Add support for automatic local-time-offset

5 files changed, 64 insertions, 25 deletions

diff --git a/doc/example.mux b/doc/example.mux
index c1657a1..86ce483 100644
--- a/doc/example.mux
+++ b/doc/example.mux
@@ -59,7 +59,11 @@ remotecontrol {
 ensemble {
     id 0x4fff ; you can also use decimal if you want
     ecc 0xec ; Extended Country Code
-    local-time-offset 1 ; in hours, supports half-hour offsets
+
+    local-time-offset 1     ; in hours, supports half-hour offsets
+                            ; or
+    ;local-time-offset auto ; autmatically calculate from system local time
+
     international-table 1 ; See TS 101 756 clause 5.7
                           ; 1 corresponds to the PTy used in RDS
                           ; 2 corresponds to program types used in north america
diff --git a/src/DabMux.cpp b/src/DabMux.cpp
index 734643c..c090738 100644
--- a/src/DabMux.cpp
+++ b/src/DabMux.cpp
@@ -77,6 +77,8 @@ typedef DWORD32 uint32_t;
 #   include <net/if_packet.h>
 #endif
 
+#include <time.h>
+
 #ifdef _WIN32
 #   pragma warning ( disable : 4103 )
 #   include "Eti.h"
@@ -1631,6 +1633,14 @@ int main(int argc, char *argv[])
 
             fig0_9->ext = 0;
             fig0_9->lto = 0; // Unique LTO for ensemble
+
+            if (ensemble->lto_auto) {
+                time_t now = time(NULL);
+                struct tm* ltime = localtime(&now);
+                time_t now2 = timegm(ltime);
+                ensemble->lto = (now2 - now) / 1800;
+            }
+
             if (ensemble->lto >= 0) {
                 fig0_9->ensembleLto = ensemble->lto;
             }
@@ -1638,6 +1648,7 @@ int main(int argc, char *argv[])
                 /* Convert to 1-complement representation */
                 fig0_9->ensembleLto = (-ensemble->lto) | (1<<5);
             }
+
             fig0_9->ensembleEcc = ensemble->ecc;
             fig0_9->tableId = ensemble->international_table;
             index += 5;
diff --git a/src/MuxElements.cpp b/src/MuxElements.cpp
index 03e9bbf..c7ac076 100644
--- a/src/MuxElements.cpp
+++ b/src/MuxElements.cpp
@@ -389,18 +389,24 @@ void dabEnsemble::set_parameter(const string& parameter, const string& value)
     ss.exceptions ( stringstream::failbit | stringstream::badbit );
 
     if (parameter == "localtimeoffset") {
-        int new_lto = atol(value.c_str());
-
-        if (new_lto < -24) {
-            throw ParameterError("Desired local time offset too small."
-                   " Minimum -24" );
-        }
-        else if (new_lto > 24) {
-            throw ParameterError("Desired local time offset too large."
-                   " Maximum 24" );
+        if (value == "auto") {
+            lto_auto = true;
         }
+        else {
+            lto_auto = false;
+            int new_lto = atol(value.c_str());
+
+            if (new_lto < -24) {
+                throw ParameterError("Desired local time offset too small."
+                        " Minimum -24" );
+            }
+            else if (new_lto > 24) {
+                throw ParameterError("Desired local time offset too large."
+                        " Maximum 24" );
+            }
 
-        this->lto = new_lto;
+            this->lto = new_lto;
+        }
     }
     else {
         stringstream ss;
@@ -414,7 +420,12 @@ const string dabEnsemble::get_parameter(const string& parameter) const
 {
     stringstream ss;
     if (parameter == "localtimeoffset") {
-        ss << this->lto;
+        if (this->lto_auto) {
+            ss << "auto(" << this->lto << ")";
+        }
+        else {
+            ss << this->lto;
+        }
     }
     else {
         ss << "Parameter '" << parameter <<
diff --git a/src/MuxElements.h b/src/MuxElements.h
index e6752e5..9895956 100644
--- a/src/MuxElements.h
+++ b/src/MuxElements.h
@@ -94,7 +94,7 @@ class dabEnsemble : public RemoteControllable {
             : RemoteControllable("ensemble")
         {
             RC_ADD_PARAMETER(localtimeoffset,
-                    "local time offset, -24 to +24 [half-hours]");
+                    "local time offset, 'auto' or -24 to +24 [half-hours]");
         }
 
         /* Remote control */
@@ -109,8 +109,13 @@ class dabEnsemble : public RemoteControllable {
         uint8_t ecc;
         DabLabel label;
         uint8_t mode;
+
+        /* Use the local time to calculate the lto */
+        bool lto_auto;
+
         int lto; // local time offset in half-hours
         // range: -24 to +24
+
         int international_table;
 
         std::vector<DabService*> services;
diff --git a/src/ParserConfigfile.cpp b/src/ParserConfigfile.cpp
index b477f1d..f515a5c 100644
--- a/src/ParserConfigfile.cpp
+++ b/src/ParserConfigfile.cpp
@@ -191,18 +191,26 @@ void parse_configfile(string configuration_file,
 
     ensemble->international_table = pt_ensemble.get("international-table", 0);
 
-    double lto_hours = pt_ensemble.get("local-time-offset", 0.0);
-    if (round(lto_hours * 2) != lto_hours * 2) {
-        etiLog.level(error) << "Ensemble local time offset " <<
-            lto_hours << "h cannot be expressed in half-hour blocks.";
-        throw runtime_error("ensemble local-time-offset definition error");
-    }
-    if (lto_hours > 12 || lto_hours < -12) {
-        etiLog.level(error) << "Ensemble local time offset " <<
-            lto_hours << "h out of bounds [-12, +12].";
-        throw runtime_error("ensemble local-time-offset definition error");
-    }
-    ensemble->lto = abs(rint(lto_hours * 2));
+    string lto_auto = pt_ensemble.get("local-time-offset", "");
+    if (lto_auto == "auto") {
+        ensemble->lto_auto = true;
+        ensemble->lto = 0;
+    }
+    else {
+        double lto_hours = pt_ensemble.get("local-time-offset", 0.0);
+        if (round(lto_hours * 2) != lto_hours * 2) {
+            etiLog.level(error) << "Ensemble local time offset " <<
+                lto_hours << "h cannot be expressed in half-hour blocks.";
+            throw runtime_error("ensemble local-time-offset definition error");
+        }
+        if (lto_hours > 12 || lto_hours < -12) {
+            etiLog.level(error) << "Ensemble local time offset " <<
+                lto_hours << "h out of bounds [-12, +12].";
+            throw runtime_error("ensemble local-time-offset definition error");
+        }
+        ensemble->lto_auto = false;
+        ensemble->lto = abs(rint(lto_hours * 2));
+    }
 
     int success = -5;
     string ensemble_label = pt_ensemble.get<string>("label");