VSE: Add frame interpolation option to speed effect

Do cross transition from current to next frame instead of displaying
one image for n frames.

Reviewed By: ISS, sergey, campbellbarton

Differential Revision: https://developer.blender.org/D7417

6 files changed, 100 insertions, 57 deletions

diff --git a/release/scripts/startup/bl_ui/space_sequencer.py b/release/scripts/startup/bl_ui/space_sequencer.py
index e4539ec7ca7..e1f675871ef 100644
--- a/release/scripts/startup/bl_ui/space_sequencer.py
+++ b/release/scripts/startup/bl_ui/space_sequencer.py
@@ -1139,6 +1139,8 @@ class SEQUENCER_PT_effect(SequencerButtonsPanel, Panel):
         col = layout.column(align=True)
         if strip_type == 'SPEED':
             col.prop(strip, "multiply_speed")
+            col.prop(strip, "frame_interpolation_mode")
+
         elif strip_type in {'CROSS', 'GAMMA_CROSS', 'WIPE', 'ALPHA_OVER', 'ALPHA_UNDER', 'OVER_DROP'}:
             col.prop(strip, "use_default_fade", text="Default fade")
             if not strip.use_default_fade:
diff --git a/source/blender/blenkernel/BKE_sequencer.h b/source/blender/blenkernel/BKE_sequencer.h
index 939fcb33b2d..8b7be11e852 100644
--- a/source/blender/blenkernel/BKE_sequencer.h
+++ b/source/blender/blenkernel/BKE_sequencer.h
@@ -218,6 +218,15 @@ struct ImBuf *BKE_sequencer_give_ibuf_seqbase(const SeqRenderData *context,
                                               float cfra,
                                               int chan_shown,
                                               struct ListBase *seqbasep);
+struct ImBuf *BKE_sequencer_effect_execute_threaded(struct SeqEffectHandle *sh,
+                                                    const SeqRenderData *context,
+                                                    struct Sequence *seq,
+                                                    float cfra,
+                                                    float facf0,
+                                                    float facf1,
+                                                    struct ImBuf *ibuf1,
+                                                    struct ImBuf *ibuf2,
+                                                    struct ImBuf *ibuf3);
 
 /* **********************************************************************
  * sequencer.c
@@ -374,6 +383,10 @@ struct Sequence *BKE_sequencer_prefetch_get_original_sequence(struct Sequence *s
 /* intern */
 struct SeqEffectHandle BKE_sequence_get_blend(struct Sequence *seq);
 void BKE_sequence_effect_speed_rebuild_map(struct Scene *scene, struct Sequence *seq, bool force);
+float BKE_sequencer_speed_effect_target_frame_get(const SeqRenderData *context,
+                                                  struct Sequence *seq,
+                                                  float cfra,
+                                                  int input);
 
 /* extern */
 struct SeqEffectHandle BKE_sequence_get_effect(struct Sequence *seq);
@@ -507,6 +520,7 @@ void BKE_sequence_alpha_mode_from_extension(struct Sequence *seq);
 void BKE_sequence_init_colorspace(struct Sequence *seq);
 
 float BKE_sequence_get_fps(struct Scene *scene, struct Sequence *seq);
+float BKE_sequencer_give_stripelem_index(struct Sequence *seq, float cfra);
 
 /* RNA enums, just to be more readable */
 enum {
diff --git a/source/blender/blenkernel/intern/seqeffects.c b/source/blender/blenkernel/intern/seqeffects.c
index c1644e39afa..9fa43ed0a5f 100644
--- a/source/blender/blenkernel/intern/seqeffects.c
+++ b/source/blender/blenkernel/intern/seqeffects.c
@@ -61,6 +61,8 @@
 
 #include "BLF_api.h"
 
