fix hermes lite buffering

source_modules/hermes_source/src/hermes.cpp

@@ -2,6 +2,13 @@
 #include <utils/flog.h>
 
 namespace hermes {
+    const int SAMPLERATE_LIST[] = {
+        48000,
+        96000,
+        192000,
+        384000
+    };
+
     Client::Client(std::shared_ptr<net::Socket> sock) {
         this->sock = sock;
 
@@ -33,6 +40,7 @@ namespace hermes {
 
     void Client::setSamplerate(HermesLiteSamplerate samplerate) {
         writeReg(0, (uint32_t)samplerate << 24);
+        blockSize = SAMPLERATE_LIST[samplerate] / 200;
     }
 
     void Client::setFrequency(double freq) {
@@ -157,6 +165,8 @@ namespace hermes {
     void Client::worker() {
         uint8_t rbuf[2048];
         MetisUSBPacket* pkt = (MetisUSBPacket*)rbuf;
+        int sampleCount = 0;
+
         while (true) {
             // Wait for a packet or exit if connection closed
             int len = sock->recv(rbuf, 2048);
@@ -183,9 +193,10 @@ namespace hermes {
                     flog::warn("Got response! Reg={0}, Seq={1}", reg, (uint32_t)htonl(pkt->seq));
                 }
 
-                // Decode and send IQ to stream
+                // Decode and save IQ to buffer
                 uint8_t* iq = &frame[8];
-                for (int i = 0; i < 63; i++) {
+                dsp::complex_t* writeBuf = &out.writeBuf[sampleCount];
+                for (int i = 0; i < HERMES_SAMPLES_PER_FRAME; i++) {
                     // Convert to 32bit
                     int32_t si = ((uint32_t)iq[(i*8) + 0] << 16) | ((uint32_t)iq[(i*8) + 1] << 8) | (uint32_t)iq[(i*8) + 2];
                     int32_t sq = ((uint32_t)iq[(i*8) + 3] << 16) | ((uint32_t)iq[(i*8) + 4] << 8) | (uint32_t)iq[(i*8) + 5];
@@ -195,11 +206,16 @@ namespace hermes {
                     sq = (sq << 8) >> 8;
 
                     // Convert to float (IQ swapped for some reason)
-                    out.writeBuf[i].im = (float)si / (float)0x1000000;
-                    out.writeBuf[i].re = (float)sq / (float)0x1000000;
+                    writeBuf[i].im = (float)si / (float)0x1000000;
+                    writeBuf[i].re = (float)sq / (float)0x1000000;
+                }
+                sampleCount += HERMES_SAMPLES_PER_FRAME;
+
+                // If enough samples are in the buffer, send to stream
+                if (sampleCount >= blockSize) {
+                    out.swap(sampleCount);
+                    sampleCount = 0;
                 }
-                out.swap(63);
-                // TODO: Buffer the data to avoid having a very high DSP frame rate
             }            
         }
     }

source_modules/hermes_source/src/hermes.h

@@ -7,11 +7,12 @@
 #include <string>
 #include <thread>
 
-#define HERMES_METIS_REPEAT     5
-#define HERMES_METIS_TIMEOUT    1000
-#define HERMES_METIS_SIGNATURE  0xEFFE
-#define HERMES_HPSDR_USB_SYNC   0x7F
-#define HERMES_I2C_DELAY        50
+#define HERMES_METIS_REPEAT         5
+#define HERMES_METIS_TIMEOUT        1000
+#define HERMES_METIS_SIGNATURE      0xEFFE
+#define HERMES_HPSDR_USB_SYNC       0x7F
+#define HERMES_I2C_DELAY            50
+#define HERMES_SAMPLES_PER_FRAME    63
 
 namespace hermes {
     enum MetisPacketType {
@@ -140,7 +141,7 @@ namespace hermes {
 
         dsp::stream<dsp::complex_t> out;
 
-    //private:
+    private:
         void sendMetisUSB(uint8_t endpoint, void* frame0, void* frame1 = NULL);
         void sendMetisControl(MetisControl ctrl);
 
@@ -149,12 +150,12 @@ namespace hermes {
 
         void writeI2C(I2CPort port, uint8_t addr, uint8_t reg, uint8_t data);
 
-        
-
         void worker();
 
         double freq = 0;
 
+        int blockSize = 63;
+
         std::thread workerThread;
         std::shared_ptr<net::Socket> sock;
         uint32_t usbSeq = 0;