fix: 透明底正常生成；静动图分离完成

konabot/plugins/ytpgif/__init__.py

@@ -15,14 +15,14 @@ from nonebot_plugin_alconna import (
 
 __plugin_meta__ = PluginMetadata(
     name="ytpgif",
-    description="生成来回镜像翻转的动图：动图按时间分段播放，静态图高频翻转（带参数范围保护）",
+    description="生成来回镜像翻转的仿 YTPMV 动图。",
-    usage="/ytpgif [倍速=1.0] （倍速范围：0.1～20.0）",
+    usage="ytpgif [倍速=1.0] （倍速范围：0.1～20.0）",
     type="application",
     config=None,
     homepage=None,
 )
 
-# 参数定义（带硬性限制）
+# 参数定义
 BASE_SEGMENT_DURATION = 0.25
 BASE_INTERVAL = 0.25
 MAX_SIZE = 256
@@ -54,12 +54,15 @@ ytpgif_cmd = on_alconna(
 
 
 async def get_image_url(event: BaseEvent) -> Optional[str]:
+    """从事件中提取图片 URL，支持直接消息和回复"""
     msg = event.get_message()
     for seg in msg:
         if seg.type == "image" and seg.data.get("url"):
             return str(seg.data["url"])
+
     if hasattr(event, "reply") and (reply := event.reply):
-        for seg in reply.message:
+        reply_msg = reply.message
+        for seg in reply_msg:
             if seg.type == "image" and seg.data.get("url"):
                 return str(seg.data["url"])
     return None
@@ -74,9 +77,11 @@ async def download_image(url: str) -> bytes:
 
 
 def resize_frame(frame: Image.Image) -> Image.Image:
+    """缩放图像，保持宽高比，不超过 MAX_SIZE"""
     w, h = frame.size
     if w <= MAX_SIZE and h <= MAX_SIZE:
         return frame
+
     scale = MAX_SIZE / max(w, h)
     new_w = int(w * scale)
     new_h = int(h * scale)
@@ -96,14 +101,15 @@ async def handle_ytpgif(event: BaseEvent, speed: float = 1.0):
     if not img_url:
         await ytpgif_cmd.send(
             await UniMessage.text(
-                "请发送一张图片并使用 /ytpgif，或回复一张图片来生成镜像动图。"
+                "请发送一张图片或回复一张图片来生成镜像动图。"
             ).export()
         )
         return
 
     try:
         image_data = await download_image(img_url)
-    except Exception:
+    except Exception as e:
+        print(f"[YTPGIF] 下载失败: {e}")
         await ytpgif_cmd.send(
             await UniMessage.text("❌ 图片下载失败，请重试。").export()
         )
@@ -119,22 +125,47 @@ async def handle_ytpgif(event: BaseEvent, speed: float = 1.0):
             output_path = tmp_out.name
 
         with Image.open(input_path) as src_img:
-            is_animated = getattr(src_img, "is_animated", False) or src_img.n_frames > 1
+            # === 判断是否为动图 ===
+            try:
+                n_frames = getattr(src_img, "n_frames", 1)
+                is_animated = n_frames > 1
+            except Exception:
+                is_animated = False
 
             output_frames = []
             output_durations_ms = []
 
