs_app_source.cpp
@@ -30,7 +30,7 @@ using namespace std;
 #include <srs_protocol_rtmp_stack.hpp>
 #include <srs_core_autofree.hpp>
 #include <srs_protocol_amf0.hpp>
-#include <srs_app_codec.hpp>
+#include <srs_kernel_codec.hpp>
 #include <srs_app_hls.hpp>
 #include <srs_app_forward.hpp>
 #include <srs_app_config.hpp>
diff --git a/trunk/src/app/srs_app_codec.cpp b/trunk/src/kernel/srs_kernel_codec.cpp
similarity index 99%
rename from trunk/src/app/srs_app_codec.cpp
rename to trunk/src/kernel/srs_kernel_codec.cpp
index 65da8d7b4..b01dcd617 100644
--- a/trunk/src/app/srs_app_codec.cpp
+++ b/trunk/src/kernel/srs_kernel_codec.cpp
@@ -21,7 +21,7 @@ IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-#include <srs_app_codec.hpp>
+#include <srs_kernel_codec.hpp>
 
 #include <string.h>
 #include <stdlib.h>
diff --git a/trunk/src/app/srs_app_codec.hpp b/trunk/src/kernel/srs_kernel_codec.hpp
similarity index 99%
rename from trunk/src/app/srs_app_codec.hpp
rename to trunk/src/kernel/srs_kernel_codec.hpp
index 4067f864a..a313afd05 100644
--- a/trunk/src/app/srs_app_codec.hpp
+++ b/trunk/src/kernel/srs_kernel_codec.hpp
@@ -21,11 +21,11 @@ IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-#ifndef SRS_APP_CODEC_HPP
-#define SRS_APP_CODEC_HPP
+#ifndef SRS_KERNEL_CODEC_HPP
+#define SRS_KERNEL_CODEC_HPP
 
 /*
-#include <srs_app_codec.hpp>
+#include <srs_kernel_codec.hpp>
 */
 
 #include <srs_core.hpp>
diff --git a/trunk/src/kernel/srs_kernel_flv.hpp b/trunk/src/kernel/srs_kernel_flv.hpp
index 1d136e0d5..b25680352 100644
--- a/trunk/src/kernel/srs_kernel_flv.hpp
+++ b/trunk/src/kernel/srs_kernel_flv.hpp
@@ -21,8 +21,8 @@ IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-#ifndef SRS_APP_FLV_HPP
-#define SRS_APP_FLV_HPP
+#ifndef SRS_KERNEL_FLV_HPP
+#define SRS_KERNEL_FLV_HPP
 
 /*
 #include <srs_kernel_flv.hpp>
diff --git a/trunk/src/libs/srs_librtmp.cpp b/trunk/src/libs/srs_librtmp.cpp
index 10cab1a1e..3f87879d7 100644
--- a/trunk/src/libs/srs_librtmp.cpp
+++ b/trunk/src/libs/srs_librtmp.cpp
@@ -40,6 +40,7 @@ using namespace std;
 #include <srs_kernel_stream.hpp>
 #include <srs_protocol_amf0.hpp>
 #include <srs_kernel_flv.hpp>
+#include <srs_kernel_codec.hpp>
 
 // if user want to define log, define the folowing macro.
 #ifndef SRS_RTMP_USER_DEFINED_LOG
@@ -496,6 +497,12 @@ int64_t srs_flv_tellg(srs_flv_t flv)
     return context->fs.tellg();
 }
 
+void srs_flv_lseek(srs_flv_t flv, int64_t offset)
+{
+    FlvContext* context = (FlvContext*)flv;
+    context->fs.lseek(offset);
+}
+
 flv_bool srs_flv_is_eof(int error_code)
 {
     return error_code == ERROR_SYSTEM_FILE_EOF;
diff --git a/trunk/src/libs/srs_librtmp.hpp b/trunk/src/libs/srs_librtmp.hpp
index 3b8e4e532..59ce79362 100644
--- a/trunk/src/libs/srs_librtmp.hpp
+++ b/trunk/src/libs/srs_librtmp.hpp
@@ -167,6 +167,8 @@ int srs_flv_read_tag_header(srs_flv_t flv, char* ptype, int32_t* pdata_size, u_i
 int srs_flv_read_tag_data(srs_flv_t flv, char* data, int32_t size);
 /* file stream tellg to get offset */
 int64_t srs_flv_tellg(srs_flv_t flv);
+/* seek file stream, offset is form the start of file */
+void srs_flv_lseek(srs_flv_t flv, int64_t offset);
 /* whether the error code indicates EOF */
 flv_bool srs_flv_is_eof(int error_code);
 
diff --git a/trunk/src/srs/srs.upp b/trunk/src/srs/srs.upp
index cb9b88010..458d3d0c8 100755
--- a/trunk/src/srs/srs.upp
+++ b/trunk/src/srs/srs.upp
@@ -17,6 +17,8 @@ file
 	kernel readonly separator,
 	..\kernel\srs_kernel_buffer.hpp,
 	..\kernel\srs_kernel_buffer.cpp,
+	..\kernel\srs_kernel_codec.hpp,
+	..\kernel\srs_kernel_codec.cpp,
 	..\kernel\srs_kernel_error.hpp,
 	..\kernel\srs_kernel_error.cpp,
 	..\kernel\srs_kernel_flv.hpp,
@@ -43,8 +45,6 @@ file
 	app readonly separator,
 	..\app\srs_app_bandwidth.hpp,
 	..\app\srs_app_bandwidth.cpp,
-	..\app\srs_app_codec.hpp,
-	..\app\srs_app_codec.cpp,
 	..\app\srs_app_conn.hpp,
 	..\app\srs_app_conn.cpp,
 	..\app\srs_app_config.hpp,