Merge branch '2981-headless-grok'

This makes it possible to configure Grok for encoding from the command
line.

17 files changed, 427 insertions, 64 deletions

diff --git a/src/lib/config.cc b/src/lib/config.cc
index 3227ea433..49c64e5b6 100644
--- a/src/lib/config.cc
+++ b/src/lib/config.cc
@@ -238,7 +238,7 @@ Config::set_defaults()
 	set_cover_sheet_to_default();
 
 #ifdef DCPOMATIC_GROK
-	_grok = boost::none;
+	_grok = {};
 #endif
 
 	_main_divider_sash_position = {};
@@ -1151,9 +1151,7 @@ Config::write_config() const
 	cxml::add_text_child(root, "LayoutForShortScreen", _layout_for_short_screen ? "1" : "0");
 
 #ifdef DCPOMATIC_GROK
-	if (_grok) {
-		_grok->as_xml(cxml::add_child(root, "Grok"));
-	}
+	_grok.as_xml(cxml::add_child(root, "Grok"));
 #endif
 
 	_export.write(cxml::add_child(root, "Export"));
diff --git a/src/lib/config.h b/src/lib/config.h
index d9a95ebfd..b2a979ffa 100644
--- a/src/lib/config.h
+++ b/src/lib/config.h
@@ -666,7 +666,7 @@ public:
 		std::string licence;
 	};
 
-	boost::optional<Grok> grok() const {
+	Grok grok() const {
 		return _grok;
 	}
 #endif
@@ -1495,7 +1495,7 @@ private:
 	bool _layout_for_short_screen;
 
 #ifdef DCPOMATIC_GROK
-	boost::optional<Grok> _grok;
+	Grok _grok;
 #endif
 
 	ExportConfig _export;
diff --git a/src/lib/encode_cli.cc b/src/lib/encode_cli.cc
index a682fa4e3..fa304b6e0 100644
--- a/src/lib/encode_cli.cc
+++ b/src/lib/encode_cli.cc
@@ -30,6 +30,7 @@
 #include "filter.h"
 #ifdef DCPOMATIC_GROK
 #include "grok/context.h"
+#include "grok/util.h"
 #endif
 #include "hints.h"
 #include "job_manager.h"
@@ -43,6 +44,7 @@
 #include "version.h"
 #include "video_content.h"
 #include <dcp/filesystem.h>
+#include <dcp/raw_convert.h>
 #include <dcp/version.h>
 #include <fmt/format.h>
 #include <getopt.h>
@@ -66,7 +68,19 @@ using boost::optional;
 static void
 help(function <void (string)> out)
 {
-	out(fmt::format("Syntax: {} [OPTION] [<FILM>]\n", program_name));
+	out(fmt::format("Syntax: {} [OPTION] [COMMAND] [<PARAMETER>]\n", program_name));
+
+	out("\nCommands:\n\n");
+	out("  make-dcp <FILM>              make DCP from the given film; default if no other command is specified\n");
+	out(variant::insert_dcpomatic("  list-servers                 display a list of encoding servers that %1 can use (until Ctrl-C)\n"));
+	out("  dump <FILM>                  show a summary of the film's settings\n");
+#ifdef DCPOMATIC_GROK
+	out("  config-params                list the parameters that can be set with `config`\n");
+	out("  config <PARAMETER> <VALUE>   set a DCP-o-matic configuration value\n");
+	out("  list-gpus                    list available GPUs\n");
+#endif
+
+	out("\nOptions:\n\n");
 	out(variant::insert_dcpomatic("  -v, --version                     show %1 version\n"));
 	out("  -h, --help                        show this help\n");
 	out("  -f, --flags                       show flags passed to C++ compiler on build\n");
@@ -77,15 +91,19 @@ help(function <void (string)> out)
 	out("  -k, --keep-going                  keep running even when the job is complete\n");
 	out("  -s, --servers <file>              specify servers to use in a text file\n");
 	out(variant::insert_dcpomatic("  -l, --list-servers                just display a list of encoding servers that %1 is configured to use; don't encode\n"));
+	out("                                      (deprecated - use the list-servers command instead)\n");
 	out("  -d, --dcp-path                    echo DCP's path to stdout on successful completion (implies -n)\n");
 	out("  -c, --config <dir>                directory containing config.xml and cinemas.xml\n");
 	out("      --dump                        just dump a summary of the film's settings; don't encode\n");
+	out("                                      (deprecated - use the dump command instead)\n");
 	out("      --no-check                    don't check project's content files for changes before making the DCP\n");
 	out("      --export-format <format>      export project to a file, rather than making a DCP: specify mov or mp4\n");
 	out("      --export-filename <filename>  filename to export to with --export-format\n");
 	out("      --hints                       analyze film for hints before encoding and abort if any are found\n");
+	out("\ne.g.\n");
+	out(fmt::format("\n  {} -t 4 make-dcp my_great_movie\n", program_name));
+	out(fmt::format("\n  {} config grok-licence 12345ABCD\n", program_name));
 	out("\n");
-	out("<FILM> is the film directory.\n");
 }
 
