fix(player): 预热直出并与视频统一封面布局

lib/pages/player/widgets/player_opening_frame.dart

@@ -12,17 +12,19 @@ import '../../../core/theme/app_colors.dart';
 import '../../../core/widgets/remote_image.dart';
 import 'scrub_preview_card.dart';
 
-const double _posterAspectRatio = 3 / 4;
-const double _posterBlurSigma = 18;
-
 /// 封面立即可见，雪碧图首帧解码完成后再覆盖封面。
-Widget? playerOpeningFrame(String? thumbnailsUrl, {String? posterUrl}) {
+Widget? playerOpeningFrame(
+  String? thumbnailsUrl, {
+  String? posterUrl,
+  BoxFit fit = BoxFit.cover,
+}) {
   final url = thumbnailsUrl?.trim() ?? '';
   final poster = posterUrl?.trim() ?? '';
   if (url.isEmpty && poster.isEmpty) return null;
   return PlayerOpeningFrame(
     thumbnailsUrl: url.isEmpty ? null : url,
     posterUrl: poster.isEmpty ? null : poster,
+    fit: fit,
   );
 }
 
@@ -32,12 +34,14 @@ class PlayerOpeningFrame extends StatefulWidget {
     super.key,
     this.thumbnailsUrl,
     this.posterUrl,
+    this.fit = BoxFit.cover,
     this.loader,
     this.cache,
   });
 
   final String? thumbnailsUrl;
   final String? posterUrl;
+  final BoxFit fit;
   final SpriteThumbnailAssetLoader? loader;
   final OpeningFrameCache? cache;
 
@@ -85,39 +89,18 @@ class _PlayerOpeningFrameState extends State<PlayerOpeningFrame> {
       children: [
         const ColoredBox(color: AppColors.mediaBlack),
         if (posterUrl != null)
-          Positioned.fill(
-            child: ImageFiltered(
-              key: const Key('player-opening-poster-blur'),
-              imageFilter: ui.ImageFilter.blur(
-                sigmaX: _posterBlurSigma,
-                sigmaY: _posterBlurSigma,
-              ),
-              child: RemoteImage(
-                posterUrl,
-                key: const Key('player-opening-poster-backdrop'),
-                fit: BoxFit.cover,
-                fallbackColor: AppColors.mediaBlack,
-              ),
-            ),
-          ),
-        if (posterUrl != null)
-          Center(
-            child: AspectRatio(
-              key: const Key('player-opening-poster-stage'),
-              aspectRatio: _posterAspectRatio,
-              child: RemoteImage(
-                posterUrl,
-                key: const Key('player-opening-poster'),
-                fit: BoxFit.cover,
-                fallbackColor: AppColors.mediaBlack,
-              ),
-            ),
+          RemoteImage(
+            posterUrl,
+            key: const Key('player-opening-poster'),
+            fit: widget.fit,
+            fallbackColor: AppColors.mediaBlack,
           ),
         if (frame != null)
           SpriteCropPreview(
             key: const Key('player-opening-sprite'),
             image: frame.image,
             sourceRect: frame.sourceRect,
+            fit: widget.fit,
           ),
       ],
     );

lib/pages/player/widgets/player_video_surface.dart

@@ -6,7 +6,6 @@ import 'package:video_player/video_player.dart';
 
 import '../../../core/theme/app_colors.dart';
 
-const Duration _videoFadeDuration = Duration(milliseconds: 200);
 const double _errorHorizontal = 32;
 const int _errorMaxLines = 3;
 
@@ -20,6 +19,7 @@ class PlayerVideoSurface extends StatefulWidget {
     this.handoff,
     this.openingFrame,
     this.holdOpeningUntilFirstFrame = false,
+    this.preparedFrameAvailable = false,
   });
 
   final VideoPlayerController? controller;
@@ -30,6 +30,9 @@ class PlayerVideoSurface extends StatefulWidget {
 
   /// 播放中的新片源在位置首次前进前继续显示封面，避免混入未出帧纹理。
   final bool holdOpeningUntilFirstFrame;
+
+  /// 相邻集预热槽已持有可用画面，进入页面时不需要封面兜底。
+  final bool preparedFrameAvailable;
   final String videoUrl;
   final bool theater;
 
