X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fdcp_video.cc;h=4a505a7e18e65996b4666d59f541e67b0f993c06;hb=c7917ecfce3200d807091cb64241e54066822cbf;hp=58e10f0ed69f349b65d5c51b92b89f59a872205d;hpb=8fedaaa75c4586a4cc7ffb393bd71d1fdb091dc8;p=dcpomatic.git

diff --git a/src/lib/dcp_video.cc b/src/lib/dcp_video.cc
index 58e10f0ed..4a505a7e1 100644
--- a/src/lib/dcp_video.cc
+++ b/src/lib/dcp_video.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -18,6 +18,7 @@
 
 */
 
+
 /** @file  src/dcp_video_frame.cc
  *  @brief A single frame of video destined for a DCP.
  *
@@ -28,23 +29,25 @@
  *  of images that require encoding.
  */
 
-#include "dcp_video.h"
+
+#include "compose.hpp"
 #include "config.h"
-#include "exceptions.h"
-#include "encode_server_description.h"
+#include "cross.h"
+#include "dcp_video.h"
+#include "dcpomatic_log.h"
 #include "dcpomatic_socket.h"
+#include "encode_server_description.h"
+#include "exceptions.h"
 #include "image.h"
 #include "log.h"
-#include "dcpomatic_log.h"
-#include "cross.h"
 #include "player_video.h"
-#include "compose.hpp"
+#include "rng.h"
 #include "warnings.h"
 #include <libcxml/cxml.h>
 #include <dcp/raw_convert.h>
 #include <dcp/openjpeg_image.h>
 #include <dcp/rgb_xyz.h>
-#include <dcp/j2k.h>
+#include <dcp/j2k_transcode.h>
 DCPOMATIC_DISABLE_WARNINGS
 #include <libxml++/libxml++.h>
 DCPOMATIC_ENABLE_WARNINGS
@@ -124,15 +127,58 @@ DCPVideo::encode_locally ()
 {
 	auto const comment = Config::instance()->dcp_j2k_comment();
 
-	auto enc = dcp::compress_j2k (
-		convert_to_xyz (_frame, boost::bind(&Log::dcp_log, dcpomatic_log.get(), _1, _2)),
-		_j2k_bandwidth,
-		_frames_per_second,
-		_frame->eyes() == Eyes::LEFT || _frame->eyes() == Eyes::RIGHT,
-		_resolution == Resolution::FOUR_K,
-		comment.empty() ? "libdcp" : comment
+	ArrayData enc = {};
+	/* 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 = convert_to_xyz (_frame, boost::bind(&Log::dcp_log, dcpomatic_log.get(), _1, _2));
+	int noise_amount = 2;
+	int pixel_skip = 16;
+	while (true) {
+		enc = dcp::compress_j2k (
+			xyz,
+			_j2k_bandwidth,
+			_frames_per_second,
+			_frame->eyes() == Eyes::LEFT || _frame->eyes() == Eyes::RIGHT,
+			_resolution == Resolution::FOUR_K,
+			comment.empty() ? "libdcp" : comment
 		);
 
+		if (enc.size() >= minimum_size) {
+			LOG_GENERAL (N_("Frame %1 encoded size was OK (%2)"), _index, enc.size());
+			break;
+		}
+
+		LOG_GENERAL (N_("Frame %1 encoded size was small (%2); adding noise at level %3 with pixel skip %4"), _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 = convert_to_xyz (_frame, boost::bind(&Log::dcp_log, dcpomatic_log.get(), _1, _2));
+		auto size = xyz->size ();
+		auto 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 (_frame->eyes()) {
 	case Eyes::BOTH:
 		LOG_DEBUG_ENCODE (N_("Finished locally-encoded frame %1 for mono"), _index);
@@ -181,7 +227,7 @@ DCPVideo::encode_remotely (EncodeServerDescription serv, int timeout)
 		/* Send XML metadata */
 		auto xml = doc.write_to_string ("UTF-8");
 		socket->write (xml.length() + 1);
-		socket->write ((uint8_t *) xml.c_str(), xml.length() + 1);
+		socket->write ((uint8_t *) xml.c_str(), xml.bytes() + 1);
 
 		/* Send binary data */
 		LOG_TIMING("start-remote-send thread=%1", thread_id ());