Silent timeline removed when hitting export

transcode/timeline.go

@@ -1,10 +1,5 @@
 package transcode
 
-// HandlerZoom holds the current scroll center for timeline zoom calculations.
-type HandlerZoom struct {
-	Center float64 // center of the visible window in seconds
-}
-
 // ZoomResult is the result of a TimelineZoom calculation.
 type ZoomResult struct {
 	Type      string  `json:"type"`
@@ -14,13 +9,13 @@ type ZoomResult struct {
 }
 
 // TimelineZoom computes the visible time window for the given zoomPercentage
-// (1–100, where 100 = full duration visible) centered on h.Center.
-func (h *HandlerZoom) TimelineZoom(zoomPercentage, duration float64) *ZoomResult {
+// (1–100, where 100 = full duration visible) centered on zoomCenter.
+func TimelineZoom(zoomCenter, zoomPercentage, duration float64) *ZoomResult {
 	visibleDuration := duration * (zoomPercentage / 100)
 	half := visibleDuration / 2
 
-	viewStart := h.Center - half
-	viewEnd := h.Center + half
+	viewStart := zoomCenter - half
+	viewEnd := zoomCenter + half
 
 	// Clamp to [0, duration], shifting the window rather than just truncating
 	// so the visible span stays the same size when near the edges.