Drop video frames when lagging

Aka, all the time. We only drop received frames, we never stop sending

core.cpp

@@ -35,11 +35,13 @@ QList<ToxFile> Core::fileRecvQueue;
 ToxCall Core::calls[TOXAV_MAX_CALLS];
 const int Core::videobufsize{TOXAV_MAX_VIDEO_WIDTH * TOXAV_MAX_VIDEO_HEIGHT * 4};
 uint8_t* Core::videobuf;
+int Core::videoBusyness;
 
 Core::Core(Camera* cam, QThread *coreThread) :
     tox(nullptr), camera(cam)
 {
     videobuf = new uint8_t[videobufsize];
+    videoBusyness=0;
 
     toxTimer = new QTimer(this);
     toxTimer->setSingleShot(true);
@@ -1312,13 +1314,14 @@ void Core::sendCallAudio(int callId, ToxAv* toxav)
 
 void Core::playCallVideo(ToxAv*, int32_t callId, vpx_image_t* img)
 {
-    qDebug() << "Core: Got video frame";
     if (!calls[callId].active || !calls[callId].videoEnabled)
         return;
 
-    qDebug() << "Core: Got video frame, call's active";
-
-    emit Widget::getInstance()->getCore()->videoFrameReceived(*img);
+    if (videoBusyness >= 2)
+        qWarning() << "Core: playCallVideo: Busy, dropping current frame";
+    else
+        emit Widget::getInstance()->getCore()->videoFrameReceived(img);
+    vpx_img_free(img);
 }
 
 void Core::sendCallVideo(int callId)
@@ -1358,3 +1361,13 @@ void Core::createGroup()
 {
     emit emptyGroupCreated(tox_add_groupchat(tox));
 }
+
+void Core::increaseVideoBusyness()
+{
+    videoBusyness++;
+}
+
+void Core::decreaseVideoBusyness()
+{
+    videoBusyness--;
+}

core.h

@@ -122,6 +122,9 @@ public:
     QString getUsername();
     QString getStatusMessage();
 
+    void increaseVideoBusyness();
+    void decreaseVideoBusyness();
+
 public slots:
     void start();
     void process();
@@ -223,7 +226,7 @@ signals:
     void avRequestTimeout(int friendId, int callIndex);
     void avPeerTimeout(int friendId, int callIndex);
 
-    void videoFrameReceived(vpx_image frame);
+    void videoFrameReceived(vpx_image* frame);
 
 private:
     static void onFriendRequest(Tox* tox, const uint8_t* cUserId, const uint8_t* cMessage, uint16_t cMessageSize, void* core);
@@ -289,6 +292,7 @@ private:
     static const QString CONFIG_FILE_NAME;
     static const int videobufsize;
     static uint8_t* videobuf;
+    static int videoBusyness; // Used to know when to drop frames
 };
 
 #endif // CORE_HPP

widget/netcamview.cpp

@@ -15,6 +15,10 @@
 */
 
 #include "netcamview.h"
+#include "core.h"
+#include "widget.h"
+#include <QApplication>
+#include <QtConcurrent/QtConcurrent>
 
 NetCamView::NetCamView(QWidget* parent)
     : QWidget(parent), displayLabel{new QLabel},
@@ -29,13 +33,28 @@ NetCamView::NetCamView(QWidget* parent)
     mainLayout->addWidget(displayLabel);
 }
 
-void NetCamView::updateDisplay(vpx_image frame)
+void NetCamView::updateDisplay(vpx_image* frame)
 {
-    int w = frame.d_w, h = frame.d_h;
-
-    if (!frame.w || !frame.h || !w || !h)
+    if (!frame->w || !frame->h)
         return;
 
+    Core* core = Widget::getInstance()->getCore();
+
+    core->increaseVideoBusyness();
+
+    QFuture<QImage> future = QtConcurrent::run(convert,*frame);
+    qApp->processEvents();
+    QImage img = future.result();
+
+    vpx_img_free(frame);
+    displayLabel->setPixmap(QPixmap::fromImage(img));
+
+    core->decreaseVideoBusyness();
+}
+
+QImage NetCamView::convert(vpx_image& frame)
+{
+    int w = frame.d_w, h = frame.d_h;
     int bpl = frame.stride[VPX_PLANE_Y], cxbpl = frame.stride[VPX_PLANE_V];
     QImage img(w, h, QImage::Format_RGB32);
 
@@ -58,7 +77,5 @@ void NetCamView::updateDisplay(vpx_image frame)
             scanline[j] = (0xFF<<24) + (R<<16) + (G<<8) + B;
         }
     }
-
-    vpx_img_free(&frame);
-    displayLabel->setPixmap(QPixmap::fromImage(img));
+    return img;
 }

widget/netcamview.h

@@ -35,7 +35,10 @@ public:
     NetCamView(QWidget *parent=0);
 
 public slots:
-    void updateDisplay(vpx_image frame);
+    void updateDisplay(vpx_image* frame);
+
+private:
+    static QImage convert(vpx_image& frame);
 
 private:
     QLabel *displayLabel;