Added a sinewave audio test source

- Added a test audio sinewave test source that should just play a sine
   wave of the middle C note.  Using unsigned 8 bit mono to test
   ffmpeg's audio resampler, seems to work pretty good.

 - Fixed a boolean trap in threading.h for the event_init function, it
   now uses enum event_type, which can be EVENT_TYPE_MANUAL or
   EVENT_TYPE_AUTO, to specify whether the event is automatically reset
   or not.

 - Changed display names of test sources to something a little less
   vague.

 - Removed te whole "if timestamp is 0 just use current system time"
   when outputting source audio, if you want to use system time you
   should just use system time yourself.  Using 0 as some sort of
   "indicator" like that just makes things confusing, and prevents you
   from legitimately using 0 as a timestamp for your audio data.

test/test-input/CMakeLists.txt

@@ -3,6 +3,7 @@ include_directories(SYSTEM ${obs_SOURCE_DIR}/libobs)
 add_library(test-input MODULE
 	test-filter.c
 	test-input.c
+	test-sinewave.c
 	test-random.c)
 
 target_link_libraries(test-input

test/test-input/makefile.am

@@ -19,4 +19,5 @@ endif
 libtest_input_la_LIBADD = $(top_srcdir)/libobs/libobs.la
 libtest_input_la_SOURCES = test-filter.c \
 			   test-input.c \
-			   test-random.c
+			   test-random.c \
+			   test-sinewave.c

test/test-input/test-input.c

@@ -1,7 +1,7 @@
 #include <obs.h>
 #include "test-input-exports.h"
 
-const char *inputs[] = {"random"};
+const char *inputs[] = {"random", "sinewave"};
 const char *filters[] = {"test"};
 
 uint32_t module_version(uint32_t in_version)

test/test-input/test-random.c

@@ -3,7 +3,7 @@
 
 const char *random_getname(const char *locale)
 {
-	return "Random Source";
+	return "20x20 Random Pixel Texture Source (Test)";
 }
 
 struct random_tex *random_create(const char *settings, obs_source_t source)

test/test-input/test-sinewave.c

@@ -0,0 +1,86 @@
+#include <math.h>
+#include "test-sinewave.h"
+
+const double rate = 261.63/48000.0;
+
+#define M_PI 3.1415926535897932384626433832795
+
+static void *sinewave_thread(void *pdata)
+{
+	struct sinewave_data *swd = pdata;
+	uint64_t last_time = os_gettime_ns();
+	uint64_t ts = 0;
+	double sin_val = 0.0;
+	uint8_t bytes[480];
+
+	while (event_try(&swd->event) == EAGAIN) {
+		os_sleepto_ns(last_time += 10000000);
+
+		for (size_t i = 0; i < 480; i++) {
+			sin_val += rate * M_PI;
+			if (sin_val > M_PI)
+				sin_val -= M_PI;
+
+			double wave = sin(sin_val);
+			bytes[i] = (uint8_t)(wave * 255.0);
+		}
+
+		struct source_audio data;
+		data.data = bytes;
+		data.frames = 480;
+		data.speakers = SPEAKERS_MONO;
+		data.samples_per_sec = 48000;
+		data.timestamp = ts;
+		data.format = AUDIO_FORMAT_U8BIT;
+		obs_source_output_audio(swd->source, &data);
+
+		ts += 10000000;
+	}
+
+	return NULL;
+}
+
+/* ------------------------------------------------------------------------- */
+
+const char *sinewave_getname(const char *locale)
+{
+	return "Sinewave Sound Source (Test)";
+}
+
+struct sinewave_data *sinewave_create(const char *settings, obs_source_t source)
+{
+	struct sinewave_data *swd = bmalloc(sizeof(struct sinewave_data));
+	memset(swd, 0, sizeof(struct sinewave_data));
+	swd->source = source;
+
+	if (event_init(&swd->event, EVENT_TYPE_MANUAL) != 0)
+		goto fail;
+	if (pthread_create(&swd->thread, NULL, sinewave_thread, swd) != 0)
+		goto fail;
+
+	swd->initialized_thread = true;
+	return swd;
+
+fail:
+	sinewave_destroy(swd);
+	return NULL;
+}
+
+void sinewave_destroy(struct sinewave_data *swd)
+{
+	if (swd) {
+		if (swd->initialized_thread) {
+			void *ret;
+			event_signal(&swd->event);
+			pthread_join(swd->thread, &ret);
+		}
+
+		event_destroy(&swd->event);
+		bfree(swd);
+	}
+}
+
+uint32_t sinewave_get_output_flags(struct sinewave_data *swd)
+{
+	return SOURCE_AUDIO;
+}

test/test-input/test-sinewave.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <util/bmem.h>
+#include <util/threading.h>
+#include <util/platform.h>
+#include <obs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct sinewave_data {
+	bool         initialized_thread;
+	pthread_t    thread;
+	event_t      event;
+	obs_source_t source;
+};
+
+EXPORT const char *sinewave_getname(const char *locale);
+
+EXPORT struct sinewave_data *sinewave_create(const char *settings,
+		obs_source_t source);
+EXPORT void sinewave_destroy(struct sinewave_data *swd);
+EXPORT uint32_t sinewave_get_output_flags(struct sinewave_data *swd);
+
+#ifdef __cplusplus
+}
+#endif