@@ -69,15 +72,27 @@ class _PlayerVideoSurfaceState extends State<PlayerVideoSurface> {
   Widget _frame(VideoPlayerValue? value) {
     final controller = widget.controller;
     final handoff = _liveHandoff(controller);
-    final firstFrameReady = _trackFrameState(controller, value);
-    final reveal = _shouldReveal(value, handoff != null) &&
+    final firstFrameSeen = _trackFrameState(controller, value);
+    final firstFrameReady =
+        widget.preparedFrameAvailable || firstFrameSeen;
+    final textureReady = _shouldReveal(value, handoff != null);
+    final reveal = textureReady &&
         (!widget.holdOpeningUntilFirstFrame ||
+            widget.preparedFrameAvailable ||
             firstFrameReady ||
             _playbackStarted &&
                 value?.isPlaying == false &&
                 value?.isBuffering != true);
+    final showOpening =
+        widget.openingFrame != null && handoff == null && !reveal;
     _logStateChange(value);
-    _logLayerState(value, handoff, reveal, firstFrameReady);
+    _logLayerState(
+      value,
+      handoff,
+      reveal,
+      firstFrameReady,
+      showOpening,
+    );
     return Stack(
       fit: StackFit.expand,
       children: [
@@ -85,19 +100,15 @@ class _PlayerVideoSurfaceState extends State<PlayerVideoSurface> {
           key: Key('player-fallback-background'),
           color: AppColors.mediaBlack,
         ),
-        if (widget.openingFrame != null)
-          AnimatedOpacity(
+        if (showOpening)
+          KeyedSubtree(
             key: const Key('player-opening-frame'),
-            opacity: reveal ? 0 : 1,
-            duration: handoff != null ? Duration.zero : _videoFadeDuration,
-            curve: Curves.easeOut,
             child: widget.openingFrame!,
           ),
         AnimatedOpacity(
           key: const Key('player-video-opacity'),
           opacity: reveal ? 1 : 0,
-          duration: handoff != null ? Duration.zero : _videoFadeDuration,
-          curve: Curves.easeOut,
+          duration: Duration.zero,
           child: reveal && controller != null
               ? _VideoLayer(
                   controller: controller,
@@ -180,20 +191,24 @@ class _PlayerVideoSurfaceState extends State<PlayerVideoSurface> {
     VideoPlayerController? handoff,
     bool reveal,
     bool firstFrameReady,
+    bool showOpening,
   ) {
     if (!kDebugMode) return;
     final reason = handoff != null
         ? 'handoff'
         : !_shouldReveal(value, handoff != null)
         ? 'uninitialized'
+        : widget.preparedFrameAvailable
+        ? 'warm-frame'
         : !firstFrameReady && widget.holdOpeningUntilFirstFrame
         ? 'awaiting-first-frame'
         : 'reveal';
     final signature =
-        'opening=${widget.openingFrame == null ? 0 : reveal ? 0 : 1} '
+        'warm=${widget.preparedFrameAvailable ? 1 : 0} '
+        'frame=${firstFrameReady ? 1 : 0} '
+        'cover=${showOpening ? 1 : 0} '
         'video=${reveal ? 1 : 0} handoff=${handoff == null ? 0 : 1} '
         'init=${value?.isInitialized == true ? 1 : 0} '
-        'frame=${firstFrameReady ? 1 : 0} '
         'playing=${value?.isPlaying == true ? 1 : 0} '
         'buffering=${value?.isBuffering == true ? 1 : 0} '
         'reason=$reason';

lib/pages/player/widgets/scrub_preview_card.dart

@@ -256,26 +256,37 @@ class SpriteCropPreview extends StatelessWidget {
     super.key,
     required this.image,
     required this.sourceRect,
+    this.fit = BoxFit.cover,
   });
 
   final ui.Image image;
   final ui.Rect sourceRect;
+  final BoxFit fit;
 
   @override
   Widget build(BuildContext context) => CustomPaint(
-    painter: _SpriteCropPainter(image: image, sourceRect: sourceRect),
+    painter: _SpriteCropPainter(
+      image: image,
+      sourceRect: sourceRect,
+      fit: fit,
+    ),
   );
 }
 
 class _SpriteCropPainter extends CustomPainter {
-  const _SpriteCropPainter({required this.image, required this.sourceRect});
+  const _SpriteCropPainter({
+    required this.image,
+    required this.sourceRect,
+    required this.fit,
+  });
 
   final ui.Image image;
   final ui.Rect sourceRect;
+  final BoxFit fit;
 
   @override
   void paint(Canvas canvas, Size size) {
-    final fitted = applyBoxFit(BoxFit.cover, sourceRect.size, size);
+    final fitted = applyBoxFit(fit, sourceRect.size, size);
     final sourceOffset = Alignment.center.inscribe(
       fitted.source,
       Offset.zero & sourceRect.size,
@@ -302,7 +313,9 @@ class _SpriteCropPainter extends CustomPainter {
 
   @override
   bool shouldRepaint(covariant _SpriteCropPainter oldDelegate) =>
-      oldDelegate.image != image || oldDelegate.sourceRect != sourceRect;
+      oldDelegate.image != image ||
+      oldDelegate.sourceRect != sourceRect ||
+      oldDelegate.fit != fit;
 }
 
 String _format(Duration value) {