Keep last known frame as thumbnail when resizing a clip

src/timeline2/view/qml/Clip.qml

@@ -208,9 +208,10 @@ Rectangle {
         //generateWaveform()
     }
 */
-    property bool variableThumbs: (isAudio || itemType == ProducerType.Color || mltService === '')
+    property bool noThumbs: (isAudio || itemType == ProducerType.Color || mltService === '')
     property bool isImage: itemType == ProducerType.Image
-    property string baseThumbPath: variableThumbs ? '' : 'image://thumbnail/' + binId + '/' + documentId + '/' + (isImage ? '#0' : '#')
+    property string baseThumbPath: noThumbs ? '' : 'image://thumbnail/' + binId + '/' + documentId + '/' + (isImage ? '#0' : '#')
+    property string baseCacheThumbPath: noThumbs ? '' : 'image://thumbnailCache/' + binId + '/' + (isImage ? '#0' : '#')
 
     DropArea { //Drop area for clips
         anchors.fill: clipRoot
@@ -291,21 +292,18 @@ Rectangle {
         }
         onWheel: zoomByWheel(wheel)
 
-        Item {
+        Loader {
             // Thumbs container
+            id: thumbsLoader
             anchors.fill: parent
             anchors.leftMargin: parentTrack.isAudio ? 0 : clipRoot.border.width
             anchors.rightMargin: parentTrack.isAudio ? 0 : clipRoot.border.width
             anchors.topMargin: clipRoot.border.width
             anchors.bottomMargin: clipRoot.border.width
             clip: true
-            Loader {
-                id: thumbsLoader
-                asynchronous: true
-                visible: status == Loader.Ready
-                anchors.fill: parent
-                source: clipRoot.hideClipViews ? "" : parentTrack.isAudio ? (timeline.showAudioThumbnails ? "ClipAudioThumbs.qml" : "") : itemType == ProducerType.Color ? "" : timeline.showThumbnails ? "ClipThumbs.qml" : ""
-            }
+            asynchronous: true
+            visible: status == Loader.Ready
+            source: clipRoot.hideClipViews ? "" : parentTrack.isAudio ? (timeline.showAudioThumbnails ? "ClipAudioThumbs.qml" : "") : itemType == ProducerType.Color ? "" : timeline.showThumbnails ? "ClipThumbs.qml" : ""
         }
 
         Item {

src/timeline2/view/qml/ClipThumbs.qml

@@ -37,9 +37,48 @@ Row {
             fillMode: Image.PreserveAspectFit
             asynchronous: true
             cache: enableCache
-            property int currentFrame: Math.floor(clipRoot.inPoint + Math.round((index) * width / timeline.scaleFactor)* clipRoot.speed)
+            property int currentFrame: thumbRepeater.count < 3 ? (index == 0 ? thumbRepeater.thumbStartFrame : thumbRepeater.thumbEndFrame) : Math.floor(clipRoot.inPoint + Math.round((index) * width / timeline.scaleFactor)* clipRoot.speed)
+            property int lastFrame: -1
             horizontalAlignment: thumbRepeater.count < 3 ? (index == 0 ? Image.AlignLeft : Image.AlignRight) : Image.AlignLeft
-            source: thumbRepeater.count < 3 ? (index == 0 ? clipRoot.baseThumbPath + thumbRepeater.thumbStartFrame : clipRoot.baseThumbPath + thumbRepeater.thumbEndFrame) : (index * width < clipRoot.scrollStart - width || index * width > clipRoot.scrollStart + scrollView.viewport.width) ? '' : clipRoot.baseThumbPath + currentFrame
+            source: thumbRepeater.count < 3 ? (clipRoot.baseThumbPath + currentFrame) : (index * width < clipRoot.scrollStart - width || index * width > clipRoot.scrollStart + scrollView.viewport.width) ? '' : clipRoot.baseThumbPath + currentFrame
+            onStatusChanged: {
+                if (thumbRepeater.count < 3) {
+                    if (status === Image.Ready) {
+                        lastFrame = currentFrame
+                    }
+                }
+            }
+            BusyIndicator {
+                running: parent.status != Image.Ready
+                anchors.left: parent.left
+                anchors.leftMargin: index < thumbRepeater.count - 1 ? 0 : parent.width - thumbRow.thumbWidth - 1
+                implicitWidth: thumbRepeater.imageWidth
+                implicitHeight: container.height
+                contentItem:
+                Image {
+                    id: thumbPlaceholder
+                    visible: parent.running
+                    anchors.fill: parent
+                    horizontalAlignment: Image.AlignLeft
+                    fillMode: Image.PreserveAspectFit
+                    asynchronous: true
+                }
+                onRunningChanged: {
+                    if (!running) {
+                        thumbPlaceholder.source = clipRoot.baseCacheThumbPath + parent.lastFrame
+                        console.log('Setting image lastframe: ', parent.lastFrame)
+                    }
+                }
+            }
+            Rectangle {
+                visible: thumbRepeater.count < 3
+                anchors.left: parent.left
+                anchors.leftMargin: index < thumbRepeater.count - 1 ? thumbRow.thumbWidth : parent.width - thumbRow.thumbWidth - 1
+                color: "#ffffff"
+                opacity: 0.3
+                width: 1
+                height: parent.height
+            }
         }
     }
 }

