Separate out local/remote encode code from DCPVideo.

Now we have a J2KEncoderCPUBackend and a J2KEncoderRemoteBackend.

1 files changed, 118 insertions, 0 deletions

diff --git a/src/lib/j2k_encoder_cpu_backend.cc b/src/lib/j2k_encoder_cpu_backend.cc
new file mode 100644
index 000000000..99963c103
--- /dev/null
+++ b/src/lib/j2k_encoder_cpu_backend.cc
@@ -0,0 +1,118 @@
+/*
+    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 "config.h"
+#include "dcp_video.h"
+#include "dcpomatic_log.h"
+#include "j2k_encoder_cpu_backend.h"
+#include "player_video.h"
+#include "rng.h"
+#include <dcp/openjpeg_image.h>
+#include <dcp/j2k_transcode.h>
+
+#include "i18n.h"
+
+
+using std::shared_ptr;
+using boost::optional;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
+
+
+optional<dcp::ArrayData>
+J2KEncoderCPUBackend::encode (DCPVideo video)
+{
+	try {
+		auto const comment = Config::instance()->dcp_j2k_comment();
+
+		/* This was empirically derived by a user: see #1902 */
+		int const minimum_size = 16384;
+		LOG_GENERAL ("Using minimum frame size %1", minimum_size);
+
+		auto xyz = DCPVideo::convert_to_xyz (video.frame(), boost::bind(&Log::dcp_log, dcpomatic_log.get(), _1, _2));
+		int noise_amount = 2;
+		int pixel_skip = 16;
+		while (true) {
+			auto enc = dcp::compress_j2k (
+				xyz,
+				video.j2k_bandwidth(),
+				video.frames_per_second(),
+				video.frame()->eyes() == Eyes::LEFT || video.frame()->eyes() == Eyes::RIGHT,
+				video.resolution() == Resolution::FOUR_K,
+				comment.empty() ? "libdcp" : comment
+			);
+
+			if (enc.size() >= minimum_size) {
+				LOG_GENERAL (N_("Frame %1 encoded size was OK (%2)"), video.index(), enc.size());
+				return enc;
+			}
+
+			LOG_GENERAL (N_("Frame %1 encoded size was small (%2); adding noise at level %3 with pixel skip %4"), video.index(), enc.size(), noise_amount, pixel_skip);
+
+			/* The JPEG2000 is too low-bitrate for some decoders <cough>DSS200</cough> so add some noise
+			 * and try again.  This is slow but hopefully won't happen too often.  We have to do
+			 * convert_to_xyz() again because compress_j2k() corrupts its xyz parameter.
+			 */
+
+			xyz = DCPVideo::convert_to_xyz (video.frame(), boost::bind(&Log::dcp_log, dcpomatic_log.get(), _1, _2));
+			auto const size = xyz->size ();
+			auto const pixels = size.width * size.height;
+			dcpomatic::RNG rng(42);
+			for (auto c = 0; c < 3; ++c) {
+				auto p = xyz->data(c);
+				auto e = xyz->data(c) + pixels;
+				while (p < e) {
+					*p = std::min(4095, std::max(0, *p + (rng.get() % noise_amount)));
+					p += pixel_skip;
+				}
+			}
+
+			if (pixel_skip > 1) {
+				--pixel_skip;
+			} else {
+				++noise_amount;
+			}
+			/* Something's gone badly wrong if this much noise doesn't help */
+			DCPOMATIC_ASSERT (noise_amount < 16);
+		}
+
+		switch (video.frame()->eyes()) {
+		case Eyes::BOTH:
+			LOG_DEBUG_ENCODE (N_("Finished locally-encoded frame %1 for mono"), video.index());
+			break;
+		case Eyes::LEFT:
+			LOG_DEBUG_ENCODE (N_("Finished locally-encoded frame %1 for L"), video.index());
+			break;
+		case Eyes::RIGHT:
+			LOG_DEBUG_ENCODE (N_("Finished locally-encoded frame %1 for R"), video.index());
+			break;
+		default:
+			break;
+		}
+	} catch (std::exception& e) {
+		LOG_ERROR (N_("Local encode failed (%1)"), e.what());
+	}
+
+	return {};
+}
+
+