image-source: Decrease slideshow source memory usage

plugins/image-source/obs-slideshow.c

@@ -57,6 +57,9 @@
 
 /* ------------------------------------------------------------------------- */
 
+#define MOD(a,b) ((((a)%(b))+(b))%(b))
+#define MAX_LOADED 11 /* needs to be an odd number */
+
 struct image_file_data {
 	char *path;
 	obs_source_t *source;
@@ -75,7 +78,6 @@ struct slideshow {
 	bool loop;
 	bool restart_on_activate;
 	bool pause_on_deactivate;
-	bool restart;
 	bool manual;
 	bool hide;
 	bool use_cut;
@@ -87,13 +89,14 @@ struct slideshow {
 	obs_source_t *transition;
 
 	float elapsed;
-	size_t cur_item;
+	int cur_item;
 
 	uint32_t cx;
 	uint32_t cy;
 
 	pthread_mutex_t mutex;
 	DARRAY(struct image_file_data) files;
+	DARRAY(char*) paths;
 
 	enum behavior behavior;
 
@@ -164,7 +167,18 @@ static void free_files(struct darray *array)
 
 static inline size_t random_file(struct slideshow *ss)
 {
-	return (size_t)rand() % ss->files.num;
+	return (size_t)rand() % ss->paths.num;
+}
+
+static void free_paths(struct darray *array)
+{
+	DARRAY(char*) paths;
+	paths.da = *array;
+
+	for (size_t i = 0; i < paths.num; i++)
+		bfree(paths.array[i]);
+
+	da_free(paths);
 }
 
 /* ------------------------------------------------------------------------- */
@@ -176,7 +190,7 @@ static const char *ss_getname(void *unused)
 }
 
 static void add_file(struct slideshow *ss, struct darray *array,
-		const char *path, uint32_t *cx, uint32_t *cy)
+		const char *path, uint32_t *cx, uint32_t *cy, bool next)
 {
 	DARRAY(struct image_file_data) new_files;
 	struct image_file_data data;
@@ -199,7 +213,11 @@ static void add_file(struct slideshow *ss, struct darray *array,
 
 		data.path = bstrdup(path);
 		data.source = new_source;
-		da_push_back(new_files, &data);
+
+		if (next)
+			da_push_back(new_files, &data);
+		else
+			da_insert(new_files, 0, &data);
 
 		if (new_cx > *cx) *cx = new_cx;
 		if (new_cy > *cy) *cy = new_cy;
@@ -208,6 +226,48 @@ static void add_file(struct slideshow *ss, struct darray *array,
 	*array = new_files.da;
 }
 
+static void clear_buffer(struct slideshow *ss, bool next)
+{
+	if (ss->paths.num <= MAX_LOADED || !ss->paths.num || !ss->files.num)
+		return;
+
+	if (next) {
+		bfree(ss->files.array[0].path);
+		obs_source_release(ss->files.array[0].source);
+		da_erase(ss->files, 0);
+	} else {
+		bfree(ss->files.array[ss->files.num - 1].path);
+		obs_source_release(ss->files.array[ss->files.num - 1].source);
+		da_pop_back(ss->files);
+	}
+
+	size_t index = 0;
+
+	if (ss->randomize)
+		index = random_file(ss);
+	else if (!ss->randomize && next)
+		index = MOD((ss->cur_item + ((MAX_LOADED / 2) + 1)),
+				ss->paths.num);
+	else if (!ss->randomize && !next)
+		index = MOD((ss->cur_item - ((MAX_LOADED / 2) + 1)),
+				ss->paths.num);
+
+	uint32_t cx, cy;
+	add_file(ss, &ss->files.da, ss->paths.array[index], &cx, &cy,
+			next);
+}
+
+static void add_path(struct darray *array, const char *path)
+{
+	DARRAY(char*) new_paths;
+	new_paths.da = *array;
+
+	const char *new_path = bstrdup(path);
+	da_push_back(new_paths, &new_path);
+
+	*array = new_paths.da;
+}
+
 static bool valid_extension(const char *ext)
 {
 	if (!ext)
@@ -222,35 +282,54 @@ static bool valid_extension(const char *ext)
 
 static inline bool item_valid(struct slideshow *ss)
 {
-	return ss->files.num && ss->cur_item < ss->files.num;
+	return ss->files.num && ss->paths.num &&
+			(size_t)ss->cur_item < ss->paths.num;
 }
 
