Add guess_crop().

diff --git a/src/lib/guess_crop.cc b/src/lib/guess_crop.cc
new file mode 100644 (file)
index 0000000..5deb0e4
--- /dev/null
+++ b/src/lib/guess_crop.cc
@@ -0,0 +1,133 @@
+/*
+    Copyright (C) 2021 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "decoder.h"
+#include "decoder_factory.h"
+#include "image_proxy.h"
+#include "guess_crop.h"
+#include "image.h"
+#include "video_decoder.h"
+
+
+using std::shared_ptr;
+using namespace dcpomatic;
+
+
+Crop
+guess_crop (shared_ptr<const Image> image, double threshold)
+{
+       auto const width = image->size().width;
+       auto const height = image->size().height;
+
+       auto image_in_line = [image, threshold](int start_x, int start_y, int pixels, bool rows) {
+               double brightest = 0;
+
+               switch (image->pixel_format()) {
+               case AV_PIX_FMT_RGB24:
+               {
+                       uint8_t const* data = image->data()[0] + start_x * 3 + start_y * image->stride()[0];
+                       for (int p = 0; p < pixels; ++p) {
+                               /* Averaging R, G and B */
+                               brightest = std::max(brightest, static_cast<double>(data[0] + data[1] + data[2]) / (3 * 256));
+                               data += rows ? 3 : image->stride()[0];
+                       }
+                       break;
+               }
+               case AV_PIX_FMT_YUV420P:
+               {
+                       uint8_t const* data = image->data()[0] + start_x + start_y * image->stride()[0];
+                       for (int p = 0; p < pixels; ++p) {
+                               /* Just using Y */
+                               brightest = std::max(brightest, static_cast<double>(*data) / 256);
+                               data += rows ? 1 : image->stride()[0];
+                       }
+                       break;
+               }
+               default:
+                       DCPOMATIC_ASSERT (false);
+               }
+
+               return brightest > threshold;
+       };
+
+       auto crop = Crop{};
+
+       for (auto y = 0; y < height; ++y) {
+               if (image_in_line(0, y, width, true)) {
+                       crop.top = y;
+                       break;
+               }
+       }
+
+       for (auto y = height - 1; y >= 0; --y) {
+               if (image_in_line(0, y, width, true)) {
+                       crop.bottom = height - 1 - y;
+                       break;
+               }
+       }
+
+       for (auto x = 0; x < width; ++x) {
+               if (image_in_line(x, 0, height, false)) {
+                       crop.left = x;
+                       break;
+               }
+       }
+
+       for (auto x = width - 1; x >= 0; --x) {
+               if (image_in_line(x, 0, height, false)) {
+                       crop.right = width - 1 - x;
+                       break;
+               }
+       }
+
+       return crop;
+}
+
+
+/** @param position Time within the content to get a video frame from when guessing the crop */
+Crop
+guess_crop (shared_ptr<const Film> film, shared_ptr<const Content> content, double threshold, ContentTime position)
+{
+       DCPOMATIC_ASSERT (content->video);
+
+       auto decoder = decoder_factory (film, content, false, false, {});
+       DCPOMATIC_ASSERT (decoder->video);
+
+       bool done = false;
+       auto crop = Crop{};
+
+       auto handle_video = [&done, &crop, threshold](ContentVideo video) {
+               crop = guess_crop(video.image->image(Image::Alignment::COMPACT).image, threshold);
+               done = true;
+       };
+
+       decoder->video->Data.connect (handle_video);
+       decoder->seek (position, false);
+
+       int tries_left = 50;
+       while (!done && tries_left >= 0) {
+               decoder->pass();
+               --tries_left;
+       }
+
+       return crop;
+}
+

diff --git a/src/lib/guess_crop.h b/src/lib/guess_crop.h
new file mode 100644 (file)
index 0000000..d749120
--- /dev/null
+++ b/src/lib/guess_crop.h
@@ -0,0 +1,34 @@
+/*
+    Copyright (C) 2021 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "dcpomatic_time.h"
+#include "types.h"
+#include <memory>
+
+
+class Content;
+class Film;
+class Image;
+
+
+Crop guess_crop (std::shared_ptr<const Image> image, double threshold);
+Crop guess_crop (std::shared_ptr<const Film> fillm, std::shared_ptr<const Content> content, double threshold, dcpomatic::ContentTime position);
+

diff --git a/src/lib/wscript b/src/lib/wscript
index a5f96ec8237e9151f44781820d722badab1ff9fa..87136576601a7815172054a8c6f389c53cbd75ea 100644 (file)
--- a/src/lib/wscript
+++ b/src/lib/wscript
@@ -116,6 +116,7 @@ sources = """
           font_data.cc
           frame_interval_checker.cc
           frame_rate_change.cc
+          guess_crop.cc
           hints.cc
           internet.cc
           image.cc

diff --git a/test/guess_crop_test.cc b/test/guess_crop_test.cc
new file mode 100644 (file)
index 0000000..c26fc5e
--- /dev/null
+++ b/test/guess_crop_test.cc
@@ -0,0 +1,69 @@
+/*
+    Copyright (C) 2021 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "lib/content.h"
+#include "lib/content_factory.h"
+#include "lib/guess_crop.h"
+#include "lib/types.h"
+#include "lib/video_content.h"
+#include "test.h"
+#include <boost/test/unit_test.hpp>
+#include <iostream>
+#include <vector>
+
+
+using namespace dcpomatic;
+
+
+BOOST_AUTO_TEST_CASE (guess_crop_image_test1)
+{
+       auto content = content_factory(TestPaths::private_data() / "arrietty_724.tiff").front();
+       auto film = new_test_film2 ("guess_crop_image_test1", { content });
+
+       BOOST_CHECK (
+               guess_crop(film, content, 0.1, ContentTime::from_frames(content->video->length(), content->video_frame_rate().get()))
+               == Crop(0, 0, 11, 11)
+               );
+}
+
+
+BOOST_AUTO_TEST_CASE (guess_crop_image_test2)
+{
+       auto content = content_factory(TestPaths::private_data() / "prophet_frame.tiff").front();
+       auto film = new_test_film2 ("guess_crop_image_test2", { content });
+
+       BOOST_CHECK (
+               guess_crop(film, content, 0.1, ContentTime::from_frames(content->video->length(), content->video_frame_rate().get()))
+               == Crop(0, 0, 22, 22)
+               );
+}
+
+
+BOOST_AUTO_TEST_CASE (guess_crop_image_test3)
+{
+       auto content = content_factory(TestPaths::private_data() / "pillarbox.png").front();
+       auto film = new_test_film2 ("guess_crop_image_test3", { content });
+
+       BOOST_CHECK (
+               guess_crop(film, content, 0.1, ContentTime::from_frames(content->video->length(), content->video_frame_rate().get()))
+               == Crop(113, 262, 0, 0)
+               );
+}

diff --git a/test/wscript b/test/wscript
index 1e24956bfab1ad6a3117d7eedb96c4649de9ff6e..b8f490eca0a0361fb75aeb3015a8e2797eb710c5 100644 (file)
--- a/test/wscript
+++ b/test/wscript
@@ -89,6 +89,7 @@ def build(bld):
                  find_missing_test.cc
                  frame_interval_checker_test.cc
                  frame_rate_test.cc
+                 guess_crop_test.cc
                  hints_test.cc
                  image_content_fade_test.cc
                  image_filename_sorter_test.cc