diff options
Diffstat (limited to 'source/blender/blenkernel/intern/tracking_stabilize.c')
| -rw-r--r-- | source/blender/blenkernel/intern/tracking_stabilize.c | 1447 |
1 files changed, 1239 insertions, 208 deletions
diff --git a/source/blender/blenkernel/intern/tracking_stabilize.c b/source/blender/blenkernel/intern/tracking_stabilize.c index eb224020977..5642ee83fde 100644 --- a/source/blender/blenkernel/intern/tracking_stabilize.c +++ b/source/blender/blenkernel/intern/tracking_stabilize.c @@ -21,6 +21,7 @@ * Contributor(s): Blender Foundation, * Sergey Sharybin * Keir Mierle + * Ichthyostega * * ***** END GPL LICENSE BLOCK ***** */ @@ -28,292 +29,1305 @@ /** \file blender/blenkernel/intern/tracking_stabilize.c * \ingroup bke * - * This file contains implementation of 2D frame stabilization. + * This file contains implementation of 2D image stabilization. */ #include <limits.h> #include "DNA_movieclip_types.h" +#include "DNA_scene_types.h" +#include "DNA_anim_types.h" +#include "RNA_access.h" #include "BLI_utildefines.h" +#include "BLI_sort_utils.h" +#include "BLI_math_vector.h" #include "BLI_math.h" #include "BKE_tracking.h" +#include "BKE_movieclip.h" +#include "BKE_fcurve.h" +#include "BLI_ghash.h" +#include "MEM_guardedalloc.h" #include "IMB_imbuf_types.h" #include "IMB_imbuf.h" -/* Calculate median point of markers of tracks marked as used for - * 2D stabilization. - * - * NOTE: frame number should be in clip space, not scene space + +/* == Parameterization constants == */ + +/* When measuring the scale changes relative to the rotation pivot point, it + * might happen accidentally that a probe point (tracking point), which doesn't + * actually move on a circular path, gets very close to the pivot point, causing + * the measured scale contribution to go toward infinity. We damp this undesired + * effect by adding a bias (floor) to the measured distances, which will + * dominate very small distances and thus cause the corresponding track's + * contribution to diminish. + * Measurements happen in normalized (0...1) coordinates within a frame. + */ +static float SCALE_ERROR_LIMIT_BIAS = 0.01f; + +/* When to consider a track as completely faded out. + * This is used in conjunction with the "disabled" flag of the track + * to determine start positions, end positions and gaps */ -static bool stabilization_median_point_get(MovieTracking *tracking, int framenr, float median[2]) +static float EPSILON_WEIGHT = 0.005f; + + + +/* == private working data == */ + +/* Per track baseline for stabilization, defined at reference frame. + * A track's reference frame is chosen as close as possible to the (global) + * anchor_frame. Baseline holds the constant part of each track's contribution + * to the observed movement; it is calculated at initialization pass, using the + * measurement value at reference frame plus the average contribution to fill + * the gap between global anchor_frame and the reference frame for this track. + * This struct with private working data is associated to the local call context + * via `StabContext::private_track_data` + */ +typedef struct TrackStabilizationBase { + float stabilization_offset_base[2]; + + /* measured relative to translated pivot */ + float stabilization_rotation_base[2][2]; + + /* measured relative to translated pivot */ + float stabilization_scale_base; + + bool is_init_for_stabilization; + FCurve *track_weight_curve; +} TrackStabilizationBase; + +/* Tracks are reordered for initialization, starting as close as possible to + * anchor_frame + */ +typedef struct TrackInitOrder { + int sort_value; + int reference_frame; + MovieTrackingTrack *data; +} TrackInitOrder; + +/* Per frame private working data, for accessing possibly animated values. */ +typedef struct StabContext { + MovieClip *clip; + MovieTracking *tracking; + MovieTrackingStabilization *stab; + GHash *private_track_data; + FCurve *locinf; + FCurve *rotinf; + FCurve *scaleinf; + FCurve *target_pos[2]; + FCurve *target_rot; + FCurve *target_scale; + bool use_animation; +} StabContext; + + +static TrackStabilizationBase *access_stabilization_baseline_data( + StabContext *ctx, + MovieTrackingTrack *track) { - bool ok = false; - float min[2], max[2]; - MovieTrackingTrack *track; + return BLI_ghash_lookup(ctx->private_track_data, track); +} - INIT_MINMAX2(min, max); +static void attach_stabilization_baseline_data( + StabContext *ctx, + MovieTrackingTrack *track, + TrackStabilizationBase *private_data) +{ + return BLI_ghash_insert(ctx->private_track_data, track, private_data); +} - track = tracking->tracks.first; - while (track) { - if (track->flag & TRACK_USE_2D_STAB) { - MovieTrackingMarker *marker = BKE_tracking_marker_get(track, framenr); +static void discard_stabilization_baseline_data(void *val) +{ + if (val != NULL) { + MEM_freeN(val); + } +} - minmax_v2v2_v2(min, max, marker->pos); - ok = true; - } +/* == access animated values for given frame == */ + +static FCurve *retrieve_stab_animation(MovieClip *clip, + const char *data_path, + int idx) +{ + return id_data_find_fcurve(&clip->id, + &clip->tracking.stabilization, + &RNA_MovieTrackingStabilization, + data_path, + idx, + NULL); +} + +static FCurve *retrieve_track_weight_animation(MovieClip *clip, + MovieTrackingTrack *track) +{ + return id_data_find_fcurve(&clip->id, + track, + &RNA_MovieTrackingTrack, + "weight_stab", + 0, + NULL); +} - track = track->next; +static float fetch_from_fcurve(FCurve *animationCurve, + int framenr, + StabContext *ctx, + float default_value) +{ + if (ctx && ctx->use_animation && animationCurve) { + int scene_framenr = BKE_movieclip_remap_clip_to_scene_frame(ctx->clip, + framenr); + return evaluate_fcurve(animationCurve, scene_framenr); } + return default_value; +} - median[0] = (max[0] + min[0]) / 2.0f; - median[1] = (max[1] + min[1]) / 2.0f; - return ok; +static float get_animated_locinf(StabContext *ctx, int framenr) +{ + return fetch_from_fcurve(ctx->locinf, framenr, ctx, ctx->stab->locinf); } -/* Calculate stabilization data (translation, scale and rotation) from - * given median of first and current frame medians, tracking data and - * frame number. - * - * NOTE: frame number should be in clip space, not scene space +static float get_animated_rotinf(StabContext *ctx, int framenr) +{ + return fetch_from_fcurve(ctx->rotinf, framenr, ctx, ctx->stab->rotinf); +} + +static float get_animated_scaleinf(StabContext *ctx, int framenr) +{ + return fetch_from_fcurve(ctx->scaleinf, framenr, ctx, ctx->stab->scaleinf); +} + +static