VSE: Improved Retiming system

Patch implements better way to control playback speed than it is
possible to do with speed effect. Speed factor property can be set in
Time panel.

There are 2 layers of control:

Option to retime movie to match scene FPS rate.
Custom speed factor to control playback rate.
Since playback rate is strip property, it is now possible to manipulate
strip as normal one even if it is retimed.

To facilitate manipulation, some functions need to consider speed factor
and apply necessary corrections to strip offset or strip start. These
corrections may need to be float numbers, so start and offsets must be
float as well.

Sound strips now use speed factor instead of pitch. This means, that
strips will change length to match usable length. In addition, it is
possible to group movie and sound strip and change speed of meta strip.

1 files changed, 6 insertions, 10 deletions

diff --git a/source/blender/sequencer/SEQ_transform.h b/source/blender/sequencer/SEQ_transform.h
index 31a7399f844..8bc7733861c 100644
--- a/source/blender/sequencer/SEQ_transform.h
+++ b/source/blender/sequencer/SEQ_transform.h
@@ -17,14 +17,6 @@ struct Scene;
 struct SeqCollection;
 struct Sequence;
 
-/**
- * Use to impose limits when dragging/extending - so impossible situations don't happen.
- * Can't use the #SEQ_LEFTSEL and #SEQ_LEFTSEL directly because the strip may be in a meta-strip.
- */
-void SEQ_transform_handle_xlimits(const struct Scene *scene,
-                                  struct Sequence *seq,
-                                  int leftflag,
-                                  int rightflag);
 bool SEQ_transform_sequence_can_be_translated(struct Sequence *seq);
 /**
  * Used so we can do a quick check for single image seq
@@ -32,8 +24,12 @@ bool SEQ_transform_sequence_can_be_translated(struct Sequence *seq);
  */
 bool SEQ_transform_single_image_check(struct Sequence *seq);
 void SEQ_transform_fix_single_image_seq_offsets(const struct Scene *scene, struct Sequence *seq);
-bool SEQ_transform_test_overlap(struct ListBase *seqbasep, struct Sequence *test);
-bool SEQ_transform_test_overlap_seq_seq(struct Sequence *seq1, struct Sequence *seq2);
+bool SEQ_transform_test_overlap(const struct Scene *scene,
+                                struct ListBase *seqbasep,
+                                struct Sequence *test);
+bool SEQ_transform_test_overlap_seq_seq(const struct Scene *scene,
+                                        struct Sequence *seq1,
+                                        struct Sequence *seq2);
 void SEQ_transform_translate_sequence(struct Scene *scene, struct Sequence *seq, int delta);
 /**
  * \return 0 if there weren't enough space.