If there is no end time in an AVSubtitle it seems we should use the AVPacket's duration.

This fixes #2110.  I don't have a particular justification for it being
the right thing to do.

diff --git a/src/lib/ffmpeg.cc b/src/lib/ffmpeg.cc
index 503f8e51cf13b146d25d81d443688428a87e5f97..eed9ab94c161fb90fdcb4d613092fc49d78860d6 100644 (file)
--- a/src/lib/ffmpeg.cc
+++ b/src/lib/ffmpeg.cc
@@ -287,16 +287,18 @@ FFmpegSubtitlePeriod
 FFmpeg::subtitle_period (AVPacket const* packet, AVStream const* stream, AVSubtitle const & sub)
 {
        auto const packet_time = ContentTime::from_seconds (packet->pts * av_q2d(stream->time_base));
+       auto const start = packet_time + ContentTime::from_seconds(sub.start_display_time / 1e3);
 
        if (sub.end_display_time == 0 || sub.end_display_time == static_cast<uint32_t>(-1)) {
-               /* End time is not known */
-               return FFmpegSubtitlePeriod (packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3));
+               /* End time is not in the AVSubtitle; perhaps we can use the AVPacket's duration */
+               if (packet->duration) {
+                       return FFmpegSubtitlePeriod(start, start + ContentTime::from_seconds(packet->duration * av_q2d(stream->time_base)));
+               } else {
+                       return FFmpegSubtitlePeriod(start);
+               }
        }
 
-       return FFmpegSubtitlePeriod (
-               packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3),
-               packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3)
-               );
+       return FFmpegSubtitlePeriod (start, packet_time + ContentTime::from_seconds(sub.end_display_time / 1e3));
 }