add utc time format.

@@ -44,6 +44,11 @@ max_connections     1000;
 # @remark: donot support reload.
 # default: on
 daemon              on;
+# whether use utc_time to generate the time struct,
+# if off, use localtime() to generate it,
+# if on, use gmtime() instead, which use UTC time.
+# default: off
+utc_time            off;
 
 #############################################################################################
 # heartbeat/stats sections

@@ -1336,7 +1336,8 @@ int SrsConfig::check_config()
             && n != "srs_log_tank" && n != "srs_log_level" && n != "srs_log_file"
             && n != "max_connections" && n != "daemon" && n != "heartbeat"
             && n != "http_api" && n != "stats" && n != "vhost" && n != "pithy_print_ms"
-            && n != "http_stream" && n != "http_server" && n != "stream_caster") 
+            && n != "http_stream" && n != "http_server" && n != "stream_caster"
+            && n != "utc_time")
         {
             ret = ERROR_SYSTEM_CONFIG_INVALID;
             srs_error("unsupported directive %s, ret=%d", n.c_str(), ret);
@@ -1896,6 +1897,16 @@ int SrsConfig::get_pithy_print_ms()
     return ::atoi(pithy->arg0().c_str());
 }
 
+bool SrsConfig::get_utc_time()
+{
+    SrsConfDirective* utc = root->get("utc_time");
+    if (!utc || utc->arg0().empty()) {
+        return SRS_CONF_DEFAULT_UTC_TIME;
+    }
+    
+    return utc->arg0() == "on";
+}
+
 vector<SrsConfDirective*> SrsConfig::get_stream_casters()
 {
     srs_assert(root);

@@ -43,6 +43,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define SRS_CONF_DEFAULT_LOG_TANK_CONSOLE "console"
 #define SRS_CONF_DEFAULT_COFNIG_FILE "conf/srs.conf"
 #define SRS_CONF_DEFAULT_FF_LOG_DIR "./objs"
+#define SRS_CONF_DEFAULT_UTC_TIME false
 
 #define SRS_CONF_DEFAULT_MAX_CONNECTIONS 1000
 #define SRS_CONF_DEFAULT_HLS_PATH "./objs/nginx/html"
@@ -435,6 +436,10 @@ public:
     * every this interval in ms.
     */
     virtual int                 get_pithy_print_ms();
+    /**
+     * whether use utc-time to format the time.
+     */
+    virtual bool                get_utc_time();
 // stream_caster section
 public:
     /**

@@ -311,12 +311,6 @@ int SrsHlsMuxer::update_config(SrsRequest* r, string entry_prefix,
     // generate the m3u8 dir and path.
     m3u8 = path + "/" + m3u8_file;
     m3u8 = srs_path_build_stream(m3u8, req->vhost, req->app, req->stream);
-    
-    m3u8_dir = m3u8;
-    size_t pos = string::npos;
-    if ((pos = m3u8_dir.rfind("/")) != string::npos) {
-        m3u8_dir = m3u8_dir.substr(0, pos);
-    }
 
     // we always keep the target duration increasing.
     int max_td = srs_max(target_duration, (int)(fragment * _srs_config->get_hls_td_ratio(r->vhost)));
@@ -336,6 +330,14 @@ int SrsHlsMuxer::update_config(SrsRequest* r, string entry_prefix,
         should_write_file = true;
     }
     
+    // create m3u8 dir once.
+    m3u8_dir = srs_path_dirname(m3u8);
+    if (should_write_file && (ret = srs_create_dir_recursively(m3u8_dir)) != ERROR_SUCCESS) {
+        srs_error("create app dir %s failed. ret=%d", m3u8_dir.c_str(), ret);
+        return ret;
+    }
+    srs_info("create m3u8 dir %s ok", m3u8_dir.c_str());
+    
     return ret;
 }
 
@@ -434,11 +436,12 @@ int SrsHlsMuxer::segment_open(int64_t segment_start_dts)
     current->uri += ts_url;
     
