feat: FFmpeg GUI desktop application

Wails v2 + Vue3 + Go project with:
- Encode/Remux/Subtitle burn with hardware acceleration
- Real-time progress with ffmpeg stderr parsing (\r delimiter handling)
- Task queue with cancel support
- Per-task log viewer with color-coded output
- Custom frameless window with resize support
- Dark/light theme toggle
- Hardware encoder detection (NVENC/QSV/AMF)

app.go

@@ -0,0 +1,223 @@
+package main
+
+import (
+	"context"
+	"ffmpeg-gui/internal/ffmpeg"
+	"ffmpeg-gui/internal/hwaccel"
+	"ffmpeg-gui/internal/media"
+	"ffmpeg-gui/internal/platform"
+	"ffmpeg-gui/internal/task"
+	"fmt"
+	"time"
+
+	"github.com/wailsapp/wails/v2/pkg/runtime"
+)
+
+// App is the main application struct. Its exported methods are bound to the frontend.
+type App struct {
+	ctx      context.Context
+	exec     *ffmpeg.Executor
+	taskMgr  *task.Manager
+	hwDetect *hwaccel.Detector
+}
+
+// NewApp creates a new App instance.
+func NewApp() *App {
+	return &App{}
+}
+
+// startup is called when the app starts.
+func (a *App) startup(ctx context.Context) {
+	a.ctx = ctx
+
+	// Detect ffmpeg/ffprobe binaries
+	bins, err := ffmpeg.Detect()
+	if err != nil {
+		runtime.LogError(ctx, fmt.Sprintf("ffmpeg detect failed: %v", err))
+		return
+	}
+	runtime.LogInfo(ctx, fmt.Sprintf("ffmpeg: %s, ffprobe: %s", bins.FFmpeg, bins.FFprobe))
+
+	a.exec = ffmpeg.NewExecutor(bins)
+	a.hwDetect = hwaccel.NewDetector(a.exec)
+	a.taskMgr = task.NewManager(a.exec)
+
+	a.taskMgr.SetEventCallback(func(eventType string, data any) {
+		runtime.EventsEmit(ctx, eventType, data)
+	})
+
+	// Enable window resize borders on frameless windows (Windows only)
+	go func() {
+		time.Sleep(200 * time.Millisecond)
+		platform.EnableResizeBorder()
+	}()
+}
+
+// shutdown is called when the app is closing.
+func (a *App) shutdown(ctx context.Context) {
+	if a.taskMgr != nil {
+		a.taskMgr.Stop()
+	}
+}
+
+// ---- Window Controls ----
+
+// MinimizeWindow minimizes the application window.
+func (a *App) MinimizeWindow() {
+	runtime.WindowMinimise(a.ctx)
+}
+
+// MaximizeWindow toggles the window between maximized and normal.
+func (a *App) MaximizeWindow() {
+	if runtime.WindowIsMaximised(a.ctx) {
+		runtime.WindowUnmaximise(a.ctx)
+	} else {
+		runtime.WindowMaximise(a.ctx)
+	}
+}
+
+// CloseWindow closes the application.
+func (a *App) CloseWindow() {
+	runtime.Quit(a.ctx)
+}
+
+// IsMaximised returns whether the window is currently maximized.
+func (a *App) IsMaximised() bool {
+	return runtime.WindowIsMaximised(a.ctx)
+}
+
+// ---- Media Info ----
+
+// GetMediaInfo retrieves media file information via ffprobe.
+func (a *App) GetMediaInfo(inputFile string) (*media.MediaInfo, error) {
+	if a.exec == nil {
+		return nil, fmt.Errorf("ffmpeg not initialized")
+	}
+	return media.GetInfo(a.exec, inputFile)
+}
+
+// ---- Hardware Detection ----
+
+// GetHardwareEncoders returns detected hardware encoders.
+func (a *App) GetHardwareEncoders() ([]hwaccel.HWEncoder, error) {
+	if a.hwDetect == nil {
+		return nil, fmt.Errorf("hw detector not initialized")
+	}
+	return a.hwDetect.DetectEncoders()
+}
+
+// GetAccelerators returns detected hardware acceleration methods.
+func (a *App) GetAccelerators() ([]hwaccel.Accelerator, error) {
