2 files changed, 26 insertions, 2 deletions
diff --git a/lib/edi/common.cpp b/lib/edi/common.cpp
index b4b0c79..4629b55 100644
--- a/lib/edi/common.cpp
+++ b/lib/edi/common.cpp
@@ -61,6 +61,25 @@ time_t frame_timestamp_t::to_unix_epoch() const
     return 946684800 + seconds - utco;
 }
 
+double frame_timestamp_t::diff_ms(const frame_timestamp_t& other) const
+{
+    const double lhs = (double)seconds + (tsta / 16384000.0);
+    const double rhs = (double)other.seconds + (other.tsta / 16384000.0);
+    return lhs - rhs;
+}
+
+frame_timestamp_t frame_timestamp_t::from_unix_epoch(std::time_t time, uint32_t tai_utc_offset, uint32_t tsta)
+{
+    frame_timestamp_t ts;
+
+    const std::time_t posix_timestamp_1_jan_2000 = 946684800;
+
+    ts.utco = tai_utc_offset - 32;
+    ts.seconds = time - posix_timestamp_1_jan_2000 + ts.utco;
+    ts.tsta = tsta;
+    return ts;
+}
+
 std::chrono::system_clock::time_point frame_timestamp_t::to_system_clock() const
 {
     auto ts = chrono::system_clock::from_time_t(to_unix_epoch());
@@ -202,7 +221,7 @@ decode_state_t TagDispatcher::decode_afpacket(
         return {false, 0};
     }
 
-    if (m_last_seq + 1 != seq) {
+    if (m_last_seq + (uint16_t)1 != seq) {
         etiLog.level(warn) << "EDI AF Packet sequence error, " << seq;
     }
     m_last_seq = seq;
diff --git a/lib/edi/common.hpp b/lib/edi/common.hpp
index 887bc3d..1aa2cb6 100644
--- a/lib/edi/common.hpp
+++ b/lib/edi/common.hpp
@@ -38,10 +38,15 @@ struct frame_timestamp_t {
 
     bool valid() const;
     std::string to_string() const;
-    time_t to_unix_epoch() const;
+    std::time_t to_unix_epoch() const;
     std::chrono::system_clock::time_point to_system_clock() const;
+
+    double diff_ms(const frame_timestamp_t& other) const;
+
+    static frame_timestamp_t from_unix_epoch(std::time_t time, uint32_t tai_utc_offset, uint32_t tsta);
 };
 
+
 struct decode_state_t {
     decode_state_t(bool _complete, size_t _num_bytes_consumed) :
         complete(_complete), num_bytes_consumed(_num_bytes_consumed) {}