Paintbuffer single frame profiling.

Added new --instrumentframe=X argument which gives a detailed run-down
of how many milliseconds each paint command of that frame takes.

Reviewed-by: Gunnar Sletta

4 files changed, 400 insertions, 25 deletions

diff --git a/src/gui/painting/qpaintbuffer.cpp b/src/gui/painting/qpaintbuffer.cpp
index 39b76c8..ca2077f 100644
--- a/src/gui/painting/qpaintbuffer.cpp
+++ b/src/gui/painting/qpaintbuffer.cpp
@@ -269,24 +269,304 @@ void QPaintBuffer::draw(QPainter *painter, int frame) const
     printf("\n");
 #endif
 
-    if (painter && !painter->isActive())
-        return;
+    processCommands(painter, frameStartIndex(frame), frameEndIndex(frame));
+
+#ifdef QPAINTBUFFER_DEBUG_DRAW
+    qDebug() << "QPaintBuffer::draw() -------------------------------- DONE!";
+#endif
+}
+
+int QPaintBuffer::frameStartIndex(int frame) const
+{
+    return (frame == 0) ? 0 : d_ptr->frames.at(frame - 1);
+}
+
+int QPaintBuffer::frameEndIndex(int frame) const
+{
+    return (frame == d_ptr->frames.size()) ? d_ptr->commands.size() : d_ptr->frames.at(frame);
+}
+
+int QPaintBuffer::processCommands(QPainter *painter, int begin, int end) const
+{
+    if (!painter || !painter->isActive())
+        return 0;
 
     QPaintEngineEx *xengine = painter->paintEngine()->isExtended()
                               ? (QPaintEngineEx *) painter->paintEngine() : 0;
     if (xengine) {
         QPaintEngineExReplayer player;
-        player.draw(*this, painter, frame);
+        player.processCommands(*this, painter, begin, end);
     } else {
         QPainterReplayer player;
-        player.draw(*this, painter, frame);
+        player.processCommands(*this, painter, begin, end);
     }
 
-#ifdef QPAINTBUFFER_DEBUG_DRAW
-    qDebug() << "QPaintBuffer::draw() -------------------------------- DONE!";
-#endif
+    int depth = 0;
+    for (int i = begin; i < end; ++i) {
+        const QPaintBufferCommand &cmd = d_ptr->commands.at(i);
+        if (cmd.id == QPaintBufferPrivate::Cmd_Save)
+            ++depth;
+        else if (cmd.id == QPaintBufferPrivate::Cmd_Restore)
+            --depth;
+    }
+    return depth;
 }
 