void get_animated_target_pos(StabContext *ctx, + int framenr, + float target_pos[2]) +{ + target_pos[0] = fetch_from_fcurve(ctx->target_pos[0], + framenr, + ctx, + ctx->stab->target_pos[0]); + target_pos[1] = fetch_from_fcurve(ctx->target_pos[1], + framenr, + ctx, + ctx->stab->target_pos[1]); +} + +static float get_animated_target_rot(StabContext *ctx, int framenr) +{ + return fetch_from_fcurve(ctx->target_rot, + framenr, + ctx, + ctx->stab->target_rot); +} + +static float get_animated_target_scale(StabContext *ctx, int framenr) +{ + return fetch_from_fcurve(ctx->target_scale, framenr, ctx, ctx->stab->scale); +} + +static float get_animated_weight(StabContext *ctx, + MovieTrackingTrack *track, + int framenr) +{ + TrackStabilizationBase *working_data = + access_stabilization_baseline_data(ctx, track); + if (working_data && working_data->track_weight_curve) { + int scene_framenr = BKE_movieclip_remap_clip_to_scene_frame(ctx->clip, + framenr); + return evaluate_fcurve(working_data->track_weight_curve, scene_framenr); + } + /* Use weight at global 'current frame' as fallback default. */ + return track->weight_stab; +} + +static void use_values_from_fcurves(StabContext *ctx, bool toggle) +{ + if (ctx != NULL) { + ctx->use_animation = toggle; + } +} + + +/* Prepare per call private working area. + * Used for access to possibly animated values: retrieve available F-curves. */ -static void stabilization_calculate_data(MovieTracking *tracking, int framenr, int width, int height, - const float firstmedian[2], const float median[2], - float translation[2], float *scale, float *angle) +static StabContext *initialize_stabilization_working_context(MovieClip *clip) { - MovieTrackingStabilization *stab = &tracking->stabilization; + StabContext *ctx = MEM_callocN(sizeof(StabContext), + "2D stabilization animation runtime data"); + ctx->clip = clip; + ctx->tracking = &clip->tracking; + ctx->stab = &clip->tracking.stabilization; + ctx->private_track_data = BLI_ghash_ptr_new( + "2D stabilization per track private working data"); + ctx->locinf = retrieve_stab_animation(clip, "influence_location", 0); + ctx->rotinf = retrieve_stab_animation(clip, "influence_rotation", 0); + ctx->scaleinf = retrieve_stab_animation(clip, "influence_scale", 0); + ctx->target_pos[0] = retrieve_stab_animation(clip, "target_pos", 0); + ctx->target_pos[1] = retrieve_stab_animation(clip, "target_pos", 1); + ctx->target_rot = retrieve_stab_animation(clip, "target_rot", 0); + ctx->target_scale = retrieve_stab_animation(clip, "target_zoom", 0); + ctx->use_animation = true; + return ctx; +} - *scale = (stab->scale - 1.0f) * stab->scaleinf + 1.0f; - *angle = 0.0f; +/* Discard all private working data attached to this call context. + * NOTE: We allocate the record for the per track baseline contribution + * locally for each call context (i.e. call to + * BKE_tracking_stabilization_data_get() + * Thus it is correct to discard all allocations found within the + * corresponding _local_ GHash + */ +static void discard_stabilization_working_context(StabContext *ctx) +{ + if (ctx != NULL) { + BLI_ghash_free(ctx->private_track_data, + NULL, + discard_stabilization_baseline_data); + MEM_freeN(ctx); + } +} - translation[0] = (firstmedian[0] - median[0]) * width * (*scale); - translation[1] = (firstmedian[1] - median[1]) * height * (*scale); +static bool is_init_for_stabilization(StabContext *ctx, + MovieTrackingTrack *track) +{ + TrackStabilizationBase *working_data = + access_stabilization_baseline_data(ctx, track); + return (working_data != NULL && working_data->is_init_for_stabilization); +} + +static bool is_usable_for_stabilization(StabContext *ctx, + MovieTrackingTrack *track) +{ + return (track->flag & TRACK_USE_2D_STAB) && + is_init_for_stabilization(ctx, track); +} - mul_v2_fl(translation, stab->locinf); +static bool is_effectively_disabled(StabContext *ctx, + MovieTrackingTrack *track, + MovieTrackingMarker *marker) +{ + return (marker->flag & MARKER_DISABLED) || + (EPSILON_WEIGHT > get_animated_weight(ctx, track, marker->framenr)); +} - if ((stab->flag & TRACKING_STABILIZE_ROTATION) && stab->rot_track && stab->rotinf) { - MovieTrackingMarker *marker; - float a[2], b[2]; - float x0 = (float)width / 2.0f, y0 = (float)height / 2.0f; - float x = median[0] * width, y = median[1] * height; - marker = BKE_tracking_marker_get(stab->rot_track, 1); - sub_v2_v2v2(a, marker->pos, firstmedian); - a[0] *= width; - a[1] *= height; +static int search_closest_marker_index(MovieTrackingTrack *track, + int ref_frame) +{ + MovieTrackingMarker *markers = track->markers; + int end = track->markersnr; + int i = track->last_marker; + + i = MAX2(0, i); + i = MIN2(i, end - 1); + for ( ; i < end - 1 && markers[i].framenr <= ref_frame; ++i); + for ( ; 0 < i && markers[i].framenr > ref_frame; --i); + + track->last_marker = i; + return i; +} + +static void retrieve_next_higher_usable_frame(StabContext *ctx, + MovieTrackingTrack *track, + int i, + int ref_frame, + int *next_higher) +{ + MovieTrackingMarker *markers = track->markers; + int end = track->markersnr; + BLI_assert(0 <= i && i < end); + + while (i < end && + (markers[i].framenr < ref_frame || + is_effectively_disabled(ctx, track, &markers[i]))) + { + ++i; + } + if (i < end && markers[i].framenr < *next_higher) { + BLI_assert(markers[i].framenr >= ref_frame); + *next_higher = markers[i].framenr; + } +} + +static void retrieve_next_lower_usable_frame(StabContext *ctx, + MovieTrackingTrack *track, + int i, + int ref_frame, + int *next_lower) +{ + MovieTrackingMarker *markers = track->markers; + BLI_assert(0 <= i && i < end); + while (i >= 0 && + (markers[i].framenr > ref_frame || + is_effectively_disabled(ctx, track, &markers[i]))) + { + --i; + } + if (0 <= i && markers[i].framenr > *next_lower) { + BLI_assert(markers[i].framenr <= ref_frame); + *next_lower = markers[i].framenr; + } +} + +/* Find closest frames with usable stabilization data. + * A frame counts as _usable_ when there is at least one track marked for + * translation stabilization, which has an enabled tracking marker at this very + * frame. We search both for the next lower and next higher position, to allow + * the caller to interpolate gaps and to extrapolate at the ends of the + * definition range. + * + * NOTE: Regarding performance note that the individual tracks will cache the + * last search position. + */ +static void find_next_working_frames(StabContext *ctx, + int framenr, + int *next_lower, + int *next_higher) +{ + for (MovieTrackingTrack *track = ctx->tracking->tracks.first; + track != NULL; + track = track->next) + { + if (is_usable_for_stabilization(ctx, track)) { + int startpoint = search_closest_marker_index(track, framenr); + retrieve_next_higher_usable_frame(ctx, + track, + startpoint, + framenr, + next_higher); + retrieve_next_lower_usable_frame(ctx, + track, + startpoint, + framenr, + next_lower); + } + } +} + - marker = BKE_tracking_marker_get(stab->rot_track, framenr); - sub_v2_v2v2(b, marker->pos, median); - b[0] *= width; - b[1] *= height; +/* Find active (enabled) marker closest to the reference frame. */ +static MovieTrackingMarker *get_closest_marker(StabContext *ctx, + MovieTrackingTrack *track, + int ref_frame) +{ + if (track->markersnr > 0) { + int next_lower = MINAFRAME; + int next_higher = MAXFRAME; + int i = search_closest_marker_index(track, ref_frame); + retrieve_next_higher_usable_frame(ctx, track, i, ref_frame, &next_higher); + retrieve_next_lower_usable_frame(ctx, track, i, ref_frame, &next_lower); + + if ((next_higher - ref_frame) < (ref_frame - next_lower)) { + return BKE_tracking_marker_get_exact(track, next_higher); + } + else { + return BKE_tracking_marker_get_exact(track, next_lower); + } + } + return NULL; +} - *angle = -atan2f(a[0] * b[1] - a[1] * b[0], a[0] * b[0] + a[1] * b[1]); - *angle *= stab->rotinf; - /* convert to rotation around image center */ - translation[0] -= (x0 + (x - x0) * cosf(*angle) - (y - y0) * sinf(*angle) - x) * (*scale); - translation[1] -= (y0 + (x - x0) * sinf(*angle) + (y - y0) * cosf(*angle) - y) * (*scale); +/* Retrieve tracking data, if available and applicable for this frame. + * The returned weight value signals the validity; data recorded for this + * tracking marker on the exact requested frame is output with the full weight + * of this track, while gaps in the data sequence cause the weight to go to zero. + */ +static MovieTrackingMarker *get_tracking_data_point( + StabContext *ctx, + MovieTrackingTrack *track, + int framenr, + float *weight) +{ + MovieTrackingMarker *marker = BKE_tracking_marker_get(track, framenr); + if (marker && marker->framenr == framenr && !(marker->flag & MARKER_DISABLED)) { + *weight = get_animated_weight(ctx, track, framenr); + return marker; + } + else { + /* no marker at this frame (=gap) or marker disabled */ + *weight = 0.0f; + return NULL; } } -/* Calculate factor of a scale, which will eliminate black areas - * appearing on the frame caused by frame translation. +/* Calculate the contribution of a single track at the time position (frame) of + * the given marker. Each track has a local reference frame, which is as close + * as possible to the global anchor_frame. Thus the translation contribution is + * comprised of the offset relative to the image position at that reference + * frame, plus a guess of the contribution for the time span between the + * anchor_frame and the local reference frame of this track. The constant part + * of this contribution is precomputed initially. At the anchor_frame, by + * definition the contribution of all tracks is zero, keeping the frame in place. + * + * track_ref is per track baseline contribution at reference frame; filled in at + * initialization + * marker is tracking data to use as contribution for current frame. + * result_offset is a total cumulated contribution of this track, + * relative to the stabilization anchor_frame, + * in normalized (0...1) coordinates. + */ +static void translation_contribution(TrackStabilizationBase *track_ref, + MovieTrackingMarker *marker, + float result_offset[2]) +{ + add_v2_v2v2(result_offset, + track_ref->stabilization_offset_base, + marker->pos); +} + +/* Similar to the ::translation_contribution(), the rotation contribution is + * comprised of the contribution by this individual track, and the averaged + * contribution from anchor_frame to the ref point of this track. + * - Contribution is in terms of angles, -pi < angle < +pi, and all averaging + * happens in this domain. + * - Yet the actual measurement happens as vector between pivot and the current + * tracking point + * - Currently we use the center of frame as approximation for the rotation pivot + * point. + * - Moreover, the pivot point has to be compensated for the already determined + * shift offset, in order to get the pure rotation around the pivot. + * To turn this into a _contribution_, the likewise corrected angle at the + * reference frame has to be subtracted, to get only the pure angle difference + * this tracking point has captured. + * - To get from vectors to angles, we have to go through an arcus tangens, + * which involves the issue of the definition range: the resulting angles will + * flip by 360deg when the measured vector passes from the 2nd to the third + * quadrant, thus messing up the average calculation. Since _any_ tracking + * point might be used, these problems are quite common in practice. + * - Thus we perform the subtraction of the reference and the addition of the + * baseline contribution in polar coordinates as simple addition of angles; + * since these parts are fixed, we can bake them into a rotation matrix. + * With this approach, the border of the arcus tangens definition range will + * be reached only, when the _whole_ contribution approaches +- 180deg, + * meaning we've already tilted the frame upside down. This situation is way + * less common and can be tolerated. + * - As an additional feature, when activated, also changes in image scale + * relative to the rotation center can be picked up. To handle those values + * in the same framework, we average the scales as logarithms. + * + * aspect is a total aspect ratio of the undistorted image (includes fame and + * pixel aspect). + */ +static void rotation_contribution(TrackStabilizationBase *track_ref, + MovieTrackingMarker *marker, + float aspect, + float target_pos[2], + float averaged_translation_contribution[2], + float *result_angle, + float *result_scale) +{ + float len; + float pos[2]; + float pivot[2]; + copy_v2_fl(pivot, 0.5f); /* Use center of frame as hard wired pivot. */ + add_v2_v2(pivot, averaged_translation_contribution); + sub_v2_v2(pivot, target_pos); + sub_v2_v2v2(pos, marker->pos, pivot); + + pos[0] *= aspect; + mul_m2v2(track_ref->stabilization_rotation_base, pos); + + *result_angle = atan2f(pos[1],pos[0]); + + len = len_v2(pos) + SCALE_ERROR_LIMIT_BIAS; + *result_scale = len * track_ref->stabilization_scale_base; + BLI_assert(0.0 < *result_scale); +} + + +/* Weighted average of