 
@@ -270,6 +288,10 @@ encode_cli(int argc, char* argv[], function<void (string)> out, function<void ()
 	optional<string> export_format;
 	optional<boost::filesystem::path> export_filename;
 	bool hints = false;
+	string command = "make-dcp";
+
+	/* This makes it possible to call getopt several times in the same executable, for tests */
+	optind = 0;
 
 	int option_index = 0;
 	while (true) {
@@ -357,6 +379,77 @@ encode_cli(int argc, char* argv[], function<void (string)> out, function<void ()
 		}
 	}
 
+	vector<string> commands = {
+		"make-dcp",
+		"list-servers",
+#ifdef DCPOMATIC_GROK
+		"dump",
+		"config-params",
+		"config",
+		"list-gpus"
+#else
+		"dump"
+#endif
+	};
+
+	if (optind < argc - 1) {
+		/* Command with a film specified afterwards */
+		command = argv[optind++];
+	} else if (optind < argc) {
+		/* Look for a valid command, hoping that it's not the name of a film */
+		if (std::find(commands.begin(), commands.end(), argv[optind]) != commands.end()) {
+			command = argv[optind++];
+		}
+	}
+
+
+#ifdef DCPOMATIC_GROK
+	if (command == "config-params") {
+		out("Configurable parameters:\n\n");
+		out("  grok-licence           licence string for using the Grok JPEG2000 encoder\n");
+		out("  grok-enable            1 to enable the Grok encoder, 0 to disable it\n");
+		out("  grok-binary-location   directory containing Grok binaries\n");
+		out("  grok-gpu-index         index of GPU to use (from 0, see list-gpus)\n");
+		return {};
+	}
+
+	if (command == "config") {
+		if (optind < argc - 1) {
+			string const parameter = argv[optind++];
+			string const value = argv[optind++];
+			auto grok = Config::instance()->grok();
+			if (parameter == "grok-licence") {
+				grok.licence = value;
+			} else if (parameter == "grok-enable") {
+				if (value == "1") {
+					grok.enable = true;
+				} else if (value == "0") {
+					grok.enable = false;
+				} else {
+					return fmt::format("Invalid value {} for grok-enable (use 1 to enable, 0 to disable)", value);
+				}
+			} else if (parameter == "grok-binary-location") {
+				grok.binary_location = value;
+			} else if (parameter == "grok-gpu-index") {
+				grok.selected = dcp::raw_convert<int>(value);
+			} else {
+				return fmt::format("Unrecognised configuration parameter `{}'", parameter);
+			}
+			Config::instance()->set_grok(grok);
+			Config::instance()->write();
+		} else {
+			return fmt::format("Missing configuration parameter: use {} config <parameter> <value>", program_name);
+		}
+		return {};
+	} else if (command == "list-gpus") {
+		int N = 0;
+		for (auto gpu: get_gpu_names()) {
+			out(fmt::format("{}: {}\n", N++, gpu));
+		}
+		return {};
+	}
+#endif
+
 	if (config) {
 		State::override_path = *config;
 	}
@@ -376,7 +469,7 @@ encode_cli(int argc, char* argv[], function<void (string)> out, function<void ()
 		Config::instance()->set_servers(servers);
 	}
 