+static struct SeqEffectHandle get_sequence_effect_impl(int seq_type);
+
 static void slice_get_byte_buffers(const SeqRenderData *context,
                                    const ImBuf *ibuf1,
                                    const ImBuf *ibuf2,
@@ -3118,7 +3120,7 @@ static void copy_speed_effect(Sequence *dst, Sequence *src, const int UNUSED(fla
 
 static int early_out_speed(Sequence *UNUSED(seq), float UNUSED(facf0), float UNUSED(facf1))
 {
-  return EARLY_USE_INPUT_1;
+  return EARLY_DO_EFFECT;
 }
 
 static void store_icu_yrange_speed(Sequence *seq, short UNUSED(adrcode), float *ymin, float *ymax)
@@ -3248,36 +3250,60 @@ void BKE_sequence_effect_speed_rebuild_map(Scene *scene, Sequence *seq, bool for
   }
 }
 
+/* Override cfra when rendering speed effect input. */
+float BKE_sequencer_speed_effect_target_frame_get(const SeqRenderData *context,
+                                                  Sequence *seq,
+                                                  float cfra,
+                                                  int input)
+{
+  int nr = BKE_sequencer_give_stripelem_index(seq, cfra);
+  SpeedControlVars *s = (SpeedControlVars *)seq->effectdata;
+  BKE_sequence_effect_speed_rebuild_map(context->scene, seq, false);
+
+  /* No interpolation. */
+  if ((s->flags & SEQ_SPEED_USE_INTERPOLATION) == 0) {
+    return seq->start + s->frameMap[nr];
+  }
+
+  /* We need to provide current and next image for interpolation. */
+  if (input == 0) { /* Current frame. */
+    return floor(seq->start + s->frameMap[nr]);
+  }
+  else { /* Next frame. */
+    return ceil(seq->start + s->frameMap[nr]);
+  }
+}
+
+static float speed_effect_interpolation_ratio_get(SpeedControlVars *s, Sequence *seq, float cfra)
+{
+  int nr = BKE_sequencer_give_stripelem_index(seq, cfra);
+  return s->frameMap[nr] - floor(s->frameMap[nr]);
+}
+
 static ImBuf *do_speed_effect(const SeqRenderData *context,
-                              Sequence *UNUSED(seq),
-                              float UNUSED(cfra),
+                              Sequence *seq,
+                              float cfra,
                               float facf0,
                               float facf1,
                               ImBuf *ibuf1,
                               ImBuf *ibuf2,
                               ImBuf *ibuf3)
 {
-  ImBuf *out = prepare_effect_imbufs(context, ibuf1, ibuf2, ibuf3);
+  SpeedControlVars *s = (SpeedControlVars *)seq->effectdata;
+  struct SeqEffectHandle cross_effect = get_sequence_effect_impl(SEQ_TYPE_CROSS);
+  ImBuf *out;
 
-  if (out->rect_float) {
-    do_cross_effect_float(facf0,
-                          facf1,
-                          context->rectx,
-                          context->recty,
-                          ibuf1->rect_float,
-                          ibuf2->rect_float,
-                          out->rect_float);
+  if (s->flags & SEQ_SPEED_USE_INTERPOLATION) {
+    out = prepare_effect_imbufs(context, ibuf1, ibuf2, ibuf3);
+    facf0 = facf1 = speed_effect_interpolation_ratio_get(s, seq, cfra);
+    /* Current frame is ibuf1, next frame is ibuf2. */
+    out = BKE_sequencer_effect_execute_threaded(
+        &cross_effect, context, NULL, cfra, facf0, facf1, ibuf1, ibuf2, ibuf3);
+    return out;
   }
-  else {
-    do_cross_effect_byte(facf0,
-                         facf1,
-                         context->rectx,
-                         context->recty,
-                         (unsigned char *)ibuf1->rect,
-                         (unsigned char *)ibuf2->rect,
-                         (unsigned char *)out->rect);
-  }
-  return out;
+
+  /* No interpolation. */
+  return IMB_dupImBuf(ibuf1);
 }
 
 /*********************** overdrop *************************/
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index 5136c526416..b962c99b109 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -1394,7 +1394,7 @@ static void multibuf(ImBuf *ibuf, const float fmul)
   }
 }
 
-static float give_stripelem_index(Sequence *seq, float cfra)
+float BKE_sequencer_give_stripelem_index(Sequence *seq, float cfra)
 {
   float nr;
   int sta = seq->start;
@@ -1452,7 +1452,7 @@ StripElem *BKE_sequencer_give_stripelem(Sequence *seq, int cfra)
      * all other strips don't use this...
      */
 
