Adding new Clear() method to Timeline, to delete all allocated clips, effects, and frame mapeprs (freeing memory). Also, keep track of allocated clips and effects on timeline (when using SetJson to create them), so we can clean them up correctly on Clear() or RemoveClip()/RemoveEffect(). Added new test case for Clear().

src/Timeline.cpp

@@ -208,23 +208,14 @@ Timeline::~Timeline() {
 		// Auto Close if not already
 		Close();
 
-	// Free all allocated frame mappers
-	std::set<FrameMapper *>::iterator it;
-	for (it = allocated_frame_mappers.begin(); it != allocated_frame_mappers.end(); ) {
-		// Dereference and clean up FrameMapper object
-		FrameMapper *mapper = (*it);
-		mapper->Reader(NULL);
-		mapper->Close();
-		delete mapper;
-		// Remove reference and proceed to next element
-		it = allocated_frame_mappers.erase(it);
-	}
+        // Remove all clips, effects, and frame mappers
+        Clear();
 
-	// Destroy previous cache (if managed by timeline)
-	if (managed_cache && final_cache) {
-		delete final_cache;
-		final_cache = NULL;
-	}
+        // Destroy previous cache (if managed by timeline)
+        if (managed_cache && final_cache) {
+            delete final_cache;
+            final_cache = NULL;
+        }
 }
 
 // Add to the tracked_objects map a pointer to a tracked object (TrackedObjectBBox)
@@ -375,12 +366,26 @@ void Timeline::AddEffect(EffectBase* effect)
 void Timeline::RemoveEffect(EffectBase* effect)
 {
 	effects.remove(effect);
+
+    // Delete effect object (if timeline allocated it)
+    bool allocated = allocated_effects.count(effect);
+    if (allocated) {
+        delete effect;
+        effect = NULL;
+    }
 }
 
 // Remove an openshot::Clip to the timeline
 void Timeline::RemoveClip(Clip* clip)
 {
 	clips.remove(clip);
+    
+    // Delete clip object (if timeline allocated it)
+    bool allocated = allocated_clips.count(clip);
+    if (allocated) {
+        delete clip;
+        clip = NULL;
+    }
 }
 
 // Look up a clip
@@ -473,6 +478,10 @@ void Timeline::apply_mapper_to_clip(Clip* clip)
 		// Get the existing reader
 		clip_reader = (ReaderBase*) clip->Reader();
 
+        // Update the mapping
+        FrameMapper* clip_mapped_reader = (FrameMapper*) clip_reader;
+        clip_mapped_reader->ChangeMapping(info.fps, PULLDOWN_NONE, info.sample_rate, info.channels, info.channel_layout);
+
 	} else {
 
 		// Create a new FrameMapper to wrap the current reader
@@ -481,10 +490,6 @@ void Timeline::apply_mapper_to_clip(Clip* clip)
 		clip_reader = (ReaderBase*) mapper;
 	}
 
-	// Update the mapping
-	FrameMapper* clip_mapped_reader = (FrameMapper*) clip_reader;
-	clip_mapped_reader->ChangeMapping(info.fps, PULLDOWN_NONE, info.sample_rate, info.channels, info.channel_layout);
-
 	// Update clip reader
 	clip->Reader(clip_reader);
 }
@@ -763,6 +768,49 @@ void Timeline::sort_effects()
 	effects.sort(CompareEffects());
 }
 
+// Clear all clips from timeline
+void Timeline::Clear()
+{
+    ZmqLogger::Instance()->AppendDebugMethod("Timeline::Clear");
+    
+	// Close all open clips
+	for (auto clip : clips)
+	{
+        update_open_clips(clip, false);
+
+        // Delete clip object (if timeline allocated it)
+        bool allocated = allocated_clips.count(clip);
+        if (allocated) {
+            delete clip;
+            clip = NULL;
+        }
+	}
+    // Clear all clips
+    clips.clear();
+
+    // Close all effects
+    for (auto effect : effects)
+    {
+        // Delete effect object (if timeline allocated it)
+        bool allocated = allocated_effects.count(effect);
+        if (allocated) {
+            delete effect;
+            effect = NULL;
+        }
+    }
+    // Clear all effects
+    effects.clear();
+
+    // Delete all FrameMappers
+    for (auto mapper : allocated_frame_mappers)
+    {
+        mapper->Reader(NULL);
+        mapper->Close();
+        delete mapper;
+    }
+    allocated_frame_mappers.clear();
+}
+
 // Close the reader (and any resources it was consuming)
 void Timeline::Close()
 {
@@ -1072,7 +1120,7 @@ void Timeline::SetJson(const std::string value) {
 // Load Json::Value into this object
 void Timeline::SetJsonValue(const Json::Value root) {
 