-	if (list_servers_) {
+	if (command == "list-servers" || list_servers_) {
 		list_servers(out);
 		return {};
 	}
@@ -420,7 +513,7 @@ encode_cli(int argc, char* argv[], function<void (string)> out, function<void ()
 		return fmt::format("{}: error reading film `{}' ({})\n", program_name, film_dir.string(), e.what());
 	}
 
-	if (dump) {
+	if (command == "dump" || dump) {
 		print_dump(out, film);
 		return {};
 	}
@@ -489,9 +582,9 @@ encode_cli(int argc, char* argv[], function<void (string)> out, function<void ()
 
 	if (progress) {
 		if (export_format) {
-			out(fmt::format("\nExporting {}\n", film->name()));
+			out(fmt::format("Exporting {}\n", film->name()));
 		} else {
-			out(fmt::format("\nMaking DCP for {}\n", film->name()));
+			out(fmt::format("Making DCP for {}\n", film->name()));
 		}
 	}
 
diff --git a/src/lib/grok/context.h b/src/lib/grok/context.h
index 602c8b13f..b31867cf6 100644
--- a/src/lib/grok/context.h
+++ b/src/lib/grok/context.h
@@ -99,7 +99,7 @@ public:
 	explicit GrokContext(DcpomaticContext* dcpomatic_context)
 		: _dcpomatic_context(dcpomatic_context)
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		if (!grok.enable) {
 			return;
 		}
@@ -216,7 +216,7 @@ public:
 
 			auto s = dcpv.get_size();
 			_dcpomatic_context->set_dimensions(s.width, s.height);
-			auto grok = Config::instance()->grok().get_value_or({});
+			auto grok = Config::instance()->grok();
 			if (!_messenger->launch_grok(
 					_dcpomatic_context->location,
 					_dcpomatic_context->width,
diff --git a/src/lib/grok/util.cc b/src/lib/grok/util.cc
new file mode 100644
index 000000000..3cbc55678
--- /dev/null
+++ b/src/lib/grok/util.cc
@@ -0,0 +1,53 @@
+/*
+    Copyright (C) 2023 Grok Image Compression Inc.
+
+    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 "util.h"
+#include "../config.h"
+#include <boost/process.hpp>
+#include <future>
+
+
+using std::string;
+using std::vector;
+
+
+vector<string>
+get_gpu_names()
+{
+	namespace bp = boost::process;
+
+	auto binary = Config::instance()->grok().binary_location / "gpu_lister";
+
+	bp::ipstream stream;
+	bp::child child(binary, bp::std_out > stream);
+
+	string line;
+	vector<string> gpu_names;
+	while (child.running() && std::getline(stream, line) && !line.empty()) {
+		gpu_names.push_back(line);
+	}
+
+	child.wait();
+
+	return gpu_names;
+}
+
+
diff --git a/src/lib/grok/util.h b/src/lib/grok/util.h
new file mode 100644
index 000000000..a78ecabca
--- /dev/null
+++ b/src/lib/grok/util.h
@@ -0,0 +1,27 @@
+/*
+    Copyright (C) 2023 Grok Image Compression Inc.
+
+    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 <boost/filesystem.hpp>
+#include <string>
+#include <vector>
+
+
+extern std::vector<std::string> get_gpu_names();
diff --git a/src/lib/grok_j2k_encoder_thread.cc b/src/lib/grok_j2k_encoder_thread.cc
index e6c256f11..d6825113c 100644
--- a/src/lib/grok_j2k_encoder_thread.cc
+++ b/src/lib/grok_j2k_encoder_thread.cc
@@ -62,7 +62,7 @@ try
 
 		LOG_TIMING("encoder-pop thread=%1 frame=%2 eyes=%3", thread_id(), frame.index(), static_cast<int>(frame.eyes()));
 
