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 7a3a3e19b08b16220e1fd39c3deeefab47a575f4..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())
 {
 
 }
@@ -54,26 +56,24 @@ VideoDecoder::VideoDecoder (Decoder* parent, shared_ptr<const Content> c)
  *  and so on.
  */
 void
-VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> image, Frame frame)
+VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> image, Frame decoder_frame)
 {
        if (ignore ()) {
                return;
        }
 
-       switch (_content->video->frame_type ()) {
-       case VIDEO_FRAME_TYPE_2D:
-               Data (ContentVideo (image, frame, EYES_BOTH, PART_WHOLE));
-               break;
-       case VIDEO_FRAME_TYPE_3D:
-       {
-               /* We should receive the same frame index twice for 3D; hence we know which
-                  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.
-                       */
+       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(
@@ -84,16 +84,62 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                                        )
                                );
                }
-               Eyes const eyes = same ? EYES_RIGHT : EYES_LEFT;
+
+               if (_frame_interval_checker->guess() != FrameIntervalChecker::AGAIN) {
+                       _frame_interval_checker.reset ();
+               }
+       }
+
+       Frame frame;
+       Eyes eyes = EYES_BOTH;
+       if (!_position) {
+               /* This is the first data we have received since initialisation or seek.  Set
+                  the position based on the frame that was given.  After this first time
+                  we just cound frames, since (as with audio) it seems that ContentTimes
+                  are unreliable from FFmpegDecoder.  They are much better than audio times
+                  but still we get the occasional one which is duplicated.  In this case
+                  ffmpeg seems to carry on regardless, processing the video frame as normal.
+                  If we drop the frame with the duplicated timestamp we obviously lose sync.
+               */
+               _position = ContentTime::from_frames (decoder_frame, afr);
+               if (vft == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
+                       frame = decoder_frame / 2;
+                       _last_emitted_eyes = EYES_RIGHT;
+               } else {
+                       frame = decoder_frame;
+               }
+       } else {
+               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;
+                               eyes = EYES_LEFT;
+                       } else {
+                               frame = _position->frames_round(afr);
+                               eyes = EYES_RIGHT;
+                       }
+               } else {
+                       frame = _position->frames_round(afr) + 1;
+               }
+       }
+
+       switch (vft) {
+       case VIDEO_FRAME_TYPE_2D:
+               Data (ContentVideo (image, frame, EYES_BOTH, PART_WHOLE));
+               break;
+       case VIDEO_FRAME_TYPE_3D:
+       {
                Data (ContentVideo (image, frame, eyes, PART_WHOLE));
                _last_emitted_frame = frame;
                _last_emitted_eyes = eyes;
                break;
        }
        case VIDEO_FRAME_TYPE_3D_ALTERNATE:
-               Data (ContentVideo (image, frame / 2, (frame % 2) ? EYES_RIGHT : EYES_LEFT, PART_WHOLE));
-               frame /= 2;
+       {
+               Data (ContentVideo (image, frame, eyes, PART_WHOLE));
+               _last_emitted_eyes = eyes;
                break;
+       }
        case VIDEO_FRAME_TYPE_3D_LEFT_RIGHT:
                Data (ContentVideo (image, frame, EYES_LEFT, PART_LEFT_HALF));
                Data (ContentVideo (image, frame, EYES_RIGHT, PART_RIGHT_HALF));
@@ -112,13 +158,14 @@ VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> im
                DCPOMATIC_ASSERT (false);
        }
 
-       _position = ContentTime::from_frames (frame, _content->active_video_frame_rate(film));
+       _position = ContentTime::from_frames (frame, afr);
 }
 
 void
 VideoDecoder::seek ()
 {
-       _position = boost::optional<ContentTime>();
+       _position = boost::none;
        _last_emitted_frame.reset ();
        _last_emitted_eyes.reset ();
+       _frame_interval_checker.reset (new FrameIntervalChecker());
 }