diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..e00be0e
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,45 @@
+name: Build
+
+on: [push]
+
+env:
+  BUILD_TYPE: Release
+  # For macOS qt keg-only package
+  CMAKE_PREFIX_PATH: '/usr/local/opt/qt@5'
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os: ['macos-latest', 'ubuntu-20.04', 'ubuntu-18.04']
+    runs-on: ${{ matrix.os }}
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install dependencies (macOS)
+      run: brew install fftw liquid-dsp qt@5
+      if: matrix.os == 'macos-latest'
+
+    - name: Install dependencies (Ubuntu)
+      run: sudo apt install libfftw3-dev libliquid-dev qtbase5-dev
+      if: startsWith(matrix.os, 'ubuntu-')
+
+    - name: Create Build Environment
+      run: cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Configure CMake
+      shell: bash
+      working-directory: ${{runner.workspace}}/build
+      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      shell: bash
+      run: cmake --build . --config $BUILD_TYPE
+
+    - name: Test
+      working-directory: ${{runner.workspace}}/build
+      shell: bash
+      run: ctest -C $BUILD_TYPE
+
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index ee3f9fa..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,43 +0,0 @@
-language: c
-
-cache: apt
-
-sudo: required
-dist: bionic
-
-os:
-  - linux
-  - osx
-
-compiler:
-  - gcc
-  - clang
-
-matrix:
-  exclude:
-    # /usr/bin/gcc on OS X is clang, so it's not meaningful to build against both.
-    - os: osx
-      compiler: gcc
-
-addons:
-  apt:
-    sources:
-#      - ubuntu-sdk-team
-    packages:
-      - qtbase5-dev
-      - qtdeclarative5-dev
-      - libfftw3-dev
-      - libliquid-dev
-
-before_install:
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew update; fi
-  # cmake and pkg-config are already installed.
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install qt5 fftw liquid-dsp; fi
-
-script:
-  - mkdir build
-  - cd build
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then export CMAKE_PREFIX_PATH=$(brew --prefix qt5)/lib/cmake; fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then DYLIB_SUFFIX=dylib; else DYLIB_SUFFIX=so; fi
-  - CFLAGS="-g -Wall -Wextra -Werror -Wno-zero-length-array" cmake ..
-  - make
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ddb0bd9..462a682 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,89 +1,5 @@
-cmake_minimum_required(VERSION 2.8.11)
+cmake_minimum_required(VERSION 3.1)
 project(inspectrum CXX)
 enable_testing()
 
-set(CMAKE_AUTOMOC ON)
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/Modules)
-
-# For OSX - don't clear RPATH on install
-set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
-
-if (MSVC)
-    #force std::complex<> typedefs in liquiddsp
-    add_definitions(-D_LIBCPP_COMPLEX)
-
-    #enable math definitions in math.h
-    add_definitions(-D_USE_MATH_DEFINES)
-
-    #build a graphical application without the console
-    option(BUILD_WIN32 "Build win32 app, false for console" TRUE)
-    if (BUILD_WIN32)
-        set(EXE_ARGS WIN32)
-        set(CMAKE_EXE_LINKER_FLAGS "/entry:mainCRTStartup ${CMAKE_EXE_LINKER_FLAGS}")
-    endif (BUILD_WIN32)
-endif (MSVC)
-
-if (NOT CMAKE_CXX_FLAGS)
-    set(CMAKE_CXX_FLAGS "-O2")
-endif (NOT CMAKE_CXX_FLAGS)
-
-# This only works in cmake >3.1
-#set_property(TARGET inspectrum PROPERTY CXX_STANDARD 11)
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
-
-list(APPEND inspectrum_sources 
-    abstractsamplesource.cpp
-    amplitudedemod.cpp
-    cursor.cpp
-    cursors.cpp
-    main.cpp
-    fft.cpp
-    frequencydemod.cpp
-    mainwindow.cpp
-    inputsource.cpp
-    phasedemod.cpp
-    plot.cpp
-    plots.cpp
-    plotview.cpp
-    samplebuffer.cpp
-    samplesource.cpp
-    spectrogramcontrols.cpp
-    spectrogramplot.cpp
-    threshold.cpp
-    traceplot.cpp
-    tuner.cpp
-    tunertransform.cpp
-    util.cpp
-)
-
-find_package(Qt5Widgets REQUIRED)
-find_package(Qt5Concurrent REQUIRED)
-find_package(FFTW REQUIRED)
-find_package(Liquid REQUIRED)
-
-include_directories(
-    ${FFTW_INCLUDES}
-    ${LIQUID_INCLUDES}
-)
-
-add_executable(inspectrum ${EXE_ARGS} ${inspectrum_sources})
-
-target_link_libraries(inspectrum
-    Qt5::Core Qt5::Widgets Qt5::Concurrent
-    ${FFTW_LIBRARIES}
-    ${LIQUID_LIBRARIES}
-)
-set(INSTALL_DEFAULT_BINDIR "bin" CACHE STRING "Appended to CMAKE_INSTALL_PREFIX")
-
-install(TARGETS inspectrum RUNTIME DESTINATION ${INSTALL_DEFAULT_BINDIR})
-
-# Create uninstall target
-configure_file(
-    ${PROJECT_SOURCE_DIR}/cmake/cmake_uninstall.cmake.in
-    ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake
-@ONLY)
-
-add_custom_target(uninstall
-    ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake
-)
+add_subdirectory(src)
diff --git a/README.md b/README.md
index b5d439c..102ff71 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,12 @@ inspectrum is a tool for analysing captured signals, primarily from software-def
 ## Try it
 ### Prerequisites
 
- * cmake >= 2.8.11
+ * cmake >= 3.1
  * fftw 3.x
  * [liquid-dsp](https://github.com/jgaeddert/liquid-dsp) >= v1.3.0
  * pkg-config
  * qt5
+ * [libsigmf](https://github.com/deepsig/libsigmf) (optional, for SigMF support)
 
