ffmpeg: set dts for subtitles

dts is not optional, its required for muxing,
previously it was set from AVStream.pts

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 1 insertions, 0 deletions

diff --git a/ffmpeg.c b/ffmpeg.c
index aa30cd0..4c738ca 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -837,6 +837,7 @@ static void do_subtitle_out(AVFormatContext *s,
             else
                 pkt.pts += 90 * sub->end_display_time;
         }
+        pkt.dts = pkt.pts;
         write_frame(s, &pkt, ost);
     }
 }