Speedup loading of projects with timeline preview.

Related to #1266

src/core.cpp

@@ -1195,3 +1195,8 @@ void Core::addBin(const QString &id)
     const QString folderName = bin->setDocument(pCore->currentDoc(), id);
     m_mainWindow->addBin(bin, folderName);
 }
+
+void Core::loadTimelinePreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enablePreview, Mlt::Playlist &playlist)
+{
+    pCore->window()->getMainTimeline()->controller()->loadPreview(chunks, dirty, documentDate, enablePreview, playlist);
+}

src/core.h

@@ -22,7 +22,8 @@ SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
 #include <unordered_set>
 #include "timecode.h"
 
-#include "mlt++/MltProfile.h"
+#include <mlt++/MltProfile.h>
+#include <mlt++/MltPlaylist.h>
 
 class Bin;
 class DocUndoStack;
@@ -271,6 +272,7 @@ public:
     int getNewStuff(const QString &configFile);
     /** @brief Get the frame size of the clip above a composition */
     const QSize getCompositionSizeOnTrack(const ObjectId &id);
+    void loadTimelinePreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enablePreview, Mlt::Playlist &playlist);
 
 private:
     explicit Core();

src/project/projectmanager.cpp

@@ -222,7 +222,7 @@ void ProjectManager::newFile(QString profileName, bool showProjectSettings)
     pCore->bin()->setDocument(doc);
     m_project = doc;
     pCore->monitorManager()->activateMonitor(Kdenlive::ProjectMonitor);
-    updateTimeline(0);
+    updateTimeline(0, QString(), QString(), QDateTime(), 0);
     pCore->window()->connectDocument();
     pCore->mixer()->setModel(m_mainTimelineModel);
     bool disabled = m_project->getDocumentProperty(QStringLiteral("disabletimelineeffects")) == QLatin1String("1");
@@ -615,19 +615,15 @@ void ProjectManager::doOpenFile(const QUrl &url, KAutoSaveFile *stale)
 
     // Set default target tracks to upper audio / lower video tracks
     m_project = doc;
-    doc->loadDocumentGuides();
-    if (!updateTimeline(m_project->getDocumentProperty(QStringLiteral("position")).toInt())) {
+    m_project->loadDocumentGuides();
+    QDateTime documentDate = QFileInfo(m_project->url().toLocalFile()).lastModified();
+    if (!updateTimeline(m_project->getDocumentProperty(QStringLiteral("position")).toInt(), m_project->getDocumentProperty(QStringLiteral("previewchunks")), m_project->getDocumentProperty(QStringLiteral("dirtypreviewchunks")), documentDate, m_project->getDocumentProperty(QStringLiteral("disablepreview")).toInt())) {
         delete m_progressDialog;
         m_progressDialog = nullptr;
         return;
     }
     pCore->window()->connectDocument();
     pCore->mixer()->setModel(m_mainTimelineModel);
-    QDateTime documentDate = QFileInfo(m_project->url().toLocalFile()).lastModified();
-    pCore->window()->getMainTimeline()->controller()->loadPreview(m_project->getDocumentProperty(QStringLiteral("previewchunks")),
-                                                                  m_project->getDocumentProperty(QStringLiteral("dirtypreviewchunks")), documentDate,
-                                                                  m_project->getDocumentProperty(QStringLiteral("disablepreview")).toInt());
-
     emit docOpened(m_project);
     pCore->displayMessage(QString(), OperationCompletedMessage, 100);
     if (openBackup) {
@@ -929,7 +925,7 @@ void ProjectManager::slotMoveFinished(KJob *job)
     }
 }
 