 ### Build instructions
 
@@ -22,6 +23,7 @@ Build instructions can be found here: https://github.com/miek/inspectrum/wiki/Bu
 
 ## Input
 inspectrum supports the following file types:
+ * `*.sigmf-meta, *.sigmf-data` - SigMF recordings
  * `*.cf32`, `*.cfile` - Complex 32-bit floating point samples (GNURadio, osmocom_fft)
  * `*.cs16` - Complex 16-bit signed integer samples (BladeRF)
  * `*.cs8` - Complex 8-bit signed integer samples (HackRF)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 0000000..3bdffde
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,96 @@
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/Modules)
+
+# For OSX - don't clear RPATH on install
+set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
+
+if (MSVC)
+    #force std::complex<> typedefs in liquiddsp
+    add_definitions(-D_LIBCPP_COMPLEX)
+
+    #enable math definitions in math.h
+    add_definitions(-D_USE_MATH_DEFINES)
+
+    #build a graphical application without the console
+    option(BUILD_WIN32 "Build win32 app, false for console" TRUE)
+    if (BUILD_WIN32)
+        set(EXE_ARGS WIN32)
+        set(CMAKE_EXE_LINKER_FLAGS "/entry:mainCRTStartup ${CMAKE_EXE_LINKER_FLAGS}")
+    endif (BUILD_WIN32)
+endif (MSVC)
+
+if (NOT CMAKE_CXX_FLAGS)
+    set(CMAKE_CXX_FLAGS "-O2")
+endif (NOT CMAKE_CXX_FLAGS)
+
+# This only works in cmake >3.1
+set(CMAKE_CXX_STANDARD 14)
+
+list(APPEND inspectrum_sources 
+    abstractsamplesource.cpp
+    amplitudedemod.cpp
+    cursor.cpp
+    cursors.cpp
+    main.cpp
+    fft.cpp
+    frequencydemod.cpp
+    mainwindow.cpp
+    inputsource.cpp
+    phasedemod.cpp
+    plot.cpp
+    plots.cpp
+    plotview.cpp
+    samplebuffer.cpp
+    samplesource.cpp
+    spectrogramcontrols.cpp
+    spectrogramplot.cpp
+    threshold.cpp
+    traceplot.cpp
+    tuner.cpp
+    tunertransform.cpp
+    util.cpp
+)
+
+find_package(Qt5Widgets REQUIRED)
+find_package(Qt5Concurrent REQUIRED)
+find_package(FFTW REQUIRED)
+find_package(Liquid REQUIRED)
+find_package(libsigmf QUIET)
+
+include_directories(
+    ${FFTW_INCLUDES}
+    ${LIQUID_INCLUDES}
+)
+
+add_executable(inspectrum ${EXE_ARGS} ${inspectrum_sources})
+
+target_link_libraries(inspectrum
+    Qt5::Core Qt5::Widgets Qt5::Concurrent
+    ${FFTW_LIBRARIES}
+    ${LIQUID_LIBRARIES}
+)
+
+if (libsigmf_FOUND)
+    message("-- libsigmf found. Enabling SigMF support")
+    target_link_libraries(inspectrum
+        libsigmf::libsigmf
+    )
+    add_definitions(-DENABLE_SIGMF)
+else()
+    message("-- libsigmf not found. Disabling SigMF support")
+endif()
+
+set(INSTALL_DEFAULT_BINDIR "bin" CACHE STRING "Appended to CMAKE_INSTALL_PREFIX")
+
+install(TARGETS inspectrum RUNTIME DESTINATION ${INSTALL_DEFAULT_BINDIR})
+
+# Create uninstall target
+configure_file(
+    ${PROJECT_SOURCE_DIR}/cmake/cmake_uninstall.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake
+@ONLY)
+
+add_custom_target(uninstall
+    ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake
+)
diff --git a/abstractsamplesource.cpp b/src/abstractsamplesource.cpp
similarity index 100%
rename from abstractsamplesource.cpp
rename to src/abstractsamplesource.cpp
diff --git a/abstractsamplesource.h b/src/abstractsamplesource.h
similarity index 100%
rename from abstractsamplesource.h
rename to src/abstractsamplesource.h
diff --git a/amplitudedemod.cpp b/src/amplitudedemod.cpp
similarity index 100%
rename from amplitudedemod.cpp
rename to src/amplitudedemod.cpp
diff --git a/amplitudedemod.h b/src/amplitudedemod.h
similarity index 100%
rename from amplitudedemod.h
rename to src/amplitudedemod.h
diff --git a/cursor.cpp b/src/cursor.cpp
similarity index 100%
rename from cursor.cpp
rename to src/cursor.cpp
diff --git a/cursor.h b/src/cursor.h
similarity index 100%
rename from cursor.h
rename to src/cursor.h
diff --git a/cursors.cpp b/src/cursors.cpp
similarity index 100%
rename from cursors.cpp
rename to src/cursors.cpp
diff --git a/cursors.h b/src/cursors.h
similarity index 100%
rename from cursors.h
rename to src/cursors.h
diff --git a/fft.cpp b/src/fft.cpp
similarity index 100%
rename from fft.cpp
rename to src/fft.cpp
diff --git a/fft.h b/src/fft.h
similarity index 100%
rename from fft.h
rename to src/fft.h
diff --git a/frequencydemod.cpp b/src/frequencydemod.cpp
similarity index 100%
rename from frequencydemod.cpp
rename to src/frequencydemod.cpp
diff --git a/frequencydemod.h b/src/frequencydemod.h
similarity index 100%
rename from frequencydemod.h
rename to src/frequencydemod.h
diff --git a/inputsource.cpp b/src/inputsource.cpp
similarity index 63%
rename from inputsource.cpp
rename to src/inputsource.cpp
index 6a7ebac..fd90020 100644
--- a/inputsource.cpp
+++ b/src/inputsource.cpp
@@ -29,6 +29,21 @@
 