-static void do_transition(void *data, bool to_null)
+static void do_transition(void *data, bool to_null, bool next)
 {
 	struct slideshow *ss = data;
 	bool valid = item_valid(ss);
 
-	if (valid && ss->use_cut)
-		obs_transition_set(ss->transition,
-				ss->files.array[ss->cur_item].source);
-
-	else if (valid && !to_null)
-		obs_transition_start(ss->transition,
-				OBS_TRANSITION_MODE_AUTO,
+	if (to_null) {
+		obs_transition_start(ss->transition, OBS_TRANSITION_MODE_AUTO,
 				ss->tr_speed,
-				ss->files.array[ss->cur_item].source);
+				NULL);
+		return;
+	}
 
-	else
+	if (!valid)
+		return;
+
+	clear_buffer(ss, next);
+
+	obs_source_t *source;
+
+	if (next && ss->paths.num > MAX_LOADED)
+		source = ss->files.array[(MAX_LOADED / 2) + 1].source;
+	else if (!next && ss->paths.num > MAX_LOADED)
+		source = ss->files.array[(MAX_LOADED / 2) - 1].source;
+	else if (ss->paths.num <= MAX_LOADED)
+		source = ss->files.array[(size_t)ss->cur_item].source;
+
+	if (!source)
+		return;
+
+	if (ss->use_cut)
+		obs_transition_set(ss->transition, source);
+
+	else if (!to_null)
 		obs_transition_start(ss->transition,
 				OBS_TRANSITION_MODE_AUTO,
-				ss->tr_speed,
-				NULL);
+				ss->tr_speed, source);
 }
 
 static void ss_update(void *data, obs_data_t *settings)
 {
 	DARRAY(struct image_file_data) new_files;
 	DARRAY(struct image_file_data) old_files;
+	DARRAY(char*) new_paths;
+	DARRAY(char*) old_paths;
 	obs_source_t *new_tr = NULL;
 	obs_source_t *old_tr = NULL;
 	struct slideshow *ss = data;
@@ -260,6 +339,8 @@ static void ss_update(void *data, obs_data_t *settings)
 	uint32_t new_speed;
 	uint32_t cx = 0;
 	uint32_t cy = 0;
+	uint32_t last_cx = 0;
+	uint32_t last_cy = 0;
 	size_t count;
 	const char *behavior;
 	const char *mode;
@@ -268,6 +349,7 @@ static void ss_update(void *data, obs_data_t *settings)
 	/* get settings data */
 
 	da_init(new_files);
+	da_init(new_paths);
 
 	behavior = obs_data_get_string(settings, S_BEHAVIOR);
 
@@ -333,14 +415,13 @@ static void ss_update(void *data, obs_data_t *settings)
 				dstr_copy(&dir_path, path);
 				dstr_cat_ch(&dir_path, '/');
 				dstr_cat(&dir_path, ent->d_name);
-				add_file(ss, &new_files.da, dir_path.array,
-						&cx, &cy);
+				add_path(&new_paths.da, dir_path.array);
 			}
 
 			dstr_free(&dir_path);
 			os_closedir(dir);
 		} else {
-			add_file(ss, &new_files.da, path, &cx, &cy);
+			add_path(&new_paths.da, path);
 		}
 
 		obs_data_release(item);
@@ -353,6 +434,8 @@ static void ss_update(void *data, obs_data_t *settings)
 
 	old_files.da = ss->files.da;
 	ss->files.da = new_files.da;
+	old_paths.da = ss->paths.da;
+	ss->paths.da = new_paths.da;
 	if (new_tr) {
 		old_tr = ss->transition;
 		ss->transition = new_tr;
@@ -369,12 +452,31 @@ static void ss_update(void *data, obs_data_t *settings)
 
 	pthread_mutex_unlock(&ss->mutex);
 