     // create dir recursively for hls.
-    if (should_write_file && (ret = srs_create_dir_recursively(m3u8_dir)) != ERROR_SUCCESS) {
-        srs_error("create app dir %s failed. ret=%d", m3u8_dir.c_str(), ret);
+    std::string ts_dir = srs_path_dirname(current->full_path);
+    if (should_write_file && (ret = srs_create_dir_recursively(ts_dir)) != ERROR_SUCCESS) {
+        srs_error("create app dir %s failed. ret=%d", ts_dir.c_str(), ret);
         return ret;
     }
-    srs_info("create app dir %s ok", m3u8_dir.c_str());
+    srs_info("create ts dir %s ok", ts_dir.c_str());
     
     // open temp ts file.
     std::string tmp_file = current->full_path + ".tmp";

@@ -274,8 +274,14 @@ bool SrsFastLog::generate_header(bool error, const char* tag, int context_id, co
     
     // to calendar time
     struct tm* tm;
-    if ((tm = localtime(&tv.tv_sec)) == NULL) {
-        return false;
+    if (_srs_config->get_utc_time()) {
+        if ((tm = gmtime(&tv.tv_sec)) == NULL) {
+            return false;
+        }
+    } else {
+        if ((tm = localtime(&tv.tv_sec)) == NULL) {
+            return false;
+        }
     }
     
     // write log header

@@ -140,8 +140,14 @@ string srs_path_build_timestamp(string template_path)
     
     // to calendar time
     struct tm* tm;
-    if ((tm = localtime(&tv.tv_sec)) == NULL) {
-        return path;
+    if (_srs_config->get_utc_time()) {
+        if ((tm = gmtime(&tv.tv_sec)) == NULL) {
+            return path;
+        }
+    } else {
+        if ((tm = localtime(&tv.tv_sec)) == NULL) {
+            return path;
+        }
     }
     
     // the buffer to format the date and time.
@@ -154,32 +160,32 @@ string srs_path_build_timestamp(string template_path)
     }
     // [2006], replace with current year.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", 1900 + tm->tm_year);
+        snprintf(buf, sizeof(buf), "%04d", 1900 + tm->tm_year);
         path = srs_string_replace(path, "[2006]", buf);
     }
     // [01], replace this const to current month.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", 1 + tm->tm_mon);
+        snprintf(buf, sizeof(buf), "%02d", 1 + tm->tm_mon);
         path = srs_string_replace(path, "[01]", buf);
     }
     // [02], replace this const to current date.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", tm->tm_mday);
+        snprintf(buf, sizeof(buf), "%02d", tm->tm_mday);
         path = srs_string_replace(path, "[02]", buf);
     }
     // [15], replace this const to current hour.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", tm->tm_hour);
+        snprintf(buf, sizeof(buf), "%02d", tm->tm_hour);
         path = srs_string_replace(path, "[15]", buf);
     }
     // [04], repleace this const to current minute.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", tm->tm_min);
+        snprintf(buf, sizeof(buf), "%02d", tm->tm_min);
         path = srs_string_replace(path, "[04]", buf);
     }
     // [05], repleace this const to current second.
     if (true) {
-        snprintf(buf, sizeof(buf), "%d", tm->tm_sec);
+        snprintf(buf, sizeof(buf), "%02d", tm->tm_sec);
         path = srs_string_replace(path, "[05]", buf);
     }
     // [999], repleace this const to current millisecond.

@@ -294,6 +294,21 @@ bool srs_path_exists(std::string path)
     return false;
 }
 
+string srs_path_dirname(string path)
+{
+    std::string dirname = path;
+    size_t pos = string::npos;
+    
+    if ((pos = dirname.rfind("/")) != string::npos) {
+        if (pos == 0) {
+            return "/";
+        }
+        dirname = dirname.substr(0, pos);
+    }
+    
+    return dirname;
+}
+
 bool srs_avc_startswith_annexb(SrsStream* stream, int* pnb_start_code)
 {
     char* bytes = stream->data() + stream->pos();

@@ -68,6 +68,8 @@ extern int srs_create_dir_recursively(std::string dir);
 
 // whether path exists.
 extern bool srs_path_exists(std::string path);
+// get the dirname of path
+extern std::string srs_path_dirname(std::string path);
 
 /**
 * whether stream starts with the avc NALU in "AnnexB"