 #include <QFileInfo>
 
+#if ENABLE_SIGMF
+#include <sigmf/sigmf.h>
+#endif
+
+#include <QElapsedTimer>
+#include <QPainter>
+#include <QPaintEvent>
+#include <QPixmapCache>
+#include <QRect>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QFile>
+
+
 class ComplexF32SampleAdapter : public SampleAdapter {
 public:
     size_t sampleSize() override {
@@ -181,44 +196,131 @@ void InputSource::cleanup()
     }
 }
 
+#if ENABLE_SIGMF
+void InputSource::readMetaData(const QString &filename)
+{
+    QFile datafile(filename);
+    if (!datafile.open(QFile::ReadOnly | QIODevice::Text)) {
+        throw std::runtime_error("Error while opening meta data file: " + datafile.errorString().toStdString());
+    }
+
+    sigmf::SigMF<sigmf::Global<core::DescrT>,
+            sigmf::Capture<core::DescrT>,
+            sigmf::Annotation<core::DescrT> > metaData = json::parse(datafile.readAll());
+
+    auto global_core = metaData.global.access<core::GlobalT>();
+
+    if(global_core.datatype.compare("cf32_le") == 0) {
+        sampleAdapter = std::make_unique<ComplexF32SampleAdapter>();
+    } else if(global_core.datatype.compare("ci16_le") == 0) {
+        sampleAdapter = std::make_unique<ComplexS16SampleAdapter>();
+    } else if(global_core.datatype.compare("ci8") == 0) {
+        sampleAdapter = std::make_unique<ComplexS8SampleAdapter>();
+    } else if(global_core.datatype.compare("cu8") == 0) {
+        sampleAdapter = std::make_unique<ComplexU8SampleAdapter>();
+    } else if(global_core.datatype.compare("rf32_le") == 0) {
+        sampleAdapter = std::make_unique<RealF32SampleAdapter>();
+        _realSignal = true;
+    } else if(global_core.datatype.compare("ri16_le") == 0) {
+        sampleAdapter = std::make_unique<RealS16SampleAdapter>();
+        _realSignal = true;
+    } else if(global_core.datatype.compare("ri8") == 0) {
+        sampleAdapter = std::make_unique<RealS8SampleAdapter>();
+        _realSignal = true;
+    } else if(global_core.datatype.compare("ru8") == 0) {
+        sampleAdapter = std::make_unique<RealU8SampleAdapter>();
+        _realSignal = true;
+    } else {
+        throw std::runtime_error("SigMF meta data specifies unsupported datatype");
+    }
+
+    setSampleRate(global_core.sample_rate);
+
+    for(auto capture : metaData.captures) {
+        auto core = capture.access<core::CaptureT>();
+        frequency = core.frequency;
+    }
+
+    for(auto annotation : metaData.annotations) {
+        Annotation a;
+        auto core = annotation.access<core::AnnotationT>();
+
+        a.sampleRange = range_t<size_t>{core.sample_start, core.sample_start + core.sample_count - 1};
+        a.frequencyRange = range_t<double>{core.freq_lower_edge, core.freq_upper_edge};
+        a.description = QString::fromStdString(core.description);
+
+        annotationList.append(a);
+    }
+}
+#endif
+
+
 void InputSource::openFile(const char *filename)
 {
     QFileInfo fileInfo(filename);
     std::string suffix = std::string(fileInfo.suffix().toLower().toUtf8().constData());
     if(_fmt!=""){ suffix = _fmt; } // allow fmt override
     if ((suffix == "cfile") || (suffix == "cf32")  || (suffix == "fc32")) {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new ComplexF32SampleAdapter());
+        sampleAdapter = std::make_unique<ComplexF32SampleAdapter>();
     }
     else if ((suffix == "cs16") || (suffix == "sc16") || (suffix == "c16")) {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new ComplexS16SampleAdapter());
+        sampleAdapter = std::make_unique<ComplexS16SampleAdapter>();
     }
     else if ((suffix == "cs8") || (suffix == "sc8") || (suffix == "c8")) {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new ComplexS8SampleAdapter());
+        sampleAdapter = std::make_unique<ComplexS8SampleAdapter>();
     }
     else if ((suffix == "cu8") || (suffix == "uc8")) {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new ComplexU8SampleAdapter());
+        sampleAdapter = std::make_unique<ComplexU8SampleAdapter>();
     }
     else if (suffix == "f32") {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new RealF32SampleAdapter());
+        sampleAdapter = std::make_unique<RealF32SampleAdapter>();
         _realSignal = true;
     }
     else if (suffix == "s16") {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new RealS16SampleAdapter());
+        sampleAdapter = std::make_unique<RealS16SampleAdapter>();
         _realSignal = true;
     }
     else if (suffix == "s8") {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new RealS8SampleAdapter());
+        sampleAdapter = std::make_unique<RealS8SampleAdapter>();
         _realSignal = true;
     }
     else if (suffix == "u8") {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new RealU8SampleAdapter());
+        sampleAdapter = std::make_unique<RealU8SampleAdapter>();
         _realSignal = true;
     }
     else {
-        sampleAdapter = std::unique_ptr<SampleAdapter>(new ComplexF32SampleAdapter());
+        sampleAdapter = std::make_unique<ComplexF32SampleAdapter>();
+    }
+
+    QString dataFilename;
+
+#if ENABLE_SIGMF
+    annotationList.clear();
+    QString metaFilename;
+
+    if (suffix == "sigmf-meta") {
+        dataFilename = fileInfo.path() + "/" + fileInfo.completeBaseName() + ".sigmf-data";
+        metaFilename = filename;
+        readMetaData(metaFilename);
+    }
+    else if (suffix == "sigmf-data") {
+        dataFilename = filename;
+        metaFilename = fileInfo.path() + "/" + fileInfo.completeBaseName() + ".sigmf-meta";
+        readMetaData(metaFilename);
+    }
+    else if (suffix == "sigmf") {
+        throw std::runtime_error("SigMF archives are not supported. Consider extracting a recording.");
+    }
+#else
+    if (suffix == "sigmf-meta" || suffix == "sigmf-data" || suffix == "sigmf") {
+        throw std::runtime_error("Support for SigMF recordings is not enabled");
+    }
+#endif
+    else {
+        dataFilename = filename;
     }
 
