From 75073b2f5d7b9503d2759ad7910505b67d8f061e Mon Sep 17 00:00:00 2001
From: Stu Leak <leaktechnologies@proton.me>
Date: Wed, 17 Dec 2025 01:18:27 -0500
Subject: [PATCH] Fix DVD format merges to preserve chapter metadata

Removed -target ntsc-dvd and -target pal-dvd preset flags which
strip metadata including chapters. Instead, manually specify all
DVD parameters (bitrate, maxrate, bufsize, format) to maintain
full control and preserve chapter metadata.

Chapters now retained in both new 'dvd' format and legacy DVD formats.
---
 main.go | 53 ++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/main.go b/main.go
index 39cafb3..1f64cb4 100644
--- a/main.go
+++ b/main.go
@@ -2577,6 +2577,7 @@ func (s *appState) executeMergeJob(ctx context.Context, job *queue.Job, progress
 		}
 
 		// Force MPEG-2 / AC-3
+		// Note: Don't use -target flags as they strip metadata including chapters
 		args = append(args,
 			"-c:v", "mpeg2video",
 			"-c:a", "ac3",
@@ -2585,16 +2586,32 @@ func (s *appState) executeMergeJob(ctx context.Context, job *queue.Job, progress
 		)
 
 		if dvdRegion == "NTSC" {
-			args = append(args, "-vf", "scale=720:480,setsar=1", "-r", "30000/1001", "-pix_fmt", "yuv420p", "-aspect", dvdAspect)
-			args = append(args, "-target", "ntsc-dvd")
+			args = append(args,
+				"-vf", "scale=720:480,setsar=1",
+				"-r", "30000/1001",
+				"-pix_fmt", "yuv420p",
+				"-aspect", dvdAspect,
+				"-b:v", "5000k",      // DVD video bitrate
+				"-maxrate", "8000k",  // DVD max bitrate
+				"-bufsize", "1835008", // DVD buffer size
+				"-f", "dvd",          // DVD format
+			)
 		} else {
-			args = append(args, "-vf", "scale=720:576,setsar=1", "-r", "25", "-pix_fmt", "yuv420p", "-aspect", dvdAspect)
-			args = append(args, "-target", "pal-dvd")
+			args = append(args,
+				"-vf", "scale=720:576,setsar=1",
+				"-r", "25",
+				"-pix_fmt", "yuv420p",
+				"-aspect", dvdAspect,
+				"-b:v", "5000k",      // DVD video bitrate
+				"-maxrate", "8000k",  // DVD max bitrate
+				"-bufsize", "1835008", // DVD buffer size
+				"-f", "dvd",          // DVD format
+			)
 		}
 
 	case "dvd-ntsc-169", "dvd-ntsc-43", "dvd-pal-169", "dvd-pal-43":
 		// Legacy DVD formats for backward compatibility
-		// Force MPEG-2 / AC-3
+		// Note: Don't use -target flags as they strip metadata including chapters
 		args = append(args,
 			"-c:v", "mpeg2video",
 			"-c:a", "ac3",
@@ -2606,13 +2623,27 @@ func (s *appState) executeMergeJob(ctx context.Context, job *queue.Job, progress
 			aspect = "4:3"
 		}
 		if strings.Contains(format, "ntsc") {
-			args = append(args, "-vf", "scale=720:480,setsar=1", "-r", "30000/1001", "-pix_fmt", "yuv420p", "-aspect", aspect)
+			args = append(args,
+				"-vf", "scale=720:480,setsar=1",
+				"-r", "30000/1001",
+				"-pix_fmt", "yuv420p",
+				"-aspect", aspect,
+				"-b:v", "5000k",
+				"-maxrate", "8000k",
+				"-bufsize", "1835008",
+				"-f", "dvd",
+			)
 		} else {
-			args = append(args, "-vf", "scale=720:576,setsar=1", "-r", "25", "-pix_fmt", "yuv420p", "-aspect", aspect)
-		}
-		args = append(args, "-target", "ntsc-dvd")
-		if strings.Contains(format, "pal") {
-			args[len(args)-1] = "pal-dvd"
+			args = append(args,
+				"-vf", "scale=720:576,setsar=1",
+				"-r", "25",
+				"-pix_fmt", "yuv420p",
+				"-aspect", aspect,
+				"-b:v", "5000k",
+				"-maxrate", "8000k",
+				"-bufsize", "1835008",
+				"-f", "dvd",
+			)
 		}
 	case "bd-h264":
 		args = append(args,