src/timeline2/view/qmltypes/thumbnailprovider.cpp

@@ -30,7 +30,6 @@
 
 ThumbnailProvider::ThumbnailProvider()
     : QQuickImageProvider(QQmlImageProviderBase::Image, QQmlImageProviderBase::ForceAsynchronousImageLoading)
-//, m_profile(pCore->getCurrentProfilePath().toUtf8().constData())
 {
 }
 
@@ -57,40 +56,6 @@ QImage ThumbnailProvider::requestImage(const QString &id, QSize *size, const QSi
                 ThumbnailCache::get()->storeThumbnail(binId, frameNumber, result, false);
             }
         }
-
-        /*if (m_producers.contains(binId.toInt())) {
-            producer = m_producers.object(binId.toInt());
-        } else {
-            m_binClip->thumbProducer();
-            if (!resource.isEmpty()) {
-                producer = new Mlt::Producer(m_profile, service.toUtf8().constData(), resource.toUtf8().constData());
-            } else {
-                producer = new Mlt::Producer(m_profile, service.toUtf8().constData());
-            }
-            std::shared_ptr<ProjectClip> binClip = pCore->projectItemModel()->getClipByBinID(binId);
-            if (binClip) {
-                std::shared_ptr<Mlt::Producer> projectProducer = binClip->originalProducer();
-                Mlt::Properties original(projectProducer->get_properties());
-                Mlt::Properties cloneProps(producer->get_properties());
-                cloneProps.pass_list(original, "video_index,force_aspect_num,force_aspect_den,force_aspect_ratio,force_fps,force_progressive,force_tff,"
-                "force_colorspace,set.force_full_luma,templatetext,autorotate,xmldata");
-            }
-            Mlt::Filter scaler(m_profile, "swscale");
-            Mlt::Filter padder(m_profile, "resize");
-            Mlt::Filter converter(m_profile, "avcolor_space");
-            producer->attach(scaler);
-            producer->attach(padder);
-            producer->attach(converter);
-            m_producers.insert(binId.toInt(), producer);
-        }
-        if ((producer != nullptr) && producer->is_valid()) {
-            // result = KThumb::getFrame(producer, frameNumber, 0, 0);
-            result = makeThumbnail(producer, frameNumber, requestedSize);
-            ThumbnailCache::get()->storeThumbnail(binId, frameNumber, result, false);
-            //m_cache->insertImage(key, result);
-        } else {
-            qDebug() << "INVALID PRODUCER; " << service << " / " << resource;
-        }*/
     }
     if (size) *size = result.size();
     return result;
@@ -122,13 +87,8 @@ QImage ThumbnailProvider::makeThumbnail(const std::shared_ptr<Mlt::Producer> &pr
     if (frame == nullptr || !frame->is_valid()) {
         return QImage();
     }
-    int ow = 0; // requestedSize.width();
-    int oh = 0; // requestedSize.height();
-    /*if (ow > 0 && oh > 0) {
-        frame->set("rescale.interp", "fastest");
-        frame->set("deinterlace_method", "onefield");
-        frame->set("top_field_first", -1);
-    }*/
+    int ow = 0;
+    int oh = 0;
     mlt_image_format format = mlt_image_rgb24a;
     const uchar *image = frame->get_image(format, ow, oh);
     if (image) {
@@ -138,3 +98,28 @@ QImage ThumbnailProvider::makeThumbnail(const std::shared_ptr<Mlt::Producer> &pr
     }
     return QImage();
 }
+
+ThumbnailCacheProvider::ThumbnailCacheProvider()
+    : QQuickImageProvider(QQmlImageProviderBase::Image, QQmlImageProviderBase::ForceAsynchronousImageLoading)
+{
+}
+
+ThumbnailCacheProvider::~ThumbnailCacheProvider() = default;
+
+QImage ThumbnailCacheProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+{
+    QImage result;
+    // id is binID/#frameNumber
+    QString binId = id.section('/', 0, 0);
+    bool ok;
+    int frameNumber = id.section('#', -1).toInt(&ok);
+    if (ok) {
+        if (ThumbnailCache::get()->hasThumbnail(binId, frameNumber, false)) {
+            result = ThumbnailCache::get()->getThumbnail(binId, frameNumber);
+            *size = result.size();
+            return result;
+        }
+    }
+    if (size) *size = result.size();
+    return result;
+}

