From 2f390da4e0c47247a9080df7f3761b2e7ad011c5 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 6 Jun 2018 00:01:50 +0200
Subject: [PATCH] Actually start showing JPEGs on the screen.

---
 Makefile              |  2 +-
 jpeg_frame_view.cpp   | 27 +++++++++++++++++++++++++++
 jpeg_frame_view.h     | 36 ++++++++++++++++++++++++++++++++++++
 main.cpp              | 10 ++++++++++
 mainwindow.h          |  2 +-
 post_to_main_thread.h | 16 ++++++++++++++++
 ui_mainwindow.ui      | 33 ++++++++++++++++++++-------------
 7 files changed, 111 insertions(+), 15 deletions(-)
 create mode 100644 jpeg_frame_view.cpp
 create mode 100644 jpeg_frame_view.h
 create mode 100644 post_to_main_thread.h

diff --git a/Makefile b/Makefile
index 379a0a6..2608903 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ CXXFLAGS += -std=gnu++11 -fPIC $(shell pkg-config --cflags $(PKG_MODULES)) -pthr
 LDLIBS=$(shell pkg-config --libs $(PKG_MODULES)) -pthread -lavformat -lavcodec -lavutil -lswscale
 
 # Qt objects
-OBJS_WITH_MOC = mainwindow.o
+OBJS_WITH_MOC = mainwindow.o jpeg_frame_view.o
 OBJS += $(OBJS_WITH_MOC)
 OBJS += $(OBJS_WITH_MOC:.o=.moc.o) 
 
diff --git a/jpeg_frame_view.cpp b/jpeg_frame_view.cpp
new file mode 100644
index 0000000..55a4857
--- /dev/null
+++ b/jpeg_frame_view.cpp
@@ -0,0 +1,27 @@
+#include "jpeg_frame_view.h"
+
+#include <QGraphicsPixmapItem>
+#include <QPixmap>
+
+using namespace std;
+
+string filename_for_frame(unsigned stream_idx, int64_t pts);
+
+JPEGFrameView::JPEGFrameView(QWidget *parent)
+	: QGraphicsView(parent) {
+	scene.addItem(&item);
+	setScene(&scene);
+	setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+	setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+}
+
+void JPEGFrameView::update()
+{
+	item.setPixmap(QPixmap(QString::fromStdString(filename_for_frame(stream_idx, pts))));
+	fitInView(&item, Qt::KeepAspectRatio);
+}
+
+void JPEGFrameView::resizeEvent(QResizeEvent *event)
+{
+	fitInView(&item, Qt::KeepAspectRatio);
+}
diff --git a/jpeg_frame_view.h b/jpeg_frame_view.h
new file mode 100644
index 0000000..219ee58
--- /dev/null
+++ b/jpeg_frame_view.h
@@ -0,0 +1,36 @@
+#ifndef _JPEG_FRAME_VIEW_H
+#define _JPEG_FRAME_VIEW_H 1
+
+#include <QGraphicsView>
+#include <QGraphicsPixmapItem>
+#include <QGraphicsScene>
+
+#include <stdint.h>
+
+class JPEGFrameView : public QGraphicsView {
+	Q_OBJECT
+
+public:
+	JPEGFrameView(QWidget *parent);
+
+	void setFrame(unsigned stream_idx, int64_t pts)
+	{
+		this->stream_idx = stream_idx;
+		this->pts = pts;
+		update();
+	}
+
+protected:
+	void resizeEvent(QResizeEvent *event) override;
+
+private:
+	void update();
+
+	QGraphicsPixmapItem item;
+	QGraphicsScene scene;
+
+	unsigned stream_idx;
+	int64_t pts;
+};
+
+#endif  // !defined(_JPEG_FRAME_VIEW_H)
diff --git a/main.cpp b/main.cpp
index 17431aa..0a976c3 100644
--- a/main.cpp
+++ b/main.cpp
@@ -17,6 +17,8 @@ extern "C" {
 
 #include "mainwindow.h"
 #include "ffmpeg_raii.h"
+#include "post_to_main_thread.h"
+#include "ui_mainwindow.h"
 
 #define MAX_STREAMS 16
 
@@ -78,6 +80,14 @@ int thread_func()
 		fwrite(pkt.data, pkt.size, 1, fp);
 		fclose(fp);
 
