From 4b591f58fc1ab6d644540b468763b09bcf7cd5f3 Mon Sep 17 00:00:00 2001
From: misteraddons <51079966+misteraddons@users.noreply.github.com>
Date: Fri, 12 Sep 2025 00:08:50 -0600
Subject: [PATCH] Automatic Direct Video (#1035)

* Simple Auto Direct Video

direct_video=2
Checks for 1024x768 HDMI resolution and sets direct_video=1
No hot plug detect
No EDID parsing
No device whitelist
No hdmi_limited set based on EDID whitelist

* Add EDID detection and set hdmi_limited for common DACs

- AG6200 sets hdmi_limited=2
- CS5213 sets hdmi_limited=0

* Fix logic to pass normal EDID resolution if not 1024x768

* Update MiSTer.ini

* Remove 1024x768 resolution check

- Only use mfg_id from EDID to identify known compatible DACs

* Add DAC id and settings to dv_dac.txt and dv_dac_user.txt

- mfg_id
- rgb range
- hdmi_audio_96khz
- composite_sync: 0, 1, or "" (default is "")
- dv_dac_user.txt for HDMI video upscalers that support direct video
  - device commented out by default
---
 MiSTer.ini      |   3 +
 cfg.cpp         |   2 +-
 dv_dac.txt      |  24 ++++++++
 dv_dac_user.txt |  31 ++++++++++
 video.cpp       | 156 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 215 insertions(+), 1 deletion(-)
 create mode 100644 dv_dac.txt
 create mode 100644 dv_dac_user.txt

diff --git a/MiSTer.ini b/MiSTer.ini
index e83e484..7f6ea88 100644
--- a/MiSTer.ini
+++ b/MiSTer.ini
@@ -23,6 +23,9 @@ menu_pal=0             ; 1 - PAL mode for menu core
 hdmi_limited=0         ; 1 - use limited (16..235) color range over HDMI
                        ; 2 - use limited (16..255) color range over HDMI, for VGA converters.
 direct_video=0         ; 1 - enable core video timing over HDMI, use only with VGA converters.
+                       ; 2 - auto-mode for HDMI DACs that report 1024x768 resolution (AG6200, CS5213). 
+                       ; Power cycle when switching between HDMI displays and DACs. No hot-plug detection.
+
 hdr=0                  ; 1 - enable HDR using HLG (recommended for most users)
                        ; 2 - enable HDR using the DCI P3 color space (use color controls to tweak, suggestion: set saturation to 80).
 fb_size=0              ; 0 - automatic, 1 - full size, 2 - 1/2 of resolution, 4 - 1/4 of resolution.
diff --git a/cfg.cpp b/cfg.cpp
index fe00eef..8c3cb73 100644
--- a/cfg.cpp
+++ b/cfg.cpp
@@ -65,7 +65,7 @@ static const ini_var_t ini_vars[] =
 	{ "FB_SIZE", (void*)(&(cfg.fb_size)), UINT8, 0, 4 },
 	{ "FB_TERMINAL", (void*)(&(cfg.fb_terminal)), UINT8, 0, 1 },
 	{ "OSD_TIMEOUT", (void*)(&(cfg.osd_timeout)), INT16, 0, 3600 },
-	{ "DIRECT_VIDEO", (void*)(&(cfg.direct_video)), UINT8, 0, 1 },
+	{ "DIRECT_VIDEO", (void*)(&(cfg.direct_video)), UINT8, 0, 2 },
 	{ "OSD_ROTATE", (void*)(&(cfg.osd_rotate)), UINT8, 0, 2 },
 	{ "DEADZONE", (void*)(&(cfg.controller_deadzone)), STRINGARR, sizeof(cfg.controller_deadzone) / sizeof(*cfg.controller_deadzone), sizeof(*cfg.controller_deadzone) },