src/timeline2/view/qmltypes/thumbnailprovider.h

@@ -34,9 +34,16 @@ public:
     QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
 
 private:
-    QString cacheKey(Mlt::Properties &properties, const QString &service, const QString &resource, const QString &hash, int frameNumber);
     QImage makeThumbnail(const std::shared_ptr<Mlt::Producer> &producer, int frameNumber, const QSize &requestedSize);
-    QCache<int, Mlt::Producer> m_producers;
+    QString cacheKey(Mlt::Properties &properties, const QString &service, const QString &resource, const QString &hash, int frameNumber);
+};
+
+class ThumbnailCacheProvider : public QQuickImageProvider
+{
+public:
+    explicit ThumbnailCacheProvider();
+    ~ThumbnailCacheProvider() override;
+    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
 };
 
 #endif // THUMBNAILPROVIDER_H

src/timeline2/view/timelinewidget.cpp

@@ -81,8 +81,8 @@ TimelineWidget::TimelineWidget(QWidget *parent)
     connect(m_proxy, &TimelineController::zoneMoved, this, &TimelineWidget::zoneMoved);
     connect(m_proxy, &TimelineController::ungrabHack, this, &TimelineWidget::slotUngrabHack);
     setResizeMode(QQuickWidget::SizeRootObjectToView);
-    m_thumbnailer = new ThumbnailProvider;
-    engine()->addImageProvider(QStringLiteral("thumbnail"), m_thumbnailer);
+    engine()->addImageProvider(QStringLiteral("thumbnail"), new ThumbnailProvider);
+    engine()->addImageProvider(QStringLiteral("thumbnailCache"), new ThumbnailCacheProvider);
     setVisible(false);
     setFont(QFontDatabase::systemFont(QFontDatabase::SmallestReadableFont));
     setFocusPolicy(Qt::StrongFocus);

src/timeline2/view/timelinewidget.h

@@ -71,7 +71,6 @@ private slots:
     void slotUngrabHack();
 
 private:
-    ThumbnailProvider *m_thumbnailer;
     TimelineController *m_proxy;
     static const int comboScale[];
     std::shared_ptr<AssetTreeModel> m_transitionModel;