Stop trying to get frames from a video source when an attempt

to get an earlier frame has already failed because the decoder
said it has no more data.  Before this the VideoDecoder would
repeatedly seek to try to get a frame which does not exist.

This happens when the header of a file is wrong, it would seem;
in the file that triggered the bug the header (as read by DoM or ffprobe)
has a length of 137275 frames but the last frame in the file
(according to DoM or ffprobe -show_frames) is 136207 (44.5s earlier).

diff --git a/ChangeLog b/ChangeLog
index 427c362943e9908f5f0edf8e083dfd26e56e5f73..c2d05c5eb0ba8bb71486a7019a60002e7574a5d1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-01-24  Carl Hetherington  <cth@carlh.net>
+
+       * Fix encodes getting stuck in some cases (#783).
+
 2016-01-23  Carl Hetherington  <cth@carlh.net>
 
        * Fix estimate of required disk space to take referencing

diff --git a/src/lib/video_decoder.cc b/src/lib/video_decoder.cc
index fd5779a657f0304124a28ef27980a62a85a1945a..1de2cd8060a3e0616ff152914e1ccd835934f95f 100644 (file)
--- a/src/lib/video_decoder.cc
+++ b/src/lib/video_decoder.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -70,6 +70,10 @@ VideoDecoder::decoded_video (Frame frame)
 list<ContentVideo>
 VideoDecoder::get_video (Frame frame, bool accurate)
 {
+       if (_no_data_frame && frame >= _no_data_frame.get()) {
+               return list<ContentVideo> ();
+       }
+       
        /* At this stage, if we have get_video()ed before, _decoded_video will contain the last frame that this
           method returned (and possibly a few more).  If the requested frame is not in _decoded_video and it is not the next
           one after the end of _decoded_video we need to seek.
@@ -100,6 +104,7 @@ VideoDecoder::get_video (Frame frame, bool accurate)
 
                        if (pass (PASS_REASON_VIDEO, accurate)) {
                                /* The decoder has nothing more for us */
+                               _no_data_frame = frame;
                                break;
                        }
 
@@ -121,9 +126,9 @@ VideoDecoder::get_video (Frame frame, bool accurate)
                }
        }
 
-       /* Clean up _decoded_video; keep the frame we are returning (which may have two images
+       /* Clean up _decoded_video; keep the frame we are returning, if any (which may have two images
           for 3D), but nothing before that */
-       while (!_decoded_video.empty() && _decoded_video.front().frame < dec.front().frame) {
+       while (!_decoded_video.empty() && !dec.empty() && _decoded_video.front().frame < dec.front().frame) {
                _decoded_video.pop_front ();
        }
 

diff --git a/src/lib/video_decoder.h b/src/lib/video_decoder.h
index 42cfc49063de396fa5043f193430ccffc6279eb0..af24b93bc9ca1c016f74f29169a53e59daa68d10 100644 (file)
--- a/src/lib/video_decoder.h
+++ b/src/lib/video_decoder.h
@@ -70,9 +70,12 @@ protected:
        boost::shared_ptr<Image> _black_image;
        boost::optional<ContentTime> _last_seek_time;
        bool _last_seek_accurate;
-
        /** true if this decoder should ignore all video; i.e. never produce any */
        bool _ignore_video;
+       /** if set, this is a frame for which we got no data because the Decoder said
+        *  it has no more to give.
+        */
+       boost::optional<Frame> _no_data_frame;
 };
 
 #endif