             if is_animated:
-                # === 动图模式：播放两段，每段最多 BASE_SEGMENT_DURATION * speed 秒，且帧数 ≤ 100 ===
+                # === 动图模式：截取正向 + 镜像两段 ===
                 frames_with_duration = []
-                for frame in ImageSequence.Iterator(src_img):
+                palette = src_img.getpalette()
-                    rgb_frame = frame.convert("RGB")
+
-                    resized_frame = resize_frame(rgb_frame)
+                for idx in range(n_frames):
+                    src_img.seek(idx)
+                    frame = src_img.copy()
+                    # 检查是否需要透明通道
+                    has_alpha = (
+                        frame.mode in ("RGBA", "LA")
+                        or (frame.mode == "P" and "transparency" in frame.info)
+                    )
+                    if has_alpha:
+                        frame = frame.convert("RGBA")
+                    else:
+                        frame = frame.convert("RGB")
+                    resized_frame = resize_frame(frame)
+
+                    # 若原图有调色板，尝试保留（可选）
+                    if palette and resized_frame.mode == "P":
+                        try:
+                            resized_frame.putpalette(palette)
+                        except Exception:  # noqa
+                            pass
+
                     ms = frame.info.get("duration", int(BASE_SEGMENT_DURATION * 1000))
-                    dur_sec = max(0.01, ms / 1000.0)  # 至少 10ms
+                    dur_sec = max(0.01, ms / 1000.0)
                     frames_with_duration.append((resized_frame, dur_sec))
 
-                max_dur = BASE_SEGMENT_DURATION * speed  # 每段最大播放时间
+                max_dur = BASE_SEGMENT_DURATION * speed
                 accumulated = 0.0
                 frame_count = 0
 
@@ -167,10 +198,10 @@ async def handle_ytpgif(event: BaseEvent, speed: float = 1.0):
 
             else:
                 # === 静态图模式：制作翻转动画 ===
-                raw_frame = src_img.convert("RGB")
+                raw_frame = src_img.convert("RGBA")
                 resized_frame = resize_frame(raw_frame)
 
-                interval_sec = max(0.025, min(2.5, BASE_INTERVAL / speed))  # 限制在 25ms ~ 2.5s
+                interval_sec = max(0.025, min(2.5, BASE_INTERVAL / speed))
                 duration_ms = int(interval_sec * 1000)
 
                 frame1 = resized_frame
@@ -185,16 +216,38 @@ async def handle_ytpgif(event: BaseEvent, speed: float = 1.0):
                 )
                 return
 
-            # 保存 GIF
+            # === 🔐 关键修复：防止无透明图的颜色被当成透明 ===
-            output_frames[0].save(
+            need_transparency = False
-                output_path,
+            for frame in output_frames:
-                save_all=True,
+                if frame.mode == "RGBA":
-                append_images=output_frames[1:],
+                    alpha_channel = frame.getchannel("A")
-                format="GIF",
+                    if any(pix < 255 for pix in alpha_channel.getdata()):
-                loop=0,
+                        need_transparency = True
-                duration=output_durations_ms,
+                        break
-                disposal=2,
+                elif frame.mode == "P" and "transparency" in frame.info:
-            )
+                    need_transparency = True
+                    break
+
+            # 如果不需要透明，则统一转为 RGB 避免调色板污染
+            if not need_transparency:
+                output_frames = [f.convert("RGB") for f in output_frames]
+
+            # 构建保存参数
+            save_kwargs = {
+                "save_all": True,
+                "append_images": output_frames[1:],
+                "format": "GIF",
+                "loop": 0,           # 无限循环
+                "duration": output_durations_ms,
+                "disposal": 2,       # 清除到背景色，避免残留
+                "optimize": False,   # 关闭抖动（等效 -dither none）
+            }
+
+            # 只有真正需要透明时才启用 transparency
+            if need_transparency:
+                save_kwargs["transparency"] = 0
+
+            output_frames[0].save(output_path, **save_kwargs)
 
         # 发送结果
         with open(output_path, "rb") as f:
@@ -204,9 +257,12 @@ async def handle_ytpgif(event: BaseEvent, speed: float = 1.0):
     except Exception as e:
         print(f"[YTPGIF] 处理失败: {e}")
         await ytpgif_cmd.send(
-            await UniMessage.text("❌ 处理失败，可能是图片格式不支持或文件过大。").export()
+            await UniMessage.text("❌ 处理失败，可能是图片格式不支持、文件损坏或过大。").export()
         )
     finally:
         for path in filter(None, [input_path, output_path]):
             if os.path.exists(path):
-                os.unlink(path)
+                try:
+                    os.unlink(path)
+                except:  # noqa
+                    pass