the per track cumulated contributions at given frame. + * Returns truth if all desired calculations could be done and all averages are + * available. + * + * NOTE: Even if the result is not `true`, the returned translation and angle + * are always sensible and as good as can be. Especially in the + * initialization phase we might not be able to get any average (yet) or + * get only a translation value. Since initialization visits tracks in a + * specific order, starting from anchor_frame, the result is logically + * correct non the less. But under normal operation conditions, + * a result of `false` should disable the stabilization function */ -static float stabilization_calculate_autoscale_factor(MovieTracking *tracking, int width, int height) +static bool average_track_contributions(StabContext *ctx, + int framenr, + float aspect, + float r_translation[2], + float *r_angle, + float *r_scale_step) { - float firstmedian[2]; + bool ok; + float weight_sum; + MovieTrackingTrack *track; + MovieTracking *tracking = ctx->tracking; MovieTrackingStabilization *stab = &tracking->stabilization; - float aspect = tracking->camera.pixel_aspect; - - /* Early output if stabilization data is already up-to-date. */ - if (stab->ok) - return stab->scale; - - /* See comment in BKE_tracking_stabilization_data_get about first frame. */ - if (stabilization_median_point_get(tracking, 1, firstmedian)) { - int sfra = INT_MAX, efra = INT_MIN, cfra; - float scale = 1.0f; - MovieTrackingTrack *track; - - stab->scale = 1.0f; - - /* Calculate frame range of tracks used for stabilization. */ - track = tracking->tracks.first; - while (track) { - if (track->flag & TRACK_USE_2D_STAB || - ((stab->flag & TRACKING_STABILIZE_ROTATION) && track == stab->rot_track)) - { - sfra = min_ii(sfra, track->markers[0].framenr); - efra = max_ii(efra, track->markers[track->markersnr - 1].framenr); - } + BLI_assert(stab->flag & TRACKING_2D_STABILIZATION); - track = track->next; + zero_v2(r_translation); + *r_scale_step = 0.0f; /* logarithm */ + *r_angle = 0.0f; + + ok = false; + weight_sum = 0.0f; + for (track = tracking->tracks.first; track; track = track->next) { + if (!is_init_for_stabilization(ctx, track)) { + continue; + } + if (track->flag & TRACK_USE_2D_STAB) { + float weight = 0.0f; + MovieTrackingMarker *marker = get_tracking_data_point(ctx, + track, + framenr, + &weight); + if (marker) { + TrackStabilizationBase *stabilization_base = + access_stabilization_baseline_data(ctx, track); + BLI_assert(stabilization_base != NULL); + float offset[2]; + weight_sum += weight; + translation_contribution(stabilization_base, marker, offset); + mul_v2_fl(offset, weight); + add_v2_v2(r_translation, offset); + ok |= (weight_sum > EPSILON_WEIGHT); + } } + } + if (!ok) { + return false; + } - /* For every frame we calculate scale factor needed to eliminate black - * area and choose largest scale factor as final one. - */ - for (cfra = sfra; cfra <= efra; cfra++) { - float median[2]; - float translation[2], angle, tmp_scale; - int i; - float mat[4][4]; - float points[4][2] = {{0.0f, 0.0f}, {0.0f, height}, {width, height}, {width, 0.0f}}; - float si, co; + r_translation[0] /= weight_sum; + r_translation[1] /= weight_sum; - stabilization_median_point_get(tracking, cfra, median); + if (!(stab->flag & TRACKING_STABILIZE_ROTATION)) { + return ok; + } - stabilization_calculate_data(tracking, cfra, width, height, firstmedian, median, translation, - &tmp_scale, &angle); + ok = false; + weight_sum = 0.0f; + for (track = tracking->tracks.first; track; track = track->next) { + if (!is_init_for_stabilization(ctx, track)) { + continue; + } + if (track->flag & TRACK_USE_2D_STAB_ROT) { + float weight = 0.0f; + MovieTrackingMarker *marker = get_tracking_data_point(ctx, + track, + framenr, + &weight); + if (marker) { + TrackStabilizationBase *stabilization_base = + access_stabilization_baseline_data(ctx, track); + BLI_assert(stabilization_base != NULL); + float rotation, scale; + float target_pos[2]; + weight_sum += weight; + get_animated_target_pos(ctx, framenr, target_pos); + rotation_contribution(stabilization_base, + marker, + aspect, + target_pos, + r_translation, + &rotation, + &scale); + *r_angle += rotation * weight; + if (stab->flag & TRACKING_STABILIZE_SCALE) { + *r_scale_step += logf(scale) * weight; + } + else { + *r_scale_step = 0; + } + ok |= (weight_sum > EPSILON_WEIGHT); + } + } + } + if (ok) { + *r_scale_step /= weight_sum; + *r_angle /= weight_sum; + } + else { + /* We reach this point because translation could be calculated, + * but rotation/scale found no data to work on. + */ + *r_scale_step = 0.0f; + *r_angle = 0.0f; + } + return true; +} - BKE_tracking_stabilization_data_to_mat4(width, height, aspect, translation, 1.0f, angle, mat); - si = sinf(angle); - co = cosf(angle); +/* Linear interpolation of data retrieved at two measurement points. + * This function is used to fill gaps in the middle of the covered area, + * at frames without any usable tracks for stabilization. + * + * framenr is a position to interpolate for. + * frame_a is a valid measurement point below framenr + * frame_b is a valid measurement point above framenr + * Returns truth if both measurements could actually be retrieved. + * Otherwise output parameters remain unaltered + */ +static bool interpolate_averaged_track_contributions(StabContext *ctx, + int framenr, + int frame_a, + int frame_b, + float aspect, + float translation[2], + float *r_angle, + float *r_scale_step) +{ + float t, s; + float trans_a[2], trans_b[2]; + float angle_a, angle_b; + float scale_a, scale_b; + bool success = false; + + BLI_assert(frame_a <= frame_b); + BLI_assert(frame_a <= framenr); + BLI_assert(framenr <= frame_b); + + t = ((float)framenr - frame_a) / (frame_b - frame_a); + s = 1.0f - t; + + success = average_track_contributions(ctx, frame_a, aspect, trans_a, &angle_a, &scale_a); + if (!success) { + return false; + } + success = average_track_contributions(ctx, frame_b, aspect, trans_b, &angle_b, &scale_b); + if (!success) { + return false; + } - for (i = 0; i < 4; i++) { - int j; - float a[3] = {0.0f, 0.0f, 0.0f}, b[3] = {0.0f, 0.0f, 0.0f}; + interp_v2_v2v2(translation, trans_a, trans_b, t); + *r_scale_step = s * scale_a + t * scale_b; + *r_angle = s * angle_a + t * angle_b; + return true; +} - copy_v3_v3(a, points[i]); - copy_v3_v3(b, points[(i + 1) % 4]); - mul_m4_v3(mat, a); - mul_m4_v3(mat, b); +/* Reorder tracks starting with those providing a tracking data frame + * closest to the global