+	if (ss->paths.num > MAX_LOADED && !ss->randomize) {
+		for (int i = -(MAX_LOADED / 2); i <= (MAX_LOADED / 2); i++) {
+			size_t index = MOD(i, ss->paths.num);
+			add_file(ss, &ss->files.da, ss->paths.array[index],
+					&cx, &cy, true);
+		}
+	} else if (ss->paths.num > MAX_LOADED && ss->randomize)  {
+		for (size_t i = 0; i < MAX_LOADED; i++) {
+			size_t index = random_file(ss);
+			add_file(ss, &ss->files.da, ss->paths.array[index],
+					&cx, &cy, true);
+		}
+	} else if (ss->paths.num <= MAX_LOADED) {
+		for (size_t i = 0; i < ss->paths.num; i++)
+			add_file(ss, &ss->files.da, ss->paths.array[i],
+					&cx, &cy, true);
+	}
+
 	/* ------------------------------------- */
 	/* clean up and restart transition */
 
 	if (old_tr)
 		obs_source_release(old_tr);
 	free_files(&old_files.da);
+	free_paths(&old_paths.da);
 
 	/* ------------------------- */
 
@@ -418,21 +520,32 @@ static void ss_update(void *data, obs_data_t *settings)
 
 	/* ------------------------- */
 
+	obs_data_t *priv_settings = obs_source_get_private_settings(ss->source);
+	last_cx = (uint32_t)obs_data_get_int(priv_settings, "last_cx");
+	last_cy = (uint32_t)obs_data_get_int(priv_settings, "last_cy");
+
+	if (ss->randomize && last_cx > 0 && last_cy > 0) {
+		cx = last_cx;
+		cy = last_cy;
+	}
+
+	obs_data_set_int(priv_settings, "last_cx", cx);
+	obs_data_set_int(priv_settings, "last_cy", cy);
+	obs_data_release(priv_settings);
+
 	ss->cx = cx;
 	ss->cy = cy;
-	ss->cur_item = 0;
 	ss->elapsed = 0.0f;
+	ss->cur_item = 0;
 	obs_transition_set_size(ss->transition, cx, cy);
 	obs_transition_set_alignment(ss->transition, OBS_ALIGN_CENTER);
 	obs_transition_set_scale_type(ss->transition,
 			OBS_TRANSITION_SCALE_ASPECT);
 
-	if (ss->randomize && ss->files.num)
-		ss->cur_item = random_file(ss);
 	if (new_tr)
 		obs_source_add_active_child(ss->source, new_tr);
 	if (ss->files.num)
-		do_transition(ss, false);
+		do_transition(ss, false, true);
 
 	obs_data_array_release(array);
 }
@@ -449,14 +562,15 @@ static void ss_restart(void *data)
 {
 	struct slideshow *ss = data;
 
-	ss->elapsed = 0.0f;
-	ss->cur_item = 0;
+	ss->stop = false;
+	ss->use_cut = true;
+	ss->restart_on_activate = false;
 
-	obs_transition_set(ss->transition,
-			ss->files.array[ss->cur_item].source);
+	obs_data_t *settings = obs_source_get_settings(ss->source);
+	ss_update(ss, settings);
+	obs_data_release(settings);
 
-	ss->stop = false;
-	ss->paused = false;
+	ss->use_cut = false;
 }
 
 static void ss_stop(void *data)
@@ -466,7 +580,7 @@ static void ss_stop(void *data)
 	ss->elapsed = 0.0f;
 	ss->cur_item = 0;
 
-	do_transition(ss, true);
+	do_transition(ss, true, true);
 	ss->stop = true;
 	ss->paused = false;
 }
@@ -475,28 +589,26 @@ static void ss_next_slide(void *data)
 {
 	struct slideshow *ss = data;
 
-	if (!ss->files.num)
+	if (!ss->paths.num)
 		return;
 
