Decimate more.

plugins/channel/CMakeLists.txt

@@ -1,7 +1,7 @@
 project(demod)
 
 add_subdirectory(lora)
-add_subdirectory(nfm)
+add_subdirectory(nfm_testing)
 add_subdirectory(ssb)
 add_subdirectory(tcpsrc)
 add_subdirectory(usb)

plugins/samplesource/v4l-msi/v4linput.cpp

@@ -94,7 +94,7 @@ bool V4LInput::startInput(int device)
 		return false;
 	}
 
-	m_deviceDescription = QString("RTL-SDR /dev/swradio0");
+	m_deviceDescription = QString("SDRplay /dev/swradio0");
 
 	qDebug("V4LInput: start");
 	//MsgReportV4L::create(m_gains)->submit(m_guiMessageQueue);
@@ -123,7 +123,7 @@ const QString& V4LInput::getDeviceDescription() const
 int V4LInput::getSampleRate() const
 {
 	// The output rate is lower than the device rate
-	int result = SAMPLERATE / 2;
+	int result = SAMPLERATE / 4;
 	return result;
 }
 

plugins/samplesource/v4l-msi/v4lplugin.cpp

@@ -1,6 +1,5 @@
 #include <QtPlugin>
 #include <QAction>
-#include <rtl-sdr.h>
 #include "plugin/pluginapi.h"
 #include "util/simpleserializer.h"
 #include "v4lplugin.h"
@@ -8,7 +7,7 @@
 
 const PluginDescriptor V4LPlugin::m_pluginDescriptor = {
 	QString("V4L Input"),
-	QString("3.18"),
+	QString("4.0"),
 	QString("(c) 2014 John Greb"),
 	QString("http://palosaari.fi/linux/"),
 	true,
@@ -36,7 +35,7 @@ PluginInterface::SampleSourceDevices V4LPlugin::enumSampleSources()
 {
 	SampleSourceDevices result;
 
-	QString displayedName(QString("Kernel Source #1"));
+	QString displayedName(QString("Linux V4L (SDRplay)"));
 	SimpleSerializer s(1);
 	s.writeS32(1, 0);
 	result.append(SampleSourceDevice(displayedName, "org.osmocom.sdr.samplesource.v4l", s.final()));

plugins/samplesource/v4l-msi/v4lsource.cpp

@@ -218,6 +218,7 @@ V4LThread::set_tuner_gain(double gain)
 		return;
 	}
 
+#define CASTUP (int)(qint16)
 int
 V4LThread::work(int noutput_items)
 {
@@ -230,20 +231,20 @@ V4LThread::work(int noutput_items)
 	SampleVector::iterator it;
 
 	unsigned int pos = 0;
-	// MSI format is 252 sample pairs : 63 * 4
+	// MSI format is 252 sample pairs :( 63 * 4) * 4bytes
 	it = m_convertBuffer.begin();
-	if (recebuf_len >= 8) { // in bytes
+	if (recebuf_len >= 16) { // in bytes
 		b = (uint16_t *) recebuf_ptr;
-		unsigned int len = 4 * noutput_items; // decimation (i+q * 2 : cmplx)
+		unsigned int len = 8 * noutput_items; // decimation (i+q * 4 : cmplx)
 		if (len * 2 > recebuf_len)
 			len = recebuf_len / 2;
 		// Decimate by two for lower cpu usage
-		for (pos = 0; pos < len - 3; pos += 4) {
-			xreal = (qint16)(b[pos+0]<<2) + (qint16)(b[pos+2]<<2);
-				// + (qint16)(b[pos+4]<<2) + (qint16)(b[pos+6]<<2);
-			yimag = (qint16)(b[pos+1]<<2) + (qint16)(b[pos+3]<<2);
-				// + (int)(b[pos+5]<<2) + (int)(b[pos+7]<<2);
-			Sample s( (qint16)(xreal >> 2) , (qint16)(yimag>>2) );
+		for (pos = 0; pos < len - 7; pos += 8) {
+			xreal = CASTUP(b[pos+0]<<2) + CASTUP(b[pos+2]<<2)
+				+ CASTUP(b[pos+4]<<2) + CASTUP(b[pos+6]<<2);
+			yimag = CASTUP(b[pos+1]<<2) + CASTUP(b[pos+3]<<2)
+				+ CASTUP(b[pos+5]<<2) + CASTUP(b[pos+7]<<2);
+			Sample s( (qint16)(xreal >> 2) , (qint16)(yimag >> 2) );
 			*it = s;
 			it++;
 		}
@@ -252,8 +253,8 @@ V4LThread::work(int noutput_items)
 		recebuf_ptr = (void*)(b + pos);	
 	}
 	// return now if there is still data in buffer, else free buffer and get another.
-	if (recebuf_len >= 8)
-		return pos / 4;
+	if (recebuf_len >= 16)
+		return pos / 8;
 	{	// free buffer, if there was one.
 		if (pos > 0) { 
 			CLEAR(buf);
@@ -290,5 +291,5 @@ V4LThread::work(int noutput_items)
 		recebuf_len = buf.bytesused;
 		recebuf_mmap_index = buf.index;
 	}
-	return pos / 4;
+	return pos / 8;
 }

plugins/samplesource/v4l-msi/v4lthread.h

@@ -26,6 +26,7 @@
 
 // lowest samplerate in the kernel is 1.2M, but this works better
 #define SAMPLERATE 1536000
+//#define SAMPLERATE 768000
 #define BLOCKSIZE 8192
 
 class V4LThread : public QThread {