obs-outputs: Add null output

Allows encoding without necessarily outputting to a file or stream.
Useful for running encoding tests.

plugins/obs-outputs/CMakeLists.txt

@@ -69,6 +69,7 @@ set(obs-outputs_HEADERS
 	librtmp)
 set(obs-outputs_SOURCES
 	obs-outputs.c
+	null-output.c
 	rtmp-stream.c
 	rtmp-windows.c
 	flv-output.c

plugins/obs-outputs/null-output.c

+/******************************************************************************
+    Copyright (C) 2017 by Hugh Bailey <obs.jim@gmail.com>
+
+    This program 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.
+
+    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+******************************************************************************/
+
+#include <util/threading.h>
+#include <obs-module.h>
+
+struct null_output {
+	obs_output_t *output;
+
+	pthread_t stop_thread;
+	bool stop_thread_active;
+};
+
+static const char *null_output_getname(void *unused)
+{
+	UNUSED_PARAMETER(unused);
+	return "Null Encoding Output";
+}
+
+static void *null_output_create(obs_data_t *settings, obs_output_t *output)
+{
+	struct null_output *context = bzalloc(sizeof(*context));
+	context->output = output;
+	UNUSED_PARAMETER(settings);
+	return context;
+}
+
+static void null_output_destroy(void *data)
+{
+	struct null_output *context = data;
+	if (context->stop_thread_active)
+		pthread_join(context->stop_thread, NULL);
+	bfree(context);
+}
+
+static bool null_output_start(void *data)
+{
+	struct null_output *context = data;
+
+	if (!obs_output_can_begin_data_capture(context->output, 0))
+		return false;
+	if (!obs_output_initialize_encoders(context->output, 0))
+		return false;
+
+	if (context->stop_thread_active)
+		pthread_join(context->stop_thread, NULL);
+
+	obs_output_begin_data_capture(context->output, 0);
+	return true;
+}
+
+static void *stop_thread(void *data)
+{
+	struct null_output *context = data;
+	obs_output_end_data_capture(context->output);
+	context->stop_thread_active = false;
+	return NULL;
+}
+
+static void null_output_stop(void *data, uint64_t ts)
+{
+	struct null_output *context = data;
+	UNUSED_PARAMETER(ts);
+
+	context->stop_thread_active = pthread_create(&context->stop_thread,
+			NULL, stop_thread, data) == 0;
+}
+
+static void null_output_data(void *data, struct encoder_packet *packet)
+{
+	struct null_output *context = data;
+	UNUSED_PARAMETER(packet);
+}
+
+struct obs_output_info null_output_info = {
+	.id                 = "null_output",
+	.flags              = OBS_OUTPUT_AV |
+	                      OBS_OUTPUT_ENCODED,
+	.get_name           = null_output_getname,
+	.create             = null_output_create,
+	.destroy            = null_output_destroy,
+	.start              = null_output_start,
+	.stop               = null_output_stop,
+	.encoded_packet     = null_output_data
+};

plugins/obs-outputs/obs-outputs.c

@@ -9,6 +9,7 @@ OBS_DECLARE_MODULE()
 OBS_MODULE_USE_DEFAULT_LOCALE("obs-outputs", "en-US")
 
 extern struct obs_output_info rtmp_output_info;
+extern struct obs_output_info null_output_info;
 extern struct obs_output_info flv_output_info;
 
 bool obs_module_load(void)
@@ -19,6 +20,7 @@ bool obs_module_load(void)
 #endif
 
 	obs_register_output(&rtmp_output_info);
+	obs_register_output(&null_output_info);
 	obs_register_output(&flv_output_info);
 	return true;
 }