Rework 2D stabilizator

See this page for motivation and description of concepts:
https://github.com/Ichthyostega/blender/wiki

See this video for UI explanation and demonstration of usage
http://vimeo.com/blenderHack/stabilizerdemo

This proposal attempts to improve usability of Blender's image stabilization
feature for real-world footage esp. with moving and panning camera. It builds
upon the feature tracking to get a measurement of 2D image movement.

  - Use a weighted average of movement contributions (instead of a median).
  - Allow for rotation compensation and zoom (image scale) compensation.
  - Allow to pick a different set of tracks for translation and for
    rotation/zoom.
  - Treat translation / rotation / zoom contributions systematically in a
    similar way.
  - Improve handling of partial tracking data with gaps and varying
    start / end points.
  - Have a user definable anchor frame and interpolate / extrapolate data to
    avoid jumping back to "neutral" position when no tracking data is available.
  - Support for travelling and panning shots by including an //intended//
    position/rotation/zoom ("target position"). The idea is for these parameters
    to be //animated// by the user, in order to supply an smooth, intended
    camera movement. This way, we can keep the image content roughly in frame
    even when moving completely away from the initial view.

A known shortcoming is that the pivot point for rotation compensation is set to
the translation compensated image center. This can produce spurious rotation on
travelling shots, which needs to be compensated manually (by animating the
target rotation parameter). There are several possible ways to address that
problem, yet all of them are considered beyond the scope of this improvement
proposal for now.

Own modifications:

- Restrict line length, it's really handy for split-view editing
- In motion tracking we prefer fully human-readable comments, meaning we
  don't use doxygen with it's weird markup and comments are supposed to
  start with capital and end with a full stop,
- Add explicit comparison of pointer to NULL.

Reviewers: sergey

Subscribers: kusi, kdawg, forest-house, mardy, Samoth, plasmasolutions, willolis, sebastian_k, hype, enetheru, sunboy, jta, leon_cheung

Maniphest Tasks: T49036

Differential Revision: https://developer.blender.org/D583

5 files changed, 156 insertions, 47 deletions

diff --git a/source/blender/editors/space_clip/clip_intern.h b/source/blender/editors/space_clip/clip_intern.h
index 2a5d959bb84..13dcd405ee6 100644
--- a/source/blender/editors/space_clip/clip_intern.h
+++ b/source/blender/editors/space_clip/clip_intern.h
@@ -185,7 +185,10 @@ void CLIP_OT_detect_features(struct wmOperatorType *ot);
 void CLIP_OT_stabilize_2d_add(struct wmOperatorType *ot);
 void CLIP_OT_stabilize_2d_remove(struct wmOperatorType *ot);
 void CLIP_OT_stabilize_2d_select(struct wmOperatorType *ot);
-void CLIP_OT_stabilize_2d_set_rotation(struct wmOperatorType *ot);
+
+void CLIP_OT_stabilize_2d_rotation_add(struct wmOperatorType *ot);
+void CLIP_OT_stabilize_2d_rotation_remove(struct wmOperatorType *ot);
+void CLIP_OT_stabilize_2d_rotation_select(struct wmOperatorType *ot);
 
 void CLIP_OT_clean_tracks(struct wmOperatorType *ot);
 
diff --git a/source/blender/editors/space_clip/clip_utils.c b/source/blender/editors/space_clip/clip_utils.c
index 5964e9a898b..547c2fba66f 100644
--- a/source/blender/editors/space_clip/clip_utils.c
+++ b/source/blender/editors/space_clip/clip_utils.c
@@ -175,21 +175,14 @@ void clip_graph_tracking_iterate(SpaceClip *sc, bool selected_only, bool include
 void clip_delete_track(bContext *C, MovieClip *clip, MovieTrackingTrack *track)
 {
 	MovieTracking *tracking = &clip->tracking;
-	MovieTrackingStabilization *stab = &tracking->stabilization;
 	MovieTrackingTrack *act_track = BKE_tracking_track_get_active(tracking);
 	ListBase *tracksbase = BKE_tracking_get_active_tracks(tracking);
-	bool has_bundle = false, update_stab = false;
+	bool has_bundle = false;
 	char track_name_escaped[MAX_NAME], prefix[MAX_NAME * 2];
 
 	if (track == act_track)
 		tracking->act_track = NULL;
 
-	if (track == stab->rot_track) {
-		stab->rot_track = NULL;
-
-		update_stab = true;
-	}
-
 	/* handle reconstruction display in 3d viewport */
 	if (track->flag & TRACK_HAS_BUNDLE)
 		has_bundle = true;
@@ -207,8 +200,7 @@ void clip_delete_track(bContext *C, MovieClip *clip, MovieTrackingTrack *track)
 