-    int nr = (int)give_stripelem_index(seq, cfra);
+    int nr = (int)BKE_sequencer_give_stripelem_index(seq, cfra);
 
     if (nr == -1 || se == NULL) {
       return NULL;
@@ -1889,7 +1889,7 @@ static bool seq_proxy_get_fname(Editing *ed,
     frameno = 1;
   }
   else {
-    frameno = (int)give_stripelem_index(seq, cfra) + seq->anim_startofs;
+    frameno = (int)BKE_sequencer_give_stripelem_index(seq, cfra) + seq->anim_startofs;
     BLI_snprintf(name, PROXY_MAXFILE, "%s/proxy_misc/%d/####%s", dir, proxy_size_number, suffix);
   }
 
@@ -1922,7 +1922,7 @@ static ImBuf *seq_proxy_fetch(const SeqRenderData *context, Sequence *seq, int c
   }
 
   if (proxy->storage & SEQ_STORAGE_PROXY_CUSTOM_FILE) {
-    int frameno = (int)give_stripelem_index(seq, cfra) + seq->anim_startofs;
+    int frameno = (int)BKE_sequencer_give_stripelem_index(seq, cfra) + seq->anim_startofs;
     if (proxy->anim == NULL) {
       if (seq_proxy_get_fname(ed, seq, cfra, psize, name, context->view_id) == 0) {
         return NULL;
@@ -2887,15 +2887,15 @@ static void *render_effect_execute_do_thread(void *thread_data_v)
   return NULL;
 }
 
-static ImBuf *seq_render_effect_execute_threaded(struct SeqEffectHandle *sh,
-                                                 const SeqRenderData *context,
-                                                 Sequence *seq,
-                                                 float cfra,
-                                                 float facf0,
-                                                 float facf1,
-                                                 ImBuf *ibuf1,
-                                                 ImBuf *ibuf2,
-                                                 ImBuf *ibuf3)
+ImBuf *BKE_sequencer_effect_execute_threaded(struct SeqEffectHandle *sh,
+                                             const SeqRenderData *context,
+                                             Sequence *seq,
+                                             float cfra,
+                                             float facf0,
+                                             float facf1,
+                                             ImBuf *ibuf1,
+                                             ImBuf *ibuf2,
+                                             ImBuf *ibuf3)
 {
   RenderEffectInitData init_data;
   ImBuf *out = sh->init_execution(context, ibuf1, ibuf2, ibuf3);
@@ -2969,14 +2969,21 @@ static ImBuf *seq_render_effect_strip_impl(const SeqRenderData *context,
       break;
     case EARLY_DO_EFFECT:
       for (i = 0; i < 3; i++) {
-        if (input[i]) {
-          ibuf[i] = seq_render_strip(context, state, input[i], cfra);
+        /* Speed effect requires time remapping of cfra for input(s). */
+        if (input[1] && seq->type == SEQ_TYPE_SPEED) {
+          float target_frame = BKE_sequencer_speed_effect_target_frame_get(context, seq, cfra, i);
+          ibuf[i] = seq_render_strip(context, state, input[i], target_frame);
+        }
+        else { /* Other effects. */
+          if (input[i]) {
+            ibuf[i] = seq_render_strip(context, state, input[i], cfra);
+          }
         }
       }
 
       if (ibuf[0] && ibuf[1]) {
         if (sh.multithreaded) {
-          out = seq_render_effect_execute_threaded(
+          out = BKE_sequencer_effect_execute_threaded(
               &sh, context, seq, cfra, fac, facf, ibuf[0], ibuf[1], ibuf[2]);
         }
         else {
@@ -3679,9 +3686,8 @@ static ImBuf *do_render_strip_uncached(const SeqRenderData *context,
                                        float cfra)
 {
   ImBuf *ibuf = NULL;
-  float nr = give_stripelem_index(seq, cfra);
-  int type = (seq->type & SEQ_TYPE_EFFECT && seq->type != SEQ_TYPE_SPEED) ? SEQ_TYPE_EFFECT :
-                                                                            seq->type;
+  float nr = BKE_sequencer_give_stripelem_index(seq, cfra);
+  int type = (seq->type & SEQ_TYPE_EFFECT) ? SEQ_TYPE_EFFECT : seq->type;
   switch (type) {
     case SEQ_TYPE_META: {
       ibuf = do_render_strip_seqbase(context, state, seq, nr);
@@ -3723,21 +3729,8 @@ static ImBuf *do_render_strip_uncached(const SeqRenderData *context,
       break;
     }
 
