obs-studio/libobs/obs.c

/******************************************************************************
    Copyright (C) 2013-2014 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 "callback/calldata.h"

#include "obs.h"
#include "obs-internal.h"

struct obs_core *obs = NULL;

extern char *find_libobs_data_file(const char *file);

static inline void make_gs_init_data(struct gs_init_data *gid,
		struct obs_video_info *ovi)
{
	memcpy(&gid->window, &ovi->window, sizeof(struct gs_window));
	gid->cx              = ovi->window_width;
	gid->cy              = ovi->window_height;
	gid->num_backbuffers = 2;
	gid->format          = GS_RGBA;
	gid->zsformat        = GS_ZS_NONE;
	gid->adapter         = ovi->adapter;
}

static inline void make_video_info(struct video_output_info *vi,
		struct obs_video_info *ovi)
{
	vi->name    = "video";
	vi->format  = ovi->output_format;
	vi->fps_num = ovi->fps_num;
	vi->fps_den = ovi->fps_den;
	vi->width   = ovi->output_width;
	vi->height  = ovi->output_height;
}

#define PIXEL_SIZE 4

#define GET_ALIGN(val, align) \
	(((val) + (align-1)) & ~(align-1))

static inline void set_420p_sizes(const struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	uint32_t chroma_pixels;
	uint32_t total_bytes;

	chroma_pixels = (ovi->output_width * ovi->output_height / 4);
	chroma_pixels = GET_ALIGN(chroma_pixels, PIXEL_SIZE);

	video->plane_offsets[0] = 0;
	video->plane_offsets[1] = ovi->output_width * ovi->output_height;
	video->plane_offsets[2] = video->plane_offsets[1] + chroma_pixels;

	video->plane_linewidth[0] = ovi->output_width;
	video->plane_linewidth[1] = ovi->output_width/2;
	video->plane_linewidth[2] = ovi->output_width/2;

	video->plane_sizes[0] = video->plane_offsets[1];
	video->plane_sizes[1] = video->plane_sizes[0]/4;
	video->plane_sizes[2] = video->plane_sizes[1];

	total_bytes = video->plane_offsets[2] + chroma_pixels;

	video->conversion_height =
		(total_bytes/PIXEL_SIZE + ovi->output_width-1) /
		ovi->output_width;

	video->conversion_height = GET_ALIGN(video->conversion_height, 2);
	video->conversion_tech = "Planar420";
}

static inline void set_nv12_sizes(const struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	uint32_t chroma_pixels;
	uint32_t total_bytes;

	chroma_pixels = (ovi->output_width * ovi->output_height / 2);
	chroma_pixels = GET_ALIGN(chroma_pixels, PIXEL_SIZE);

	video->plane_offsets[0] = 0;
	video->plane_offsets[1] = ovi->output_width * ovi->output_height;

	video->plane_linewidth[0] = ovi->output_width;
	video->plane_linewidth[1] = ovi->output_width;

	video->plane_sizes[0] = video->plane_offsets[1];
	video->plane_sizes[1] = video->plane_sizes[0]/2;

	total_bytes = video->plane_offsets[1] + chroma_pixels;

	video->conversion_height =
		(total_bytes/PIXEL_SIZE + ovi->output_width-1) /
		ovi->output_width;

	video->conversion_height = GET_ALIGN(video->conversion_height, 2);
	video->conversion_tech = "NV12";
}

static inline void calc_gpu_conversion_sizes(const struct obs_video_info *ovi)
{
	obs->video.conversion_height = 0;
	memset(obs->video.plane_offsets, 0, sizeof(obs->video.plane_offsets));
	memset(obs->video.plane_sizes, 0, sizeof(obs->video.plane_sizes));
	memset(obs->video.plane_linewidth, 0,
		sizeof(obs->video.plane_linewidth));

	switch ((uint32_t)ovi->output_format) {
	case VIDEO_FORMAT_I420:
		set_420p_sizes(ovi);
		break;
	case VIDEO_FORMAT_NV12:
		set_nv12_sizes(ovi);
		break;
	}
}

static bool obs_init_gpu_conversion(struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;

	calc_gpu_conversion_sizes(ovi);

	if (!video->conversion_height) {
		blog(LOG_INFO, "GPU conversion not available for format: %u",
				(unsigned int)ovi->output_format);
		video->gpu_conversion = false;
		return true;
	}