+		post_to_main_thread([pkt] {
+			if (pkt.stream_index == 0) {
+				global_mainwindow->ui->input1_display->setFrame(pkt.stream_index, pkt.pts);
+			} else if (pkt.stream_index == 1) {
+				global_mainwindow->ui->input2_display->setFrame(pkt.stream_index, pkt.pts);
+			}
+		});
+
 		assert(pkt.stream_index < MAX_STREAMS);
 		frames[pkt.stream_index].push_back(pkt.pts);
 
diff --git a/mainwindow.h b/mainwindow.h
index 4ee3bd9..f17757f 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -16,7 +16,7 @@ class MainWindow : public QMainWindow
 public:
 	MainWindow();
 
-private:
+//private:
 	Ui::MainWindow *ui;
 };
 
diff --git a/post_to_main_thread.h b/post_to_main_thread.h
new file mode 100644
index 0000000..0462c7b
--- /dev/null
+++ b/post_to_main_thread.h
@@ -0,0 +1,16 @@
+#ifndef _POST_TO_MAIN_THREAD_H
+#define _POST_TO_MAIN_THREAD_H 1
+
+#include <QApplication>
+#include <QObject>
+#include <memory>
+
+// http://stackoverflow.com/questions/21646467/how-to-execute-a-functor-in-a-given-thread-in-qt-gcd-style
+template<typename F>
+static inline void post_to_main_thread(F &&fun)
+{
+	QObject signalSource;
+	QObject::connect(&signalSource, &QObject::destroyed, qApp, std::move(fun));
+}
+
+#endif  // !defined(_POST_TO_MAIN_THREAD_H)
diff --git a/ui_mainwindow.ui b/ui_mainwindow.ui
index aeff6cb..17ff670 100644
--- a/ui_mainwindow.ui
+++ b/ui_mainwindow.ui
@@ -17,32 +17,32 @@
    <widget class="QWidget" name="gridLayoutWidget">
     <property name="geometry">
      <rect>
-      <x>20</x>
+      <x>10</x>
       <y>20</y>
-      <width>381</width>
-      <height>211</height>
+      <width>391</width>
+      <height>291</height>
      </rect>
     </property>
     <layout class="QGridLayout" name="gridLayout_2">
      <item row="0" column="1">
-      <widget class="QGraphicsView" name="input2_display"/>
+      <widget class="JPEGFrameView" name="input2_display"/>
      </item>
      <item row="0" column="0">
-      <widget class="QGraphicsView" name="input1_display"/>
+      <widget class="JPEGFrameView" name="input1_display"/>
      </item>
      <item row="1" column="0">
-      <widget class="QGraphicsView" name="input3_display"/>
+      <widget class="JPEGFrameView" name="input3_display"/>
      </item>
      <item row="1" column="1">
-      <widget class="QGraphicsView" name="input4_display"/>
+      <widget class="JPEGFrameView" name="input4_display"/>
      </item>
     </layout>
    </widget>
    <widget class="QLabel" name="label">
     <property name="geometry">
      <rect>
-      <x>90</x>
-      <y>240</y>
+      <x>70</x>
+      <y>320</y>
       <width>261</width>
       <height>17</height>
      </rect>
@@ -57,7 +57,7 @@
    <widget class="QGraphicsView" name="preview_display">
     <property name="geometry">
      <rect>
-      <x>410</x>
+      <x>430</x>
       <y>20</y>
       <width>281</width>
       <height>192</height>
@@ -67,7 +67,7 @@
    <widget class="QGraphicsView" name="live_display">
     <property name="geometry">
      <rect>
-      <x>705</x>
+      <x>730</x>
       <y>20</y>
       <width>291</width>
       <height>192</height>
@@ -78,7 +78,7 @@
     <property name="geometry">
      <rect>
       <x>470</x>
-      <y>240</y>
+      <y>230</y>
       <width>191</width>
       <height>17</height>
      </rect>
@@ -93,7 +93,7 @@
    <widget class="QLabel" name="label_3">
     <property name="geometry">
      <rect>
-      <x>760</x>
+      <x>770</x>
       <y>230</y>
       <width>191</width>
       <height>17</height>
@@ -108,6 +108,13 @@
    </widget>
   </widget>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>JPEGFrameView</class>
+   <extends>QGraphicsView</extends>
+   <header>jpeg_frame_view.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>
-- 
2.39.2