+QString QPaintBuffer::commandDescription(int command) const
+{
+    QString desc;
+    QDebug debug(&desc);
+
+    const QPaintBufferCommand &cmd = d_ptr->commands.at(command);
+
+    switch (cmd.id) {
+    case QPaintBufferPrivate::Cmd_Save: {
+        debug << "Cmd_Save";
+        break; }
+
+    case QPaintBufferPrivate::Cmd_Restore: {
+        debug << "Cmd_Restore";
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetBrush: {
+        QBrush brush = qVariantValue<QBrush>(d_ptr->variants.at(cmd.offset));
+        debug << "Cmd_SetBrush: " << brush;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetBrushOrigin: {
+        debug << "Cmd_SetBrushOrigin: " << d_ptr->variants.at(cmd.offset).toPointF();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetCompositionMode: {
+        QPainter::CompositionMode mode = (QPainter::CompositionMode) cmd.extra;
+        debug << "ExCmd_SetCompositionMode, mode: " << mode;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetOpacity: {
+        debug << "ExCmd_SetOpacity: " << d_ptr->variants.at(cmd.offset).toDouble();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawVectorPath: {
+        debug << "ExCmd_DrawVectorPath: size: " << cmd.size
+//                 << ", hints:" << d->ints[cmd.offset2+cmd.size]
+                 << "pts/elms:" << cmd.offset << cmd.offset2;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_StrokeVectorPath: {
+        QPen pen = qVariantValue<QPen>(d_ptr->variants.at(cmd.extra));
+        debug << "ExCmd_StrokeVectorPath: size: " << cmd.size
+//                 << ", hints:" << d->ints[cmd.offset2+cmd.size]
+                 << "pts/elms:" << cmd.offset << cmd.offset2 << pen;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_FillVectorPath: {
+        QBrush brush = qVariantValue<QBrush>(d_ptr->variants.at(cmd.extra));
+        debug << "ExCmd_FillVectorPath: size: " << cmd.size
+//                 << ", hints:" << d->ints[cmd.offset2+cmd.size]
+                 << "pts/elms:" << cmd.offset << cmd.offset2 << brush;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_FillRectBrush: {
+        QBrush brush = qVariantValue<QBrush>(d_ptr->variants.at(cmd.extra));
+        QRectF *rect = (QRectF *)(d_ptr->floats.constData() + cmd.offset);
+        debug << "ExCmd_FillRectBrush, offset: " << cmd.offset << " rect: " << *rect << " brush: " << brush;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_FillRectColor: {
+        QColor color = qVariantValue<QColor>(d_ptr->variants.at(cmd.extra));
+        QRectF *rect = (QRectF *)(d_ptr->floats.constData() + cmd.offset);
+        debug << "ExCmd_FillRectBrush, offset: " << cmd.offset << " rect: " << *rect << " color: " << color;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPolygonF: {
+        debug << "ExCmd_DrawPolygonF, offset: " << cmd.offset << " size: " << cmd.size
+                 << " mode: " << cmd.extra
+                 << d_ptr->floats.at(cmd.offset)
+                 << d_ptr->floats.at(cmd.offset+1);
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPolygonI: {
+        debug << "ExCmd_DrawPolygonI, offset: " << cmd.offset << " size: " << cmd.size
+                 << " mode: " << cmd.extra
+                 << d_ptr->ints.at(cmd.offset)
+                 << d_ptr->ints.at(cmd.offset+1);
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawEllipseF: {
+        debug << "ExCmd_DrawEllipseF, offset: " << cmd.offset;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawLineF: {
+        debug << "ExCmd_DrawLineF, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawLineI: {
+        debug << "ExCmd_DrawLineI, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPointsF: {
+        debug << "ExCmd_DrawPointsF, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPointsI: {
+        debug << "ExCmd_DrawPointsI, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPolylineF: {
+        debug << "ExCmd_DrawPolylineF, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPolylineI: {
+        debug << "ExCmd_DrawPolylineI, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawRectF: {
+        debug << "ExCmd_DrawRectF, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawRectI: {
+        debug << "ExCmd_DrawRectI, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetClipEnabled: {
+        bool clipEnabled = d_ptr->variants.at(cmd.offset).toBool();
+        debug << "ExCmd_SetClipEnabled:" << clipEnabled;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_ClipVectorPath: {
+        QVectorPathCmd path(d_ptr, cmd);
+        debug << "ExCmd_ClipVectorPath:" << path().elementCount();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_ClipRect: {
+        QRect rect(QPoint(d_ptr->ints.at(cmd.offset), d_ptr->ints.at(cmd.offset + 1)),
+                   QPoint(d_ptr->ints.at(cmd.offset + 2), d_ptr->ints.at(cmd.offset + 3)));
+        debug << "ExCmd_ClipRect:" << rect << cmd.extra;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_ClipRegion: {
+        QRegion region(d_ptr->variants.at(cmd.offset).value<QRegion>());