	for (size_t i = 0; i < NUM_TEXTURES; i++) {
		video->convert_textures[i] = gs_create_texture(
				ovi->output_width, video->conversion_height,
				GS_RGBA, 1, NULL, GS_RENDERTARGET);

		if (!video->convert_textures[i])
			return false;
	}

	return true;
}

static bool obs_init_textures(struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	bool yuv = format_is_yuv(ovi->output_format);
	uint32_t output_height = video->gpu_conversion ?
		video->conversion_height : ovi->output_height;
	size_t i;

	for (i = 0; i < NUM_TEXTURES; i++) {
		video->copy_surfaces[i] = gs_create_stagesurface(
				ovi->output_width, output_height, GS_RGBA);

		if (!video->copy_surfaces[i])
			return false;

		video->render_textures[i] = gs_create_texture(
				ovi->base_width, ovi->base_height,
				GS_RGBA, 1, NULL, GS_RENDERTARGET);

		if (!video->render_textures[i])
			return false;

		video->output_textures[i] = gs_create_texture(
				ovi->output_width, ovi->output_height,
				GS_RGBA, 1, NULL, GS_RENDERTARGET);

		if (!video->output_textures[i])
			return false;

		if (yuv)
			source_frame_init(&video->convert_frames[i],
					ovi->output_format,
					ovi->output_width, ovi->output_height);
	}

	return true;
}

static int obs_init_graphics(struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	struct gs_init_data graphics_data;
	bool success = true;
	int errorcode;

	make_gs_init_data(&graphics_data, ovi);

	errorcode = gs_create(&video->graphics, ovi->graphics_module,
			&graphics_data);
	if (errorcode != GS_SUCCESS) {
		switch (errorcode) {
		case GS_ERROR_MODULE_NOT_FOUND:
			return OBS_VIDEO_MODULE_NOT_FOUND;
		case GS_ERROR_NOT_SUPPORTED:
			return OBS_VIDEO_NOT_SUPPORTED;
		default:
			return OBS_VIDEO_FAIL;
		}
	}

	gs_entercontext(video->graphics);

	char *filename = find_libobs_data_file("default.effect");
	video->default_effect = gs_create_effect_from_file(filename,
			NULL);
	bfree(filename);

	filename = find_libobs_data_file("solid.effect");
	video->solid_effect = gs_create_effect_from_file(filename,
			NULL);
	bfree(filename);

	filename = find_libobs_data_file("format_conversion.effect");
	video->conversion_effect = gs_create_effect_from_file(filename,
			NULL);
	bfree(filename);

	if (!video->default_effect)
		success = false;
	if (!video->solid_effect)
		success = false;
	if (!video->conversion_effect)
		success = false;

	gs_leavecontext();
	return success ? OBS_VIDEO_SUCCESS : OBS_VIDEO_FAIL;
}

static int obs_init_video(struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	struct video_output_info vi;
	int errorcode;

	make_video_info(&vi, ovi);
	video->base_width     = ovi->base_width;
	video->base_height    = ovi->base_height;
	video->output_width   = ovi->output_width;
	video->output_height  = ovi->output_height;
	video->gpu_conversion = ovi->gpu_conversion;

	errorcode = video_output_open(&video->video, &vi);

	if (errorcode != VIDEO_OUTPUT_SUCCESS) {
		if (errorcode == VIDEO_OUTPUT_INVALIDPARAM) {
			blog(LOG_ERROR, "Invalid video parameters specified");
			return OBS_VIDEO_INVALID_PARAM;
		} else {
			blog(LOG_ERROR, "Could not open video output");
		}
		return OBS_VIDEO_FAIL;
	}

	if (!obs_display_init(&video->main_display, NULL))
		return OBS_VIDEO_FAIL;

	video->main_display.cx = ovi->window_width;
	video->main_display.cy = ovi->window_height;

	gs_entercontext(video->graphics);

	if (ovi->gpu_conversion && !obs_init_gpu_conversion(ovi))
		return OBS_VIDEO_FAIL;
	if (!obs_init_textures(ovi))
		return OBS_VIDEO_FAIL;

	gs_leavecontext();

	errorcode = pthread_create(&video->video_thread, NULL,
			obs_video_thread, obs);
	if (errorcode != 0)
		return OBS_VIDEO_FAIL;

	video->thread_initialized = true;
	return OBS_VIDEO_SUCCESS;
}

static void stop_video(void)
{
	struct obs_core_video *video = &obs->video;
	void *thread_retval;

	if (video->video) {
		video_output_stop(video->video);
		if (video->thread_initialized) {
			pthread_join(video->video_thread, &thread_retval);
			video->thread_initialized = false;
		}
	}