-bool ProjectManager::updateTimeline(int pos)
+bool ProjectManager::updateTimeline(int pos, const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enablePreview)
 {
     pCore->taskManager.slotCancelJobs();
     pCore->window()->getMainTimeline()->loading = true;
@@ -960,7 +956,7 @@ bool ProjectManager::updateTimeline(int pos)
     m_mainTimelineModel->addSnap(0);
     pCore->window()->getMainTimeline()->setModel(m_mainTimelineModel, pCore->monitorManager()->projectMonitor()->getControllerProxy());
     bool projectErrors = false;
-    if (!constructTimelineFromMelt(m_mainTimelineModel, tractor, m_progressDialog, m_project->modifiedDecimalPoint(), &projectErrors)) {
+    if (!constructTimelineFromMelt(m_mainTimelineModel, tractor, m_progressDialog, m_project->modifiedDecimalPoint(), chunks, dirty, documentDate, enablePreview, &projectErrors)) {
         //TODO: act on project load failure
         qDebug()<<"// Project failed to load!!";
     }

src/project/projectmanager.h

@@ -185,7 +185,7 @@ signals:
 
 protected:
     /** @brief Update the timeline according to the MLT XML */
-    bool updateTimeline(int pos);
+    bool updateTimeline(int pos, const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enablePreview);
 
 private:
     /** @brief checks if autoback files exists, recovers from it if user says yes, returns true if files were recovered. */

src/timeline2/model/builders/meltBuilder.cpp

@@ -36,7 +36,7 @@ bool constructTrackFromMelt(const std::shared_ptr<TimelineItemModel> &timeline,
 bool constructTrackFromMelt(const std::shared_ptr<TimelineItemModel> &timeline, int tid, Mlt::Playlist &track,
                             const std::unordered_map<QString, QString> &binIdCorresp, Fun &undo, Fun &redo, bool audioTrack, QString originalDecimalPoint, int playlist, QList<Mlt::Transition *> compositions, QProgressDialog *progressDialog = nullptr);
 
-bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timeline, Mlt::Tractor tractor, QProgressDialog *progressDialog, QString originalDecimalPoint, bool *projectErrors)
+bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timeline, Mlt::Tractor tractor, QProgressDialog *progressDialog, const QString &originalDecimalPoint, const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enablePreview, bool *projectErrors)
 {
     Fun undo = []() { return true; };
     Fun redo = []() { return true; };
@@ -72,6 +72,10 @@ bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timelin
         std::unique_ptr<Mlt::Producer> track(tractor.track(i));
         QString playlist_name = track->get("id");
         if (reserved_names.contains(playlist_name)) {
+            if (playlist_name == QLatin1String("timeline_preview")) {
+                Mlt::Playlist local_playlist(*track);
+                pCore->loadTimelinePreview(chunks, dirty, documentDate, enablePreview, local_playlist);
+            }
             continue;
         }
         switch (track->type()) {

src/timeline2/model/builders/meltBuilder.hpp

@@ -8,12 +8,13 @@
 #include <memory>
 #include <mlt++/MltTractor.h>
 #include <QtCore/QString>
+#include <QDateTime>
 
 class TimelineItemModel;
 class QProgressDialog;
 
 /** @brief This function can be used to construct a TimelineModel object from a Mlt object hierarchy
  */
-bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timeline, Mlt::Tractor mlt_timeline, QProgressDialog *progressDialog = nullptr, QString originalDecimalPoint = QString(), bool *projectErrors = nullptr);
+bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timeline, Mlt::Tractor mlt_timeline, QProgressDialog *progressDialog = nullptr, const QString &originalDecimalPoint = QString(), const QString &chunks = QString(), const QString &dirty = QString(), const QDateTime &documentDate = QDateTime(), int enablePreview = 0, bool *projectErrors = nullptr);
 
 #endif

src/timeline2/view/previewmanager.cpp

@@ -127,7 +127,7 @@ bool PreviewManager::buildPreviewTrack()
     return true;
 }
 
