1 files changed, 154 insertions, 0 deletions
diff --git a/src/TimestampDecoder.h b/src/TimestampDecoder.h
new file mode 100644
index 0000000..3a1fb1b
--- /dev/null
+++ b/src/TimestampDecoder.h
@@ -0,0 +1,154 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+
+   Includes modifications for which no copyright is claimed
+   2012, Matthias P. Braendli, matthias.braendli@mpb.li
+ */
+/*
+   This file is part of CRC-DADMOD.
+
+   CRC-DADMOD is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   CRC-DADMOD is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with CRC-DADMOD.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TIMESTAMP_DECODER_H
+#define TIMESTAMP_DECODER_H
+
+#include "Eti.h"
+#include <time.h>
+#include <math.h>
+#include <stdio.h>
+
+struct modulator_offset_config
+{
+    bool use_offset_fixed;
+    double offset_fixed;
+
+    bool use_offset_file;
+    char* offset_filename;
+};
+
+struct frame_timestamp
+{
+    uint32_t timestamp_sec;
+    double timestamp_pps_offset;
+    bool timestamp_valid;
+    bool timestamp_refresh;
+
+    struct frame_timestamp operator=(const struct frame_timestamp &rhs)
+    {
+        if (this != &rhs) {
+            this->timestamp_sec = rhs.timestamp_sec;
+            this->timestamp_pps_offset = rhs.timestamp_pps_offset;
+            this->timestamp_valid = rhs.timestamp_valid;
+            this->timestamp_refresh = rhs.timestamp_refresh;
+        }
+
+        return *this;
+    }
+
+    struct frame_timestamp& operator+=(const double& diff)
+    {
+        double offset_pps, offset_secs;
+        offset_pps = modf(diff, &offset_secs);
+
+        this->timestamp_sec += lrintf(offset_secs);
+        this->timestamp_pps_offset += offset_pps;
+
+        while (this->timestamp_pps_offset > 1)
+        {
+            this->timestamp_pps_offset -= 1.0;
+            this->timestamp_sec += 1;
+        };
+        return *this;
+    }
+
+    const struct frame_timestamp operator+(const double diff)
+    {
+        struct frame_timestamp ts = *this;
+        ts += diff;
+        return ts;
+    }
+
+    void print(const char* t)
+    {
+        fprintf(stderr,
+                "%s <struct frame_timestamp(%s, %d, %.9f)>\n", 
+                t, this->timestamp_valid ? "valid" : "invalid",
+                 this->timestamp_sec, this->timestamp_pps_offset);
+    }
+};
+
+/* This module decodes MNSC time information */
+class TimestampDecoder
+{
+    public: 
+        TimestampDecoder(struct modulator_offset_config& config):
+            modconfig(config)
+        {
+            inhibit_second_update = 0;
+            time_pps = 0.0;
+            time_secs = 0;
+            enableDecode = false;
+            full_timestamp_received_mnsc = false;
+            gmtime_r(0, &temp_time);
+            offset_changed = false;
+        };
+
+        /* Calculate the timestamp for the current frame. */
+        void calculateTimestamp(struct frame_timestamp& ts);
+
+        /* Update timestamp data from data in ETI */
+        void updateTimestampEti(int framephase, uint16_t mnsc, double pps);
+
+        /* Update the modulator timestamp offset according to the modconf
+         */
+        bool updateModulatorOffset();
+
+    protected:
+        /* Push a new MNSC field into the decoder */
+        void pushMNSCData(int framephase, uint16_t mnsc);
+
+        /* Each frame contains the TIST field with the PPS offset.
+         * For each frame, this function must be called to update
+         * the timestamp
+         */
+        void updateTimestampPPS(double pps);
+        
+        /* Update the timestamp when a full set of MNSC data is
+         * known. This function can be called at most every four
+         * frames when the data is transferred using the MNSC.
+         */
+        void updateTimestampSeconds(uint32_t secs);
+
+        struct tm temp_time;
+        uint32_t time_secs;
+        double time_pps;
+        double timestamp_offset;
+        int inhibit_second_update;
+        bool offset_changed;
+
+        /* configuration for the offset management */
+        struct modulator_offset_config& modconfig;
+
+        /* When the type or identifier don't match, the decoder must
+         * be disabled
+         */
+        bool enableDecode;
+
+        /* Disable timstamps until full time has been received in mnsc */
+        bool full_timestamp_received_mnsc;
+};
+
+#endif