}

static void obs_free_video(void)
{
	struct obs_core_video *video = &obs->video;

	if (video->video) {
		obs_display_free(&video->main_display);
		video_output_close(video->video);
		video->video = NULL;

		if (!video->graphics)
			return;

		gs_entercontext(video->graphics);

		if (video->mapped_surface) {
			stagesurface_unmap(video->mapped_surface);
			video->mapped_surface = NULL;
		}

		for (size_t i = 0; i < NUM_TEXTURES; i++) {
			stagesurface_destroy(video->copy_surfaces[i]);
			texture_destroy(video->render_textures[i]);
			texture_destroy(video->convert_textures[i]);
			texture_destroy(video->output_textures[i]);
			source_frame_free(&video->convert_frames[i]);

			video->copy_surfaces[i]    = NULL;
			video->render_textures[i]  = NULL;
			video->convert_textures[i] = NULL;
			video->output_textures[i]  = NULL;
		}

		gs_leavecontext();

		video->cur_texture = 0;
	}
}

static void obs_free_graphics(void)
{
	struct obs_core_video *video = &obs->video;

	if (video->graphics) {
		gs_entercontext(video->graphics);

		effect_destroy(video->default_effect);
		effect_destroy(video->solid_effect);
		effect_destroy(video->conversion_effect);
		video->default_effect = NULL;

		gs_leavecontext();

		gs_destroy(video->graphics);
		video->graphics = NULL;
	}
}

static bool obs_init_audio(struct audio_output_info *ai)
{
	struct obs_core_audio *audio = &obs->audio;
	int errorcode;

	/* TODO: sound subsystem */

	audio->user_volume    = 1.0f;
	audio->present_volume = 1.0f;

	errorcode = audio_output_open(&audio->audio, ai);
	if (errorcode == AUDIO_OUTPUT_SUCCESS)
		return true;
	else if (errorcode == AUDIO_OUTPUT_INVALIDPARAM)
		blog(LOG_ERROR, "Invalid audio parameters specified");
	else
		blog(LOG_ERROR, "Could not open audio output");

	return false;
}

static void obs_free_audio(void)
{
	struct obs_core_audio *audio = &obs->audio;
	if (audio->audio)
		audio_output_close(audio->audio);

	memset(audio, 0, sizeof(struct obs_core_audio));
}

static bool obs_init_data(void)
{
	struct obs_core_data *data = &obs->data;
	pthread_mutexattr_t attr;

	assert(data != NULL);

	pthread_mutex_init_value(&obs->data.displays_mutex);

	if (pthread_mutexattr_init(&attr) != 0)
		return false;
	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0)
		goto fail;
	if (pthread_mutex_init(&data->user_sources_mutex, &attr) != 0)
		goto fail;
	if (pthread_mutex_init(&data->sources_mutex, &attr) != 0)
		goto fail;
	if (pthread_mutex_init(&data->displays_mutex, &attr) != 0)
		goto fail;
	if (pthread_mutex_init(&data->outputs_mutex, &attr) != 0)
		goto fail;
	if (pthread_mutex_init(&data->encoders_mutex, &attr) != 0)
		goto fail;
	if (pthread_mutex_init(&data->services_mutex, &attr) != 0)
		goto fail;
	if (!obs_view_init(&data->main_view))
		goto fail;

	data->valid = true;

fail:
	pthread_mutexattr_destroy(&attr);
	return data->valid;
}

#define FREE_OBS_LINKED_LIST(type) \
	do { \
		int unfreed = 0; \
		while (data->first_ ## type ) { \
			obs_ ## type ## _destroy(data->first_ ## type ); \
			unfreed++; \
		} \
		if (unfreed) \
			blog(LOG_INFO, "\t%d " #type "(s) were remaining", \
					unfreed); \
	} while (false)

static void obs_free_data(void)
{
	struct obs_core_data *data = &obs->data;

	data->valid = false;

	obs_view_free(&data->main_view);

	blog(LOG_INFO, "Freeing OBS context data");

	if (data->user_sources.num)
		blog(LOG_INFO, "\t%d user source(s) were remaining",
				(int)data->user_sources.num);

	while (data->user_sources.num)
		obs_source_remove(data->user_sources.array[0]);
	da_free(data->user_sources);