-	// Close timeline before we do anything (this also removes all open and closing clips)
+	// Close timeline before we do anything (this closes all clips)
 	bool was_open = is_open;
 	Close();
 
@@ -1092,6 +1140,9 @@ void Timeline::SetJsonValue(const Json::Value root) {
 			// Create Clip
 			Clip *c = new Clip();
 
+			// Keep track of allocated clip objects
+            allocated_clips.insert(c);
+
 			// When a clip is attached to an object, it searches for the object
 			// on it's parent timeline. Setting the parent timeline of the clip here
 			// allows attaching it to an object when exporting the project (because)
@@ -1120,6 +1171,9 @@ void Timeline::SetJsonValue(const Json::Value root) {
 				// Create instance of effect
 				if ( (e = EffectInfo().CreateEffect(existing_effect["type"].asString())) ) {
 
+				    // Keep track of allocated effect objects
+                    allocated_effects.insert(e);
+
 					// Load Json into Effect
 					e->SetJsonValue(existing_effect);
 
@@ -1255,9 +1309,14 @@ void Timeline::apply_json_to_clips(Json::Value change) {
 	// Determine type of change operation
 	if (change_type == "insert") {
 
-		// Create new clip
+		// Create clip
 		Clip *clip = new Clip();
-		clip->SetJsonValue(change["value"]); // Set properties of new clip from JSON
+
+        // Keep track of allocated clip objects
+        allocated_clips.insert(clip);
+
+        // Set properties of clip from JSON
+		clip->SetJsonValue(change["value"]);
 		AddClip(clip); // Add clip to timeline
 
 		// Apply framemapper (or update existing framemapper)
@@ -1363,6 +1422,9 @@ void Timeline::apply_json_to_effects(Json::Value change, EffectBase* existing_ef
 		// Init the matching effect object
 		if ( (e = EffectInfo().CreateEffect(effect_type)) ) {
 
+            // Keep track of allocated effect objects
+            allocated_effects.insert(e);
+
 			// Load Json into Effect
 			e->SetJsonValue(change["value"]);
 

src/Timeline.h

@@ -154,7 +154,9 @@ namespace openshot {
 		std::list<openshot::Clip*> clips; ///<List of clips on this timeline
 		std::list<openshot::Clip*> closing_clips; ///<List of clips that need to be closed
 		std::map<openshot::Clip*, openshot::Clip*> open_clips; ///<List of 'opened' clips on this timeline
+        std::set<openshot::Clip*> allocated_clips; ///<List of clips that were allocated by this timeline
 		std::list<openshot::EffectBase*> effects; ///<List of clips on this timeline
+        std::set<openshot::EffectBase*> allocated_effects; ///<List of effects that were allocated by this timeline
 		openshot::CacheBase *final_cache; ///<Final cache of timeline frames
 		std::set<openshot::FrameMapper*> allocated_frame_mappers; ///< all the frame mappers we allocated and must free
 		bool managed_cache; ///< Does this timeline instance manage the cache object
@@ -258,6 +260,9 @@ namespace openshot {
 		/// @brief Automatically map all clips to the timeline's framerate and samplerate
 		void AutoMapClips(bool auto_map) { auto_map_clips = auto_map; };
 
+        /// Clear all clips, effects, and frame mappers from timeline (and free memory)
+        void Clear();
+        
         /// Clear all cache for this timeline instance, including all clips' cache
         /// @param deep If True, clear all FrameMappers and nested Readers (QtImageReader, FFmpegReader, etc...)
         void ClearAllCache(bool deep=false);