Fix for crash when using 2D stabilization for float movie clips

Also removed unneeded image buffer scaling, it was only needed
for "early output" if there was no rotation. That is no longer
supported since it used to pixelate result a lot and interpolation
is always used now.

Saves quite a few of memory and CPU cycles.

source/blender/blenkernel/intern/tracking.c

@@ -154,9 +154,6 @@ void BKE_tracking_free(MovieTracking *tracking)
 	tracking_reconstruction_free(&tracking->reconstruction);
 	tracking_objects_free(&tracking->objects);
 
-	if (tracking->stabilization.scaleibuf)
-		IMB_freeImBuf(tracking->stabilization.scaleibuf);
-
 	if (tracking->camera.intrinsics)
 		BKE_tracking_distortion_free(tracking->camera.intrinsics);
 
@@ -3488,34 +3485,6 @@ static float stabilization_calculate_autoscale_factor(MovieTracking *tracking, i
 	return stab->scale;
 }
 
-static ImBuf *stabilization_allocate_ibuf(ImBuf *cacheibuf, ImBuf *srcibuf, int fill)
-{
-	int flags;
-
-	if (cacheibuf && (cacheibuf->x != srcibuf->x || cacheibuf->y != srcibuf->y)) {
-		IMB_freeImBuf(cacheibuf);
-		cacheibuf = NULL;
-	}
-
-	flags = IB_rect;
-
-	if (srcibuf->rect_float)
-		flags |= IB_rectfloat;
-
-	if (cacheibuf) {
-		if (fill) {
-			float col[4] = {0.0f, 0.0f, 0.0f, 0.0f};
-
-			IMB_rectfill(cacheibuf, col);
-		}
-	}
-	else {
-		cacheibuf = IMB_allocImBuf(srcibuf->x, srcibuf->y, srcibuf->planes, flags);
-	}
-
-	return cacheibuf;
-}
-
 /* NOTE: frame number should be in clip space, not scene space */
 void BKE_tracking_stabilization_data_get(MovieTracking *tracking, int framenr, int width, int height,
                                          float loc[2], float *scale, float *angle)
@@ -3568,6 +3537,7 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf
 	float mat[4][4];
 	int j, filter = tracking->stabilization.filter;
 	void (*interpolation)(struct ImBuf *, struct ImBuf *, float, float, int, int) = NULL;
+	int ibuf_flags;
 
 	if (loc)
 		copy_v2_v2(tloc, loc);
@@ -3575,6 +3545,7 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf
 	if (scale)
 		tscale = *scale;
 
+	/* Perform early output if no stabilization is used. */
 	if ((stab->flag & TRACKING_2D_STABILIZATION) == 0) {
 		if (loc)
 			zero_v2(loc);
@@ -3588,25 +3559,17 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf
 		return ibuf;
 	}
 
+	/* Allocate frame for stabilization result. */
+	ibuf_flags = 0;
+	if (ibuf->rect)
+		ibuf_flags |= IB_rect;
+	if (ibuf->rect_float)
+		ibuf_flags |= IB_rectfloat;
+
+	tmpibuf = IMB_allocImBuf(ibuf->x, ibuf->y, ibuf->planes, ibuf_flags);
+
+	/* Calculate stabilization matrix. */
 	BKE_tracking_stabilization_data_get(tracking, framenr, width, height, tloc, &tscale, &tangle);
-
-	tmpibuf = stabilization_allocate_ibuf(NULL, ibuf, TRUE);
-
-	/* scale would be handled by matrix transformation when angle is non-zero */
-	if (tscale != 1.0f && tangle == 0.0f) {
-		ImBuf *scaleibuf;
-
-		stabilization_calculate_autoscale_factor(tracking, width, height);
-
-		scaleibuf = stabilization_allocate_ibuf(stab->scaleibuf, ibuf, 0);
-		stab->scaleibuf = scaleibuf;
-
-		IMB_rectcpy(scaleibuf, ibuf, 0, 0, 0, 0, ibuf->x, ibuf->y);
-		IMB_scalefastImBuf(scaleibuf, ibuf->x * tscale, ibuf->y * tscale);
-
-		ibuf = scaleibuf;
-	}
-
 	BKE_tracking_stabilization_data_to_mat4(ibuf->x, ibuf->y, aspect, tloc, tscale, tangle, mat);
 	invert_m4(mat);
 
@@ -3627,7 +3590,7 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf
 	 * But need to keep an eye on this if the function will be
 	 * used in other cases.
 	 */
-    #pragma omp parallel for if(tmpibuf->y > 128)
+	#pragma omp parallel for if(tmpibuf->y > 128)
 	for (j = 0; j < tmpibuf->y; j++) {
 		int i;
 		for (i = 0; i < tmpibuf->x; i++) {
@@ -3639,6 +3602,7 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf
 		}
 	}
 
+	/* TODO(sergey): we've got no mipmaps actually? */
 	tmpibuf->userflags |= IB_MIPMAP_INVALID;
 
 	if (tmpibuf->rect_float)

source/blender/blenloader/intern/readfile.c

@@ -6633,7 +6633,6 @@ static void direct_link_movieclip(FileData *fd, MovieClip *clip)
 	clip->tracking.stats = NULL;
 
 	clip->tracking.stabilization.ok = 0;
-	clip->tracking.stabilization.scaleibuf = NULL;
 	clip->tracking.stabilization.rot_track = newdataadr(fd, clip->tracking.stabilization.rot_track);
 
 	clip->tracking.dopesheet.ok = 0;

source/blender/makesdna/DNA_tracking_types.h

@@ -205,8 +205,6 @@ typedef struct MovieTrackingStabilization {
 	/* some pre-computing run-time variables */
 	int ok;                     /* are precomputed values and scaled buf relevant? */
 	float scale;                /* autoscale factor */
-
-	struct ImBuf *scaleibuf;    /* currently scaled ibuf */
 } MovieTrackingStabilization;
 
 typedef struct MovieTrackingReconstruction {