	FREE_OBS_LINKED_LIST(source);
	FREE_OBS_LINKED_LIST(output);
	FREE_OBS_LINKED_LIST(encoder);
	FREE_OBS_LINKED_LIST(display);
	FREE_OBS_LINKED_LIST(service);

	pthread_mutex_destroy(&data->user_sources_mutex);
	pthread_mutex_destroy(&data->sources_mutex);
	pthread_mutex_destroy(&data->displays_mutex);
	pthread_mutex_destroy(&data->outputs_mutex);
	pthread_mutex_destroy(&data->encoders_mutex);
	pthread_mutex_destroy(&data->services_mutex);
}

static const char *obs_signals[] = {
	"void source_create(ptr source)",
	"void source_destroy(ptr source)",
	"void source_add(ptr source)",
	"void source_remove(ptr source)",
	"void source_activate(ptr source)",
	"void source_deactivate(ptr source)",
	"void source_show(ptr source)",
	"void source_hide(ptr source)",
	"void source_rename(ptr source, string new_name, string prev_name)",
	"void source_volume(ptr source, in out float volume)",
	"void source_volume_level(ptr source, float level, float magnitude, "
		"float peak)",

	"void channel_change(int channel, in out ptr source, ptr prev_source)",
	"void master_volume(in out float volume)",

	NULL
};

static inline bool obs_init_handlers(void)
{
	obs->signals = signal_handler_create();
	if (!obs->signals)
		return false;

	obs->procs   = proc_handler_create();
	if (!obs->procs)
		return false;

	return signal_handler_add_array(obs->signals, obs_signals);
}

extern const struct obs_source_info scene_info;

extern void log_system_info(void);

static bool obs_init(const char *locale)
{
	obs = bzalloc(sizeof(struct obs_core));

	log_system_info();

	if (!obs_init_data())
		return false;
	if (!obs_init_handlers())
		return false;

	obs->locale = bstrdup(locale);
	obs_register_source(&scene_info);
	return true;
}

bool obs_startup(const char *locale)
{
	bool success;

	if (obs) {
		blog(LOG_WARNING, "Tried to call obs_startup more than once");
		return false;
	}

	success = obs_init(locale);
	if (!success)
		obs_shutdown();

	return success;
}

void obs_shutdown(void)
{
	if (!obs)
		return;

	da_free(obs->input_types);
	da_free(obs->filter_types);
	da_free(obs->encoder_types);
	da_free(obs->transition_types);
	da_free(obs->output_types);
	da_free(obs->service_types);
	da_free(obs->modal_ui_callbacks);
	da_free(obs->modeless_ui_callbacks);

	stop_video();

	obs_free_data();
	obs_free_video();
	obs_free_graphics();
	obs_free_audio();
	proc_handler_destroy(obs->procs);
	signal_handler_destroy(obs->signals);

	for (size_t i = 0; i < obs->modules.num; i++)
		free_module(obs->modules.array+i);
	da_free(obs->modules);

	bfree(obs->locale);
	bfree(obs);
	obs = NULL;
}

bool obs_initialized(void)
{
	return obs != NULL;
}

void obs_set_locale(const char *locale)
{
	if (!obs)
		return;

	if (obs->locale)
		bfree(obs->locale);
	obs->locale = bstrdup(locale);

	for (size_t i = 0; i < obs->modules.num; i++) {
		struct obs_module *module = obs->modules.array+i;

		if (module->set_locale)
			module->set_locale(locale);
	}
}

const char *obs_get_locale(void)
{
	return obs ? obs->locale : NULL;
}

#define OBS_SIZE_MIN 2
#define OBS_SIZE_MAX (32 * 1024)

static inline bool size_valid(uint32_t width, uint32_t height)
{
	return (width >= OBS_SIZE_MIN && height >= OBS_SIZE_MIN &&
	        width <= OBS_SIZE_MAX && height <= OBS_SIZE_MAX);
}

int obs_reset_video(struct obs_video_info *ovi)
{
	if (!obs) return OBS_VIDEO_FAIL;

