Soapy: set hw time if device supports

2 files changed, 16 insertions, 6 deletions

diff --git a/src/output/SDR.cpp b/src/output/SDR.cpp
index 34341bd..b5741a6 100644
--- a/src/output/SDR.cpp
+++ b/src/output/SDR.cpp
@@ -247,7 +247,6 @@ void SDR::handle_frame(struct FrameData& frame)
         return;
     }
 
-    double device_time = m_device->get_real_secs();
     const auto& time_spec = frame.ts;
 
     if (m_config.enableSync and m_config.muteNoTimestamps and
@@ -264,6 +263,8 @@ void SDR::handle_frame(struct FrameData& frame)
         const uint32_t tx_second = frame.ts.timestamp_sec;
         const uint32_t tx_pps    = frame.ts.timestamp_pps;
 
+        const double device_time = m_device->get_real_secs();
+
         if (not frame.ts.timestamp_valid) {
             /* We have not received a full timestamp through
              * MNSC. We sleep through the frame.
@@ -277,11 +278,13 @@ void SDR::handle_frame(struct FrameData& frame)
 
         if (last_tx_time_initialised) {
             const size_t sizeIn = frame.buf.size() / sizeof(complexf);
-            uint64_t increment = (uint64_t)sizeIn * 16384000ul /
-                                 (uint64_t)m_config.sampleRate;
-                                  // samps  * ticks/s  / (samps/s)
-                                  // (samps * ticks * s) / (s * samps)
-                                  // ticks
+
+            // Checking units for the increment calculation:
+            // samps  * ticks/s  / (samps/s)
+            // (samps * ticks * s) / (s * samps)
+            // ticks
+            const uint64_t increment = (uint64_t)sizeIn * 16384000ul /
+                                       (uint64_t)m_config.sampleRate;
 
             uint32_t expected_sec = last_tx_second + increment / 16384000ul;
             uint32_t expected_pps = last_tx_pps + increment % 16384000ul;
diff --git a/src/output/Soapy.cpp b/src/output/Soapy.cpp
index 8ee420e..3093b65 100644
--- a/src/output/Soapy.cpp
+++ b/src/output/Soapy.cpp
@@ -97,6 +97,13 @@ Soapy::Soapy(SDRDeviceConfig& config) :
     etiLog.level(info) << "SoapySDR:Actual tx antenna: " <<
         m_device->getAntenna(SOAPY_SDR_TX, 0);
 
+    if (m_device->hasHardwareTime()) {
+        using namespace std::chrono;
+        auto n = system_clock::now();
+        const long long ticks = duration_cast<nanoseconds>(n.time_since_epoch()).count();
+        m_device->setHardwareTime(ticks);
+    }
+
     const std::vector<size_t> channels({0});
     m_tx_stream = m_device->setupStream(SOAPY_SDR_TX, "CF32", channels);
     m_device->activateStream(m_tx_stream);