Fix Mask/Transitions for Global Timeline Effects

src/Clip.cpp

@@ -335,15 +335,36 @@ std::shared_ptr<Frame> Clip::GetFrame(int64_t frame_number)
 
 		// Get the original frame and pass it to GetFrame overload
 		std::shared_ptr<Frame> original_frame = GetOrCreateFrame(frame_number);
-		return GetFrame(original_frame, frame_number);
+		return GetFrame(original_frame, frame_number, NULL);
 	}
 	else
 		// Throw error if reader not initialized
 		throw ReaderClosed("No Reader has been initialized for this Clip.  Call Reader(*reader) before calling this method.");
 }
 
-// Use an existing openshot::Frame object and draw this Clip's frame onto it
+// Create an openshot::Frame object for a specific frame number of this reader.
 std::shared_ptr<Frame> Clip::GetFrame(std::shared_ptr<openshot::Frame> background_frame, int64_t frame_number)
+{
+    // Check for open reader (or throw exception)
+    if (!is_open)
+        throw ReaderClosed("The Clip is closed.  Call Open() before calling this method.");
+
+    if (reader)
+    {
+        // Adjust out of bounds frame number
+        frame_number = adjust_frame_number_minimum(frame_number);
+
+        // Get the original frame and pass it to GetFrame overload
+        std::shared_ptr<Frame> original_frame = GetOrCreateFrame(frame_number);
+        return GetFrame(original_frame, frame_number, NULL);
+    }
+    else
+        // Throw error if reader not initialized
+        throw ReaderClosed("No Reader has been initialized for this Clip.  Call Reader(*reader) before calling this method.");
+}
+
+// Use an existing openshot::Frame object and draw this Clip's frame onto it
+std::shared_ptr<Frame> Clip::GetFrame(std::shared_ptr<openshot::Frame> background_frame, int64_t frame_number, openshot::TimelineInfoStruct* options)
 {
 	// Check for open reader (or throw exception)
 	if (!is_open)
@@ -367,9 +388,18 @@ std::shared_ptr<Frame> Clip::GetFrame(std::shared_ptr<openshot::Frame> backgroun
 		// TODO: Handle variable # of samples, since this resamples audio for different speeds (only when time curve is set)
 		get_time_mapped_frame(original_frame, new_frame_number);
 
-		// Apply effects to the frame (if any)
+		// Apply local effects to the frame (if any)
 		apply_effects(original_frame);
 
+        // Apply global timeline effects (i.e. transitions & masks... if any)
+        if (timeline != NULL && options != NULL) {
+            if (options->is_top_clip) {
+                // Apply global timeline effects (only to top clip... if overlapping)
+                Timeline* timeline_instance = (Timeline*) timeline;
+                original_frame = timeline_instance->apply_effects(original_frame, options->timeline_frame_number, Layer());
+            }
+        }
+
 		// Apply keyframe / transforms
 		apply_keyframes(original_frame, background_frame->GetImage());
 

src/Clip.h

@@ -214,25 +214,40 @@ namespace openshot {
 		/// Look up an effect by ID
 		openshot::EffectBase* GetEffect(const std::string& id);
 
-		/// @brief Get an openshot::Frame object for a specific frame number of this timeline. The image size and number
+		/// @brief Get an openshot::Frame object for a specific frame number of this clip. The image size and number
 		/// of samples match the source reader.
 		///
 		/// @returns A new openshot::Frame object
-		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
+		/// @param frame_number The frame number (starting at 1) of the clip
 		std::shared_ptr<openshot::Frame> GetFrame(int64_t frame_number) override;
 
-		/// @brief Get an openshot::Frame object for a specific frame number of this timeline. The image size and number
-		/// of samples can be customized to match the Timeline, or any custom output. Extra samples will be moved to the
-		/// next Frame. Missing samples will be moved from the next Frame.
+		/// @brief Get an openshot::Frame object for a specific frame number of this clip. The image size and number
+        /// of samples match the background_frame passed in and the timeline (if available).
 		///
 		/// A new openshot::Frame objects is returned, based on a copy from the source image, with all keyframes and clip effects
-		/// rendered.
+		/// rendered/rasterized.
 		///
 		/// @returns The modified openshot::Frame object
 		/// @param background_frame The frame object to use as a background canvas (i.e. an existing Timeline openshot::Frame instance)
-		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
+		/// @param frame_number The frame number (starting at 1) of the clip. The image size and number
+        /// of samples match the background_frame passed in and the timeline (if available)
 		std::shared_ptr<openshot::Frame> GetFrame(std::shared_ptr<openshot::Frame> background_frame, int64_t frame_number);
 
+        /// @brief Get an openshot::Frame object for a specific frame number of this clip. The image size and number
+        /// of samples match the background_frame passed in and the timeline (if available).
+        ///
+        /// A new openshot::Frame objects is returned, based on a copy from the source image, with all keyframes and clip effects
+        /// rendered/rasterized.
+        ///
+        /// @returns The modified openshot::Frame object
+        /// @param background_frame The frame object to use as a background canvas (i.e. an existing Timeline openshot::Frame instance)
+        /// @param frame_number The frame number (starting at 1) of the clip on the timeline. The image size and number
+        /// of samples match the timeline.
+        /// @param options The openshot::TimelineInfoStruct pointer, with more details about this specific timeline clip,
+        /// such as, if it's a top clip, and what the absolute timeline frame number is. This info is used to apply global
+        /// transitions and masks, if needed.
+        std::shared_ptr<openshot::Frame> GetFrame(std::shared_ptr<openshot::Frame> background_frame, int64_t frame_number, openshot::TimelineInfoStruct* options);
+
 		/// Open the internal reader
 		void Open() override;
 

src/Timeline.cpp

@@ -444,7 +444,7 @@ std::shared_ptr<Frame> Timeline::apply_effects(std::shared_ptr<Frame> frame, int
 }
 