+        debug << "ExCmd_ClipRegion:" << region.boundingRect() << cmd.extra;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetPen: {
+        QPen pen = qVariantValue<QPen>(d_ptr->variants.at(cmd.offset));
+        debug << "Cmd_SetPen: " << pen;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetTransform: {
+        QTransform xform = qVariantValue<QTransform>(d_ptr->variants.at(cmd.offset));
+        debug << "Cmd_SetTransform, offset: " << cmd.offset << xform;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetRenderHints: {
+        debug << "Cmd_SetRenderHints, hints: " << cmd.extra;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_SetBackgroundMode: {
+        debug << "Cmd_SetBackgroundMode: " << cmd.extra;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawConvexPolygonF: {
+        debug << "Cmd_DrawConvexPolygonF, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawConvexPolygonI: {
+        debug << "Cmd_DrawConvexPolygonI, offset: " << cmd.offset << " size: " << cmd.size;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawEllipseI: {
+        debug << "Cmd_DrawEllipseI, offset: " << cmd.offset;
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPixmapRect: {
+        QPixmap pm(d_ptr->variants.at(cmd.offset).value<QPixmap>());
+        QRectF r(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1),
+                 d_ptr->floats.at(cmd.extra+2), d_ptr->floats.at(cmd.extra+3));
+
+        QRectF sr(d_ptr->floats.at(cmd.extra+4), d_ptr->floats.at(cmd.extra+5),
+                  d_ptr->floats.at(cmd.extra+6), d_ptr->floats.at(cmd.extra+7));
+        debug << "Cmd_DrawPixmapRect:" << r << sr << pm.size();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawPixmapPos: {
+        QPixmap pm(d_ptr->variants.at(cmd.offset).value<QPixmap>());
+        QPointF pos(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        debug << "Cmd_DrawPixmapPos:" << pos << pm.size();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawTiledPixmap: {
+        QPixmap pm(d_ptr->variants.at(cmd.offset).value<QPixmap>());
+        QRectF r(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1),
+                 d_ptr->floats.at(cmd.extra+2), d_ptr->floats.at(cmd.extra+3));
+
+        QPointF offset(d_ptr->floats.at(cmd.extra+4), d_ptr->floats.at(cmd.extra+5));
+        debug << "Cmd_DrawTiledPixmap:" << r << offset << pm.size();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawImageRect: {
+        QImage image(d_ptr->variants.at(cmd.offset).value<QImage>());
+        QRectF r(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1),
+                 d_ptr->floats.at(cmd.extra+2), d_ptr->floats.at(cmd.extra+3));
+        QRectF sr(d_ptr->floats.at(cmd.extra+4), d_ptr->floats.at(cmd.extra+5),
+                  d_ptr->floats.at(cmd.extra+6), d_ptr->floats.at(cmd.extra+7));
+        debug << "Cmd_DrawImageRect:" << r << sr << image.size();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawImagePos: {
+        QImage image(d_ptr->variants.at(cmd.offset).value<QImage>());
+        QPointF pos(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        debug << "Cmd_DrawImagePos:" << pos << image.size();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawText: {
+        QPointF pos(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        QList<QVariant> variants(d_ptr->variants.at(cmd.offset).value<QList<QVariant> >());
+
+        QFont font(variants.at(0).value<QFont>());
+        QString text(variants.at(1).value<QString>());
+
+        debug << "Cmd_DrawText:" << pos << text << font.family();
+        break; }
+
+    case QPaintBufferPrivate::Cmd_DrawTextItem: {
+        QPointF pos(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        QTextItemIntCopy *tiCopy = reinterpret_cast<QTextItemIntCopy *>(qVariantValue<void *>(d_ptr->variants.at(cmd.offset)));
+        QTextItemInt &ti = (*tiCopy)();
+        QString text(ti.text());
+
+        QFont font(ti.font());
+        font.setUnderline(false);
+        font.setStrikeOut(false);
+        font.setOverline(false);
+
+        const QTextItemInt &si = static_cast<const QTextItemInt &>(ti);
+        qreal justificationWidth = 0;
+        if (si.justified)
+            justificationWidth = si.width.toReal();
+
+        debug << "Cmd_DrawTextItem:" << pos << " " << text;
+        break; }
+    case QPaintBufferPrivate::Cmd_SystemStateChanged: {
+        QRegion systemClip(d_ptr->variants.at(cmd.offset).value<QRegion>());
+
+        debug << "Cmd_SystemStateChanged:" << systemClip;
+        break; }
+    case QPaintBufferPrivate::Cmd_Translate: {
+        QPointF delta(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        debug << "Cmd_Translate:" << delta;
+        break; }
+    case QPaintBufferPrivate::Cmd_DrawStaticText: {
+        QPointF delta(d_ptr->floats.at(cmd.extra), d_ptr->floats.at(cmd.extra+1));
+        QVariantList variants(d_ptr->variants.at(cmd.offset).value<QVariantList>());
+
+        QStaticText text(variants.at(0).value<QStaticText>());
+        debug << "Cmd_DrawStaticText:" << text.text();
+        break; }
+    }
+
+    return desc;
+}
 
