X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fsubtitle.cc;h=37c372c20548f2f01508ead78346daf363494afc;hb=44b57d623dec97a3f9955082f0b8a7a8d27b7518;hp=451d836913f5a07e4476d0dd3c50de29e98e9723;hpb=5d2ba0d2f7855ffe18ff8e5a96156ca17e50cd2b;p=dcpomatic.git

diff --git a/src/lib/subtitle.cc b/src/lib/subtitle.cc
index 451d83691..37c372c20 100644
--- a/src/lib/subtitle.cc
+++ b/src/lib/subtitle.cc
@@ -32,11 +32,14 @@ using namespace boost;
 /** Construct a TimedSubtitle.  This is a subtitle image, position,
  *  and a range of time over which it should be shown.
  *  @param sub AVSubtitle to read.
+ *  @param c Fractional seconds that should be subtracted from the AVSubtitle's PTS.
  */
-TimedSubtitle::TimedSubtitle (AVSubtitle const & sub)
+TimedSubtitle::TimedSubtitle (AVSubtitle const & sub, double c)
 {
+	assert (sub.rects > 0);
+	
 	/* subtitle PTS in seconds */
-	float const packet_time = (sub.pts / AV_TIME_BASE) + float (sub.pts % AV_TIME_BASE) / 1e6;
+	double const packet_time = ((sub.pts / AV_TIME_BASE) + float (sub.pts % AV_TIME_BASE) / 1e6) - c;
 	
 	/* hence start time for this sub */
 	_from = packet_time + (double (sub.start_display_time) / 1e3);