	/* don't allow changing of video settings if active. */
	if (obs->video.video && video_output_active(obs->video.video))
		return OBS_VIDEO_CURRENTLY_ACTIVE;

	if (!size_valid(ovi->output_width, ovi->output_height) ||
	    !size_valid(ovi->base_width,   ovi->base_height))
		return OBS_VIDEO_INVALID_PARAM;

	struct obs_core_video *video = &obs->video;

	stop_video();
	obs_free_video();

	if (!ovi) {
		obs_free_graphics();
		return OBS_VIDEO_SUCCESS;
	}

	/* align to multiple-of-two and SSE alignment sizes */
	ovi->output_width  &= 0xFFFFFFFC;
	ovi->output_height &= 0xFFFFFFFE;

	if (!video->graphics) {
		int errorcode = obs_init_graphics(ovi);
		if (errorcode != OBS_VIDEO_SUCCESS)
			return errorcode;
	}

	blog(LOG_INFO, "video settings reset:\n"
	               "\tbase resolution:   %dx%d\n"
	               "\toutput resolution: %dx%d\n"
	               "\tfps:               %d/%d",
	               ovi->base_width, ovi->base_height,
	               ovi->output_width, ovi->output_height,
	               ovi->fps_num, ovi->fps_den);

	return obs_init_video(ovi);
}

bool obs_reset_audio(struct audio_output_info *ai)
{
	if (!obs) return false;

	/* don't allow changing of audio settings if active. */
	if (obs->audio.audio && audio_output_active(obs->audio.audio))
		return false;

	obs_free_audio();
	if(!ai)
		return true;

	blog(LOG_INFO, "audio settings reset:\n"
	               "\tsamples per sec: %d\n"
	               "\tspeakers:        %d\n"
	               "\tbuffering (ms):  %d\n",
	               (int)ai->samples_per_sec,
	               (int)ai->speakers,
	               (int)ai->buffer_ms);

	return obs_init_audio(ai);
}

bool obs_get_video_info(struct obs_video_info *ovi)
{
	struct obs_core_video *video = &obs->video;
	const struct video_output_info *info;

	if (!obs || !video->graphics)
		return false;

	info = video_output_getinfo(video->video);

	memset(ovi, 0, sizeof(struct obs_video_info));
	ovi->base_width    = video->base_width;
	ovi->base_height   = video->base_height;
	ovi->output_width  = info->width;
	ovi->output_height = info->height;
	ovi->output_format = info->format;
	ovi->fps_num       = info->fps_num;
	ovi->fps_den       = info->fps_den;

	return true;
}

bool obs_get_audio_info(struct audio_output_info *aoi)
{
	struct obs_core_audio *audio = &obs->audio;
	const struct audio_output_info *info;

	if (!obs || !audio->audio)
		return false;

	info = audio_output_getinfo(audio->audio);
	memcpy(aoi, info, sizeof(struct audio_output_info));

	return true;
}

bool obs_enum_input_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->input_types.num)
		return false;
	*id = obs->input_types.array[idx].id;
	return true;
}

bool obs_enum_filter_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->filter_types.num)
		return false;
	*id = obs->filter_types.array[idx].id;
	return true;
}

bool obs_enum_transition_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->transition_types.num)
		return false;
	*id = obs->transition_types.array[idx].id;
	return true;
}

bool obs_enum_output_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->output_types.num)
		return false;
	*id = obs->output_types.array[idx].id;
	return true;
}

bool obs_enum_encoder_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->encoder_types.num)
		return false;
	*id = obs->encoder_types.array[idx].id;
	return true;
}

bool obs_enum_service_types(size_t idx, const char **id)
{
	if (!obs) return false;

	if (idx >= obs->service_types.num)
		return false;
	*id = obs->service_types.array[idx].id;
	return true;
}

graphics_t obs_graphics(void)
{
	return (obs != NULL) ? obs->video.graphics : NULL;
}

audio_t obs_audio(void)
{
	return (obs != NULL) ? obs->audio.audio : NULL;
}

video_t obs_video(void)
{
	return (obs != NULL) ? obs->video.video : NULL;
}

/* TODO: optimize this later so it's not just O(N) string lookups */
static inline struct obs_modal_ui *get_modal_ui_callback(const char *id,
		const char *task, const char *target)
{
	for (size_t i = 0; i < obs->modal_ui_callbacks.num; i++) {
		struct obs_modal_ui *callback = obs->modal_ui_callbacks.array+i;

		if (strcmp(callback->id,     id)     == 0 &&
		    strcmp(callback->task,   task)   == 0 &&
		    strcmp(callback->target, target) == 0)
			return callback;
	}

	return NULL;
}

static inline struct obs_modeless_ui *get_modeless_ui_callback(const char *id,
		const char *task, const char *target)
{
	for (size_t i = 0; i < obs->modeless_ui_callbacks.num; i++) {
		struct obs_modeless_ui *callback;
		callback = obs->modeless_ui_callbacks.array+i;

