VSE: Use timecodes by default

Movies with variable frame rate can cause mismatch of displayed frame
when proxies are used. Since proxies are not used for rendering, this
means, that output may be different than expected. This problem can be
avoided when timecodes are used.

Set used timecode to Record Run. Timecodes are built with proxies at
the same time, therefore if proxies are built and used this will
resolve possible mismatch of output.

Record run is chosen, because it will show frames based on time they
were encoded by encoder and should match behavior as if movie was
played back at normal speed. This change is done only for new strips
in order to not overwrite user defined settings.

Other minor changes:
- When proxies are enabled, size 25% is no longer set by default. It was mostly annoying anyway.
- Silence warning when timecode file is not present. This was introduced in 4adbe31e2f.
  Previously use of timecodes was hard-coded in sequencer and this error would spam console if timecodes would be
  enabled by default and proxies would be never built.

ref: T95093

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D13905

source/blender/imbuf/intern/indexer.c

@@ -170,7 +170,6 @@ struct anim_index *IMB_indexer_open(const char *name)
   int i;
 
   if (!fp) {
-    fprintf(stderr, "Couldn't open indexer file: %s\n", name);
     return NULL;
   }
 

source/blender/sequencer/intern/proxy.c

@@ -601,10 +601,7 @@ void SEQ_proxy_set(struct Sequence *seq, bool value)
   if (value) {
     seq->flag |= SEQ_USE_PROXY;
     if (seq->strip->proxy == NULL) {
-      seq->strip->proxy = MEM_callocN(sizeof(struct StripProxy), "StripProxy");
-      seq->strip->proxy->quality = 50;
-      seq->strip->proxy->build_tc_flags = SEQ_PROXY_TC_ALL;
-      seq->strip->proxy->build_size_flags = SEQ_PROXY_IMAGE_SIZE_25;
+      seq->strip->proxy = seq_strip_proxy_alloc();
     }
   }
   else {

source/blender/sequencer/intern/sequencer.c

@@ -66,6 +66,15 @@
 /** \name Allocate / Free Functions
  * \{ */
 
+StripProxy *seq_strip_proxy_alloc(void)
+{
+  StripProxy *strip_proxy = MEM_callocN(sizeof(struct StripProxy), "StripProxy");
+  strip_proxy->quality = 50;
+  strip_proxy->build_tc_flags = SEQ_PROXY_TC_ALL;
+  strip_proxy->tc = SEQ_PROXY_TC_RECORD_RUN;
+  return strip_proxy;
+}
+
 static Strip *seq_strip_alloc(int type)
 {
   Strip *strip = MEM_callocN(sizeof(Strip), "strip");

source/blender/sequencer/intern/sequencer.h

@@ -29,12 +29,13 @@ extern "C" {
 
 struct Scene;
 struct Sequence;
-
+struct StripProxy;
 /**
  * Cache must be freed before calling this function
  * since it leaves the seqbase in an invalid state.
  */
 void seq_free_sequence_recurse(struct Scene *scene, struct Sequence *seq, bool do_id_user);
+struct StripProxy *seq_strip_proxy_alloc(void);
 
 #ifdef __cplusplus
 }