 // Get or generate a blank frame
-std::shared_ptr<Frame> Timeline::GetOrCreateFrame(std::shared_ptr<Frame> background_frame, Clip* clip, int64_t number)
+std::shared_ptr<Frame> Timeline::GetOrCreateFrame(std::shared_ptr<Frame> background_frame, Clip* clip, int64_t number, openshot::TimelineInfoStruct* options)
 {
 	std::shared_ptr<Frame> new_frame;
 
@@ -456,7 +456,7 @@ std::shared_ptr<Frame> Timeline::GetOrCreateFrame(std::shared_ptr<Frame> backgro
 		ZmqLogger::Instance()->AppendDebugMethod("Timeline::GetOrCreateFrame (from reader)", "number", number, "samples_in_frame", samples_in_frame);
 
 		// Attempt to get a frame (but this could fail if a reader has just been closed)
-		new_frame = std::shared_ptr<Frame>(clip->GetFrame(background_frame, number));
+		new_frame = std::shared_ptr<Frame>(clip->GetFrame(background_frame, number, options));
 
 		// Return real frame
 		return new_frame;
@@ -477,9 +477,15 @@ std::shared_ptr<Frame> Timeline::GetOrCreateFrame(std::shared_ptr<Frame> backgro
 // Process a new layer of video or audio
 void Timeline::add_layer(std::shared_ptr<Frame> new_frame, Clip* source_clip, int64_t clip_frame_number, int64_t timeline_frame_number, bool is_top_clip, float max_volume)
 {
-	// Get the clip's frame, composited on top of the current timeline frame
+    // Create timeline options (with details about this current frame request)
+    TimelineInfoStruct* options = new TimelineInfoStruct();
+    options->timeline_frame_number = timeline_frame_number;
+    options->is_top_clip = is_top_clip;
+
+    // Get the clip's frame, composited on top of the current timeline frame
 	std::shared_ptr<Frame> source_frame;
-	source_frame = GetOrCreateFrame(new_frame, source_clip, clip_frame_number);
+	source_frame = GetOrCreateFrame(new_frame, source_clip, clip_frame_number, options);
+    delete options;
 
 	// No frame found... so bail
 	if (!source_frame)
@@ -488,12 +494,6 @@ void Timeline::add_layer(std::shared_ptr<Frame> new_frame, Clip* source_clip, in
 	// Debug output
 	ZmqLogger::Instance()->AppendDebugMethod("Timeline::add_layer", "new_frame->number", new_frame->number, "clip_frame_number", clip_frame_number, "timeline_frame_number", timeline_frame_number);
 
-	/* Apply effects to the source frame (if any). If multiple clips are overlapping, only process the
-	 * effects on the top clip. */
-	if (is_top_clip) {
-		source_frame = apply_effects(source_frame, timeline_frame_number, source_clip->Layer());
-	}
-
 	/* COPY AUDIO - with correct volume */
 	if (source_clip->Reader()->info.has_audio) {
 		// Debug output

src/Timeline.h

@@ -198,10 +198,7 @@ namespace openshot {
 		std::vector<openshot::Clip*> find_intersecting_clips(int64_t requested_frame, int number_of_frames, bool include);
 
 		/// Get a clip's frame or generate a blank frame
-		std::shared_ptr<openshot::Frame> GetOrCreateFrame(std::shared_ptr<Frame> background_frame, openshot::Clip* clip, int64_t number);
-
-		/// Apply effects to the source frame (if any)
-		std::shared_ptr<openshot::Frame> apply_effects(std::shared_ptr<openshot::Frame> frame, int64_t timeline_frame_number, int layer);
+		std::shared_ptr<openshot::Frame> GetOrCreateFrame(std::shared_ptr<Frame> background_frame, openshot::Clip* clip, int64_t number, openshot::TimelineInfoStruct* options);
 
 		/// Compare 2 floating point numbers for equality
 		bool isEqual(double a, double b);
@@ -249,6 +246,9 @@ namespace openshot {
 		/// @param effect Add an effect to the timeline. An effect can modify the audio or video of an openshot::Frame.
 		void AddEffect(openshot::EffectBase* effect);
 
+        /// Apply global/timeline effects to the source frame (if any)
+        std::shared_ptr<openshot::Frame> apply_effects(std::shared_ptr<openshot::Frame> frame, int64_t timeline_frame_number, int layer);
+
 		/// Apply the timeline's framerate and samplerate to all clips
 		void ApplyMapperToClips();
 

src/TimelineBase.h

@@ -31,8 +31,25 @@
 #ifndef OPENSHOT_TIMELINE_BASE_H
 #define OPENSHOT_TIMELINE_BASE_H
 
+#include <cstdint>
+
 
 namespace openshot {
+    /**
+     * @brief This struct contains info about the current Timeline clip instance
+     *
+     * When the Timeline requests an openshot::Frame instance from a Clip, it passes
+     * this struct along, with some additional details from the Timeline, such as the absolute
+     * timeline frame number requested, and if this clip is above or below overlapping clips, etc...
+     * This info can help determine if a Clip should apply global effects from the Timeline, such
+     * as a global Transition/Mask effect.
+     */
+    struct TimelineInfoStruct
+    {
+        int64_t timeline_frame_number;    ///< The absolute frame number from the timeline we are requesting
+        bool is_top_clip;                 ///< Is clip on top (if overlapping another clip)
+    };
+
 	/**
 	 * @brief This class represents a timeline (used for building generic timeline implementations)
 	 */