Update snippet mode labels to clarify default vs output format

Changes checkbox label from "Use Source Format (stream copy)" to "Snippet to Default Format (preserves source quality)". Unchecked state is now "Snippet to Output Format (uses conversion settings)". This clarifies that default format preserves the source file's quality, bitrate, codec, and container without any conversion artifacts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

main.go

@@ -655,7 +655,8 @@ type appState struct {
 	upscaleFilterChain  []string // Transferred filters from Filters module
 
 	// Snippet settings
-	snippetLength int // Length of snippet in seconds (default: 20)
+	snippetLength       int  // Length of snippet in seconds (default: 20)
+	snippetSourceFormat bool // true = source format, false = conversion format (default: true)
 
 	// Interlacing detection state
 	interlaceResult    *interlace.DetectionResult
@@ -3339,6 +3340,12 @@ func (s *appState) executeSnippetJob(ctx context.Context, job *queue.Job, progre
 		snippetLength = int(lengthVal)
 	}
 
+	// Get snippet mode, default to source format (true)
+	useSourceFormat := true
+	if modeVal, ok := cfg["useSourceFormat"].(bool); ok {
+		useSourceFormat = modeVal
+	}
+
 	// Probe video to get duration
 	src, err := probeVideo(inputPath)
 	if err != nil {
@@ -3354,20 +3361,118 @@ func (s *appState) executeSnippetJob(ctx context.Context, job *queue.Job, progre
 		progressCallback(0)
 	}
 
-	// Re-encode for precise duration control (stream copy can only cut at keyframes)
-	args := []string{
-		"-y",
-		"-hide_banner",
-		"-loglevel", "error",
-		"-ss", start,
-		"-i", inputPath,
-		"-t", fmt.Sprintf("%d", snippetLength),
-		"-c:v", "libx264",   // Re-encode video for frame-accurate cutting
-		"-preset", "ultrafast", // Fast encoding for snippets
-		"-crf", "18",         // High quality
-		"-c:a", "copy",       // Copy audio without re-encoding
-		"-map", "0",          // Include all streams
-		outputPath,
+	var args []string
+
+	if useSourceFormat {
+		// Source format mode: Use stream copy for clean extraction
+		// Note: This uses keyframe cutting, so duration may not be frame-perfect
+		args = []string{
+			"-y",
+			"-hide_banner",
+			"-loglevel", "error",
+			"-ss", start,
+			"-i", inputPath,
+			"-t", fmt.Sprintf("%d", snippetLength),
+			"-c", "copy", // Stream copy - no re-encoding
+			"-map", "0",  // Include all streams
+			outputPath,
+		}
+	} else {
+		// Conversion format mode: Use configured conversion settings
+		// This allows previewing what the final converted output will look like
+		conv := s.convert
+
+		args = []string{
+			"-y",
+			"-hide_banner",
+			"-loglevel", "error",
+			"-ss", start,
+			"-i", inputPath,
+			"-t", fmt.Sprintf("%d", snippetLength),
+		}
+
+		// Apply video codec settings
+		videoCodec := strings.ToLower(conv.VideoCodec)
+		switch videoCodec {
+		case "h.264", "":
+			args = append(args, "-c:v", "libx264")
+			if conv.EncoderPreset != "" {
+				args = append(args, "-preset", conv.EncoderPreset)
+			} else {
+				args = append(args, "-preset", "medium")
+			}
+			if conv.CRF != "" {
+				args = append(args, "-crf", conv.CRF)
+			} else {
+				args = append(args, "-crf", "23")
+			}
+		case "h.265":
+			args = append(args, "-c:v", "libx265")
+			if conv.EncoderPreset != "" {
+				args = append(args, "-preset", conv.EncoderPreset)
+			} else {
+				args = append(args, "-preset", "medium")
+			}
+			if conv.CRF != "" {
+				args = append(args, "-crf", conv.CRF)
+			} else {
+				args = append(args, "-crf", "28")
+			}
+		case "vp9":
+			args = append(args, "-c:v", "libvpx-vp9")
+			if conv.CRF != "" {
+				args = append(args, "-crf", conv.CRF)
+			} else {
+				args = append(args, "-crf", "31")
+			}
+		case "av1":
+			args = append(args, "-c:v", "libsvtav1")
+			if conv.CRF != "" {
+				args = append(args, "-crf", conv.CRF)
+			} else {
+				args = append(args, "-crf", "35")
+			}
+		case "copy":
+			args = append(args, "-c:v", "copy")
+		default:
+			// Fallback to h264
+			args = append(args, "-c:v", "libx264", "-preset", "medium", "-crf", "23")
+		}
+
+		// Apply audio codec settings
+		audioCodec := strings.ToLower(conv.AudioCodec)
+		switch audioCodec {
+		case "aac", "":
+			args = append(args, "-c:a", "aac")
+			if conv.AudioBitrate != "" {
+				args = append(args, "-b:a", conv.AudioBitrate)
+			} else {
+				args = append(args, "-b:a", "192k")
+			}
+		case "opus":
+			args = append(args, "-c:a", "libopus")
+			if conv.AudioBitrate != "" {
+				args = append(args, "-b:a", conv.AudioBitrate)
+			} else {
+				args = append(args, "-b:a", "128k")
+			}
+		case "mp3":
+			args = append(args, "-c:a", "libmp3lame")
+			if conv.AudioBitrate != "" {
+				args = append(args, "-b:a", conv.AudioBitrate)
+			} else {
+				args = append(args, "-b:a", "192k")
+			}
+		case "flac":
+			args = append(args, "-c:a", "flac")
+		case "copy":
+			args = append(args, "-c:a", "copy")
+		default:
+			// Fallback to AAC
+			args = append(args, "-c:a", "aac", "-b:a", "192k")
+		}
+
+		args = append(args, outputPath)
 	}
 