		if (strcmp(callback->id,     id)     == 0 &&
		    strcmp(callback->task,   task)   == 0 &&
		    strcmp(callback->target, target) == 0)
			return callback;
	}

	return NULL;
}

int obs_exec_ui(const char *name, const char *task, const char *target,
		void *data, void *ui_data)
{
	struct obs_modal_ui *callback;
	int errorcode = OBS_UI_NOTFOUND;

	if (!obs) return errorcode;

	callback = get_modal_ui_callback(name, task, target);
	if (callback) {
		bool success = callback->exec(data, ui_data);
		errorcode = success ? OBS_UI_SUCCESS : OBS_UI_CANCEL;
	}

	return errorcode;
}

void *obs_create_ui(const char *name, const char *task, const char *target,
		void *data, void *ui_data)
{
	struct obs_modeless_ui *callback;

	if (!obs) return NULL;

	callback = get_modeless_ui_callback(name, task, target);
	return callback ? callback->create(data, ui_data) : NULL;
}

bool obs_add_source(obs_source_t source)
{
	struct calldata params = {0};

	if (!obs) return false;
	if (!source) return false;

	pthread_mutex_lock(&obs->data.sources_mutex);
	da_push_back(obs->data.user_sources, &source);
	obs_source_addref(source);
	pthread_mutex_unlock(&obs->data.sources_mutex);

	calldata_setptr(&params, "source", source);
	signal_handler_signal(obs->signals, "source_add", &params);
	calldata_free(&params);

	return true;
}

obs_source_t obs_get_output_source(uint32_t channel)
{
	if (!obs) return NULL;
	return obs_view_getsource(&obs->data.main_view, channel);
}

void obs_set_output_source(uint32_t channel, obs_source_t source)
{
	assert(channel < MAX_CHANNELS);

	if (!obs) return;
	if (channel >= MAX_CHANNELS) return;

	struct obs_source *prev_source;
	struct obs_view *view = &obs->data.main_view;
	struct calldata params = {0};

	pthread_mutex_lock(&view->channels_mutex);

	obs_source_addref(source);

	prev_source = view->channels[channel];

	calldata_setint(&params, "channel", channel);
	calldata_setptr(&params, "prev_source", prev_source);
	calldata_setptr(&params, "source", source);
	signal_handler_signal(obs->signals, "channel_change", &params);
	calldata_getptr(&params, "source", &source);
	calldata_free(&params);

	view->channels[channel] = source;

	pthread_mutex_unlock(&view->channels_mutex);

	if (source)
		obs_source_activate(source, MAIN_VIEW);

	if (prev_source) {
		obs_source_deactivate(prev_source, MAIN_VIEW);
		obs_source_release(prev_source);
	}
}

void obs_enum_sources(bool (*enum_proc)(void*, obs_source_t), void *param)
{
	if (!obs) return;

	pthread_mutex_lock(&obs->data.user_sources_mutex);

	for (size_t i = 0; i < obs->data.user_sources.num; i++) {
		struct obs_source *source = obs->data.user_sources.array[i];
		if (!enum_proc(param, source))
			break;
	}

	pthread_mutex_unlock(&obs->data.user_sources_mutex);
}

static inline void obs_enum(void *pstart, pthread_mutex_t *mutex, void *proc,
		void *param)
{
	struct obs_context_data **start = pstart, *context;
	bool (*enum_proc)(void*, void*) = proc;

	assert(start);
	assert(mutex);
	assert(enum_proc);

	pthread_mutex_lock(mutex);

	context = *start;
	while (context) {
		if (!enum_proc(param, context))
			break;

		context = context->next;
	}

	pthread_mutex_unlock(mutex);
}

void obs_enum_outputs(bool (*enum_proc)(void*, obs_output_t), void *param)
{
	if (!obs) return;
	obs_enum(&obs->data.first_output, &obs->data.outputs_mutex,
			enum_proc, param);
}

void obs_enum_encoders(bool (*enum_proc)(void*, obs_encoder_t), void *param)
{
	if (!obs) return;
	obs_enum(&obs->data.first_encoder, &obs->data.encoders_mutex,
			enum_proc, param);
}

void obs_enum_services(bool (*enum_proc)(void*, obs_service_t), void *param)
{
	if (!obs) return;
	obs_enum(&obs->data.first_service, &obs->data.services_mutex,
			enum_proc, param);
}

