Nicer fix for 2D-labelled-3D checking from master.

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

diff --git a/src/lib/video_decoder.cc b/src/lib/video_decoder.cc
index 508ed90b71c71f62e874f0a763b4b19f2d9db8d7..2850b5aa031a939700bad58ff6a0e7ee2b15b614 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>
@@ -40,6 +41,7 @@ using namespace dcpomatic;
 VideoDecoder::VideoDecoder (Decoder* parent, shared_ptr<const Content> c)
        : DecoderPart (parent)
        , _content (c)
+       , _frame_interval_checker (new FrameIntervalChecker())
 {
 
 }
@@ -60,33 +62,33 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                return;
        }
 
-       /* Before we `re-write' the frame indexes of these incoming data we need to check for
-          the case where the user has some 2D content which they have marked as 3D.  With 3D
-          we should get two frames for each frame index, but in this `bad' case we only get
-          one.  We need to throw an exception if this happens.
-       */
-
-       if (_content->video->frame_type() == VIDEO_FRAME_TYPE_3D) {
-               if (_last_threed_frames.size() > 4) {
-                       _last_threed_frames.erase (_last_threed_frames.begin());
-               }
-               _last_threed_frames.push_back (decoder_frame);
-               if (_last_threed_frames.size() == 4) {
-                       if (_last_threed_frames[0] != _last_threed_frames[1] || _last_threed_frames[2] != _last_threed_frames[3]) {
-                               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)
-                                                       )
+       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 && vft == 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)
                                                )
-                                       );
-                       }
+                                       )
+                               );
                }
-       }
 
-       double const afr = _content->active_video_frame_rate(film);
+               if (_frame_interval_checker->guess() != FrameIntervalChecker::AGAIN) {
+                       _frame_interval_checker.reset ();
+               }
+       }
 
        Frame frame;
        Eyes eyes = EYES_BOTH;
@@ -100,15 +102,14 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                   If we drop the frame with the duplicated timestamp we obviously lose sync.
                */
                _position = ContentTime::from_frames (decoder_frame, afr);
-               if (_content->video->frame_type() == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
+               if (vft == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
                        frame = decoder_frame / 2;
                        _last_emitted_eyes = EYES_RIGHT;
                } else {
                        frame = decoder_frame;
                }
        } else {
-               VideoFrameType const ft = _content->video->frame_type ();
-               if (ft == VIDEO_FRAME_TYPE_3D_ALTERNATE || ft == VIDEO_FRAME_TYPE_3D) {
+               if (vft == VIDEO_FRAME_TYPE_3D || vft == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
                        DCPOMATIC_ASSERT (_last_emitted_eyes);
                        if (_last_emitted_eyes.get() == EYES_RIGHT) {
                                frame = _position->frames_round(afr) + 1;
@@ -122,7 +123,7 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                }
        }
 
-       switch (_content->video->frame_type ()) {
+       switch (vft) {
        case VIDEO_FRAME_TYPE_2D:
                Data (ContentVideo (image, frame, EYES_BOTH, PART_WHOLE));
                break;
@@ -163,7 +164,8 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
 void
 VideoDecoder::seek ()
 {
-       _position = boost::optional<ContentTime>();
+       _position = boost::none;
        _last_emitted_frame.reset ();
        _last_emitted_eyes.reset ();
+       _frame_interval_checker.reset (new FrameIntervalChecker());
 }