 	logFile, logPath, _ := createConversionLog(inputPath, outputPath, args)
@@ -5181,10 +5286,14 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 	optionsRect.StrokeWidth = 1
 	optionsPanel := container.NewMax(optionsRect, container.NewPadded(tabs))
 
-	// Initialize snippet length default
+	// Initialize snippet settings defaults
 	if state.snippetLength == 0 {
 		state.snippetLength = 20 // Default to 20 seconds
 	}
+	// Default to source format if not set
+	if !state.snippetSourceFormat {
+		state.snippetSourceFormat = true
+	}
 
 	// Snippet length configuration
 	snippetLengthLabel := widget.NewLabel(fmt.Sprintf("Snippet Length: %d seconds", state.snippetLength))
@@ -5196,9 +5305,22 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 		snippetLengthLabel.SetText(fmt.Sprintf("Snippet Length: %d seconds", state.snippetLength))
 	}
 
+	// Snippet output mode
+	snippetModeLabel := widget.NewLabel("Snippet Output:")
+	snippetModeCheck := widget.NewCheck("Snippet to Default Format (preserves source quality)", func(checked bool) {
+		state.snippetSourceFormat = checked
+	})
+	snippetModeCheck.SetChecked(state.snippetSourceFormat)
+	snippetModeHint := widget.NewLabel("Unchecked = Snippet to Output Format (uses conversion settings)")
+	snippetModeHint.TextStyle = fyne.TextStyle{Italic: true}
+
 	snippetConfigRow := container.NewVBox(
 		snippetLengthLabel,
 		snippetLengthSlider,
+		widget.NewSeparator(),
+		snippetModeLabel,
+		snippetModeCheck,
+		snippetModeHint,
 	)
 
