diff --git a/trunk/src/app/srs_app_config.cpp b/trunk/src/app/srs_app_config.cpp
index 461fe6f6b4..9c3b9afee8 100644
--- a/trunk/src/app/srs_app_config.cpp
+++ b/trunk/src/app/srs_app_config.cpp
@@ -2293,6 +2293,29 @@ int SrsConfig::raw_set_chunk_size(string chunk_size, bool& applied)
     return ret;
 }
 
+int SrsConfig::raw_set_ff_log_dir(string ff_log_dir, bool& applied)
+{
+    int ret = ERROR_SUCCESS;
+    
+    applied = false;
+    
+    
+    SrsConfDirective* conf = root->get_or_create("ff_log_dir");
+    
+    if (conf->arg0() == ff_log_dir) {
+        return ret;
+    }
+    
+    conf->args.clear();
+    conf->args.push_back(ff_log_dir);
+    
+    // directly supported reload for ff_log_dir change.
+    
+    applied = true;
+    
+    return ret;
+}
+
 int SrsConfig::do_reload_listen()
 {
     int ret = ERROR_SUCCESS;
diff --git a/trunk/src/app/srs_app_config.hpp b/trunk/src/app/srs_app_config.hpp
index 8b716f6b14..d531ef0a83 100644
--- a/trunk/src/app/srs_app_config.hpp
+++ b/trunk/src/app/srs_app_config.hpp
@@ -345,6 +345,10 @@ class SrsConfig
      * raw set the global chunk size.
      */
     virtual int raw_set_chunk_size(std::string chunk_size, bool& applied);
+    /**
+     * raw set the global ffmpeg log dir.
+     */
+    virtual int raw_set_ff_log_dir(std::string ff_log_dir, bool& applied);
 private:
     virtual int do_reload_listen();
     virtual int do_reload_pid();
diff --git a/trunk/src/app/srs_app_http_api.cpp b/trunk/src/app/srs_app_http_api.cpp
index 741d966fca..16a16ddc5c 100755
--- a/trunk/src/app/srs_app_http_api.cpp
+++ b/trunk/src/app/srs_app_http_api.cpp
@@ -998,7 +998,14 @@ int SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage* r)
         
         std::string scope = r->query_get("scope");
         std::string value = r->query_get("value");
-        if (scope.empty() || (scope != "listen" && scope != "pid" && scope != "chunk_size")) {
+        if (scope.empty()) {
+            ret = ERROR_SYSTEM_CONFIG_RAW_NOT_ALLOWED;
+            srs_error("raw api query invalid empty scope. ret=%d", ret);
+            return srs_api_response_code(w, r, ret);
+        }
+        if (scope != "listen" && scope != "pid" && scope != "chunk_size"
+            && scope != "ff_log_dir"
+        ) {
             ret = ERROR_SYSTEM_CONFIG_RAW_NOT_ALLOWED;
             srs_error("raw api query invalid scope=%s. ret=%d", scope.c_str(), ret);
             return srs_api_response_code(w, r, ret);
@@ -1028,16 +1035,7 @@ int SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage* r)
                 return srs_api_response_code(w, r, ret);
             }
         } else if (scope == "pid") {
-            bool invalid = value.empty();
-            if (!invalid) {
-                invalid = !srs_string_starts_with(value, "./")
-                    && !srs_string_starts_with(value, "/tmp")
-                    && !srs_string_starts_with(value, "/var");
-            }
-            if (!invalid) {
-                invalid = !srs_string_ends_with(value, ".pid");
-            }
-            if (invalid) {
+            if (value.empty() || !srs_string_starts_with(value, "./", "/tmp/", "/var/") || !srs_string_ends_with(value, ".pid")) {
                 ret = ERROR_SYSTEM_CONFIG_RAW_PARAMS;
                 srs_error("raw api update check pid=%s failed. ret=%d", value.c_str(), ret);
                 return srs_api_response_code(w, r, ret);
@@ -1059,6 +1057,17 @@ int SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage* r)
                 srs_error("raw api update chunk_size=%s/%d failed. ret=%d", value.c_str(), csv, ret);
                 return srs_api_response_code(w, r, ret);
             }
+        } else if (scope == "ff_log_dir") {
+            if (value.empty() || (value != "/dev/null" && !srs_string_starts_with(value, "./", "/tmp/", "/var/"))) {
+                ret = ERROR_SYSTEM_CONFIG_RAW_PARAMS;
+                srs_error("raw api update check ff_log_dir=%s failed. ret=%d", value.c_str(), ret);
+                return srs_api_response_code(w, r, ret);
+            }
+            
+            if ((ret = _srs_config->raw_set_ff_log_dir(value, applied)) != ERROR_SUCCESS) {
+                srs_error("raw api update ff_log_dir=%s failed. ret=%d", value.c_str(), ret);
+                return srs_api_response_code(w, r, ret);
+            }
         }
         
         // whether the config applied.
diff --git a/trunk/src/kernel/srs_kernel_utility.cpp b/trunk/src/kernel/srs_kernel_utility.cpp
index c341e0c8e0..6db8205d72 100644
--- a/trunk/src/kernel/srs_kernel_utility.cpp
+++ b/trunk/src/kernel/srs_kernel_utility.cpp
@@ -280,6 +280,21 @@ bool srs_string_starts_with(string str, string flag)
     return str.find(flag) == 0;
 }
 
+bool srs_string_starts_with(string str, string flag0, string flag1)
+{
+    return srs_string_starts_with(str, flag0) || srs_string_starts_with(str, flag1);
+}
+
+bool srs_string_starts_with(string str, string flag0, string flag1, string flag2)
+{
+    return srs_string_starts_with(str, flag0, flag1) || srs_string_starts_with(str, flag2);
+}
+
+bool srs_string_starts_with(string str, string flag0, string flag1, string flag2, string flag3)
+{
+    return srs_string_starts_with(str, flag0, flag1, flag2) || srs_string_starts_with(str, flag3);
+}
+
 bool srs_string_contains(string str, string flag)
 {
     return str.find(flag) != string::npos;
diff --git a/trunk/src/kernel/srs_kernel_utility.hpp b/trunk/src/kernel/srs_kernel_utility.hpp
index 6688679362..a5c7bfad69 100644
--- a/trunk/src/kernel/srs_kernel_utility.hpp
+++ b/trunk/src/kernel/srs_kernel_utility.hpp
@@ -68,6 +68,9 @@ extern std::string srs_string_remove(std::string str, std::string remove_chars);
 extern bool srs_string_ends_with(std::string str, std::string flag);
 // whether string starts with
 extern bool srs_string_starts_with(std::string str, std::string flag);
+extern bool srs_string_starts_with(std::string str, std::string flag0, std::string flag1);
+extern bool srs_string_starts_with(std::string str, std::string flag0, std::string flag1, std::string flag2);
+extern bool srs_string_starts_with(std::string str, std::string flag0, std::string flag1, std::string flag2, std::string flag3);
 // whether string contains with
 extern bool srs_string_contains(std::string str, std::string flag);
 // split the string by flag to array.