anchor_frame. Tracks with a gap at anchor_frame or + * starting farer away from anchor_frame altogether will be visited later. + * This allows to build up baseline contributions incrementally. + * + * order is an array for sorting the tracks. Must be of suitable size to hold + * all tracks. + * Returns number of actually usable tracks, can be less than the overall number + * of tracks. + * + * NOTE: After returning, the order array holds entries up to the number of + * usable tracks, appropriately sorted starting with the closest tracks. + * Initialization includes disabled tracks, since they might be enabled + * through automation later. + */ +static int establish_track_initialization_order(StabContext *ctx, + TrackInitOrder *order) +{ + size_t tracknr = 0; + MovieTrackingTrack *track; + MovieTracking *tracking = ctx->tracking; + int anchor_frame = tracking->stabilization.anchor_frame; - for (j = 0; j < 4; j++) { - float point[3] = {points[j][0], points[j][1], 0.0f}; - float v1[3], v2[3]; + for (track = tracking->tracks.first; track != NULL; track = track->next) { + MovieTrackingMarker *marker; + order[tracknr].data = track; + marker = get_closest_marker(ctx, track, anchor_frame); + if (marker != NULL && + (track->flag & (TRACK_USE_2D_STAB | TRACK_USE_2D_STAB_ROT))) + { + order[tracknr].sort_value = abs(marker->framenr - anchor_frame); + order[tracknr].reference_frame = marker->framenr; + ++tracknr; + } + } + if (tracknr) { + qsort(order, tracknr, sizeof(TrackInitOrder), BLI_sortutil_cmp_int); + } + return tracknr; +} - sub_v3_v3v3(v1, b, a); - sub_v3_v3v3(v2, point, a); - if (cross_v2v2(v1, v2) >= 0.0f) { - const float rotDx[4][2] = {{1.0f, 0.0f}, {0.0f, -1.0f}, {-1.0f, 0.0f}, {0.0f, 1.0f}}; - const float rotDy[4][2] = {{0.0f, 1.0f}, {1.0f, 0.0f}, {0.0f, -1.0f}, {-1.0f, 0.0f}}; +/* Setup the constant part of this track's contribution to the determined frame + * movement. Tracks usually don't provide tracking data for every frame. Thus, + * for determining data at a given frame, we split up the contribution into a + * part covered by actual measurements on this track, and the initial gap + * between this track's reference frame and the global anchor_frame. + * The (missing) data for the gap can be substituted by the average offset + * observed by the other tracks covering the gap. This approximation doesn't + * introduce wrong data, but it records data with incorrect weight. A totally + * correct solution would require us to average the contribution per frame, and + * then integrate stepwise over all frames -- which of course would be way more + * expensive, especially for longer clips. To the contrary, our solution + * cumulates the total contribution per track and averages afterwards over all + * tracks; it can thus be calculated just based on the data of a single frame, + * plus the "baseline" for the reference frame, which is what we are computing + * here. + * + * Since we're averaging _contributions_, we have to calculate the _difference_ + * of the measured position at current frame and the position at the reference + * frame. But the "reference" part of this difference is constant and can thus + * be packed together with the baseline contribution into a single precomputed + * vector per track. + * + * In case of the rotation contribution, the principle is the same, but we have + * to compensate for the already determined translation and measure the pure + * rotation, simply because this is how we model the offset: shift plus rotation + * around the shifted rotation center. To circumvent problems with the + * definition range of the arcus tangens function, we perform this baseline + * addition and reference angle subtraction in polar coordinates and bake this + * operation into a precomputed rotation matrix. + * + * track is a track to be initialized to initialize + * reference_frame is a local frame for this track, the closest pick to the + * global anchor_frame. + * aspect is a total aspect ratio of the undistorted image (includes fame and + * pixel aspect). + * target_pos is a possibly animated target position as set by the user for + * the reference_frame + * average_translation is a value observed by the _other_ tracks for the gap + * between reference_frame and anchor_frame. This + * average must not contain contributions of frames + * not yet initialized + * average_angle in a similar way, the rotation value observed by the + * _other_ tracks. + * average_scale_step is an image scale factor observed on average by the other + * tracks for this frame. This value is recorded and + * averaged as logarithm. The recorded scale changes + * are damped for very small contributions, to limit + * the effect of probe points approaching the pivot + * too closely. + * + * NOTE: when done, this track is marked as initialized + */ +static void initialize_track_for_stabilization(StabContext *ctx, + MovieTrackingTrack *track, + int reference_frame, + float aspect, + const float target_pos[2], + const float average_translation[2], + float average_angle, + float average_scale_step) +{ + float pos[2], angle, len; + float pivot[2]; + TrackStabilizationBase *local_data = + access_stabilization_baseline_data(ctx, track); + MovieTrackingMarker *marker = + BKE_tracking_marker_get_exact(track, reference_frame); + /* Logic for initialization order ensures there *is* a marker on that + * very frame. + */ + BLI_assert(marker != NULL); + BLI_assert(local_data != NULL); - float dx = translation[0] * rotDx[j][0] + translation[1] * rotDx[j][1], - dy = translation[0] * rotDy[j][0] + translation[1] * rotDy[j][1]; + /* Per track baseline value for translation. */ + sub_v2_v2v2(local_data->stabilization_offset_base, + average_translation, + marker->pos); - float w, h, E, F, G, H, I, J, K, S; + /* Per track baseline value for rotation. */ + copy_v2_fl(pivot, 0.5f); /* Use center of frame as hard wired pivot. */ + add_v2_v2(pivot, average_translation); + sub_v2_v2(pivot, target_pos); + sub_v2_v2v2(pos, marker->pos, pivot); - if (j % 2) { - w = (float)height / 2.0f; - h = (float)width / 2.0f; - } - else { - w = (float)width / 2.0f; - h = (float)height / 2.0f; - } + pos[0] *= aspect; + angle = average_angle - atan2f(pos[1],pos[0]); + rotate_m2(local_data->stabilization_rotation_base, angle); - E = -w * co + h * si; - F = -h * co - w * si; + /* Per track baseline value for zoom. */ + len = len_v2(pos) + SCALE_ERROR_LIMIT_BIAS; + local_data->stabilization_scale_base = expf(average_scale_step) / len; - if ((i % 2) == (j % 