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 
 		if (_context->launch(frame, grok.selected) && _context->scheduleCompress(frame)) {
 			frame_guard.cancel();
diff --git a/src/lib/j2k_encoder.cc b/src/lib/j2k_encoder.cc
index 309fce0b3..50452fbad 100644
--- a/src/lib/j2k_encoder.cc
+++ b/src/lib/j2k_encoder.cc
@@ -98,7 +98,7 @@ J2KEncoder::J2KEncoder(shared_ptr<const Film> film, Writer& writer)
 #endif
 {
 #ifdef DCPOMATIC_GROK
-	auto grok = Config::instance()->grok().get_value_or({});
+	auto grok = Config::instance()->grok();
 	_dcpomatic_context = new grk_plugin::DcpomaticContext(film, writer, _history, grok.binary_location);
 	if (grok.enable) {
 		_context = new grk_plugin::GrokContext(_dcpomatic_context);
@@ -135,7 +135,7 @@ J2KEncoder::servers_list_changed()
 {
 	auto config = Config::instance();
 #ifdef DCPOMATIC_GROK
-	auto const grok_enable = config->grok().get_value_or({}).enable;
+	auto const grok_enable = config->grok().enable;
 #else
 	auto const grok_enable = false;
 #endif
@@ -162,7 +162,7 @@ void
 J2KEncoder::pause()
 {
 #ifdef DCPOMATIC_GROK
-	if (!Config::instance()->grok().get_value_or({}).enable) {
+	if (!Config::instance()->grok().enable) {
 		return;
 	}
 	return;
@@ -183,7 +183,7 @@ J2KEncoder::pause()
 void J2KEncoder::resume()
 {
 #ifdef DCPOMATIC_GROK
-	if (!Config::instance()->grok().get_value_or({}).enable) {
+	if (!Config::instance()->grok().enable) {
 		return;
 	}
 
@@ -226,7 +226,7 @@ J2KEncoder::end()
 	*/
 	for (auto & i: _queue) {
 #ifdef DCPOMATIC_GROK
-		if (Config::instance()->grok().get_value_or({}).enable) {
+		if (Config::instance()->grok().enable) {
 			if (!_context->scheduleCompress(i)){
 				LOG_GENERAL (N_("[%1] J2KEncoder thread pushes frame %2 back onto queue after failure"), thread_id(), i.index());
 				// handle error
diff --git a/src/lib/util.cc b/src/lib/util.cc
index df15e1abb..1e2f7d61f 100644
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -1146,7 +1146,7 @@ setup_grok_library_path()
 		}
 	}
 	auto const grok = Config::instance()->grok();
-	if (!grok || grok->binary_location.empty()) {
+	if (grok.binary_location.empty()) {
 		setenv("LD_LIRARY_PATH", old_path.c_str(), 1);
 		return;
 	}
@@ -1155,7 +1155,7 @@ setup_grok_library_path()
 	if (!new_path.empty()) {
 		new_path += ":";
 	}
-	new_path += grok->binary_location.string();
+	new_path += grok.binary_location.string();
 
 	setenv("LD_LIBRARY_PATH", new_path.c_str(), 1);
 }
diff --git a/src/lib/wscript b/src/lib/wscript
index 79f0d563e..cae78fc4a 100644
--- a/src/lib/wscript
+++ b/src/lib/wscript
@@ -267,7 +267,7 @@ def build(bld):
             obj.uselib += ' POLKIT'
 
     if bld.env.ENABLE_GROK:
-        obj.source += ' grok_j2k_encoder_thread.cc'
+        obj.source += ' grok_j2k_encoder_thread.cc grok/util.cc'
 
     if bld.env.TARGET_WINDOWS_64 or bld.env.TARGET_WINDOWS_32:
         obj.uselib += ' WINSOCK2 DBGHELP SHLWAPI MSWSOCK BOOST_LOCALE SETUPAPI OLE32 UUID'
diff --git a/src/wx/grok/gpu_config_panel.h b/src/wx/grok/gpu_config_panel.h
index df38f9373..34bf38f12 100644
--- a/src/wx/grok/gpu_config_panel.h
+++ b/src/wx/grok/gpu_config_panel.h
@@ -22,30 +22,10 @@
 #pragma once
 