 	{ "GAMEPAD_DEFAULTS", (void*)(&(cfg.gamepad_defaults)), UINT8, 0, 1 },
diff --git a/dv_dac.txt b/dv_dac.txt
new file mode 100644
index 0000000..e54b44c
--- /dev/null
+++ b/dv_dac.txt
@@ -0,0 +1,24 @@
+# Direct Video DAC Configuration File
+# Format: mfg_id,hdmi_limited,hdmi_audio_96k,composite_sync,name
+# 
+# mfg_id: Manufacturer ID from EDID bytes 0x08-0x09 (hex, e.g. 0x48F4)
+#         This is the raw 16-bit value from EDID, NOT the decoded 3-letter code
+# hdmi_limited: 0=full range RGB (0-255)
+#               1=limited range RGB (16-235) 
+#               2=limited range RGB (16-255)
+# hdmi_audio_96k: 0=48kHz audio, 1=96kHz audio
+# composite_sync: 0=disable composite sync, 1=enable composite sync, blank=use MiSTer.ini setting
+# name: Description of the DAC (optional, for logging purposes)
+#
+# The mfg_id comes from EDID bytes:
+#   Byte 0x08: High byte of manufacturer ID
+#   Byte 0x09: Low byte of manufacturer ID
+#   Combined as: (byte_08 << 8) | byte_09
+#
+# Examples:
+# 0x48F4,0,0,,Full-range CS5213 DAC
+# 0x04EF,2,0,1,Limited-range AG6200 DAC
+
+# Known DACs
+0x48F4,0,0,,Full-range CS5213 DAC
+0x04EF,2,0,,Limited-range AG6200 DAC
diff --git a/dv_dac_user.txt b/dv_dac_user.txt
new file mode 100644
index 0000000..4ba782d
--- /dev/null
+++ b/dv_dac_user.txt
@@ -0,0 +1,31 @@
+# User Direct Video DAC Configuration File
+# This file allows users to add their own DAC configurations
+# or override settings from dv_dac.txt
+#
+# Format: mfg_id,hdmi_limited,hdmi_audio_96k,composite_sync,name
+# 
+# mfg_id: Manufacturer ID from EDID bytes 0x08-0x09 (hex, e.g. 0x48F4)
+#         This is the raw 16-bit value from EDID, NOT the decoded 3-letter code
+# hdmi_limited: 0=full range RGB (0-255)
+#               1=limited range RGB (16-235) 
+#               2=limited range RGB (16-255)
+# hdmi_audio_96k: 0=48kHz audio, 1=96kHz audio
+# composite_sync: 0=disable composite sync, 1=enable composite sync, blank=use MiSTer.ini setting
+# name: Description of the DAC (optional, for logging purposes)
+#
+# The mfg_id comes from EDID bytes:
+#   Byte 0x08: High byte of manufacturer ID
+#   Byte 0x09: Low byte of manufacturer ID
+#   Combined as: (byte_08 << 8) | byte_09
+#
+# Examples:
+# 0x40D8,0,1,,PixelFX Morph (full range, use MiSTer.ini csync setting)
+# 0x1234,1,1,1,Custom DAC (limited 16-235, force composite sync on)
+# 0x5678,2,0,0,Another DAC (limited 16-255, force composite sync off)
+#
+# Note: Entries in this file will override any matching mfg_id from dv_dac.txt
+#
+# Known video upscalers that support direct video
+# (remove "# " in front of device if you want to use automatic direct video mode):
+# 0x40D8,0,1,1,PixelFX Morph 4K
+# 0x4A8B,0,1,1,RetroTink 4K Pro
diff --git a/video.cpp b/video.cpp
index a10970b..7726d99 100644
--- a/video.cpp
+++ b/video.cpp
@@ -2425,8 +2425,164 @@ static void fb_init()
 	spi_uio_cmd16(UIO_SET_FBUF, 0);
 }
 