obs_source_t obs_get_source_by_name(const char *name)
{
	struct obs_core_data *data = &obs->data;
	struct obs_source *source = NULL;
	size_t i;

	if (!obs) return NULL;

	pthread_mutex_lock(&data->user_sources_mutex);

	for (i = 0; i < data->user_sources.num; i++) {
		struct obs_source *cur_source = data->user_sources.array[i];
		if (strcmp(cur_source->context.name, name) == 0) {
			source = cur_source;
			obs_source_addref(source);
			break;
		}
	}

	pthread_mutex_unlock(&data->user_sources_mutex);
	return source;
}

static inline void *get_context_by_name(void *vfirst, const char *name,
		pthread_mutex_t *mutex)
{
	struct obs_context_data **first = vfirst;
	struct obs_context_data *context;

	pthread_mutex_lock(mutex);

	context = *first;
	while (context) {
		if (strcmp(context->name, name) == 0)
			break;
		context = context->next;
	}

	pthread_mutex_unlock(mutex);
	return context;
}

obs_output_t obs_get_output_by_name(const char *name)
{
	if (!obs) return NULL;
	return get_context_by_name(&obs->data.first_output, name,
			&obs->data.outputs_mutex);
}

obs_encoder_t obs_get_encoder_by_name(const char *name)
{
	if (!obs) return NULL;
	return get_context_by_name(&obs->data.first_encoder, name,
			&obs->data.encoders_mutex);
}

obs_service_t obs_get_service_by_name(const char *name)
{
	if (!obs) return NULL;
	return get_context_by_name(&obs->data.first_service, name,
			&obs->data.services_mutex);
}

effect_t obs_get_default_effect(void)
{
	if (!obs) return NULL;
	return obs->video.default_effect;
}

effect_t obs_get_solid_effect(void)
{
	if (!obs) return NULL;
	return obs->video.solid_effect;
}

signal_handler_t obs_signalhandler(void)
{
	if (!obs) return NULL;
	return obs->signals;
}

proc_handler_t obs_prochandler(void)
{
	if (!obs) return NULL;
	return obs->procs;
}

void obs_add_draw_callback(
		void (*draw)(void *param, uint32_t cx, uint32_t cy),
		void *param)
{
	if (!obs) return;

	obs_display_add_draw_callback(&obs->video.main_display, draw, param);
}

void obs_remove_draw_callback(
		void (*draw)(void *param, uint32_t cx, uint32_t cy),
		void *param)
{
	if (!obs) return;

	obs_display_remove_draw_callback(&obs->video.main_display, draw, param);
}

void obs_resize(uint32_t cx, uint32_t cy)
{
	if (!obs || !obs->video.video || !obs->video.graphics) return;
	obs_display_resize(&obs->video.main_display, cx, cy);
}

void obs_render_main_view(void)
{
	if (!obs) return;
	obs_view_render(&obs->data.main_view);
}

void obs_set_master_volume(float volume)
{
	struct calldata data = {0};

	if (!obs) return;

	calldata_setfloat(&data, "volume", volume);
	signal_handler_signal(obs->signals, "master_volume", &data);
	volume = (float)calldata_float(&data, "volume");
	calldata_free(&data);

	obs->audio.user_volume = volume;
}

void obs_set_present_volume(float volume)
{
	if (!obs) return;
	obs->audio.present_volume = volume;
}

float obs_get_master_volume(void)
{
	return obs ? obs->audio.user_volume : 0.0f;
}

float obs_get_present_volume(void)
{
	return obs ? obs->audio.present_volume : 0.0f;
}

obs_source_t obs_load_source(obs_data_t source_data)
{
	obs_source_t source;
	const char   *name    = obs_data_getstring(source_data, "name");
	const char   *id      = obs_data_getstring(source_data, "id");
	obs_data_t   settings = obs_data_getobj(source_data, "settings");
	double       volume;

	source = obs_source_create(OBS_SOURCE_TYPE_INPUT, id, name, settings);

	obs_data_set_default_double(source_data, "volume", 1.0);
	volume = obs_data_getdouble(source_data, "volume");
	obs_source_setvolume(source, (float)volume);

	obs_data_release(settings);

	return source;
}

void obs_load_sources(obs_data_array_t array)
{
	size_t count;
	size_t i;

	if (!obs) return;

	count = obs_data_array_count(array);

	pthread_mutex_lock(&obs->data.user_sources_mutex);

	for (i = 0; i < count; i++) {
		obs_data_t   source_data = obs_data_array_item(array, i);
		obs_source_t source      = obs_load_source(source_data);