-    std::unique_ptr<QFile> file(new QFile(filename));
+    auto file = std::make_unique<QFile>(dataFilename);
     if (!file->open(QFile::ReadOnly)) {
         throw std::runtime_error(file->errorString().toStdString());
     }
@@ -263,7 +365,7 @@ std::unique_ptr<std::complex<float>[]> InputSource::getSamples(size_t start, siz
     if (start + length > sampleCount)
         return nullptr;
 
-    std::unique_ptr<std::complex<float>[]> dest(new std::complex<float>[length]);
+    auto dest = std::make_unique<std::complex<float>[]>(length);
     sampleAdapter->copyRange(mmapData, start, length, dest.get());
 
     return dest;
diff --git a/inputsource.h b/src/inputsource.h
similarity index 95%
rename from inputsource.h
rename to src/inputsource.h
index d6d76e0..47b457c 100644
--- a/inputsource.h
+++ b/src/inputsource.h
@@ -28,6 +28,7 @@ class SampleAdapter {
 public:
     virtual size_t sampleSize() = 0;
     virtual void copyRange(const void* const src, size_t start, size_t length, std::complex<float>* const dest) = 0;
+    virtual ~SampleAdapter() { };
 };
 
 class InputSource : public SampleSource<std::complex<float>>
@@ -41,6 +42,8 @@ class InputSource : public SampleSource<std::complex<float>>
     std::string _fmt;
     bool _realSignal = false;
 
+    void readMetaData(const QString &filename);
+
 public:
     InputSource();
     ~InputSource();
diff --git a/main.cpp b/src/main.cpp
similarity index 100%
rename from main.cpp
rename to src/main.cpp
diff --git a/mainwindow.cpp b/src/mainwindow.cpp
similarity index 85%
rename from mainwindow.cpp
rename to src/mainwindow.cpp
index b5aa3ac..f1adf7a 100644
--- a/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -37,8 +37,12 @@ MainWindow::MainWindow()
     addDockWidget(Qt::LeftDockWidgetArea, dock);
 
     input = new InputSource();
+    input->subscribe(this);
 
-    plots = new PlotView(input);
+    QSettings settings;
+    tuner = new Tuner(settings.value("FFTSize", 9).toInt(), this);
+
+    plots = new PlotView(input, tuner);
     setCentralWidget(plots);
 
     // Connect dock inputs
@@ -50,6 +54,7 @@ MainWindow::MainWindow()
     connect(dock->cursorsCheckBox, &QCheckBox::stateChanged, plots, &PlotView::enableCursors);
     connect(dock->scalesCheckBox, &QCheckBox::stateChanged, plots, &PlotView::enableScales);
     connect(dock->cursorSymbolsSpinBox, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), plots, &PlotView::setCursorSegments);
+    connect(tuner, &Tuner::tunerMoved, dock, &SpectrogramControls::tunerMoved);
 
     // Connect dock outputs
     connect(plots, &PlotView::timeSelectionChanged, dock, &SpectrogramControls::timeSelectionChanged);
@@ -96,6 +101,19 @@ void MainWindow::openFile(QString fileName)
     }
 }
 
+void MainWindow::invalidateEvent()
+{
+    plots->setSampleRate(input->rate());
+
+    // Only update the text box if it is not already representing
+    // the current value. Otherwise the cursor might jump or the
+    // representation might change (e.g. to scientific).
+    double currentValue = dock->sampleRate->text().toDouble();
+    if(QString::number(input->rate()) != QString::number(currentValue)) {
+        setSampleRate(input->rate());
+    }
+}
+
 void MainWindow::setSampleRate(QString rate)
 {
     auto sampleRate = rate.toDouble();
diff --git a/mainwindow.h b/src/mainwindow.h
similarity index 92%
rename from mainwindow.h
rename to src/mainwindow.h
index 187400c..c7a45a6 100644
--- a/mainwindow.h
+++ b/src/mainwindow.h
@@ -24,7 +24,7 @@
 #include "spectrogramcontrols.h"
 #include "plotview.h"
 
-class MainWindow : public QMainWindow
+class MainWindow : public QMainWindow, Subscriber
 {
     Q_OBJECT
 
@@ -37,9 +37,11 @@ public slots:
     void setSampleRate(QString rate);
     void setSampleRate(double rate);
     void setFormat(QString fmt);
+    void invalidateEvent() override;
 
 private:
     SpectrogramControls *dock;
     PlotView *plots;
     InputSource *input;
+    Tuner *tuner;
 };
diff --git a/phasedemod.cpp b/src/phasedemod.cpp
similarity index 100%
rename from phasedemod.cpp
rename to src/phasedemod.cpp
diff --git a/phasedemod.h b/src/phasedemod.h
similarity index 100%
rename from phasedemod.h
rename to src/phasedemod.h
diff --git a/plot.cpp b/src/plot.cpp
similarity index 100%
rename from plot.cpp
rename to src/plot.cpp
diff --git a/plot.h b/src/plot.h
similarity index 100%
rename from plot.h
rename to src/plot.h
diff --git a/plots.cpp b/src/plots.cpp
similarity index 100%
rename from plots.cpp
rename to src/plots.cpp
diff --git a/plots.h b/src/plots.h
similarity index 100%
rename from plots.h
rename to src/plots.h
diff --git a/plotview.cpp b/src/plotview.cpp
similarity index 98%
rename from plotview.cpp
rename to src/plotview.cpp
index 5db1b2a..d74496a 100644
--- a/plotview.cpp
+++ b/src/plotview.cpp
@@ -34,7 +34,7 @@
 #include <QClipboard>
 #include "plots.h"
 