 	WM_event_add_notifier(C, NC_MOVIECLIP | NA_EDITED, clip);
 
-	if (update_stab) {
-		tracking->stabilization.ok = false;
+	if (track->flag & (TRACK_USE_2D_STAB | TRACK_USE_2D_STAB_ROT)) {
 		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
 	}
 
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index 396d71f0a20..4f653bab682 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -225,18 +225,6 @@ static void clip_scopes_check_gpencil_change(ScrArea *sa)
 	}
 }
 
-static void clip_stabilization_tag_refresh(ScrArea *sa)
-{
-	SpaceClip *sc = (SpaceClip *) sa->spacedata.first;
-	MovieClip *clip = ED_space_clip_get_clip(sc);
-
-	if (clip) {
-		MovieTrackingStabilization *stab = &clip->tracking.stabilization;
-
-		stab->ok = false;
-	}
-}
-
 /* ******************** default callbacks for clip space ***************** */
 
 static SpaceLink *clip_new(const bContext *C)
@@ -368,7 +356,6 @@ static void clip_listener(bScreen *UNUSED(sc), ScrArea *sa, wmNotifier *wmn)
 				case NA_REMOVED:
 				case NA_EDITED:
 				case NA_EVALUATED:
-					clip_stabilization_tag_refresh(sa);
 					/* fall-through */
 
 				case NA_SELECTED:
@@ -412,7 +399,6 @@ static void clip_listener(bScreen *UNUSED(sc), ScrArea *sa, wmNotifier *wmn)
 		case NC_SPACE:
 			if (wmn->data == ND_SPACE_CLIP) {
 				clip_scopes_tag_refresh(sa);
-				clip_stabilization_tag_refresh(sa);
 				ED_area_tag_redraw(sa);
 			}
 			break;
@@ -457,7 +443,7 @@ static void clip_operatortypes(void)
 	/* navigation */
 	WM_operatortype_append(CLIP_OT_frame_jump);
 
-	/* foorage */
+	/* set optical center to frame center */
 	WM_operatortype_append(CLIP_OT_set_center_principal);
 
 	/* selection */
@@ -505,7 +491,9 @@ static void clip_operatortypes(void)
 	WM_operatortype_append(CLIP_OT_stabilize_2d_add);
 	WM_operatortype_append(CLIP_OT_stabilize_2d_remove);
 	WM_operatortype_append(CLIP_OT_stabilize_2d_select);
-	WM_operatortype_append(CLIP_OT_stabilize_2d_set_rotation);
+	WM_operatortype_append(CLIP_OT_stabilize_2d_rotation_add);
+	WM_operatortype_append(CLIP_OT_stabilize_2d_rotation_remove);
+	WM_operatortype_append(CLIP_OT_stabilize_2d_rotation_select);
 
 	/* clean-up */
 	WM_operatortype_append(CLIP_OT_clear_track_path);
diff --git a/source/blender/editors/space_clip/tracking_ops.c b/source/blender/editors/space_clip/tracking_ops.c
index 61bfa5b315b..d28cbe5fb1d 100644
--- a/source/blender/editors/space_clip/tracking_ops.c
+++ b/source/blender/editors/space_clip/tracking_ops.c
@@ -1509,8 +1509,10 @@ static int join_tracks_exec(bContext *C, wmOperator *op)
 	SpaceClip *sc = CTX_wm_space_clip(C);
 	MovieClip *clip = ED_space_clip_get_clip(sc);
 	MovieTracking *tracking = &clip->tracking;
+	MovieTrackingStabilization *stab = &tracking->stabilization;
 	ListBase *tracksbase = BKE_tracking_get_active_tracks(tracking);
 	ListBase *plane_tracks_base = BKE_tracking_get_active_plane_tracks(tracking);
+	bool update_stabilization = false;
 
 	MovieTrackingTrack *act_track = BKE_tracking_track_get_active(tracking);
 	if (act_track == NULL) {
@@ -1528,8 +1530,23 @@ static int join_tracks_exec(bContext *C, wmOperator *op)
 		if (TRACK_VIEW_SELECTED(sc, track) && track != act_track) {
 			BKE_tracking_tracks_join(tracking, act_track, track);
 
