obs-filters: Add HDR support to Render Delay

plugins/obs-filters/gpu-delay.c

@@ -7,6 +7,7 @@
 
 struct frame {
 	gs_texrender_t *render;
+	enum gs_color_space space;
 	uint64_t ts;
 };
 
@@ -187,27 +188,73 @@ static void gpu_delay_filter_tick(void *data, float t)
 	check_interval(f);
 }
 
+static const char *
+get_tech_name_and_multiplier(enum gs_color_space current_space,
+			     enum gs_color_space source_space,
+			     float *multiplier)
+{
+	const char *tech_name = "Draw";
+	*multiplier = 1.f;
+
+	switch (source_space) {
+	case GS_CS_SRGB:
+	case GS_CS_SRGB_16F:
+		switch (current_space) {
+		case GS_CS_709_SCRGB:
+			tech_name = "DrawMultiply";
+			*multiplier = obs_get_video_sdr_white_level() / 80.0f;
+		}
+		break;
+	case GS_CS_709_EXTENDED:
+		switch (current_space) {
+		case GS_CS_SRGB:
+		case GS_CS_SRGB_16F:
+			tech_name = "DrawTonemap";
+			break;
+		case GS_CS_709_SCRGB:
+			tech_name = "DrawMultiply";
+			*multiplier = obs_get_video_sdr_white_level() / 80.0f;
+		}
+		break;
+	case GS_CS_709_SCRGB:
+		switch (current_space) {
+		case GS_CS_SRGB:
+		case GS_CS_SRGB_16F:
+			tech_name = "DrawMultiplyTonemap";
+			*multiplier = 80.0f / obs_get_video_sdr_white_level();
+			break;
+		case GS_CS_709_EXTENDED:
+			tech_name = "DrawMultiply";
+			*multiplier = 80.0f / obs_get_video_sdr_white_level();
+		}
+	}
+
+	return tech_name;
+}
+
 static void draw_frame(struct gpu_delay_filter_data *f)
 {
 	struct frame frame;
 	circlebuf_peek_front(&f->frames, &frame, sizeof(frame));
 
+	const enum gs_color_space current_space = gs_get_color_space();
+	float multiplier;
+	const char *technique = get_tech_name_and_multiplier(
+		current_space, frame.space, &multiplier);
+
 	gs_effect_t *effect = obs_get_base_effect(OBS_EFFECT_DEFAULT);
 	gs_texture_t *tex = gs_texrender_get_texture(frame.render);
 	if (tex) {
-		const bool linear_srgb = gs_get_linear_srgb();
-
 		const bool previous = gs_framebuffer_srgb_enabled();
-		gs_enable_framebuffer_srgb(linear_srgb);
+		gs_enable_framebuffer_srgb(true);
 
-		gs_eparam_t *image =
-			gs_effect_get_param_by_name(effect, "image");
-		if (linear_srgb)
-			gs_effect_set_texture_srgb(image, tex);
-		else
-			gs_effect_set_texture(image, tex);
+		gs_effect_set_texture_srgb(
+			gs_effect_get_param_by_name(effect, "image"), tex);
+		gs_effect_set_float(gs_effect_get_param_by_name(effect,
+								"multiplier"),
+				    multiplier);
 
-		while (gs_effect_loop(effect, "Draw"))
+		while (gs_effect_loop(effect, technique))
 			gs_draw_sprite(tex, 0, f->cx, f->cy);
 
 		gs_enable_framebuffer_srgb(previous);
@@ -233,12 +280,26 @@ static void gpu_delay_filter_render(void *data, gs_effect_t *effect)
 	struct frame frame;
 	circlebuf_pop_front(&f->frames, &frame, sizeof(frame));
 
+	const enum gs_color_space preferred_spaces[] = {
+		GS_CS_SRGB,
+		GS_CS_SRGB_16F,
+		GS_CS_709_EXTENDED,
+	};
+	const enum gs_color_space space = obs_source_get_color_space(
+		parent, OBS_COUNTOF(preferred_spaces), preferred_spaces);
+	const enum gs_color_format format = gs_get_format_from_space(space);
+	if (gs_texrender_get_format(frame.render) != format) {
+		gs_texrender_destroy(frame.render);
+		frame.render = gs_texrender_create(format, GS_ZS_NONE);
+	}
+
 	gs_texrender_reset(frame.render);
 
 	gs_blend_state_push();
 	gs_blend_function(GS_BLEND_ONE, GS_BLEND_ZERO);
 
-	if (gs_texrender_begin(frame.render, f->cx, f->cy)) {
+	if (gs_texrender_begin_with_color_space(frame.render, f->cx, f->cy,
+						space)) {
 		uint32_t parent_flags = obs_source_get_output_flags(target);
 		bool custom_draw = (parent_flags & OBS_SOURCE_CUSTOM_DRAW) != 0;
 		bool async = (parent_flags & OBS_SOURCE_ASYNC) != 0;
@@ -255,6 +316,8 @@ static void gpu_delay_filter_render(void *data, gs_effect_t *effect)
 			obs_source_video_render(target);
 
 		gs_texrender_end(frame.render);
+
+		frame.space = space;
 	}
 
 	gs_blend_state_pop();
@@ -266,6 +329,30 @@ static void gpu_delay_filter_render(void *data, gs_effect_t *effect)
 	UNUSED_PARAMETER(effect);
 }
 
+static enum gs_color_space
+gpu_delay_filter_get_color_space(void *data, size_t count,
+				 const enum gs_color_space *preferred_spaces)
+{
+	struct gpu_delay_filter_data *const f = data;
+	obs_source_t *target = obs_filter_get_target(f->context);
+	obs_source_t *parent = obs_filter_get_parent(f->context);
+
+	if (!f->target_valid || !target || !parent || !f->frames.size) {
+		return (count > 0) ? preferred_spaces[0] : GS_CS_SRGB;
+	}
+
+	struct frame frame;
+	circlebuf_peek_front(&f->frames, &frame, sizeof(frame));
+	enum gs_color_space space = frame.space;
+	for (size_t i = 0; i < count; ++i) {
+		space = preferred_spaces[i];
+		if (space == frame.space)
+			break;
+	}
+
+	return space;
+}
+
 struct obs_source_info gpu_delay_filter = {
 	.id = "gpu_delay",
 	.type = OBS_SOURCE_TYPE_FILTER,
@@ -277,4 +364,5 @@ struct obs_source_info gpu_delay_filter = {
 	.get_properties = gpu_delay_filter_properties,
 	.video_tick = gpu_delay_filter_tick,
 	.video_render = gpu_delay_filter_render,
+	.video_get_color_space = gpu_delay_filter_get_color_space,
 };