-PlotView::PlotView(InputSource *input) : cursors(this), viewRange({0, 0})
+PlotView::PlotView(InputSource *input, Tuner *tuner) : cursors(this), viewRange({0, 0})
 {
     mainSampleSource = input;
     setDragMode(QGraphicsView::ScrollHandDrag);
@@ -43,9 +43,11 @@ PlotView::PlotView(InputSource *input) : cursors(this), viewRange({0, 0})
     enableCursors(false);
     connect(&cursors, &Cursors::cursorsMoved, this, &PlotView::cursorsMoved);
 
-    spectrogramPlot = new SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>>(mainSampleSource));
+    spectrogramPlot = new SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>>(mainSampleSource), tuner);
     auto tunerOutput = std::dynamic_pointer_cast<SampleSource<std::complex<float>>>(spectrogramPlot->output());
 
+    connect(tuner, &Tuner::tunerMoved, spectrogramPlot, &SpectrogramPlot::tunerMoved);
+
     enableScales(true);
 
     addPlot(spectrogramPlot);
@@ -532,6 +534,11 @@ void PlotView::scrollContentsBy(int dx, int dy)
     updateView();
 }
 
+void PlotView::showEvent(QShowEvent *event)
+{
+    // Intentionally left blank. See #171
+}
+
 void PlotView::updateViewRange(bool reCenter)
 {
     // Update current view
diff --git a/plotview.h b/src/plotview.h
similarity index 96%
rename from plotview.h
rename to src/plotview.h
index d558936..528add4 100644
--- a/plotview.h
+++ b/src/plotview.h
@@ -34,7 +34,7 @@ class PlotView : public QGraphicsView, Subscriber
     Q_OBJECT
 
 public:
-    PlotView(InputSource *input);
+    PlotView(InputSource *input, Tuner *tuner);
     void setSampleRate(double rate);
 
 signals:
@@ -59,6 +59,7 @@ public slots:
     void resizeEvent(QResizeEvent * event) override;
     void scrollContentsBy(int dx, int dy) override;
     bool viewportEvent(QEvent *event) override;
+    void showEvent(QShowEvent *event) override;
 
 private:
     Cursors cursors;
diff --git a/samplebuffer.cpp b/src/samplebuffer.cpp
similarity index 94%
rename from samplebuffer.cpp
rename to src/samplebuffer.cpp
index f008a3c..4fb0e09 100644
--- a/samplebuffer.cpp
+++ b/src/samplebuffer.cpp
@@ -42,8 +42,8 @@ std::unique_ptr<Tout[]> SampleBuffer<Tin, Tout>::getSamples(size_t start, size_t
     if (samples == nullptr)
     	return nullptr;
 
-    std::unique_ptr<Tout[]> temp(new Tout[history + length]);
-    std::unique_ptr<Tout[]> dest(new Tout[length]);
+    auto temp = std::make_unique<Tout[]>(history + length);
+    auto dest = std::make_unique<Tout[]>(length);
     QMutexLocker ml(&mutex);
     work(samples.get(), temp.get(), history + length, start);
     memcpy(dest.get(), temp.get() + history, length * sizeof(Tout));
diff --git a/samplebuffer.h b/src/samplebuffer.h
similarity index 100%
rename from samplebuffer.h
rename to src/samplebuffer.h
diff --git a/samplesource.cpp b/src/samplesource.cpp
similarity index 91%
rename from samplesource.cpp
rename to src/samplesource.cpp
index 619a2cd..3d6eaf0 100644
--- a/samplesource.cpp
+++ b/src/samplesource.cpp
@@ -25,5 +25,11 @@ std::type_index SampleSource<T>::sampleType()
     return typeid(T);
 }
 
+template<typename T>
+double SampleSource<T>::getFrequency()
+{
+    return frequency;
+}
+
 template class SampleSource<std::complex<float>>;
 template class SampleSource<float>;
diff --git a/samplesource.h b/src/samplesource.h
similarity index 82%
rename from samplesource.h
rename to src/samplesource.h
index ed0c0e3..9995eb4 100644
--- a/samplesource.h
+++ b/src/samplesource.h
@@ -23,9 +23,23 @@
 #include <memory>
 #include "abstractsamplesource.h"
 
+#include "util.h"
+#include <QString>
+#include <QObject>
+
+class Annotation
+{
+public:
+    range_t<size_t> sampleRange;
+    range_t<double> frequencyRange;
+    QString description;
+};
+
 template<typename T>
 class SampleSource : public AbstractSampleSource
 {
+protected:
+    double frequency;
 
 public:
     virtual ~SampleSource() {};
@@ -35,6 +49,8 @@ class SampleSource : public AbstractSampleSource
     virtual size_t count() = 0;
     virtual double rate() = 0;
     virtual float relativeBandwidth() = 0;
+    QList<Annotation> annotationList;
     std::type_index sampleType() override;
     virtual bool realSignal() { return false; };
+    double getFrequency();
 };
diff --git a/spectrogramcontrols.cpp b/src/spectrogramcontrols.cpp
similarity index 93%
rename from spectrogramcontrols.cpp
rename to src/spectrogramcontrols.cpp
index 08007d9..6d6e7f8 100644
--- a/spectrogramcontrols.cpp
+++ b/src/spectrogramcontrols.cpp
@@ -93,6 +93,9 @@ SpectrogramControls::SpectrogramControls(const QString & title, QWidget * parent
     symbolPeriodLabel = new QLabel();
     layout->addRow(new QLabel(tr("Symbol period:")), symbolPeriodLabel);
 