+// Structure to hold DAC configuration
+struct dac_config {
+	uint16_t mfg_id;
+	uint8_t hdmi_limited;
+	uint8_t hdmi_audio_96k;
+	int8_t composite_sync; // -1=use MiSTer.ini, 0=force off, 1=force on
+	char name[64];
+};
+
+static dac_config dac_configs[32];
+static int dac_config_count = 0;
+
+static void load_dac_file(const char *filename)
+{
+	fileTextReader reader;
+	const char *line;
+	
+	if (!FileOpenTextReader(&reader, filename)) {
+		return;
+	}
+	
+	printf("Loading DAC configuration from %s\n", filename);
+	
+	while ((line = FileReadLine(&reader)) && dac_config_count < 32) {
+		// Skip comments and empty lines
+		if (line[0] == '#' || line[0] == '\n' || line[0] == '\r' || line[0] == '\0') continue;
+		
+		// Parse format: mfg_id,hdmi_limited,hdmi_audio_96k,composite_sync,name
+		// Example: 0x48F4,0,0,,Full-range CS5213 DAC
+		unsigned int mfg, limited, audio_96k = 0;
+		char name[64] = {0};
+		char csync_str[16] = {0};
+		int8_t csync = -1; // Default to use MiSTer.ini setting
+		
+		// Parse with optional composite_sync field
+		int fields = sscanf(line, "%x,%u,%u,%15[^,],%63[^\n]", &mfg, &limited, &audio_96k, csync_str, name);
+		if (fields >= 2) {
+			// Parse composite sync field if present
+			if (fields >= 4 && strlen(csync_str) > 0) {
+				csync = (csync_str[0] == '1') ? 1 : 0;
+			}
+			// Check if this mfg_id already exists and update it
+			bool found = false;
+			for (int i = 0; i < dac_config_count; i++) {
+				if (dac_configs[i].mfg_id == mfg) {
+					dac_configs[i].hdmi_limited = limited;
+					dac_configs[i].hdmi_audio_96k = audio_96k;
+					dac_configs[i].composite_sync = csync;
+					strncpy(dac_configs[i].name, name, 63);
+					printf("  Updated DAC: mfg=0x%04X, hdmi_limited=%d, hdmi_audio_96k=%d, csync=%d, %s\n", 
+						mfg, limited, audio_96k, csync, name);
+					found = true;
+					break;
+				}
+			}
+			
+			if (!found) {
+				dac_configs[dac_config_count].mfg_id = mfg;
+				dac_configs[dac_config_count].hdmi_limited = limited;
+				dac_configs[dac_config_count].hdmi_audio_96k = audio_96k;
+				dac_configs[dac_config_count].composite_sync = csync;
+				strncpy(dac_configs[dac_config_count].name, name, 63);
+				printf("  DAC[%d]: mfg=0x%04X, hdmi_limited=%d, hdmi_audio_96k=%d, csync=%d, %s\n", 
+					dac_config_count, mfg, limited, audio_96k, csync, name);
+				dac_config_count++;
+			}
+		}
+	}
+}
+
+static void load_dac_config()
+{
+	dac_config_count = 0;
+	
+	// Try to load main DAC file
+	load_dac_file("dv_dac.txt");
+	
+	// Load user DAC file (overrides/adds to main file)
+	load_dac_file("dv_dac_user.txt");
+	
+	if (dac_config_count == 0) {
+		// If no files found, use built-in defaults
+		dac_configs[0].mfg_id = 0x48F4;
+		dac_configs[0].hdmi_limited = 0;
+		dac_configs[0].hdmi_audio_96k = 0;
+		dac_configs[0].composite_sync = -1;
+		strcpy(dac_configs[0].name, "Full-range DAC (built-in)");
+		
+		dac_configs[1].mfg_id = 0x04EF;
+		dac_configs[1].hdmi_limited = 2;
+		dac_configs[1].hdmi_audio_96k = 0;
+		dac_configs[1].composite_sync = -1;
+		strcpy(dac_configs[1].name, "Limited-range DAC (built-in)");
+		
+		dac_config_count = 2;
+		printf("No DAC config files found, using built-in defaults\n");
+	}
+	
+	printf("Total: %d DAC configurations loaded\n", dac_config_count);
+}
+
+static int should_auto_enable_direct_video()
+{
+	// Load DAC config on first call
+	static bool dac_config_loaded = false;
+	if (!dac_config_loaded) {
+		load_dac_config();
+		dac_config_loaded = true;
+	}
+	
+	// Read EDID if not already valid
+	if (!is_edid_valid()) {
+		get_active_edid();
+	}
+	
+	if (!is_edid_valid()) return 0;
+	
+	// Check manufacturer ID (bytes 0x08-0x09)
+	uint16_t mfg_id = (edid[0x08] << 8) | edid[0x09];
+	
+	// Check against known DACs from config
+	for (int i = 0; i < dac_config_count; i++) {
+		if (mfg_id == dac_configs[i].mfg_id) {
+			printf("EDID: Detected known DAC: %s\n", dac_configs[i].name);
+			printf("EDID: Auto-enabling direct video with hdmi_limited=%d, hdmi_audio_96k=%d\n", 
+				dac_configs[i].hdmi_limited, dac_configs[i].hdmi_audio_96k);
+			cfg.hdmi_limited = dac_configs[i].hdmi_limited;
+			cfg.hdmi_audio_96k = dac_configs[i].hdmi_audio_96k;
+			
+			// Set composite sync if specified
+			if (dac_configs[i].composite_sync >= 0) {
+				cfg.csync = dac_configs[i].composite_sync;
+				printf("EDID: Auto-setting composite_sync=%d\n", dac_configs[i].composite_sync);
+			} else {
+				printf("EDID: Composite sync setting deferred to MiSTer.ini\n");
+			}
+			return 1;
+		}
+	}
+	
+	// Not a known DAC, don't enable direct video
+	return 0;
+}
+
 static void video_mode_load()
 {
+	// Auto-detect and enable direct video if configured
+	if (cfg.direct_video == 2) {
+		if (should_auto_enable_direct_video()) {
+			printf("Auto-enabling direct video for known DAC.\n");
+			// Enable direct video, preserve all other user settings
+			cfg.direct_video = 1;
+		} else {
+			// Not a DAC, use normal HDMI mode
+			cfg.direct_video = 0;
+		}
+	}
+
 	if (cfg.direct_video && cfg.vsync_adjust)
 	{
 		printf("Disabling vsync_adjust because of enabled direct video.\n");