 QRectF QPaintBuffer::boundingRect() const
 {
@@ -1110,15 +1390,12 @@ void QPainterReplayer::setupTransform(QPainter *_painter)
     painter->setTransform(m_world_matrix);
 }
 
-void QPainterReplayer::draw(const QPaintBuffer &buffer, QPainter *_painter, int frame)
+void QPainterReplayer::processCommands(const QPaintBuffer &buffer, QPainter *p, int begin, int end)
 {
     d = buffer.d_ptr;
-    setupTransform(_painter);
-
-    int frameStart = (frame == 0) ? 0 : d->frames.at(frame-1);
-    int frameEnd = (frame == d->frames.size()) ? d->commands.size() : d->frames.at(frame);
+    painter = p;
 
-    for (int cmdIndex=frameStart; cmdIndex<frameEnd; ++cmdIndex) {
+    for (int cmdIndex = begin; cmdIndex < end; ++cmdIndex) {
         const QPaintBufferCommand &cmd = d->commands.at(cmdIndex);
         process(cmd);
     }
diff --git a/src/gui/painting/qpaintbuffer_p.h b/src/gui/painting/qpaintbuffer_p.h
index 0fde290..4576947 100644
--- a/src/gui/painting/qpaintbuffer_p.h
+++ b/src/gui/painting/qpaintbuffer_p.h
@@ -78,6 +78,12 @@ public:
     int numFrames() const;
 
     void draw(QPainter *painter, int frame = 0) const;
+
+    int frameStartIndex(int frame) const;
+    int frameEndIndex(int frame) const;
+    int processCommands(QPainter *painter, int begin, int end) const;
+    QString commandDescription(int command) const;
+
     void setBoundingRect(const QRectF &rect);
     QRectF boundingRect() const;
 
@@ -317,7 +323,7 @@ public:
 
     void setupTransform(QPainter *painter);
     virtual void process(const QPaintBufferCommand &cmd);
-    void draw(const QPaintBuffer &buffer, QPainter *painter, int frame);
+    void processCommands(const QPaintBuffer &buffer, QPainter *painter, int begin, int end);
 
 protected:
     QPaintBufferPrivate *d;
diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp
index 4f42a58..988d678 100644
--- a/src/gui/painting/qtransform.cpp
+++ b/src/gui/painting/qtransform.cpp
@@ -1037,8 +1037,18 @@ QDataStream & operator>>(QDataStream &s, QTransform &t)
 #ifndef QT_NO_DEBUG_STREAM
 QDebug operator<<(QDebug dbg, const QTransform &m)
 {
-    dbg.nospace() << "QTransform("
-                  << "11="  << m.m11()
+    static const char *typeStr[] =
+    {
+        "TxNone",
+        "TxTranslate",
+        "TxScale",
+        "TxRotate",
+        "TxShear",
+        "TxProject"
+    };
+
+    dbg.nospace() << "QTransform(type=" << typeStr[m.type()] << ','
+                  << " 11=" << m.m11()
                   << " 12=" << m.m12()
                   << " 13=" << m.m13()
                   << " 21=" << m.m21()
@@ -1048,6 +1058,7 @@ QDebug operator<<(QDebug dbg, const QTransform &m)
                   << " 32=" << m.m32()
                   << " 33=" << m.m33()
                   << ')';
+
     return dbg.space();
 }
 #endif
diff --git a/tools/qttracereplay/main.cpp b/tools/qttracereplay/main.cpp
index be7906b..101d512 100644
--- a/tools/qttracereplay/main.cpp
+++ b/tools/qttracereplay/main.cpp
@@ -49,7 +49,7 @@ class ReplayWidget : public QWidget
 {
     Q_OBJECT
 public:
-    ReplayWidget(const QString &filename, int from, int to, bool single);
+    ReplayWidget(const QString &filename, int from, int to, bool single, int frame);
 
     void paintEvent(QPaintEvent *event);
     void resizeEvent(QResizeEvent *event);
@@ -66,27 +66,96 @@ public:
     QTime timer;
 
     QList<uint> visibleUpdates;
-    QList<uint> iterationTimes;
+
+    QVector<uint> iterationTimes;
     QString filename;
 
     int from;
     int to;
 
     bool single;
+
+    int frame;
+    int currentCommand;
 };
 
 void ReplayWidget::updateRect()
 {
-    if (!visibleUpdates.isEmpty())
+    if (frame >= 0 && !updates.isEmpty())
+        update(updates.at(frame));
+    else if (!visibleUpdates.isEmpty())
         update(updates.at(visibleUpdates.at(currentFrame)));
 }
 
+const int singleFrameRepeatsPerCommand = 100;
+const int singleFrameIterations = 4;
+
 void ReplayWidget::paintEvent(QPaintEvent *)
 {
     QPainter p(this);
 
+    QTimer::singleShot(0, this, SLOT(updateRect()));
+
 //    p.setClipRegion(frames.at(currentFrame).updateRegion);
 