+    bandwidthLabel = new QLabel();
+    layout->addRow(new QLabel(tr("Bandwidth:")), bandwidthLabel);
+
     widget->setLayout(layout);
     setWidget(widget);
 
@@ -110,6 +113,7 @@ void SpectrogramControls::clearCursorLabels()
     rateLabel->setText("");
     symbolPeriodLabel->setText("");
     symbolRateLabel->setText("");
+    bandwidthLabel->setText("");
 }
 
 void SpectrogramControls::cursorsStateChanged(int state)
@@ -226,3 +230,16 @@ void SpectrogramControls::zoomOut()
 {
     zoomLevelSlider->setValue(zoomLevelSlider->value() - 1);
 }
+
+void SpectrogramControls::tunerMoved(int deviation)
+{
+    // int deviation is width in pixels from plot
+    bandwidthLabel->setText(QString::number(getBandwidth(deviation)) + "kHz");
+}
+
+int SpectrogramControls::getBandwidth(int deviation) {
+    double rate = sampleRate->text().toDouble();
+    double fftSize = pow(2, fftSizeSlider->value());
+    double hzPerPx = rate / fftSize;
+    return deviation * hzPerPx / 1000 * 2;
+}
\ No newline at end of file
diff --git a/spectrogramcontrols.h b/src/spectrogramcontrols.h
similarity index 94%
rename from spectrogramcontrols.h
rename to src/spectrogramcontrols.h
index abe06d6..f1a1255 100644
--- a/spectrogramcontrols.h
+++ b/src/spectrogramcontrols.h
@@ -27,6 +27,7 @@
 #include <QSpinBox>
 #include <QCheckBox>
 #include <QLabel>
+#include "tuner.h"
 
 class SpectrogramControls : public QDockWidget
 {
@@ -44,6 +45,7 @@ public slots:
     void timeSelectionChanged(float time);
     void zoomIn();
     void zoomOut();
+    void tunerMoved(int deviation);
 
 private slots:
     void fftSizeChanged(int value);
@@ -58,6 +60,7 @@ private slots:
     QFormLayout *layout;
     void clearCursorLabels();
     void fftOrZoomChanged(void);
+    int getBandwidth(int deviation);
 
 public:
     QPushButton *fileOpenButton;
@@ -72,5 +75,7 @@ private slots:
     QLabel *periodLabel;
     QLabel *symbolRateLabel;
     QLabel *symbolPeriodLabel;
+    QLabel *bandwidthLabel;
     QCheckBox *scalesCheckBox;
+
 };
diff --git a/spectrogramplot.cpp b/src/spectrogramplot.cpp
similarity index 73%
rename from spectrogramplot.cpp
rename to src/spectrogramplot.cpp
index 975c69b..ba719ef 100644
--- a/spectrogramplot.cpp
+++ b/src/spectrogramplot.cpp
@@ -31,8 +31,10 @@
 #include "util.h"
 
 
-SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src) : Plot(src), inputSource(src), fftSize(512), tuner(fftSize, this)
+SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src, Tuner *tuner)
+    : Plot(src), inputSource(src), fftSize(512) //, tuner(fftSize, this)
 {
+    this->tuner = tuner;
     setFFTSize(fftSize);
     zoomLevel = 1;
     powerMax = 0.0f;
@@ -46,7 +48,7 @@ SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float
     }
 
     tunerTransform = std::make_shared<TunerTransform>(src);
-    connect(&tuner, &Tuner::tunerMoved, this, &SpectrogramPlot::tunerMoved);
+//    connect(&tuner, &Tuner::tunerMoved, this, &SpectrogramPlot::tunerMoved);
 }
 
 void SpectrogramPlot::invalidateEvent()
@@ -62,14 +64,23 @@ void SpectrogramPlot::invalidateEvent()
 void SpectrogramPlot::paintFront(QPainter &painter, QRect &rect, range_t<size_t> sampleRange)
 {
     if (tunerEnabled())
-        tuner.paintFront(painter, rect, sampleRange);
+        tuner->paintFront(painter, rect, sampleRange);
 
     if (frequencyScaleEnabled)
         paintFrequencyScale(painter, rect);
+    paintAnnotations(painter, rect, sampleRange);
 }
 
 void SpectrogramPlot::paintFrequencyScale(QPainter &painter, QRect &rect)
 {
+    if (sampleRate == 0) {
+        return;
+    }
+
+    if (sampleRate / 2 > UINT64_MAX) {
+        return;
+    }
+
     // At which pixel is F_+sampleRate/2
     int y = rect.y();
 
@@ -80,7 +91,7 @@ void SpectrogramPlot::paintFrequencyScale(QPainter &painter, QRect &rect)
     double bwPerPixel = (double)sampleRate / plotHeight;
     int tickHeight = 50;
 
-    int bwPerTick = 10 * pow(10, floor(log(bwPerPixel * tickHeight) / log(10)));
+    uint64_t bwPerTick = 10 * pow(10, floor(log(bwPerPixel * tickHeight) / log(10)));
 
     if (bwPerTick < 1) {
         return;
@@ -93,7 +104,7 @@ void SpectrogramPlot::paintFrequencyScale(QPainter &painter, QRect &rect)
     QFontMetrics fm(painter.font());
 
 
-    int tick = 0;
+    uint64_t tick = 0;
 
     while (tick <= sampleRate / 2) {
 
@@ -107,12 +118,14 @@ void SpectrogramPlot::paintFrequencyScale(QPainter &painter, QRect &rect)
         if (tick != 0) {
             char buf[128];
 
