Fix: Export subtitles timecode relative to scene start frame, ignore muted strips

This patch writes the timecode in the .srt file relative to the start
frame of the scene. If the timecode is global but scene does not start
at frame 0 the subtitles don't match if they get loaded in an external
video player. Muted strips will be ignored. Don't allow negative
timecodes in .srt.

Reviewed By: Richard Antalik
Differential Revision: http://developer.blender.org/D11762

1 files changed, 6 insertions, 3 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_edit.c b/source/blender/editors/space_sequencer/sequencer_edit.c
index 25009532dd0..48b8a1b87a3 100644
--- a/source/blender/editors/space_sequencer/sequencer_edit.c
+++ b/source/blender/editors/space_sequencer/sequencer_edit.c
@@ -2984,8 +2984,10 @@ static int sequencer_export_subtitles_exec(bContext *C, wmOperator *op)
     return OPERATOR_CANCELLED;
   }
 
+  /* Only text strips that are not muted and don't end with negative frame. */
   SEQ_ALL_BEGIN (ed, seq) {
-    if (seq->type == SEQ_TYPE_TEXT) {
+    if ((seq->type == SEQ_TYPE_TEXT) && ((seq->flag & SEQ_MUTE) == 0) &&
+        (seq->enddisp > scene->r.sfra)) {
       BLI_addtail(&text_seq, MEM_dupallocN(seq));
     }
   }
@@ -3006,16 +3008,17 @@ static int sequencer_export_subtitles_exec(bContext *C, wmOperator *op)
     char timecode_str_start[32];
     char timecode_str_end[32];
 
+    /* Write timecode relative to start frame of scene. Don't allow negative timecodes. */
     BLI_timecode_string_from_time(timecode_str_start,
                                   sizeof(timecode_str_start),
                                   -2,
-                                  FRA2TIME(seq->startdisp),
+                                  FRA2TIME(max_ii(seq->startdisp - scene->r.sfra, 0)),
                                   FPS,
                                   USER_TIMECODE_SUBRIP);
     BLI_timecode_string_from_time(timecode_str_end,
                                   sizeof(timecode_str_end),
                                   -2,
-                                  FRA2TIME(seq->enddisp),
+                                  FRA2TIME(seq->enddisp - scene->r.sfra),
                                   FPS,
                                   USER_TIMECODE_SUBRIP);