-    case SEQ_TYPE_SPEED: {
-      float f_cfra;
-      SpeedControlVars *s = (SpeedControlVars *)seq->effectdata;
-
-      BKE_sequence_effect_speed_rebuild_map(context->scene, seq, false);
-
-      /* weeek! */
-      f_cfra = seq->start + s->frameMap[(int)nr];
-      ibuf = seq_render_strip(context, state, seq->seq1, f_cfra);
-
-      break;
-    }
-
     case SEQ_TYPE_EFFECT: {
-      ibuf = seq_render_effect_strip_impl(context, state, seq, seq->start + nr);
+      ibuf = seq_render_effect_strip_impl(context, state, seq, cfra);
       break;
     }
 
@@ -3931,7 +3924,7 @@ static ImBuf *seq_render_strip_stack_apply_effect(
 
   if (swap_input) {
     if (sh.multithreaded) {
-      out = seq_render_effect_execute_threaded(
+      out = BKE_sequencer_effect_execute_threaded(
           &sh, context, seq, cfra, facf, facf, ibuf2, ibuf1, NULL);
     }
     else {
@@ -3940,7 +3933,7 @@ static ImBuf *seq_render_strip_stack_apply_effect(
   }
   else {
     if (sh.multithreaded) {
-      out = seq_render_effect_execute_threaded(
+      out = BKE_sequencer_effect_execute_threaded(
           &sh, context, seq, cfra, facf, facf, ibuf1, ibuf2, NULL);
     }
     else {
diff --git a/source/blender/makesdna/DNA_sequence_types.h b/source/blender/makesdna/DNA_sequence_types.h
index 1714ec8b498..9fee839f979 100644
--- a/source/blender/makesdna/DNA_sequence_types.h
+++ b/source/blender/makesdna/DNA_sequence_types.h
@@ -468,6 +468,7 @@ typedef struct SequencerScopes {
 #define SEQ_SPEED_INTEGRATE (1 << 0)
 #define SEQ_SPEED_UNUSED_1 (1 << 1) /* cleared */
 #define SEQ_SPEED_COMPRESS_IPO_Y (1 << 2)
+#define SEQ_SPEED_USE_INTERPOLATION (1 << 3)
 
 /* ***************** SEQUENCE ****************** */
 #define SEQ_NAME_MAXSTR 64
diff --git a/source/blender/makesrna/intern/rna_sequencer.c b/source/blender/makesrna/intern/rna_sequencer.c
index 8724cac9227..fd8ddfff14f 100644
--- a/source/blender/makesrna/intern/rna_sequencer.c
+++ b/source/blender/makesrna/intern/rna_sequencer.c
@@ -2761,6 +2761,13 @@ static void rna_def_speed_control(StructRNA *srna)
       prop, "Scale to Length", "Scale values from 0.0 to 1.0 to target sequence length");
   RNA_def_property_update(
       prop, NC_SCENE | ND_SEQUENCER, "rna_Sequence_invalidate_preprocessed_update");
+
+  prop = RNA_def_property(srna, "frame_interpolation_mode", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flags", SEQ_SPEED_USE_INTERPOLATION);
+  RNA_def_property_ui_text(
+      prop, "Frame interpolation", "Do crossfade blending between current and next frame");
+  RNA_def_property_update(
+      prop, NC_SCENE | ND_SEQUENCER, "rna_Sequence_invalidate_preprocessed_update");
 }
 
 static void rna_def_gaussian_blur(StructRNA *srna)