New way of checking for 2D content mislabelled as 3D (#1565).

[dcpomatic.git] / src / lib / video_decoder.cc

diff --git a/src/lib/video_decoder.cc b/src/lib/video_decoder.cc
index 613ec9c7311f8c162b34b7306c341f8c0ad4fdd7..e817c4754caea68e82498098f608ab8d9adbafe0 100644 (file)
--- a/src/lib/video_decoder.cc
+++ b/src/lib/video_decoder.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2020 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -23,6 +23,7 @@
 #include "raw_image_proxy.h"
 #include "film.h"
 #include "log.h"
+#include "frame_interval_checker.h"
 #include "compose.hpp"
 #include <boost/foreach.hpp>
 #include <iostream>
@@ -39,6 +40,7 @@ using boost::optional;
 VideoDecoder::VideoDecoder (Decoder* parent, shared_ptr<const Content> c)
        : DecoderPart (parent)
        , _content (c)
+       , _frame_interval_checker (new FrameIntervalChecker())
 {
 
 }
@@ -62,6 +64,31 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
        double const afr = _content->active_video_frame_rate(film);
        VideoFrameType const vft = _content->video->frame_type();
 
+       ContentTime frame_time = ContentTime::from_frames (decoder_frame, afr);
+
+       /* Do some heuristics to try and spot the case where the user sets content to 3D
+        * when it is not.  We try to tell this by looking at the differences in time between
+        * the first few frames.  Real 3D content should have two frames for each timestamp.
+        */
+       if (_frame_interval_checker) {
+               _frame_interval_checker->feed (frame_time, afr);
+               if (_frame_interval_checker->guess() == FrameIntervalChecker::PROBABLY_NOT_3D && _content->video->frame_type() == VIDEO_FRAME_TYPE_3D) {
+                       boost::throw_exception (
+                               DecodeError(
+                                       String::compose(
+                                               _("The content file %1 is set as 3D but does not appear to contain 3D images.  Please set it to 2D.  "
+                                                 "You can still make a 3D DCP from this content by ticking the 3D option in the DCP video tab."),
+                                               _content->path(0)
+                                               )
+                                       )
+                               );
+               }
+
+               if (_frame_interval_checker->guess() != FrameIntervalChecker::AGAIN) {
+                       _frame_interval_checker.reset ();
+               }
+       }
+
        Frame frame;
        if (!_position) {
                /* This is the first data we have received since initialisation or seek.  Set
@@ -105,20 +132,6 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                   frame this one is.
                */
                bool const same = (_last_emitted_frame && _last_emitted_frame.get() == frame);
-               if (!same && _last_emitted_eyes && *_last_emitted_eyes == EYES_LEFT) {
-                       /* We just got a new frame index but the last frame was left-eye; it looks like
-                          this content is not really 3D.
-                       */
-                       boost::throw_exception (
-                               DecodeError(
-                                       String::compose(
-                                               _("The content file %1 is set as 3D but does not appear to contain 3D images.  Please set it to 2D.  "
-                                                 "You can still make a 3D DCP from this content by ticking the 3D option in the DCP video tab."),
-                                               _content->path(0)
-                                               )
-                                       )
-                               );
-               }
                Eyes const eyes = same ? EYES_RIGHT : EYES_LEFT;
                Data (ContentVideo (image, frame, eyes, PART_WHOLE));
                _last_emitted_frame = frame;
@@ -160,4 +173,5 @@ VideoDecoder::seek ()
        _position = boost::none;
        _last_emitted_frame.reset ();
        _last_emitted_eyes.reset ();
+       _frame_interval_checker.reset (new FrameIntervalChecker());
 }