-			if (tracking->stabilization.rot_track == track) {
-				tracking->stabilization.rot_track = act_track;
+			if (track->flag & TRACK_USE_2D_STAB) {
+				update_stabilization = true;
+				if ((act_track->flag & TRACK_USE_2D_STAB) == 0) {
+					act_track->flag |= TRACK_USE_2D_STAB;
+				} else {
+					stab->tot_track--;
+				}
+				BLI_assert(0 <= stab->tot_track);
+			}
+			if (track->flag & TRACK_USE_2D_STAB_ROT) {
+				update_stabilization = true;
+				if ((act_track->flag & TRACK_USE_2D_STAB_ROT) == 0) {
+					act_track->flag |= TRACK_USE_2D_STAB_ROT;
+				} else {
+					stab->tot_rot_track--;
+				}
+				BLI_assert(0 <= stab->tot_rot_track);
 			}
 
 			for (MovieTrackingPlaneTrack *plane_track = plane_tracks_base->first;
@@ -1551,6 +1568,10 @@ static int join_tracks_exec(bContext *C, wmOperator *op)
 		}
 	}
 
+	if (update_stabilization) {
+		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
+	}
+
 	GSetIterator gs_iter;
 	int framenr = ED_space_clip_get_clip_frame_number(sc);
 	GSET_ITER (gs_iter, point_tracks) {
diff --git a/source/blender/editors/space_clip/tracking_ops_stabilize.c b/source/blender/editors/space_clip/tracking_ops_stabilize.c
index 8d6173e1cea..35b1aead343 100644
--- a/source/blender/editors/space_clip/tracking_ops_stabilize.c
+++ b/source/blender/editors/space_clip/tracking_ops_stabilize.c
@@ -84,7 +84,6 @@ static int stabilize_2d_add_exec(bContext *C, wmOperator *UNUSED(op))
 	}
 
 	if (update) {
-		stab->ok = 0;
 		DAG_id_tag_update(&clip->id, 0);
 		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
 	}
@@ -96,7 +95,7 @@ void CLIP_OT_stabilize_2d_add(wmOperatorType *ot)
 {
 	/* identifiers */
 	ot->name = "Add Stabilization Tracks";
-	ot->description = "Add selected tracks to 2D stabilization tool";
+	ot->description = "Add selected tracks to 2D translation stabilization";
 	ot->idname = "CLIP_OT_stabilize_2d_add";
 
 	/* api callbacks */
@@ -139,7 +138,6 @@ static int stabilize_2d_remove_exec(bContext *C, wmOperator *UNUSED(op))
 	}
 
 	if (update) {
-		stab->ok = 0;
 		DAG_id_tag_update(&clip->id, 0);
 		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
 	}
@@ -151,7 +149,7 @@ void CLIP_OT_stabilize_2d_remove(wmOperatorType *ot)
 {
 	/* identifiers */
 	ot->name = "Remove Stabilization Track";
-	ot->description = "Remove selected track from stabilization";
+	ot->description = "Remove selected track from translation stabilization";
 	ot->idname = "CLIP_OT_stabilize_2d_remove";
 
 	/* api callbacks */
@@ -193,7 +191,7 @@ void CLIP_OT_stabilize_2d_select(wmOperatorType *ot)
 {
 	/* identifiers */
 	ot->name = "Select Stabilization Tracks";
-	ot->description = "Select tracks which are used for stabilization";
+	ot->description = "Select tracks which are used for translation stabilization";
 	ot->idname = "CLIP_OT_stabilize_2d_select";
 
 	/* api callbacks */
@@ -204,20 +202,85 @@ void CLIP_OT_stabilize_2d_select(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
 
-/***************** set 2d stabilization rotation track operator ****************/
+/********************** add 2d stabilization tracks for rotation operator ****************/
 
