From efc3486f2acf36bd0dc7b5528e7b3110ea8c4afe Mon Sep 17 00:00:00 2001 From: Carl Hetherington Date: Thu, 9 Jan 2020 23:52:20 +0000 Subject: [PATCH] Give DCPDecoder its own ::position which just returns its internal _next time. This is important because Decoder::position does the wrong thing with DCPs in the following case. 1. DCPDecoder emits a subtitle event (start/stop) at time t. 2. There follows a long time T with no subtitle events. During this time the DCPDecoder's position is reported as t (since TextDecoder notes its position as the time of the last thing it emitted --- which is all it reasonably can do, I think). 3. During this T the DCPDecoder may be incorrectly pass()ed because its position is reported as earlier than it really is; this results in video/audio being emitted by the DCPDecoder but other contemporary sources may not be pass()ed. The upshot of this can be that no audio is emitted, as a contemporary audio source is not pass()ed and hence the merger is waiting for audio that will take a long time to come. When the butler is running this can result in audio underruns as the video buffers overflow with no sign of any audio. It is also simpler this way; DCPDecoder was already maintaining the required information. --- src/lib/dcp_decoder.cc | 6 ++++++ src/lib/dcp_decoder.h | 2 ++ src/lib/decoder.h | 2 +- 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc index a3c42a321..03ac66e94 100644 --- a/src/lib/dcp_decoder.cc +++ b/src/lib/dcp_decoder.cc @@ -457,3 +457,9 @@ DCPDecoder::calculate_lazy_digest (shared_ptr c) const } return d.get (); } + +ContentTime +DCPDecoder::position () const +{ + return ContentTime::from_frames(_offset, _dcp_content->active_video_frame_rate(film())) + _next; +} diff --git a/src/lib/dcp_decoder.h b/src/lib/dcp_decoder.h index 496d95740..4de8c8629 100644 --- a/src/lib/dcp_decoder.h +++ b/src/lib/dcp_decoder.h @@ -62,6 +62,8 @@ public: return _lazy_digest; } + dcpomatic::ContentTime position () const; + private: friend struct dcp_subtitle_within_dcp_test; diff --git a/src/lib/decoder.h b/src/lib/decoder.h index 92082ca18..ddea58aac 100644 --- a/src/lib/decoder.h +++ b/src/lib/decoder.h @@ -57,7 +57,7 @@ public: virtual bool pass () = 0; virtual void seek (dcpomatic::ContentTime time, bool accurate); - dcpomatic::ContentTime position () const; + virtual dcpomatic::ContentTime position () const; protected: boost::shared_ptr film () const; -- 2.30.2