		obs_add_source(source);

		obs_source_release(source);
		obs_data_release(source_data);
	}

	/* tell sources that we want to load */
	for (i = 0; i < obs->data.user_sources.num; i++)
		obs_source_load(obs->data.user_sources.array[i]);

	pthread_mutex_unlock(&obs->data.user_sources_mutex);
}

obs_data_t obs_save_source(obs_source_t source)
{
	obs_data_t source_data = obs_data_create();
	obs_data_t settings    = obs_source_getsettings(source);
	float      volume      = obs_source_getvolume(source);
	const char *name       = obs_source_getname(source);
	const char *id;

	obs_source_save(source);

	obs_source_gettype(source, NULL, &id);

	obs_data_setstring(source_data, "name",     name);
	obs_data_setstring(source_data, "id",       id);
	obs_data_setobj   (source_data, "settings", settings);
	obs_data_setdouble(source_data, "volume",   volume);

	obs_data_release(settings);

	return source_data;
}

obs_data_array_t obs_save_sources(void)
{
	obs_data_array_t array;
	size_t i;

	if (!obs) return NULL;

	array = obs_data_array_create();

	pthread_mutex_lock(&obs->data.user_sources_mutex);

	for (i = 0; i < obs->data.user_sources.num; i++) {
		obs_source_t source      = obs->data.user_sources.array[i];
		obs_data_t   source_data = obs_save_source(source);

		obs_data_array_push_back(array, source_data);
		obs_data_release(source_data);
	}

	pthread_mutex_unlock(&obs->data.user_sources_mutex);

	return array;
}

/* ensures that names are never blank */
static inline char *dup_name(const char *name)
{
	if (!name || !*name) {
		struct dstr unnamed = {0};
		dstr_printf(&unnamed, "__unnamed%004lld",
				obs->data.unnamed_index++);

		return unnamed.array;
	} else {
		return bstrdup(name);
	}
}

static inline bool obs_context_data_init_wrap(
		struct obs_context_data *context,
		obs_data_t              settings,
		const char              *name)
{
	assert(context);
	memset(context, 0, sizeof(*context));

	pthread_mutex_init_value(&context->rename_cache_mutex);
	if (pthread_mutex_init(&context->rename_cache_mutex, NULL) < 0)
		return false;

	context->signals = signal_handler_create();
	if (!context)
		return false;

	context->procs = proc_handler_create();
	if (!context->procs)
		return false;

	context->name     = dup_name(name);
	context->settings = obs_data_newref(settings);
	return true;
}

bool obs_context_data_init(
		struct obs_context_data *context,
		obs_data_t              settings,
		const char              *name)
{
	if (obs_context_data_init_wrap(context, settings, name)) {
		return true;
	} else {
		obs_context_data_free(context);
		return false;
	}
}

void obs_context_data_free(struct obs_context_data *context)
{
	signal_handler_destroy(context->signals);
	proc_handler_destroy(context->procs);
	obs_data_release(context->settings);
	obs_context_data_remove(context);
	pthread_mutex_destroy(&context->rename_cache_mutex);
	bfree(context->name);

	for (size_t i = 0; i < context->rename_cache.num; i++)
		bfree(context->rename_cache.array[i]);
	da_free(context->rename_cache);

	memset(context, 0, sizeof(*context));
}

void obs_context_data_insert(struct obs_context_data *context,
		pthread_mutex_t *mutex, void *pfirst)
{
	struct obs_context_data **first = pfirst;

	assert(context);
	assert(mutex);
	assert(first);

	context->mutex = mutex;

	pthread_mutex_lock(mutex);
	context->prev_next  = first;
	context->next       = *first;
	*first              = context;
	if (context->next)
		context->next->prev_next = &context->next;
	pthread_mutex_unlock(mutex);
}

void obs_context_data_remove(struct obs_context_data *context)
{
	if (context && context->mutex) {
		pthread_mutex_lock(context->mutex);
		*context->prev_next = context->next;
		if (context->next)
			context->next->prev_next = context->prev_next;
		pthread_mutex_unlock(context->mutex);

		context->mutex = NULL;
	}
}

void obs_context_data_setname(struct obs_context_data *context,
		const char *name)
{
	pthread_mutex_lock(&context->rename_cache_mutex);

	if (context->name)
		da_push_back(context->rename_cache, &context->name);
	context->name = dup_name(name);

	pthread_mutex_unlock(&context->rename_cache_mutex);
}