+	if a.hwDetect == nil {
+		return nil, fmt.Errorf("hw detector not initialized")
+	}
+	return a.hwDetect.DetectAccelerators()
+}
+
+// ---- Task Management ----
+
+// AddTask adds a new task to the queue and returns the task ID.
+func (a *App) AddTask(t *task.Task) (string, error) {
+	if a.taskMgr == nil {
+		return "", fmt.Errorf("task manager not initialized")
+	}
+	id := a.taskMgr.Add(t)
+	return id, nil
+}
+
+// StartTask starts a specific task by ID.
+func (a *App) StartTask(taskID string) error {
+	if a.taskMgr == nil {
+		return fmt.Errorf("task manager not initialized")
+	}
+	return a.taskMgr.Start(taskID)
+}
+
+// StartAllTasks starts all pending tasks sequentially.
+func (a *App) StartAllTasks() {
+	if a.taskMgr != nil {
+		a.taskMgr.StartAll()
+	}
+}
+
+// CancelTask cancels a running or pending task.
+func (a *App) CancelTask(taskID string) error {
+	if a.taskMgr == nil {
+		return fmt.Errorf("task manager not initialized")
+	}
+	return a.taskMgr.Cancel(taskID)
+}
+
+// RemoveTask removes a completed/failed/canceled task.
+func (a *App) RemoveTask(taskID string) error {
+	if a.taskMgr == nil {
+		return fmt.Errorf("task manager not initialized")
+	}
+	return a.taskMgr.Remove(taskID)
+}
+
+// GetTasks returns all tasks in the queue.
+func (a *App) GetTasks() []*task.Task {
+	if a.taskMgr == nil {
+		return nil
+	}
+	return a.taskMgr.List()
+}
+
+// GetTaskLogs returns the stderr logs for a specific task.
+func (a *App) GetTaskLogs(taskID string) []string {
+	if a.taskMgr == nil {
+		return nil
+	}
+	for _, t := range a.taskMgr.List() {
+		if t.ID == taskID {
+			return t.Logs
+		}
+	}
+	return nil
+}
+
+// SetHWAccel sets the hardware acceleration method for encoding.
+func (a *App) SetHWAccel(accel string) {
+	if a.taskMgr != nil {
+		a.taskMgr.SetHWAccel(accel)
+	}
+}
+
+// ---- File Dialogs ----
+
+// SelectInputFile opens a file dialog for selecting an input media file.
+func (a *App) SelectInputFile() (string, error) {
+	return runtime.OpenFileDialog(a.ctx, runtime.OpenDialogOptions{
+		Title: "选择输入文件",
+		Filters: []runtime.FileFilter{
+			{DisplayName: "视频文件 (*.mp4;*.mkv;*.mov;*.ts;*.avi;*.webm;*.flv)", Pattern: "*.mp4;*.mkv;*.mov;*.ts;*.avi;*.webm;*.flv"},
+			{DisplayName: "所有文件 (*.*)", Pattern: "*.*"},
+		},
+	})
+}
+
+// SelectOutputFile opens a save file dialog.
+func (a *App) SelectOutputFile(defaultName string) (string, error) {
+	return runtime.SaveFileDialog(a.ctx, runtime.SaveDialogOptions{
+		Title:          "选择输出文件",
+		DefaultFilename: defaultName,
+		Filters: []runtime.FileFilter{
+			{DisplayName: "MP4 (*.mp4)", Pattern: "*.mp4"},
+			{DisplayName: "MKV (*.mkv)", Pattern: "*.mkv"},
+			{DisplayName: "MOV (*.mov)", Pattern: "*.mov"},
+			{DisplayName: "所有文件 (*.*)", Pattern: "*.*"},
+		},
+	})
+}
+
+// SelectSubtitleFile opens a file dialog for selecting an external subtitle file.
+func (a *App) SelectSubtitleFile() (string, error) {
+	return runtime.OpenFileDialog(a.ctx, runtime.OpenDialogOptions{
+		Title: "选择字幕文件",
+		Filters: []runtime.FileFilter{
+			{DisplayName: "字幕文件 (*.srt;*.ass;*.ssa;*.vtt;*.sub)", Pattern: "*.srt;*.ass;*.ssa;*.vtt;*.sub"},
+			{DisplayName: "所有文件 (*.*)", Pattern: "*.*"},
+		},
+	})
+}