feat(重构): 实现新的渲染服务架构

- 新增 RenderTask

entity/effects/zoom.py

@@ -0,0 +1,89 @@
+from typing import List
+import json
+from .base import EffectProcessor
+
+class ZoomEffect(EffectProcessor):
+    """缩放效果处理器"""
+    
+    def validate_params(self) -> bool:
+        """验证参数：start_time,zoom_factor,duration"""
+        params = self.parse_params()
+        if len(params) < 3:
+            return False
+            
+        try:
+            start_time = float(params[0])
+            zoom_factor = float(params[1])
+            duration = float(params[2])
+            
+            return (start_time >= 0 and
+                   zoom_factor > 0 and
+                   duration >= 0)
+        except (ValueError, IndexError):
+            return False
+            
+    def generate_filter_args(self, video_input: str, effect_index: int) -> tuple[List[str], str]:
+        """生成缩放效果的滤镜参数"""
+        if not self.validate_params():
+            return [], video_input
+            
+        params = self.parse_params()
+        start_time = float(params[0])
+        zoom_factor = float(params[1]) 
+        duration = float(params[2])
+        
+        if zoom_factor == 1:
+            return [], video_input  # 不需要缩放
+            
+        output_stream = f"[v_eff{effect_index}]"
+        
+        # 获取缩放中心点
+        center_x, center_y = self._get_zoom_center()
+        
+        filter_args = []
+        
+        if duration == 0:
+            # 静态缩放（整个视频时长）
+            x_expr = f"({center_x})-(ow*zoom)/2"
+            y_expr = f"({center_y})-(oh*zoom)/2"
+            filter_args.append(
+                f"{video_input}trim=start={start_time},zoompan=z={zoom_factor}:x={x_expr}:y={y_expr}:d=1{output_stream}"
+            )
+        else:
+            # 动态缩放（指定时间段内）
+            zoom_expr = f"if(between(t\\,{start_time}\\,{start_time + duration})\\,{zoom_factor}\\,1)"
+            x_expr = f"({center_x})-(ow*zoom)/2"
+            y_expr = f"({center_y})-(oh*zoom)/2"
+            filter_args.append(
+                f"{video_input}zoompan=z={zoom_expr}:x={x_expr}:y={y_expr}:d=1{output_stream}"
+            )
+            
+        return filter_args, output_stream
+        
+    def _get_zoom_center(self) -> tuple[str, str]:
+        """获取缩放中心点坐标表达式"""
+        # 默认中心点
+        center_x = "iw/2"
+        center_y = "ih/2"
+        
+        pos_json = self.get_pos_json()
+        if pos_json:
+            _f_x = pos_json.get('ltX', 0)
+            _f_x2 = pos_json.get('rbX', 0)
+            _f_y = pos_json.get('ltY', 0)
+            _f_y2 = pos_json.get('rbY', 0)
+            _v_w = pos_json.get('imgWidth', 1)
+            _v_h = pos_json.get('imgHeight', 1)
+            
+            if _v_w > 0 and _v_h > 0:
+                # 计算坐标系统中的中心点
+                center_x_ratio = (_f_x + _f_x2) / (2 * _v_w)
+                center_y_ratio = (_f_y + _f_y2) / (2 * _v_h)
+                # 转换为视频坐标系统
+                center_x = f"iw*{center_x_ratio:.6f}"
+                center_y = f"ih*{center_y_ratio:.6f}"
+                
+        return center_x, center_y
+        
+    def get_effect_name(self) -> str:
+        return "zoom"