-	if (++ss->cur_item >= ss->files.num)
+	if (++ss->cur_item >= (int)ss->paths.num)
 		ss->cur_item = 0;
 
-	do_transition(ss, false);
+	do_transition(ss, false, true);
 }
 
 static void ss_previous_slide(void *data)
 {
 	struct slideshow *ss = data;
 
-	if (!ss->files.num)
+	if (!ss->paths.num)
 		return;
 
-	if (ss->cur_item == 0)
-		ss->cur_item = ss->files.num - 1;
-	else
-		--ss->cur_item;
+	if (--ss->cur_item < 0)
+		ss->cur_item = (int)(ss->paths.num - 1);
 
-	do_transition(ss, false);
+	do_transition(ss, false, false);
 }
 
 static void play_pause_hotkey(void *data, obs_hotkey_id id,
@@ -571,6 +683,7 @@ static void ss_destroy(void *data)
 
 	obs_source_release(ss->transition);
 	free_files(&ss->files.da);
+	free_paths(&ss->paths.da);
 	pthread_mutex_destroy(&ss->mutex);
 	bfree(ss);
 }
@@ -644,13 +757,8 @@ static void ss_video_tick(void *data, float seconds)
 	if (!ss->transition || !ss->slide_time)
 		return;
 
-	if (ss->restart_on_activate && !ss->randomize && ss->use_cut) {
-		ss->elapsed = 0.0f;
-		ss->cur_item = 0;
-		do_transition(ss, false);
-		ss->restart_on_activate = false;
-		ss->use_cut = false;
-		ss->stop = false;
+	if (ss->restart_on_activate && ss->use_cut) {
+		ss_restart(ss);
 		return;
 	}
 
@@ -659,13 +767,13 @@ static void ss_video_tick(void *data, float seconds)
 
 	/* ----------------------------------------------------- */
 	/* fade to transparency when the file list becomes empty */
-	if (!ss->files.num) {
+	if (!ss->paths.num) {
 		obs_source_t* active_transition_source =
 			obs_transition_get_active_source(ss->transition);
 
 		if (active_transition_source) {
 			obs_source_release(active_transition_source);
-			do_transition(ss, true);
+			do_transition(ss, true, true);
 		}
 	}
 
@@ -676,29 +784,17 @@ static void ss_video_tick(void *data, float seconds)
 	if (ss->elapsed > ss->slide_time) {
 		ss->elapsed -= ss->slide_time;
 
-		if (!ss->loop && ss->cur_item == ss->files.num - 1) {
+		if (!ss->loop && ss->cur_item == (int)ss->paths.num - 1 &&
+				!ss->randomize) {
 			if (ss->hide)
-				do_transition(ss, true);
+				do_transition(ss, true, true);
 			else
-				do_transition(ss, false);
+				do_transition(ss, false, true);
 
 			return;
 		}
 
-		if (ss->randomize) {
-			size_t next = ss->cur_item;
-			if (ss->files.num > 1) {
-				while (next == ss->cur_item)
-					next = random_file(ss);
-			}
-			ss->cur_item = next;
-
-		} else if (++ss->cur_item >= ss->files.num) {
-			ss->cur_item = 0;
-		}
-
-		if (ss->files.num)
-			do_transition(ss, false);
+		ss_next_slide(ss);
 	}
 }
 
@@ -861,11 +957,14 @@ static obs_properties_t *ss_properties(void *data)
 
 	if (ss) {
 		pthread_mutex_lock(&ss->mutex);
-		if (ss->files.num) {
-			struct image_file_data *last = da_end(ss->files);
+		if (ss->paths.num) {
+			char **p_last_path = da_end(ss->paths);
+			const char *last_path;
 			const char *slash;
 
-			dstr_copy(&path, last->path);
+			last_path = p_last_path ? *p_last_path : "";
+
+			dstr_copy(&path, last_path);
 			dstr_replace(&path, "\\", "/");
 			slash = strrchr(path.array, '/');
 			if (slash)