fix: Wails file drop, duplicate listeners, trim drag, crop stage, preview cache/pixfmt, NSIS temp quoting

internal/preview/server.go

@@ -22,6 +22,8 @@ import (
 type Server struct {
 	addr       string
 	httpSrv    *http.Server
+	ctx        context.Context
+	cancel     context.CancelFunc
 	ffmpegBin  string
 	mu         sync.RWMutex
 	files      map[string]registeredFile
@@ -41,8 +43,11 @@ func Start(ffmpegBin string) (*Server, error) {
 		return nil, err
 	}
 
+	ctx, cancel := context.WithCancel(context.Background())
 	s := &Server{
 		addr:       ln.Addr().String(),
+		ctx:        ctx,
+		cancel:     cancel,
 		ffmpegBin:  ffmpegBin,
 		files:      make(map[string]registeredFile),
 		proxyLocks: make(map[string]*sync.Mutex),
@@ -78,7 +83,12 @@ func (s *Server) BaseURL() string {
 }
 
 func (s *Server) Register(info *media.VideoInfo) string {
-	sum := sha1.Sum([]byte(info.Path))
+	var modUnix int64
+	if st, err := os.Stat(info.Path); err == nil {
+		modUnix = st.ModTime().UnixNano()
+	}
+	key := fmt.Sprintf("%s|%d|%d", info.Path, info.SizeBytes, modUnix)
+	sum := sha1.Sum([]byte(key))
 	id := hex.EncodeToString(sum[:8])
 
 	s.mu.Lock()
@@ -88,6 +98,9 @@ func (s *Server) Register(info *media.VideoInfo) string {
 }
 
 func (s *Server) Close() {
+	if s.cancel != nil {
+		s.cancel()
+	}
 	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
 	defer cancel()
 	if s.httpSrv != nil {
@@ -166,7 +179,7 @@ func (s *Server) handleProxy(w http.ResponseWriter, r *http.Request) {
 
 	if proxyPath == "" {
 		proxyPath = filepath.Join(os.TempDir(), fmt.Sprintf("convert_preview_%s.mp4", cacheKey))
-		if err := s.buildProxy(r.Context(), ffmpegBin, rf.info, merge, proxyPath); err != nil {
+		if err := s.buildProxy(s.ctx, ffmpegBin, rf.info, merge, proxyPath); err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -211,8 +224,8 @@ func (s *Server) buildProxy(ctx context.Context, ffmpegBin string, info *media.V
 		args = append(args, "-map", "0:v:0", "-map", "0:a:0", "-c:a", "aac", "-b:a", "128k")
 	}
 
-	if info.VideoCodec == "h264" {
-		// Remux video stream instantaneously when codec is already H.264
+	if info.VideoCodec == "h264" && media.IsH264BrowserNativePixFmt(info.PixFmt) {
+		// Remux video stream instantaneously when codec is already browser-native 8-bit H.264
 		args = append(args, "-c:v", "copy")
 	} else {
 		args = append(args,
@@ -220,7 +233,7 @@ func (s *Server) buildProxy(ctx context.Context, ffmpegBin string, info *media.V
 			"-preset", "ultrafast",
 			"-crf", "26",
 			"-pix_fmt", "yuv420p",
-			"-vf", "scale='min(1280,iw)':-2",
+			"-vf", "scale='min(1280,trunc(iw/2)*2)':-2",
 		)
 	}
 	args = append(args, "-movflags", "+faststart", outPath)

internal/preview/server_test.go

@@ -3,6 +3,7 @@ package preview
 import (
 	"io"
 	"net/http"
+	"os"
 	"os/exec"
 	"path/filepath"
 	"testing"
@@ -85,3 +86,57 @@ func TestPreviewServer_RangeThumbAndProxy(t *testing.T) {
 		t.Fatalf("expected 404, got %d", nfResp.StatusCode)
 	}
 }
+
+func TestPreviewServer_CacheInvalidationAndOddWidthProxy(t *testing.T) {
+	bins := media.FindBinaries("", "")
+	if bins.FFmpeg == "" || bins.FFprobe == "" {
+		t.Skip("ffmpeg/ffprobe not installed")
+	}
+
+	tmpDir := t.TempDir()
+	src := filepath.Join(tmpDir, "odd.mkv")
+	// Odd width (321x180) vp8 source forces libx264 transcode in /proxy
+	gen := exec.Command(bins.FFmpeg,
+		"-hide_banner", "-loglevel", "error",
+		"-f", "lavfi", "-i", "testsrc=duration=1:size=321x180:rate=30",
+		"-c:v", "libvpx", "-y", src,
+	)
+	if out, err := gen.CombinedOutput(); err != nil {
+		t.Fatalf("failed generating odd-width mkv: %v (%s)", err, string(out))
+	}
+
+	info, err := media.Probe(bins.FFprobe, src)
+	if err != nil {
+		t.Fatalf("probe failed: %v", err)
+	}
+
+	srv, err := Start(bins.FFmpeg)
+	if err != nil {
+		t.Fatalf("start failed: %v", err)
+	}
+	defer srv.Close()
+
+	id1 := srv.Register(info)
+
+	// /proxy must succeed even on odd width (321 -> 320)
+	pResp, err := http.Get(srv.BaseURL() + "/proxy?id=" + id1 + "&merge=0")
+	if err != nil {
+		t.Fatalf("GET /proxy failed: %v", err)
+	}
+	pBody, _ := io.ReadAll(pResp.Body)
+	pResp.Body.Close()
+	if pResp.StatusCode != http.StatusOK || len(pBody) < 500 {
+		t.Fatalf("expected valid MP4 proxy for odd-width source, status=%d len=%d", pResp.StatusCode, len(pBody))
+	}
+
+	// Overwrite same path with different size -> Register must yield a new ID
+	if err := os.WriteFile(src, []byte("different-content-size"), 0o644); err != nil {
+		t.Fatalf("overwrite failed: %v", err)
+	}
+	info2 := *info
+	info2.SizeBytes = 22
+	id2 := srv.Register(&info2)
+	if id1 == id2 {
+		t.Fatalf("expected different videoId after file modification at same path, both were %q", id1)
+	}
+}