-void PreviewManager::loadChunks(QVariantList previewChunks, QVariantList dirtyChunks, const QDateTime &documentDate)
+void PreviewManager::loadChunks(QVariantList previewChunks, QVariantList dirtyChunks, const QDateTime &documentDate, Mlt::Playlist &playlist)
 {
     if (previewChunks.isEmpty()) {
         previewChunks = m_renderedChunks;
@@ -135,21 +135,39 @@ void PreviewManager::loadChunks(QVariantList previewChunks, QVariantList dirtyCh
     if (dirtyChunks.isEmpty()) {
         dirtyChunks = m_dirtyChunks;
     }
-    for (const auto &frame : qAsConst(previewChunks)) {
-        const QString fileName = m_cacheDir.absoluteFilePath(QStringLiteral("%1.%2").arg(frame.toInt()).arg(m_extension));
-        QFile file(fileName);
-        if (file.exists()) {
-            if (!documentDate.isNull() && QFileInfo(file).lastModified() > documentDate) {
-                // Timeline preview file was created after document, invalidate
-                file.remove();
-                dirtyChunks << frame;
-            } else {
-                gotPreviewRender(frame.toInt(), fileName, 1000);
-            }
+
+    // First chech if there are invalid chunks (created after document date)
+    QFileInfoList chunksList = m_cacheDir.entryInfoList({QString("*.%1").arg(m_extension)}, QDir::Files, QDir::Time);
+    for (auto &chunkFile : chunksList) {
+        if (chunkFile.lastModified() > documentDate) {
+            // This chunk is invalid
+            QString chunkName = chunkFile.fileName().section(QLatin1Char('.'), 0, 0);
+            previewChunks.removeAll(chunkName);
+            dirtyChunks << chunkName;
+            // Physically remove chunk file
+            m_cacheDir.remove(chunkFile.fileName());
         } else {
-            dirtyChunks << frame;
+            // Done
+            break;
         }
     }
+
+    int max = playlist.count();
+    std::shared_ptr<Mlt::Producer> clip;
+    m_tractor->lock();
+    for (int i = 0; i < max; i++) {
+        if (playlist.is_blank(i)) {
+            continue;
+        }
+        int position = playlist.clip_start(i);
+        if (previewChunks.contains(QString::number(position))) {
+            clip.reset(playlist.get_clip(i));
+            m_renderedChunks << position;
+            m_previewTrack->insert_at(position, clip.get(), 1);
+        }
+    }
+    m_previewTrack->consolidate_blanks();
+    m_tractor->unlock();
     if (!previewChunks.isEmpty()) {
         emit m_controller->renderedChunksChanged();
     }

src/timeline2/view/previewmanager.h

@@ -65,7 +65,7 @@ public:
     /** @brief: Returns directory currently used to store the preview files. */
     const QDir getCacheDir() const;
     /** @brief: Load existing ruler chunks. */
-    void loadChunks(QVariantList previewChunks, QVariantList dirtyChunks, const QDateTime &documentDate);
+    void loadChunks(QVariantList previewChunks, QVariantList dirtyChunks, const QDateTime &documentDate, Mlt::Playlist &playlist);
     int setOverlayTrack(Mlt::Playlist *overlay);
     /** @brief Remove the effect compare overlay track */
     void removeOverlayTrack();

src/timeline2/view/timelinecontroller.cpp

@@ -2412,7 +2412,8 @@ void TimelineController::disablePreview(bool disable)
                 m_timelinePreview->reconnectTrack();
                 m_model->m_tractor->unlock();
             }
-            m_timelinePreview->loadChunks(QVariantList(), QVariantList(), QDateTime());
+            Mlt::Playlist playlist;
+            m_timelinePreview->loadChunks(QVariantList(), QVariantList(), QDateTime(), playlist);
             m_usePreview = true;
         }
     }
@@ -2452,7 +2453,7 @@ void TimelineController::resetPreview()
     }
 }
 
-void TimelineController::loadPreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enable)
+void TimelineController::loadPreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enable, Mlt::Playlist &playlist)
 {
     if (chunks.isEmpty() && dirty.isEmpty()) {
         return;
@@ -2490,7 +2491,7 @@ void TimelineController::loadPreview(const QString &chunks, const QString &dirty
             m_usePreview = true;
             m_model->m_overlayTrackCount = m_timelinePreview->addedTracks();
         }
-        m_timelinePreview->loadChunks(renderedChunks, dirtyChunks, documentDate);
+        m_timelinePreview->loadChunks(renderedChunks, dirtyChunks, documentDate, playlist);
     }
 }
 

src/timeline2/view/timelinecontroller.h

@@ -559,7 +559,7 @@ public:
 
     /** @brief Load timeline preview from saved doc
      */
-    void loadPreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enable);
+    void loadPreview(const QString &chunks, const QString &dirty, const QDateTime &documentDate, int enable, Mlt::Playlist &playlist);
     /** @brief Return document properties with added settings from timeline
      */
     QMap<QString, QString> documentProperties();