2)) { - G = -w * co - h * si; - H = h * co - w * si; - } - else { - G = w * co + h * si; - H = -h * co + w * si; - } + local_data->is_init_for_stabilization = true; +} - I = F - H; - J = G - E; - K = G * F - E * H; - S = (-w * I - h * J) / (dx * I + dy * J + K); +static void initialize_all_tracks(StabContext *ctx, float aspect) +{ + size_t i, track_cnt = 0; + MovieClip *clip = ctx->clip; + MovieTracking *tracking = ctx->tracking; + MovieTrackingTrack *track; + TrackInitOrder *order; - scale = max_ff(scale, S); - } - } - } + /* Attempt to start initialization at anchor_frame. + * By definition, offset contribution is zero there. + */ + int reference_frame = tracking->stabilization.anchor_frame; + float average_angle=0, average_scale_step=0; + float average_translation[2]; + float target_pos_at_ref_frame[2]; + zero_v2(target_pos_at_ref_frame); + zero_v2(average_translation); + + /* Initialize private working data. */ + for (track = tracking->tracks.first; track != NULL; track = track->next) { + TrackStabilizationBase *local_data = + access_stabilization_baseline_data(ctx, track); + if (!local_data) { + local_data = MEM_callocN(sizeof(TrackStabilizationBase), + "2D stabilization per track baseline data"); + attach_stabilization_baseline_data(ctx, track, local_data); } + BLI_assert(local_data != NULL); + local_data->track_weight_curve = retrieve_track_weight_animation(clip, + track); + local_data->is_init_for_stabilization = false; - stab->scale = scale; + ++track_cnt; + } + if (!track_cnt) { + return; + } - if (stab->maxscale > 0.0f) - stab->scale = min_ff(stab->scale, stab->maxscale); + order = MEM_mallocN(track_cnt * sizeof(TrackInitOrder), + "stabilization track order"); + if (!order) { + return; } - else { - stab->scale = 1.0f; + + track_cnt = establish_track_initialization_order(ctx, order); + if (track_cnt == 0) { + goto cleanup; } - stab->ok = true; + for (i = 0; i < track_cnt; ++i) { + track = order[i].data; + if (reference_frame != order[i].reference_frame) { + reference_frame = order[i].reference_frame; + average_track_contributions(ctx, + reference_frame, + aspect, + average_translation, + &average_angle, + &average_scale_step); + get_animated_target_pos(ctx, + reference_frame, + target_pos_at_ref_frame); + } + initialize_track_for_stabilization(ctx, + track, + reference_frame, + aspect, + target_pos_at_ref_frame, + average_translation, + average_angle, + average_scale_step); + } - return stab->scale; +cleanup: + MEM_freeN(order); } -/* Get stabilization data (translation, scaling and angle) for a given frame. + +/* Retrieve the measurement of frame movement by averaging contributions of + * active tracks. * - * NOTE: frame number should be in clip space, not scene space + * translation is a measurement in normalized 0..1 coordinates. + * angle is a measurement in radians -pi..+pi counter clockwise relative to + * translation compensated frame center + * scale_step is a measurement of image scale changes, in logarithmic scale + * (zero means scale == 1) + * Returns calculation enabled and all data retrieved as expected for this frame. + * + * NOTE: when returning `false`, output parameters are reset to neutral values. */ -void BKE_tracking_stabilization_data_get(MovieTracking *tracking, int framenr, int width, int height, - float translation[2], float *scale, float *angle) +static bool stabilization_determine_offset_for_frame(StabContext *ctx, + int framenr, + float aspect, + float r_translation[2], + float *r_angle, + float *r_scale_step) { - float firstmedian[2], median[2]; - MovieTrackingStabilization *stab = &tracking->stabilization; + bool success = false; /* Early output if stabilization is disabled. */ - if ((stab->flag & TRACKING_2D_STABILIZATION) == 0) { - zero_v2(translation); - *scale = 1.0f; - *angle = 0.0f; + if ((ctx->stab->flag & TRACKING_2D_STABILIZATION) == 0) { + zero_v2(r_translation); + *r_scale_step = 0.0f; + *r_angle = 0.0f; + return false; + } - return; + success = average_track_contributions(ctx, + framenr, + aspect, + r_translation, + r_angle, + r_scale_step); + if (!success) { + /* Try to hold extrapolated settings beyond the definition range + * and to interpolate in gaps without any usable tracking data + * to prevent sudden jump to image zero position. + */ + int next_lower = MINAFRAME; + int next_higher = MAXFRAME; + use_values_from_fcurves(ctx, true); + find_next_working_frames(ctx, framenr, &next_lower, &next_higher); + if (next_lower >= MINFRAME && next_higher < MAXFRAME) { + success = interpolate_averaged_track_contributions(ctx, + framenr, + next_lower, + next_higher, + aspect, + r_translation, + r_angle, + r_scale_step); + } + else if (next_higher < MAXFRAME) { + /* Before start of stabilized range: extrapolate start point + * settings. + */ + success = average_track_contributions(ctx, + next_higher, + aspect, + r_translation, + r_angle, + r_scale_step); + } + else if (next_lower >= MINFRAME) { + /* After end of stabilized range: extrapolate end point settings. */ + success = average_track_contributions(ctx, + next_lower, + aspect, + r_translation, + r_angle, + r_scale_step); + } + use_values_from_fcurves(ctx, false); } + return success; +} - /* Even if tracks does not start at frame 1, their position will - * be estimated at this frame, which will give reasonable result - * in most of cases. - * - * However, it's still better to replace this with real first - * frame number at which tracks are appearing. +/* Calculate stabilization data (translation, scale and rotation) from given raw + * measurements. Result is in absolute image dimensions (expanded image, square + * pixels), includes automatic or manual scaling and compensates for a target + * frame position, if given. + * + * size is a size of the expanded image, the width in pixels is size * aspect. + * aspect is a ratio (width / height) of the effective canvas (square pixels). + * do_compensate denotes whether to actually output values necessary to + * _compensate_ the determined frame movement. + * Otherwise, the effective target movement is returned. + */ +static void stabilization_calculate_data(StabContext *ctx, + int framenr, + int size, + float aspect, + bool do_compensate, + float scale_step, + float r_translation[2], + float *r_scale, + float *r_angle) +{ + float target_pos[2]; + float scaleinf = get_animated_scaleinf(ctx, framenr); + + *r_scale = (get_animated_target_scale(ctx,framenr) - 1.0f) * scaleinf + 1.0f; + + if (ctx->stab->flag & TRACKING_STABILIZE_SCALE) { + *r_scale *= expf(scale_step * scaleinf); /* Averaged in log scale */ + } + + mul_v2_fl(r_translation, get_animated_locinf(ctx, framenr)); + *r_angle *= get_animated_rotinf(ctx, framenr); + + /* Compensate for a target frame position. + * This allows to follow tracking / panning shots in a semi manual fashion, + * when animating the settings for the target frame position. */ - if (stabilization_median_point_get(tracking, 1, firstmedian)) { - stabilization_median_point_get(tracking, framenr, median); + get_animated_target_pos(ctx, framenr, target_pos); + sub_v2_v2(r_translation, target_pos); + *r_angle -= get_animated_target_rot(ctx,framenr); - if ((stab->flag & TRACKING_AUTOSCALE) == 0) - stab->scale = 1.0f; + /* Convert from relative to absolute coordinates, square pixels. */ + r_translation[0] *= (float)size * aspect; + r_translation[1] *= (float)size; + + /* Output measured data, or inverse of the measured values for + * compensation? + */ + if (do_compensate) { + mul_v2_fl(r_translation, -1.0f); + *r_angle *= -1.0f; + if (*r_scale != 0.0f) { + *r_scale = 1.0f / *r_scale; + } + } +} - if (!stab->ok) { - if (stab->flag & TRACKING_AUTOSCALE) - stabilization_calculate_autoscale_factor(tracking, width, height); - stabilization_calculate_data(tracking, framenr, width, height, firstmedian, median, - translation, scale, angle); +/* Determine the inner part of the frame, which is always safe to use. + * When enlarging the image by the inverse of this factor, any black areas + * appearing due to frame translation and rotation will be removed. + * + * NOTE: When calling this function, basic initialization of tracks must be + * done already + */ +static void stabilization_determine_safe_image_area(StabContext *ctx, + int size, + float image_aspect) +{ + MovieTrackingStabilization *stab = ctx->stab; + float pixel_aspect = ctx->tracking->camera.pixel_aspect; - stab->ok = true; + int sfra = INT_MAX, efra = INT_MIN, cfra; + float scale = 1.0f, scale_step = 0.0f; + MovieTrackingTrack *track; + stab->scale = 1.0f; + + /* Calculate maximal frame range of tracks where stabilization is active. */ + for (track = ctx->tracking->tracks.first; track; track = track->next) { + if ((track->flag & TRACK_USE_2D_STAB) || + ((stab->flag & TRACKING_STABILIZE_ROTATION) && + (track->flag & TRACK_USE_2D_STAB_ROT))) + { + int first_frame = track->markers[0].framenr; + int last_frame = track->markers[track->markersnr - 1].framenr; + sfra = min_ii(sfra, first_frame); + efra = max_ii(efra, last_frame); } - else { - stabilization_calculate_data(tracking, framenr, width, height, firstmedian, median, - translation, scale, angle); + } + + /* For every frame we calculate scale factor needed to eliminate black border area + * and choose largest scale factor as final one. + */ + for (cfra = sfra; cfra <= efra; cfra++) { + float translation[2], angle, tmp_scale; + int i; + float mat[4][4]; + float points[4][2] = {{0.0f, 0.0f}, + {0.0f, size}, + {image_aspect * size, size}, + {image_aspect * size, 0.0f}}; + float si, co; + bool do_compensate = true; + + stabilization_determine_offset_for_frame(ctx, + cfra, + image_aspect, + translation, + &angle, + &scale_step); + stabilization_calculate_data(ctx, + cfra, + size, + image_aspect, + do_compensate, + scale_step, + translation, + &tmp_scale, + &angle); + + BKE_tracking_stabilization_data_to_mat4(size * image_aspect, + size, + pixel_aspect, + translation, + 1.0f, + angle, + mat); + + si = sinf(angle); + co = cosf(angle); + + /* Investigate the transformed border lines for this frame; + * find out, where it cuts the original frame. + */ + for (i = 0; i < 4; i++) { + int j; + float a[3] = {0.0f, 0.0f, 0.0f}, + b[3] = {0.0f, 0.0f, 0.0f}; + + copy_v2_v2(a, points[i]); + copy_v2_v2(b, points[(i + 1) % 4]); + a[2] = b[2] = 0.0f; + + mul_m4_v3(mat, a); + mul_m4_v3(mat, b); + + for (j = 0; j < 4; j++) { + float point[3] = {points[j][0], points[j][1], 0.0f}; + float v1[3], v2[3]; + + sub_v3_v3v3(v1, b, a); + sub_v3_v3v3(v2, point, a); + + if (cross_v2v2(v1, v2) >= 0.0f) { + const float rot_dx[4][2] = {{1.0f, 0.0f}, + {0.0f, -1.0f}, + {-1.0f, 0.0f}, + {0.0f, 1.0f}}; + const float rot_dy[4][2] = {{0.0f, 1.0f}, + {1.0f, 0.0f}, + {0.0f, -1.0f}, + {-1.0f, 0.0f}}; + + float dx = translation[0] * rot_dx[j][0] + + translation[1] * rot_dx[j][1], + dy = translation[0] * rot_dy[j][0] + + translation[1] * rot_dy[j][1]; + + float w, h, E, F, G, H, I, J, K, S; + + if (j % 2) { + w = (float)size / 2.0f; + h = image_aspect*size / 2.0f; + } + else { + w = image_aspect*size / 2.0f; + h = (float)size / 2.0f; + } + + E = -w * co + h * si; + F = -h * co - w * si; + + if ((i % 2) == (j % 2)) { + G = -w * co - h * si; + H = h * co - w * si; + } + else { + G = w * co + h * si; + H = -h * co + w * si; + } + + I = F - H; + J = G - E; + K = G * F - E * H; + + S = (dx * I + dy * J + K) / (-w * I - h * J); + + scale = min_ff(scale, S); + } + } } } + + stab->scale = scale; + + if (stab->maxscale > 0.0f) { + stab->scale = max_ff(stab->scale, 1.0f / stab->maxscale); + } +} + + +/* Prepare working data and determine reference point for each track. + * + * NOTE: These calculations _could_ be cached and reused for all frames of the + * same clip. However, since proper initialization depends on (weight) + * animation and setup of tracks, ensuring consistency of cached init data + * turns out to be tricky, hard to maintain and generally not worth the + * effort. Thus we'll re-initialize on every frame. + */ +static StabContext *init_stabilizer(MovieClip *clip, int width, int height) +{ + MovieTracking *tracking = &clip->tracking; + MovieTrackingStabilization *stab = &tracking->stabilization; + float pixel_aspect = tracking->camera.pixel_aspect; + float aspect = (float)width * pixel_aspect / height; + int size = height; + + StabContext *ctx = initialize_stabilization_working_context(clip); + BLI_assert(ctx != NULL); + initialize_all_tracks(ctx, aspect); + if (stab->flag & TRACKING_AUTOSCALE) { + stabilization_determine_safe_image_area(ctx, size, aspect); + } + /* By default, just use values for the global current frame. */ + use_values_from_fcurves(ctx, false); + return ctx; +} + + +/* === public interface functions === */ + +/* Get stabilization data (translation, scaling and angle) for a given frame. + * Returned data describes how to compensate the detected movement, but with any + * chosen scale factor already applied and any target frame position already + * compensated. In case stabilization fails or is disabled, neutral values are + * returned. + * + * framenr