 
+#include "lib/grok/util.h"
 #include <wx/filepicker.h>
 
 
-static std::vector<std::string> get_gpu_names(boost::filesystem::path binary, boost::filesystem::path filename)
-{
-    // Execute the GPU listing program and redirect its output to a file
-    if (std::system((binary.string() + " > " + filename.string()).c_str()) < 0) {
-	    return {};
-    }
-
-    std::vector<std::string> gpu_names;
-    std::ifstream file(filename.c_str());
-    if (file.is_open())
-    {
-        std::string line;
-        while (std::getline(file, line))
-            gpu_names.push_back(line);
-        file.close();
-    }
-
-    return gpu_names;
-}
-
-
 class GpuList : public wxPanel
 {
 public:
@@ -63,16 +43,9 @@ public:
 
 	void update()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
-		auto lister_binary = grok.binary_location / "gpu_lister";
-		auto lister_file = grok.binary_location / "gpus.txt";
-		if (boost::filesystem::exists(lister_binary)) {
-			auto gpu_names = get_gpu_names(lister_binary, lister_file);
-
-			_combo_box->Clear();
-			for (auto const& name: gpu_names) {
-				_combo_box->Append(std_to_wx(name));
-			}
+		_combo_box->Clear();
+		for (auto const& name: get_gpu_names()) {
+			_combo_box->Append(std_to_wx(name));
 		}
 	}
 
@@ -88,7 +61,7 @@ private:
 	{
 		auto selection = _combo_box->GetSelection();
 		if (selection != wxNOT_FOUND) {
-			auto grok = Config::instance()->grok().get_value_or({});
+			auto grok = Config::instance()->grok();
 			grok.selected = selection;
 			Config::instance()->set_grok(grok);
 		}
@@ -155,7 +128,7 @@ private:
 
 	void setup_sensitivity()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 
 		_binary_location->Enable(grok.enable);
 		_gpu_list_control->Enable(grok.enable);
@@ -165,7 +138,7 @@ private:
 
 	void config_changed() override
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 
 		checked_set(_enable_gpu, grok.enable);
 		_binary_location->SetPath(std_to_wx(grok.binary_location.string()));
@@ -177,7 +150,7 @@ private:
 
 	void enable_gpu_changed()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		grok.enable = _enable_gpu->GetValue();
 		Config::instance()->set_grok(grok);
 
@@ -186,7 +159,7 @@ private:
 
 	void binary_location_changed()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		grok.binary_location = wx_to_std(_binary_location->GetPath());
 		Config::instance()->set_grok(grok);
 
@@ -195,20 +168,20 @@ private:
 
 	void server_changed()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		grok.licence_server = wx_to_std(_server->GetValue());
 		Config::instance()->set_grok(grok);
 	}
 
 	void port_changed()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		Config::instance()->set_grok(grok);
 	}
 
 	void licence_changed()
 	{
-		auto grok = Config::instance()->grok().get_value_or({});
+		auto grok = Config::instance()->grok();
 		grok.licence = _licence->get();
 		Config::instance()->set_grok(grok);
 	}
diff --git a/test/config_test.cc b/test/config_test.cc
index a9b95bedf..8fd19b693 100644
--- a/test/config_test.cc
+++ b/test/config_test.cc
@@ -182,9 +182,11 @@ BOOST_AUTO_TEST_CASE (config_upgrade_test1)
 
 	check_xml (dir / "config.xml", "test/data/2.14.config.xml", {});
 	check_xml (dir / "cinemas.xml", "test/data/2.14.cinemas.xml", {});
-#ifdef DCPOMATIC_WINDOWS
+#if defined(DCPOMATIC_WINDOWS)
 	/* This file has the windows path for dkdm_recipients.xml (with backslashes) */
 	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.windows.sqlite.xml", {});
+#elif defined(DCPOMATIC_GROK)
+	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.sqlite.grok.xml", {});
 #else
 	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.sqlite.xml", {});
 #endif
@@ -215,10 +217,13 @@ BOOST_AUTO_TEST_CASE (config_upgrade_test2)
 	Config::instance()->write();
 