+    if (frame >= 0) {
+        int start = buffer.frameStartIndex(frame);
+        int end = buffer.frameEndIndex(frame);
+
+        iterationTimes.resize(end - start);
+
+        int saveRestoreStackDepth = buffer.processCommands(&p, start, start + currentCommand);
+
+        for (int i = 0; i < saveRestoreStackDepth; ++i)
+            p.restore();
+
+        const int repeats = currentIteration >= 3 ? singleFrameRepeatsPerCommand : 1;
+
+        ++currentFrame;
+        if (currentFrame == repeats) {
+            currentFrame = 0;
+            if (currentIteration >= 3) {
+                iterationTimes[currentCommand - 1] = qMin(iterationTimes[currentCommand - 1], uint(timer.elapsed()));
+                timer.restart();
+            }
+
+            if (currentIteration >= singleFrameIterations + 3) {
+                printf(" #    | ms      | description\n");
+                printf("------+---------+------------------------------------------------------------\n");
+
+		qSort(iterationTimes);
+
+		int sum = 0;
+                for (int i = 0; i < iterationTimes.size(); ++i) {
+                    int delta = iterationTimes.at(i);
+                    if (i > 0)
+                        delta -= iterationTimes.at(i-1);
+		    sum += delta;
+                    qreal deltaF = delta / qreal(repeats);
+                    printf("%.5d | %.5f | %s\n", i, deltaF, qPrintable(buffer.commandDescription(start + i)));
+                }
+                printf("Total | %.5f | Total frame time\n", sum / qreal(repeats));
+                deleteLater();
+                return;
+            }
+
+            if (start + currentCommand >= end) {
+                currentCommand = 1;
+		++currentIteration;
+                if (currentIteration == 3) {
+                    timer.start();
+                    iterationTimes.fill(uint(-1));
+                }
+		if (currentIteration >= 3 && currentIteration < singleFrameIterations + 3)
+                    printf("Profiling iteration %d of %d\n", currentIteration - 2, singleFrameIterations);
+            } else {
+                ++currentCommand;
+	    }
+        }
+
+        return;
+    }
+
     buffer.draw(&p, visibleUpdates.at(currentFrame));
 
     ++currentFrame;
@@ -138,11 +207,9 @@ void ReplayWidget::paintEvent(QPaintEvent *)
             }
         }
     }
-
-    QTimer::singleShot(0, this, SLOT(updateRect()));
 }
 
-void ReplayWidget::resizeEvent(QResizeEvent *event)
+void ReplayWidget::resizeEvent(QResizeEvent *)
 {
     visibleUpdates.clear();
 
@@ -162,13 +229,15 @@ void ReplayWidget::resizeEvent(QResizeEvent *event)
 
 }
 
-ReplayWidget::ReplayWidget(const QString &filename_, int from_, int to_, bool single_)
+ReplayWidget::ReplayWidget(const QString &filename_, int from_, int to_, bool single_, int frame_)
     : currentFrame(0)
     , currentIteration(0)
     , filename(filename_)
     , from(from_)
     , to(to_)
     , single(single_)
+    , frame(frame_)
+    , currentCommand(1)
 {
     setWindowTitle(filename);
     QFile file(filename);
@@ -216,7 +285,8 @@ int main(int argc, char **argv)
         printf("Usage:\n  > %s [OPTIONS] [traceFile]\n", argv[0]);
         printf("OPTIONS\n"
                "   --range=from-to to specify a frame range.\n"
-               "   --singlerun to do only one run (without statistics)\n");
+               "   --singlerun to do only one run (without statistics)\n"
+               "   --instrumentframe=frame to instrument a single frame\n");
         return 1;
     }
 
@@ -228,6 +298,8 @@ int main(int argc, char **argv)
 
     bool single = false;
 
+    int frame = -1;
+
     int from = 0;
     int to = -1;
     for (int i = 1; i < app.arguments().size() - 1; ++i) {
@@ -253,13 +325,22 @@ int main(int argc, char **argv)
             }
         } else if (arg == QLatin1String("--singlerun")) {
             single = true;
+        } else if (arg.startsWith(QLatin1String("--instrumentframe="))) {
+            QString rest = arg.mid(18);
+            bool ok = false;
+            int frameCandidate = rest.toInt(&ok);
+            if (ok) {
+                frame = frameCandidate;
+            } else {
+                printf("ERROR: malformed syntax in argument %s\n", qPrintable(arg));
+            }
         } else {
             printf("Unrecognized argument: %s\n", qPrintable(arg));
             return 1;
         }
     }
 
-    ReplayWidget *widget = new ReplayWidget(app.arguments().last(), from, to, single);
+    ReplayWidget *widget = new ReplayWidget(app.arguments().last(), from, to, single, frame);
 
     if (!widget->updates.isEmpty()) {
         widget->show();