From 26c7564b5de76d0461480b634f27d9eb13e02e96 Mon Sep 17 00:00:00 2001
From: misteraddons <51079966+misteraddons@users.noreply.github.com>
Date: Thu, 23 Oct 2025 01:21:24 -0600
Subject: [PATCH] video: Make subcarrier a vga_mode option instead of
 standalone

---
 MiSTer.ini | 2 +-
 cfg.cpp    | 8 ++++++--
 cfg.h      | 1 -
 video.cpp  | 6 +++---
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/MiSTer.ini b/MiSTer.ini
index cc98465..cb9ae23 100644
--- a/MiSTer.ini
+++ b/MiSTer.ini
@@ -3,7 +3,7 @@
 key_menu_as_rgui=0     ; set to 1 to make the MENU key map to RGUI in Minimig (e.g. for Right Amiga)
 forced_scandoubler=0   ; set to 1 to run scandoubler on VGA output always (depends on core).
 ;ypbpr=0               ; set to 1 for YPbPr on VGA output. (obsolete. see vga_mode)
-vga_mode=rgb           ; supported modes: rgb, ypbpr, svideo, cvbs. rgb is default.
+vga_mode=rgb           ; supported modes: rgb, ypbpr, svideo, cvbs, and subcarrier (for external rgb converters). rgb is default.
 ntsc_mode=0            ; Only for S-Video and CVBS vga_mode. 0 - normal NTSC, 1 - PAL-60, 2 - PAL-M.
 composite_sync=1       ; set to 1 for composite sync on HSync signal of VGA output.
 vga_scaler=0           ; set to 1 to connect VGA to scaler output.
diff --git a/cfg.cpp b/cfg.cpp
index 583a438..1752ecb 100644
--- a/cfg.cpp
+++ b/cfg.cpp
@@ -48,7 +48,6 @@ static const ini_var_t ini_vars[] =
 	{ "VIDEO_MODE_NTSC", (void*)(cfg.video_conf_ntsc), STRING, 0, sizeof(cfg.video_conf_ntsc) - 1 },
 	{ "VIDEO_INFO", (void*)(&(cfg.video_info)), UINT8, 0, 10 },
 	{ "VSYNC_ADJUST", (void*)(&(cfg.vsync_adjust)), UINT8, 0, 2 },
-	{ "SUBCARRIER", (void*)(&(cfg.subcarrier)), UINT8, 0, 1 },
 	{ "HDMI_AUDIO_96K", (void*)(&(cfg.hdmi_audio_96k)), UINT8, 0, 1 },
 	{ "DVI_MODE", (void*)(&(cfg.dvi_mode)), UINT8, 0, 1 },
 	{ "HDMI_LIMITED", (void*)(&(cfg.hdmi_limited)), UINT8, 0, 2 },
@@ -583,7 +582,6 @@ void cfg_parse()
 	cfg.rumble = 1;
 	cfg.wheel_force = 50;
 	cfg.dvi_mode = 2;
-	cfg.subcarrier = 0;
 	cfg.lookahead = 2;
 	cfg.hdr = 0;
 	cfg.hdr_max_nits = 1000;
@@ -610,6 +608,12 @@ void cfg_parse()
 		if (!strcasecmp(cfg.vga_mode, "ypbpr")) cfg.vga_mode_int = 1;
 		if (!strcasecmp(cfg.vga_mode, "svideo")) cfg.vga_mode_int = 2;
 		if (!strcasecmp(cfg.vga_mode, "cvbs")) cfg.vga_mode_int = 3;
+		if (!strcasecmp(cfg.vga_mode, "subcarrier"))
+		{
+			cfg.vga_mode_int = 4;
+			cfg.csync = 1;
+			cfg.forced_scandoubler = 0;
+		}
 	}
 }
 
diff --git a/cfg.h b/cfg.h
index 8d330dc..11906cf 100644
--- a/cfg.h
+++ b/cfg.h
@@ -25,7 +25,6 @@ typedef struct {
 	float refresh_max;
 	uint8_t controller_info;
 	uint8_t vsync_adjust;
-	uint8_t subcarrier;
 	uint8_t kbd_nomouse;
 	uint8_t mouse_throttle;
 	uint8_t bootscreen;
diff --git a/video.cpp b/video.cpp
index 3531cee..78d93d6 100644
--- a/video.cpp
+++ b/video.cpp
@@ -3018,7 +3018,7 @@ bool video_mode_select(uint32_t vtime, vmode_custom_t* out_mode)
 static void set_yc_mode()
 {
 	// Enable YC for S-Video/CVBS modes, or subcarrier for CXA2075 encoders
-	if (cfg.vga_mode_int >= 2 || (cfg.subcarrier && cfg.vga_mode_int == 0 && cfg.csync && !cfg.forced_scandoubler))
+	if (cfg.vga_mode_int >= 2)
 	{
 		float fps = current_video_info.vtime ? (100000000.f / current_video_info.vtime) : 0.f;
 		int pal = fps < 55.f;
@@ -3053,7 +3053,7 @@ static void set_yc_mode()
 		spi_uio_cmd_cont(UIO_SET_YC_PAR);
 		// For traditional S-Video/CVBS modes, enable YC processing
 		// For subcarrier-only modes (RGB+subcarrier or direct video), keep yc_en=0
-		bool is_subcarrier_only = (cfg.subcarrier && (cfg.direct_video || (cfg.vga_mode_int == 0 && cfg.csync && !cfg.forced_scandoubler)));
+		bool is_subcarrier_only = (cfg.vga_mode_int == 4);
 		uint16_t yc_config;
 		if (is_subcarrier_only) {
 			// Subcarrier-only: RGB mode with just PAL flag, yc_en=0
@@ -3070,7 +3070,7 @@ static void set_yc_mode()
 		spi_w(COLORBURST_RANGE);
 		spi_w(COLORBURST_RANGE >> 16);
 		// Case 6: Send subcarrier enable flag
-		uint16_t subcarrier_enable = (cfg.subcarrier && cfg.vga_mode_int == 0 && cfg.csync && !cfg.forced_scandoubler) ? 1 : 0;
+		uint16_t subcarrier_enable = (cfg.vga_mode_int == 4) ? 1 : 0;
 		printf("Sending subcarrier enable to FPGA: %d\n", subcarrier_enable);
 		spi_w(subcarrier_enable);
 		DisableIO();