 	check_xml(dir / "cinemas.xml", "test/data/2.14.cinemas.xml", {});
-#ifdef DCPOMATIC_WINDOWS
+#if defined(DCPOMATIC_WINDOWS)
 	/* This file has the windows path for dkdm_recipients.xml (with backslashes) */
 	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.windows.xml", {});
 	check_xml(dir / "config.xml", "test/data/2.16.config.windows.xml", {});
+#elif defined(DCPOMATIC_GROK)
+	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.grok.xml", {});
+	check_xml(dir / "config.xml", "test/data/2.16.config.xml", {});
 #else
 	check_xml(dir / "2.18" / "config.xml", "test/data/2.18.config.xml", {});
 	check_xml(dir / "config.xml", "test/data/2.16.config.xml", {});
diff --git a/test/data b/test/data
-Subproject df601f1580d852de043c2eca6acc4cfc9a2446b
+Subproject 7d2ed165d8e65d92a02a20e22c1caedd15db82b
diff --git a/test/encode_cli_test.cc b/test/encode_cli_test.cc
new file mode 100644
index 000000000..0a0a17e3a
--- /dev/null
+++ b/test/encode_cli_test.cc
@@ -0,0 +1,163 @@
+/*
+    Copyright (C) 2025 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_factory.h"
+#include "lib/encode_cli.h"
+#include "lib/film.h"
+#include "test.h"
+#include <boost/optional.hpp>
+#include <boost/test/unit_test.hpp>
+#include <iostream>
+#include <string>
+#include <vector>
+
+
+using std::cout;
+using std::string;
+using std::vector;
+using boost::optional;
+
+
+static
+optional<string>
+run(vector<string> const& args, vector<string>& output)
+{
+	vector<char*> argv(args.size() + 1);
+	for (auto i = 0U; i < args.size(); ++i) {
+		argv[i] = const_cast<char*>(args[i].c_str());
+	}
+	argv[args.size()] = nullptr;
+
+	auto error = encode_cli(args.size(), argv.data(), [&output](string s) { output.push_back(s); }, []() { });
+	for (auto i: output) {
+		std::cout << "O:" << i;
+	}
+	if (error) {
+		std::cout << "E:" << *error << "\n";
+	}
+
+	return error;
+}
+
+
+static
+bool
+find_in_order(vector<string> const& output, vector<string> const& check)
+{
+	BOOST_REQUIRE(!check.empty());
+
+	auto next = check.begin();
+	for (auto line: output) {
+		if (line.find(*next) != string::npos) {
+			++next;
+			if (next == check.end()) {
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+
+BOOST_AUTO_TEST_CASE(basic_encode_cli_test)
+{
+	auto content = content_factory("test/data/flat_red.png");
+	auto film = new_test_film("basic_encode_cli_test", content);
+	film->write_metadata();
+
+	vector<string> output;
+	run({ "cli", "build/test/basic_encode_cli_test" }, output);
+
+	BOOST_CHECK(find_in_order(output, { "Making DCP for", "Examining content", "OK", "Transcoding DCP", "OK" }));
+}
+
+
+BOOST_AUTO_TEST_CASE(encode_cli_with_explicit_encode_command_test)
+{
+	auto content = content_factory("test/data/flat_red.png");
+	auto film = new_test_film("basic_encode_cli_test", content);
+	film->write_metadata();
+
+	vector<string> output;
+	run({ "cli", "make-dcp", "build/test/basic_encode_cli_test" }, output);
+
+	BOOST_CHECK(find_in_order(output, { "Making DCP for", "Examining content", "OK", "Transcoding DCP", "OK" }));
+}
+
+
+#ifdef DCPOMATIC_GROK
+BOOST_AUTO_TEST_CASE(encode_cli_set_grok_licence)
+{
+	boost::filesystem::path config = "build/encode_cli_set_grok_licence";
+	boost::filesystem::remove_all(config);
+	boost::filesystem::create_directories(config);
+	ConfigRestorer cr(config);
+
+	vector<string> output;