-            if (bwPerTick % 1000000 == 0) {
-                snprintf(buf, sizeof(buf), "-%d MHz", (int)tick / 1000000);
+            if (bwPerTick % 1000000000 == 0) {
+                snprintf(buf, sizeof(buf), "-%lu GHz", tick / 1000000000);
+            } else if (bwPerTick % 1000000 == 0) {
+                snprintf(buf, sizeof(buf), "-%lu MHz", tick / 1000000);
             } else if(bwPerTick % 1000 == 0) {
-                snprintf(buf, sizeof(buf), "-%d kHz", tick / 1000);
+                snprintf(buf, sizeof(buf), "-%lu kHz", tick / 1000);
             } else {
-                snprintf(buf, sizeof(buf), "-%d Hz", tick);
+                snprintf(buf, sizeof(buf), "-%lu Hz", tick);
             }
 
             if (!inputSource->realSignal())
@@ -145,6 +158,48 @@ void SpectrogramPlot::paintFrequencyScale(QPainter &painter, QRect &rect)
     painter.restore();
 }
 
+void SpectrogramPlot::paintAnnotations(QPainter &painter, QRect &rect, range_t<size_t> sampleRange)
+{
+    // Pixel (from the top) at which 0 Hz sits
+    int zero = rect.y() + rect.height() / 2;
+
+    painter.save();
+    QPen pen(Qt::white, 1, Qt::SolidLine);
+    painter.setPen(pen);
+    QFontMetrics fm(painter.font());
+
+    for (int i = 0; i < inputSource->annotationList.size(); i++) {
+        Annotation a = inputSource->annotationList.at(i);
+
+        size_t descriptionLength = fm.boundingRect(a.description).width() * getStride();
+
+        // Check if:
+        //  (1) End of annotation (might be maximum, or end of description text) is still visible in time
+        //  (2) Part of the annotation is already visible in time
+        //
+        // Currently there is no check if the annotation is visible in frequency. This is a
+        // possible performance improvement
+        //
+        size_t start = a.sampleRange.minimum;
+        size_t end = std::max(a.sampleRange.minimum + descriptionLength, a.sampleRange.maximum);
+
+        if(start <= sampleRange.maximum && end >= sampleRange.minimum) {
+
+            double frequency = a.frequencyRange.maximum - inputSource->getFrequency();
+            int x = (a.sampleRange.minimum - sampleRange.minimum) / getStride();
+            int y = zero - frequency / sampleRate * rect.height();
+            int height = (a.frequencyRange.maximum - a.frequencyRange.minimum) / sampleRate * rect.height();
+            int width = (a.sampleRange.maximum - a.sampleRange.minimum) / getStride();
+
+            // Draw the description 2 pixels above the box
+            painter.drawText(x, y - 2, a.description);
+            painter.drawRect(x, y, width, height);
+        }
+    }
+
+    painter.restore();
+}
+
 void SpectrogramPlot::paintMid(QPainter &painter, QRect &rect, range_t<size_t> sampleRange)
 {
     if (!inputSource || inputSource->count() == 0)
@@ -248,20 +303,20 @@ int SpectrogramPlot::getStride()
 
 float SpectrogramPlot::getTunerPhaseInc()
 {
-    auto freq = 0.5f - tuner.centre() / (float)fftSize;
+    auto freq = 0.5f - tuner->centre() / (float)fftSize;
     return freq * Tau;
 }
 
 std::vector<float> SpectrogramPlot::getTunerTaps()
 {
-    float cutoff = tuner.deviation() / (float)fftSize;
+    float cutoff = tuner->deviation() / (float)fftSize;
     float gain = pow(10.0f, powerMax / -10.0f);
     auto atten = 60.0f;
     auto len = estimate_req_filter_len(std::min(cutoff, 0.05f), atten);
     auto taps = std::vector<float>(len);
     liquid_firdes_kaiser(len, cutoff, atten, 0.0f, taps.data());
     std::transform(taps.begin(), taps.end(), taps.begin(),
-                   std::bind1st(std::multiplies<float>(), gain));
+                   std::bind(std::multiplies<float>(), std::placeholders::_1, gain));
     return taps;
 }
 
@@ -273,7 +328,7 @@ int SpectrogramPlot::linesPerTile()
 bool SpectrogramPlot::mouseEvent(QEvent::Type type, QMouseEvent event)
 {
     if (tunerEnabled())
-        return tuner.mouseEvent(type, event);
+        return tuner->mouseEvent(type, event);
 
     return false;
 }
@@ -299,18 +354,18 @@ void SpectrogramPlot::setFFTSize(int size)
     } else {
         setHeight(fftSize);
     }
-    auto dev = tuner.deviation();
-    auto centre = tuner.centre();
-    tuner.setHeight(height());
-    tuner.setDeviation( dev * sizeScale );
-    tuner.setCentre( centre * sizeScale );
+    auto dev = tuner->deviation();
+    auto centre = tuner->centre();
+    tuner->setHeight(height());
+    tuner->setDeviation( dev * sizeScale );
+    tuner->setCentre( centre * sizeScale );
 }
 
 void SpectrogramPlot::setPowerMax(int power)
 {
     powerMax = power;
     pixmapCache.clear();
-    tunerMoved();
+    tunerMoved(666);
 }
 
 void SpectrogramPlot::setPowerMin(int power)
@@ -324,7 +379,7 @@ void SpectrogramPlot::setZoomLevel(int zoom)
     zoomLevel = zoom;
 }
 
-void SpectrogramPlot::setSampleRate(size_t rate)
+void SpectrogramPlot::setSampleRate(double rate)
 {
     sampleRate = rate;
 }
@@ -339,11 +394,11 @@ bool SpectrogramPlot::tunerEnabled()
     return (tunerTransform->subscriberCount() > 0);
 }
 
-void SpectrogramPlot::tunerMoved()
+void SpectrogramPlot::tunerMoved(int deviation)
 {
     tunerTransform->setFrequency(getTunerPhaseInc());
     tunerTransform->setTaps(getTunerTaps());
-    tunerTransform->setRelativeBandwith(tuner.deviation() * 2.0 / height());
+    tunerTransform->setRelativeBandwith(deviation * 2.0 / height());
 