is a frame number, relative to the clip (not relative to the scene + * timeline) + * width is an effective width of the canvas (square pixels), used to scale the + * determined translation + * + * Outputs: + * - translation of the lateral shift, absolute canvas coordinates + * (square pixels). + * - scale of the scaling to apply + * - angle of the rotation angle, relative to the frame center + */ +/* TODO(sergey): Use r_ prefix for output parameters here. */ +void BKE_tracking_stabilization_data_get(MovieClip *clip, + int framenr, + int width, + int height, + float translation[2], + float *scale, + float *angle) +{ + StabContext *ctx = NULL; + MovieTracking *tracking = &clip->tracking; + bool enabled = (tracking->stabilization.flag & TRACKING_2D_STABILIZATION); + /* Might become a parameter of a stabilization compositor node. */ + bool do_compensate = true; + float scale_step = 0.0f; + float pixel_aspect = tracking->camera.pixel_aspect; + float aspect = (float)width * pixel_aspect / height; + int size = height; + + if (enabled) { + ctx = init_stabilizer(clip, width, height); + } + + if (enabled && + stabilization_determine_offset_for_frame(ctx, + framenr, + aspect, + translation, + angle, + &scale_step)) + { + stabilization_calculate_data(ctx, + framenr, + size, + aspect, + do_compensate, + scale_step, + translation, + scale, + angle); + } else { zero_v2(translation); *scale = 1.0f; *angle = 0.0f; } + discard_stabilization_working_context(ctx); } -/* Stabilize given image buffer using stabilization data for - * a specified frame number. +/* Stabilize given image buffer using stabilization data for a specified + * frame number. * - * NOTE: frame number should be in clip space, not scene space + * NOTE: frame number should be in clip space, not scene space. */ -ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf *ibuf, - float translation[2], float *scale, float *angle) +/* TODO(sergey): Use r_ prefix for output parameters here. */ +ImBuf *BKE_tracking_stabilize_frame(MovieClip *clip, + int framenr, + ImBuf *ibuf, + float translation[2], + float *scale, + float *angle) { float tloc[2], tscale, tangle; + MovieTracking *tracking = &clip->tracking; MovieTrackingStabilization *stab = &tracking->stabilization; ImBuf *tmpibuf; int width = ibuf->x, height = ibuf->y; - float aspect = tracking->camera.pixel_aspect; + float pixel_aspect = tracking->camera.pixel_aspect; float mat[4][4]; int j, filter = tracking->stabilization.filter; void (*interpolation)(struct ImBuf *, struct ImBuf *, float, float, int, int) = NULL; @@ -349,8 +1363,12 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf 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); - BKE_tracking_stabilization_data_to_mat4(ibuf->x, ibuf->y, aspect, tloc, tscale, tangle, mat); + BKE_tracking_stabilization_data_get(clip, framenr, width, height, tloc, &tscale, &tangle); + BKE_tracking_stabilization_data_to_mat4(ibuf->x, ibuf->y, pixel_aspect, tloc, tscale, tangle, mat); + + /* The following code visits each nominal target grid position + * and picks interpolated data "backwards" from source. + * thus we need the inverse of the transformation to apply. */ invert_m4(mat); if (filter == TRACKING_FILTER_NEAREST) @@ -397,48 +1415,61 @@ ImBuf *BKE_tracking_stabilize_frame(MovieTracking *tracking, int framenr, ImBuf return tmpibuf; } -/* Get 4x4 transformation matrix which corresponds to - * stabilization data and used for easy coordinate - * transformation. + +/* Build a 4x4 transformation matrix based on the given 2D stabilization data. + * mat is a 4x4 matrix in homogeneous coordinates, adapted to the + * final image buffer size and compensated for pixel aspect ratio, + * ready for direct OpenGL drawing. * - * NOTE: The reason it is 4x4 matrix is because it's - * used for OpenGL drawing directly. + * TODO(sergey): The signature of this function should be changed. we actually + * don't need the dimensions of the image buffer. Instead we + * should consider to provide the pivot point of the rotation as a + * further stabilization data parameter. */ -void BKE_tracking_stabilization_data_to_mat4(int width, int height, float aspect, +void BKE_tracking_stabilization_data_to_mat4(int buffer_width, + int buffer_height, + float pixel_aspect, float translation[2], float scale, float angle, float mat[4][4]) { float translation_mat[4][4], rotation_mat[4][4], scale_mat[4][4], - center_mat[4][4], inv_center_mat[4][4], + pivot_mat[4][4], inv_pivot_mat[4][4], aspect_mat[4][4], inv_aspect_mat[4][4]; - float scale_vector[3] = {scale, scale, scale}; + float scale_vector[3] = {scale, scale, 1.0f}; + + float pivot[2]; /* XXX this should be a parameter, it is part of the stabilization data */ + + /* Use the motion compensated image center as rotation center. + * This is not 100% correct, but reflects the way the rotation data was + * measured. Actually we'd need a way to find a good pivot, and use that + * both for averaging and for compensation. + */ + /* TODO(sergey) pivot shouldn't be calculated here, rather received + * as a parameter. + */ + pivot[0] = pixel_aspect * buffer_width / 2.0f - translation[0]; + pivot[1] = (float)buffer_height / 2.0f - translation[1]; unit_m4(translation_mat); unit_m4(rotation_mat); unit_m4(scale_mat); - unit_m4(center_mat); unit_m4(aspect_mat); + unit_m4(pivot_mat); + unit_m4(inv_pivot_mat); /* aspect ratio correction matrix */ - aspect_mat[0][0] = 1.0f / aspect; + aspect_mat[0][0] /= pixel_aspect; invert_m4_m4(inv_aspect_mat, aspect_mat); - /* image center as rotation center - * - * Rotation matrix is constructing in a way rotation happens around image center, - * and it's matter of calculating translation in a way, that applying translation - * after rotation would make it so rotation happens around median point of tracks - * used for translation stabilization. - */ - center_mat[3][0] = (float)width / 2.0f; - center_mat[3][1] = (float)height / 2.0f; - invert_m4_m4(inv_center_mat, center_mat); + add_v2_v2(pivot_mat[3], pivot); + sub_v2_v2(inv_pivot_mat[3], pivot); size_to_mat4(scale_mat, scale_vector); /* scale matrix */ add_v2_v2(translation_mat[3], translation); /* translation matrix */ rotate_m4(rotation_mat, 'Z', angle); /* rotation matrix */ /* compose transformation matrix */ - mul_m4_series(mat, translation_mat, center_mat, aspect_mat, rotation_mat, inv_aspect_mat, - scale_mat, inv_center_mat); + mul_m4_series(mat, aspect_mat, translation_mat, + pivot_mat, scale_mat, rotation_mat, inv_pivot_mat, + inv_aspect_mat); } |