-static int stabilize_2d_set_rotation_exec(bContext *C, wmOperator *UNUSED(op))
+static int stabilize_2d_rotation_add_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	SpaceClip *sc = CTX_wm_space_clip(C);
 	MovieClip *clip = ED_space_clip_get_clip(sc);
 	MovieTracking *tracking = &clip->tracking;
-	MovieTrackingTrack *act_track = BKE_tracking_track_get_active(tracking);
+	ListBase *tracksbase = BKE_tracking_get_active_tracks(tracking);
+	MovieTrackingStabilization *stab = &tracking->stabilization;
+
+	bool update = false;
+	for (MovieTrackingTrack *track = tracksbase->first;
+	     track != NULL;
+	     track = track->next)
+	{
+		if (TRACK_VIEW_SELECTED(sc, track) &&
+		    (track->flag & TRACK_USE_2D_STAB_ROT) == 0)
+		{
+			track->flag |= TRACK_USE_2D_STAB_ROT;
+			stab->tot_rot_track++;
+			update = true;
+		}
+	}
+
+	if (update) {
+		DAG_id_tag_update(&clip->id, 0);
+		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
+	}
+
+	return OPERATOR_FINISHED;
+}
+
+void CLIP_OT_stabilize_2d_rotation_add(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Add Stabilization Rotation Tracks";
+	ot->description = "Add selected tracks to 2D rotation stabilization";
+	ot->idname = "CLIP_OT_stabilize_2d_rotation_add";
+
+	/* api callbacks */
+	ot->exec = stabilize_2d_rotation_add_exec;
+	ot->poll = stabilize_2d_poll;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+}
+
+/********************** remove 2d stabilization tracks for rotation operator *************/
+
+static int stabilize_2d_rotation_remove_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	SpaceClip *sc = CTX_wm_space_clip(C);
+	MovieClip *clip = ED_space_clip_get_clip(sc);
+	MovieTracking *tracking = &clip->tracking;
+	MovieTrackingStabilization *stab = &tracking->stabilization;
+	ListBase *tracksbase = BKE_tracking_get_active_tracks(tracking);
+	int a = 0;
+	bool update = false;
 
-	if (act_track != NULL) {
-		MovieTrackingStabilization *stab = &tracking->stabilization;
-		stab->rot_track = act_track;
-		stab->ok = 0;
+	for (MovieTrackingTrack *track = tracksbase->first;
+	     track != NULL;
+	     track = track->next)
+	{
+		if (track->flag & TRACK_USE_2D_STAB_ROT) {
+			if (a == stab->act_rot_track) {
+				track->flag &= ~TRACK_USE_2D_STAB_ROT;
+				stab->act_rot_track--;
+				stab->tot_rot_track--;
+				if (stab->act_rot_track < 0) {
+					stab->act_rot_track = 0;
+				}
+				update = true;
+				break;
+			}
+			a++;
+		}
+	}
 
+	if (update) {
 		DAG_id_tag_update(&clip->id, 0);
 		WM_event_add_notifier(C, NC_MOVIECLIP | ND_DISPLAY, clip);
 	}
@@ -225,18 +288,60 @@ static int stabilize_2d_set_rotation_exec(bContext *C, wmOperator *UNUSED(op))
 	return OPERATOR_FINISHED;
 }
 
-void CLIP_OT_stabilize_2d_set_rotation(wmOperatorType *ot)
+void CLIP_OT_stabilize_2d_rotation_remove(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Remove Stabilization Rotation Track";
+	ot->description = "Remove selected track from rotation stabilization";
+	ot->idname = "CLIP_OT_stabilize_2d_rotation_remove";
+
+	/* api callbacks */
+	ot->exec = stabilize_2d_rotation_remove_exec;
+	ot->poll = stabilize_2d_poll;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+}
+
+/********************** select 2d stabilization rotation tracks operator *****************/
+
+static int stabilize_2d_rotation_select_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	SpaceClip *sc = CTX_wm_space_clip(C);
+	MovieClip *clip = ED_space_clip_get_clip(sc);
+	MovieTracking *tracking = &clip->tracking;
+	ListBase *tracksbase = BKE_tracking_get_active_tracks(tracking);
+	bool update = false;
+
+	for (MovieTrackingTrack *track = tracksbase->first;
+	     track != NULL;
+	     track = track->next)
+	{
+		if (track->flag & TRACK_USE_2D_STAB_ROT) {
+			BKE_tracking_track_flag_set(track, TRACK_AREA_ALL, SELECT);
+			update = true;
+		}
+	}
+
+	if (update) {
+		WM_event_add_notifier(C, NC_MOVIECLIP | ND_SELECT, clip);
+	}
+
+	return OPERATOR_FINISHED;
+}
+
+void CLIP_OT_stabilize_2d_rotation_select(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Set Rotation Track";
-	ot->description = "Use active track to compensate rotation when "
-	                  "doing 2D stabilization";
-	ot->idname = "CLIP_OT_stabilize_2d_set_rotation";
+	ot->name = "Select Stabilization Rotation Tracks";
+	ot->description = "Select tracks which are used for rotation stabilization";
+	ot->idname = "CLIP_OT_stabilize_2d_rotation_select";
 
 	/* api callbacks */
-	ot->exec = stabilize_2d_set_rotation_exec;
+	ot->exec = stabilize_2d_rotation_select_exec;
 	ot->poll = stabilize_2d_poll;
 
 	/* flags */
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
+