Restore main.go + upscale_module.go preparation

- main.go restored from corruption (13,664 lines)
- upscale_module.go created with AI helper functions
- Ready for safer incremental extraction approach

upscale_module.go

@@ -0,0 +1,173 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/dialog"
+	"fyne.io/fyne/v2/layout"
+	"fyne.io/fyne/v2/widget"
+
+	"git.leaktechnologies.dev/stu/VideoTools/internal/logging"
+	"git.leaktechnologies.dev/stu/VideoTools/internal/queue"
+	"git.leaktechnologies.dev/stu/VideoTools/internal/ui"
+	"git.leaktechnologies.dev/stu/VideoTools/internal/utils"
+)
+
+// AI Helper Functions (smaller, manageable functions)
+
+// detectAIUpscaleBackend returns the available Real-ESRGAN backend ("ncnn", "python", or "").
+func detectAIUpscaleBackend() string {
+	if _, err := exec.LookPath("realesrgan-ncnn-vulkan"); err == nil {
+		return "ncnn"
+	}
+
+	cmd := exec.Command("python3", "-c", "import realesrgan")
+	utils.ApplyNoWindow(cmd)
+	if err := cmd.Run(); err == nil {
+		return "python"
+	}
+
+	cmd = exec.Command("python", "-c", "import realesrgan")
+	utils.ApplyNoWindow(cmd)
+	if err := cmd.Run(); err == nil {
+		return "python"
+	}
+
+	return ""
+}
+
+// checkAIFaceEnhanceAvailable verifies whether face enhancement tooling is available.
+func checkAIFaceEnhanceAvailable(backend string) bool {
+	if backend != "python" {
+		return false
+	}
+	cmd := exec.Command("python3", "-c", "import realesrgan, gfpgan")
+	utils.ApplyNoWindow(cmd)
+	if err := cmd.Run(); err == nil {
+		return true
+	}
+	cmd = exec.Command("python", "-c", "import realesrgan, gfpgan")
+	utils.ApplyNoWindow(cmd)
+	return cmd.Run() == nil
+}
+
+func aiUpscaleModelOptions() []string {
+	return []string{
+		"General (RealESRGAN_x4plus)",
+		"Anime/Illustration (RealESRGAN_x4plus_anime_6B)",
+		"Anime Video (realesr-animevideov3)",
+		"General Tiny (realesr-general-x4v3)",
+		"2x General (RealESRGAN_x2plus)",
+		"Clean Restore (realesrnet-x4plus)",
+	}
+}
+
+func aiUpscaleModelID(label string) string {
+	switch label {
+	case "Anime/Illustration (RealESRGAN_x4plus_anime_6B)":
+		return "realesrgan-x4plus-anime"
+	case "Anime Video (realesr-animevideov3)":
+		return "realesr-animevideov3"
+	case "General Tiny (realesr-general-x4v3)":
+		return "realesr-general-x4v3"
+	case "2x General (RealESRGAN_x2plus)":
+		return "realesrgan-x2plus"
+	case "Clean Restore (realesrnet-x4plus)":
+		return "realesrnet-x4plus"
+	default:
+		return "realesrgan-x4plus"
+	}
+}
+
+func aiUpscaleModelLabel(modelID string) string {
+	switch modelID {
+	case "realesrgan-x4plus-anime":
+		return "Anime/Illustration (RealESRGAN_x4plus_anime_6B)"
+	case "realesr-animevideov3":
+		return "Anime Video (realesr-animevideov3)"
+	case "realesr-general-x4v3":
+		return "General Tiny (realesr-general-x4v3)"
+	case "realesrgan-x2plus":
+		return "2x General (RealESRGAN_x2plus)"
+	case "realesrnet-x4plus":
+		return "Clean Restore (realesrnet-x4plus)"
+	case "realesrgan-x4plus":
+		return "General (RealESRGAN_x4plus)"
+	default:
+		return ""
+	}
+}
+
+// parseResolutionPreset parses resolution preset strings and returns target dimensions and whether to preserve aspect.
+// Special presets like "Match Source" and relative (2X/4X) use source dimensions to preserve AR.
+func parseResolutionPreset(preset string, srcW, srcH int) (width, height int, preserveAspect bool, err error) {
+	// Default: preserve aspect
+	preserveAspect = true
+
+	// Sanitize source
+	if srcW < 1 || srcH < 1 {
+		srcW, srcH = 1920, 1080 // fallback to avoid zero division
+	}
+
+	switch preset {
+	case "", "Match Source":
+		return srcW, srcH, true, nil
+	case "2X (relative)":
+		return srcW * 2, srcH * 2, true, nil
+	case "4X (relative)":
+		return srcW * 4, srcH * 4, true, nil
+	}
+
+	presetMap := map[string][2]int{
+		"720p (1280x720)":   {1280, 720},
+		"1080p (1920x1080)": {1920, 1080},
+		"1440p (2560x1440)": {2560, 1440},
+		"4K (3840x2160)":    {3840, 2160},
+		"8K (7680x4320)":    {7680, 4320},
+		"720p":              {1280, 720},
+		"1080p":             {1920, 1080},
+		"1440p":             {2560, 1440},
+		"4K":                {3840, 2160},
+		"8K":                {7680, 4320},
+	}
+
+	if dims, ok := presetMap[preset]; ok {
+		// Keep aspect by default: use target height and let FFmpeg derive width
+		return dims[0], dims[1], true, nil
+	}
+
+	return 0, 0, true, fmt.Errorf("unknown resolution preset: %s", preset)
+}
+
+// buildUpscaleFilter builds FFmpeg scale filter string with selected method
+func buildUpscaleFilter(targetWidth, targetHeight int, method string, preserveAspect bool) string {
+	// Ensure even dimensions for encoders
+	makeEven := func(v int) int {
+		if v%2 != 0 {
+			return v + 1
+		}
+		return v
+	}
+
+	h := makeEven(targetHeight)
+	w := targetWidth
+	if preserveAspect || w <= 0 {
+		w = -2 // FFmpeg will derive width from height while preserving AR
+	}
+	return fmt.Sprintf("scale=%d:%d:flags=%s", w, h, method)
+}
+
+// sanitizeForPath creates a simple slug for filenames from user-visible labels
+func sanitizeForPath(label string) string {
+	r := strings.NewReplacer(" ", "", "(", "", ")", "", "×", "x", "/", "-", "\\", "-", ":", "-", ",", "", ".", "", "_", "")
+	return strings.ToLower(r.Replace(label))
+}
+
+// Main module functions will be added here incrementally...