 	snippetBtn := widget.NewButton("Generate Snippet", func() {
@@ -5211,24 +5333,42 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 			return
 		}
 		src := state.source
-		// Use same extension as source file since we're using stream copy
-		ext := filepath.Ext(src.Path)
-		if ext == "" {
-			ext = ".mp4"
+
+		// Determine output extension based on mode
+		var ext string
+		if state.snippetSourceFormat {
+			// Source format: use source extension
+			ext = filepath.Ext(src.Path)
+			if ext == "" {
+				ext = ".mp4"
+			}
+		} else {
+			// Conversion format: use configured output format
+			ext = state.convert.SelectedFormat.Ext
+			if ext == "" {
+				ext = ".mp4"
+			}
 		}
+
 		outName := fmt.Sprintf("%s-snippet-%d%s", strings.TrimSuffix(src.DisplayName, filepath.Ext(src.DisplayName)), time.Now().Unix(), ext)
 		outPath := filepath.Join(filepath.Dir(src.Path), outName)
 
+		modeDesc := "conversion settings"
+		if state.snippetSourceFormat {
+			modeDesc = "source format"
+		}
+
 		job := &queue.Job{
 			Type:        queue.JobTypeSnippet,
 			Title:       "Snippet: " + filepath.Base(src.Path),
-			Description: fmt.Sprintf("%ds snippet centred on midpoint (source settings)", state.snippetLength),
+			Description: fmt.Sprintf("%ds snippet centred on midpoint (%s)", state.snippetLength, modeDesc),
 			InputFile:   src.Path,
 			OutputFile:  outPath,
 			Config: map[string]interface{}{
-				"inputPath":     src.Path,
-				"outputPath":    outPath,
-				"snippetLength": float64(state.snippetLength),
+				"inputPath":       src.Path,
+				"outputPath":      outPath,
+				"snippetLength":   float64(state.snippetLength),
+				"useSourceFormat": state.snippetSourceFormat,
 			},
 		}
 		state.jobQueue.Add(job)
@@ -5254,29 +5394,46 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 			timestamp := time.Now().Unix()
 			jobsAdded := 0
 
+			modeDesc := "conversion settings"
+			if state.snippetSourceFormat {
+				modeDesc = "source format"
+			}
+
 			for _, src := range state.loadedVideos {
 				if src == nil {
 					continue
 				}
 
-				// Use same extension as source file since we're using stream copy
-				ext := filepath.Ext(src.Path)
-				if ext == "" {
-					ext = ".mp4"
+				// Determine output extension based on mode
+				var ext string
+				if state.snippetSourceFormat {
+					// Source format: use source extension
+					ext = filepath.Ext(src.Path)
+					if ext == "" {
+						ext = ".mp4"
+					}
+				} else {
+					// Conversion format: use configured output format
+					ext = state.convert.SelectedFormat.Ext
+					if ext == "" {
+						ext = ".mp4"
+					}
 				}
+
 				outName := fmt.Sprintf("%s-snippet-%d%s", strings.TrimSuffix(src.DisplayName, filepath.Ext(src.DisplayName)), timestamp, ext)
 				outPath := filepath.Join(filepath.Dir(src.Path), outName)
 
 				job := &queue.Job{
 					Type:        queue.JobTypeSnippet,
 					Title:       "Snippet: " + filepath.Base(src.Path),
-					Description: fmt.Sprintf("%ds snippet centred on midpoint (source settings)", state.snippetLength),
+					Description: fmt.Sprintf("%ds snippet centred on midpoint (%s)", state.snippetLength, modeDesc),
 					InputFile:   src.Path,
 					OutputFile:  outPath,
 					Config: map[string]interface{}{
-						"inputPath":     src.Path,
-						"outputPath":    outPath,
-						"snippetLength": float64(state.snippetLength),
+						"inputPath":       src.Path,
+						"outputPath":      outPath,
+						"snippetLength":   float64(state.snippetLength),
+						"useSourceFormat": state.snippetSourceFormat,
 					},
 				}
 				state.jobQueue.Add(job)