+	auto error = run({ "cli", "config", "grok-licence", "12345678ABC" }, output);
+	BOOST_CHECK(output.empty());
+	BOOST_CHECK(!error);
+
+	cxml::Document check("Config");
+	check.read_file(config / "2.18" / "config.xml");
+	BOOST_CHECK_EQUAL(check.node_child("Grok")->string_child("Licence"), "12345678ABC");
+}
+
+
+BOOST_AUTO_TEST_CASE(encode_cli_enable_grok)
+{
+	boost::filesystem::path config = "build/encode_cli_enable_grok";
+	boost::filesystem::remove_all(config);
+	boost::filesystem::create_directories(config);
+	ConfigRestorer cr(config);
+
+	for (auto value: vector<string>{ "1", "0"}) {
+		vector<string> output;
+		auto error = run({ "cli", "config", "grok-enable", value }, output);
+		BOOST_CHECK(output.empty());
+		BOOST_CHECK(!error);
+
+		cxml::Document check("Config");
+		check.read_file(config / "2.18" / "config.xml");
+		BOOST_CHECK_EQUAL(check.node_child("Grok")->string_child("Enable"), value);
+	}
+}
+
+
+BOOST_AUTO_TEST_CASE(encode_cli_set_grok_binary_location)
+{
+	boost::filesystem::path config = "build/encode_cli_set_grok_binary_location";
+	boost::filesystem::remove_all(config);
+	boost::filesystem::create_directories(config);
+	ConfigRestorer cr(config);
+
+	vector<string> output;
+	auto error = run({ "cli", "config", "grok-binary-location", "foo/bar/baz" }, output);
+	BOOST_CHECK(output.empty());
+	BOOST_CHECK(!error);
+
+	cxml::Document check("Config");
+	check.read_file(config / "2.18" / "config.xml");
+	BOOST_CHECK_EQUAL(check.node_child("Grok")->string_child("BinaryLocation"), "foo/bar/baz");
+}
+#endif
+
diff --git a/test/gpu_lister b/test/gpu_lister
new file mode 100755
index 000000000..6dcb750de
--- /dev/null
+++ b/test/gpu_lister
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+echo "Foo bar baz"
+echo "Spondoolix Mega Kompute 2000"
+echo "Energy Sink-o-matic"
+
diff --git a/test/grok_util_test.cc b/test/grok_util_test.cc
new file mode 100644
index 000000000..2a84fe2a4
--- /dev/null
+++ b/test/grok_util_test.cc
@@ -0,0 +1,43 @@
+/*
+    Copyright (C) 2025 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/config.h"
+#include "lib/grok/util.h"
+#include "test.h"
+#include <boost/test/unit_test.hpp>
+
+
+#ifdef DCPOMATIC_GROK
+BOOST_AUTO_TEST_CASE(get_gpu_names_test)
+{
+	ConfigRestorer cr;
+
+	Config::Grok grok;
+	grok.binary_location = "test";
+	Config::instance()->set_grok(grok);
+
+	auto names = get_gpu_names();
+	BOOST_REQUIRE_EQUAL(names.size(), 3U);
+	BOOST_CHECK_EQUAL(names[0], "Foo bar baz");
+	BOOST_CHECK_EQUAL(names[1], "Spondoolix Mega Kompute 2000");
+	BOOST_CHECK_EQUAL(names[2], "Energy Sink-o-matic");
+}
+#endif
diff --git a/test/wscript b/test/wscript
index 85bfccf56..7e53dfb02 100644
--- a/test/wscript
+++ b/test/wscript
@@ -85,6 +85,7 @@ def build(bld):
                  email_test.cc
                  empty_caption_test.cc
                  empty_test.cc
+                 encode_cli_test.cc
                  encryption_test.cc
                  file_extension_test.cc
                  ffmpeg_audio_only_test.cc
@@ -109,6 +110,7 @@ def build(bld):
                  font_id_allocator_test.cc
                  frame_interval_checker_test.cc
                  frame_rate_test.cc
+                 grok_util_test.cc
                  guess_crop_test.cc
                  hints_test.cc
                  image_content_fade_test.cc