     // TODO: for invalidating traceplot cache, this shouldn't really go here
     QPixmapCache::clear();
diff --git a/spectrogramplot.h b/src/spectrogramplot.h
similarity index 92%
rename from spectrogramplot.h
rename to src/spectrogramplot.h
index ffe1d6a..af4b794 100644
--- a/spectrogramplot.h
+++ b/src/spectrogramplot.h
@@ -38,14 +38,14 @@ class SpectrogramPlot : public Plot
     Q_OBJECT
 
 public:
-    SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src);
+    SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src, Tuner *tuner);
     void invalidateEvent() override;
     std::shared_ptr<AbstractSampleSource> output() override;
     void paintFront(QPainter &painter, QRect &rect, range_t<size_t> sampleRange) override;
     void paintMid(QPainter &painter, QRect &rect, range_t<size_t> sampleRange) override;
     bool mouseEvent(QEvent::Type type, QMouseEvent event) override;
     std::shared_ptr<SampleSource<std::complex<float>>> input() { return inputSource; };
-    void setSampleRate(size_t sampleRate);
+    void setSampleRate(double sampleRate);
     bool tunerEnabled();
     void enableScales(bool enabled);
 
@@ -54,12 +54,13 @@ public slots:
     void setPowerMax(int power);
     void setPowerMin(int power);
     void setZoomLevel(int zoom);
-    void tunerMoved();
+    void tunerMoved(int deviation);
 
 private:
     const int linesPerGraduation = 50;
     static const int tileSize = 65536; // This must be a multiple of the maximum FFT size
 
+    Tuner *tuner;
     std::shared_ptr<SampleSource<std::complex<float>>> inputSource;
     std::unique_ptr<FFT> fft;
     std::unique_ptr<float[]> window;
@@ -71,10 +72,9 @@ public slots:
     int zoomLevel;
     float powerMax;
     float powerMin;
-    size_t sampleRate;
+    double sampleRate;
     bool frequencyScaleEnabled;
 
-    Tuner tuner;
     std::shared_ptr<TunerTransform> tunerTransform;
 
     QPixmap* getPixmapTile(size_t tile);
@@ -85,6 +85,7 @@ public slots:
     std::vector<float> getTunerTaps();
     int linesPerTile();
     void paintFrequencyScale(QPainter &painter, QRect &rect);
+    void paintAnnotations(QPainter &painter, QRect &rect, range_t<size_t> sampleRange);
 };
 
 class TileCacheKey
diff --git a/subscriber.h b/src/subscriber.h
similarity index 100%
rename from subscriber.h
rename to src/subscriber.h
diff --git a/threshold.cpp b/src/threshold.cpp
similarity index 100%
rename from threshold.cpp
rename to src/threshold.cpp
diff --git a/threshold.h b/src/threshold.h
similarity index 100%
rename from threshold.h
rename to src/threshold.h
diff --git a/traceplot.cpp b/src/traceplot.cpp
similarity index 100%
rename from traceplot.cpp
rename to src/traceplot.cpp
diff --git a/traceplot.h b/src/traceplot.h
similarity index 100%
rename from traceplot.h
rename to src/traceplot.h
diff --git a/tuner.cpp b/src/tuner.cpp
similarity index 98%
rename from tuner.cpp
rename to src/tuner.cpp
index 6ccac61..c6a5b46 100644
--- a/tuner.cpp
+++ b/src/tuner.cpp
@@ -109,6 +109,7 @@ void Tuner::setDeviation(int dev)
 {
     _deviation = std::max(1, dev);
     updateCursors();
+    emit tunerMoved(_deviation);
 }
 
 void Tuner::setHeight(int height)
@@ -120,5 +121,5 @@ void Tuner::updateCursors()
 {
     minCursor->setPos(cfCursor->pos() - _deviation);
     maxCursor->setPos(cfCursor->pos() + _deviation);
-    emit tunerMoved();
+    emit tunerMoved(_deviation);
 }
diff --git a/tuner.h b/src/tuner.h
similarity index 97%
rename from tuner.h
rename to src/tuner.h
index 958d9a7..d761baa 100644
--- a/tuner.h
+++ b/src/tuner.h
@@ -44,7 +44,7 @@ public slots:
     void cursorMoved();
 
 signals:
-    void tunerMoved();
+    void tunerMoved(int deviation);
 
 private:
     void updateCursors();
diff --git a/tunertransform.cpp b/src/tunertransform.cpp
similarity index 96%
rename from tunertransform.cpp
rename to src/tunertransform.cpp
index 11fed07..fc89a36 100644
--- a/tunertransform.cpp
+++ b/src/tunertransform.cpp
@@ -29,7 +29,7 @@ TunerTransform::TunerTransform(std::shared_ptr<SampleSource<std::complex<float>>
 void TunerTransform::work(void *input, void *output, int count, size_t sampleid)
 {
     auto out = static_cast<std::complex<float>*>(output);
-    std::unique_ptr<std::complex<float>[]> temp(new std::complex<float>[count]);
+    auto temp = std::make_unique<std::complex<float>[]>(count);
 
     // Mix down
     nco_crcf mix = nco_crcf_create(LIQUID_NCO);
diff --git a/tunertransform.h b/src/tunertransform.h
similarity index 100%
rename from tunertransform.h
rename to src/tunertransform.h
diff --git a/util.cpp b/src/util.cpp
similarity index 100%
rename from util.cpp
rename to src/util.cpp
diff --git a/util.h b/src/util.h
similarity index 99%
rename from util.h
rename to src/util.h
index 0e22e9d..157d401 100644
--- a/util.h
+++ b/src/util.h
@@ -57,6 +57,7 @@ struct range_t {
     range_t<T>& operator=(const range_t<T> &other) {
         minimum = other.minimum;
         maximum = other.maximum;
+        return *this;
     }
 
     range_t<T>& operator=(const std::initializer_list<T> &other) {