验收1

fish_api/app/db.py

@@ -22,6 +22,36 @@ from app.state import HealthSnapshot, MeasureSnapshot
 DEFAULT_CLIENT_ID = "default"
 MAX_CLIENT_ID_LEN = 128
 
+# 客户端切片索引起缓存：记录每个 client_id 上次返回的切片索引（用于对齐 water/video 端点）
+_client_health_slice_index: dict[str, int] = {}
+
+
+def _parse_slice_index_from_source_path(source_path: Optional[str]) -> int:
+    """从 source_path 解析切片索引，格式为 video.mp4#slice{N}。
+
+    Returns:
+        切片序号（>=0），如果不是切片则返回 -1
+    """
+    if not source_path:
+        return -1
+    if "#slice" not in source_path:
+        return -1
+    try:
+        idx_part = source_path.split("#slice")[-1]
+        return int(idx_part)
+    except (ValueError, IndexError):
+        return -1
+
+
+def get_last_health_slice_index(client_id: str) -> int:
+    """获取指定 client_id 上次返回的切片索引（用于 water/video 端点对齐）。
+
+    Returns:
+        切片序号（>=0），如果没有记录则返回 -1
+    """
+    cid = normalize_client_id(client_id)
+    return _client_health_slice_index.get(cid, -1)
+
 
 def normalize_client_id(raw: Optional[str]) -> str:
     """供轮询接口使用；过长截断，空值回退为 DEFAULT_CLIENT_ID。"""
@@ -447,6 +477,8 @@ def pop_next_health(
     client_id: str = DEFAULT_CLIENT_ID,
 ) -> Tuple[HealthSnapshot, bool, Optional[int]]:
     """取该客户端队首未投递且可交付的 health 快照并推进其游标；跳过不可交付行仅推进游标。"""
+    global _client_health_slice_index
+
     cid = normalize_client_id(client_id)
     init_db(settings)
     conn = _connect(settings.sqlite_path)
@@ -458,7 +490,7 @@ def pop_next_health(
             next_row = conn.execute(
                 """
                 SELECT id, created_at, behavior_result, health_result,
-                       raw_class_en, error
+                       raw_class_en, error, source_path
                 FROM health_snapshots
                 WHERE id > ?
                 ORDER BY id ASC
@@ -476,6 +508,7 @@ def pop_next_health(
             hlth = next_row["health_result"] or ""
             raw_en = next_row["raw_class_en"] or ""
             err: Optional[str] = next_row["error"]
+            source_path: Optional[str] = next_row["source_path"]
 
             conn.execute(
                 """
@@ -490,6 +523,11 @@ def pop_next_health(
                 continue
 
             conn.commit()
+
+            # 解析并记录切片索引（用于与 water/video 端点对齐）
+            slice_idx = _parse_slice_index_from_source_path(source_path)
+            _client_health_slice_index[cid] = slice_idx
+
             snap = HealthSnapshot(
                 behavior_result=beh,
                 health_result=hlth,

fish_api/app/routers/biomass.py

@@ -85,7 +85,10 @@ async def get_health_result(
     settings: Settings = Depends(get_settings),
     client_id: str = Depends(_resolve_client_id),
 ):
-    """行为 / 健康结果：每次 GET 投递该客户端下一条未消费的 FishAction 快照（按 client_id 独立游标）。"""
+    """行为 / 健康结果：每次 GET 投递该客户端下一条未消费的 FishAction 快照（按 client_id 独立游标）。
+
+    每个视频切片被视为独立的视频，会分别投递。
+    """
     h, has_new, _ = pop_next_health(settings, client_id)
     if not has_new:
         return JSONResponse(
@@ -125,9 +128,19 @@ async def get_health_result(
 
 
 @router.get("/water/video/")
-async def get_water_video(settings: Settings = Depends(get_settings)):
-    """水上视频：FishAction 输入 mp4 经 H.264 转码后托管在 /media/，返回 `video_path` 绝对 URL。"""
-    video_path = await get_water_video_public_url(settings)
+async def get_water_video(
+    settings: Settings = Depends(get_settings),
+    client_id: str = Depends(_resolve_client_id),
+):
+    """水上视频：FishAction 输入 mp4 经 H.264 转码后托管在 /media/，返回 `video_path` 绝对 URL。
+
+    如果视频较长（超过15秒），会自动切分为多个10秒的片段。
+    每个切片被视为独立的视频，每次调用返回一个切片的URL（按顺序轮流返回）。
+
+    对齐机制：使用 client_id 参数（请求头 X-Fish-Client-Id 或查询参数 client_id）
+    确保与 /health/result/ 端点对齐返回同一切片。
+    """
+    video_path = await get_water_video_public_url(settings, client_id)
     return JSONResponse(
         content={
             "code": 200,

fish_api/app/routers/ingest.py

@@ -46,13 +46,18 @@ async def _action_job_serial(mp4_path: Path, settings: Settings) -> None:
     async with app_state.action_lock:
         app_state.action_status = "running"
         try:
-            snap = await asyncio.to_thread(
+            # 返回 (第一个快照, 所有切片快照列表)
+            first_snap, all_snaps = await asyncio.to_thread(
                 action_svc.run_full_action, mp4_path, settings
             )
-            if health_snapshot_deliverable(snap):
-                save_health_snapshot(
-                    settings, snap, source_path=str(mp4_path.resolve())
-                )
+
+            # 将所有切片作为独立视频保存到数据库
+            for i, snap in enumerate(all_snaps):
+                if health_snapshot_deliverable(snap):
+                    # 为每个切片生成独立的 source_path
+                    slice_source = f"{mp4_path.resolve()}#slice{i}"
+                    save_health_snapshot(settings, snap, source_path=slice_source)
+
             app_state.action_status = "idle"
         except Exception:
             app_state.action_status = "error"

fish_api/app/services/action.py

@@ -6,13 +6,19 @@ import sys
 import tempfile
 from datetime import datetime, timezone
 from pathlib import Path
+from typing import List
 
 from app.logging_config import format_json_pretty
+from app.services.video_slice import get_video_duration, slice_video
 from app.settings import Settings
 from app.state import HealthSnapshot
 from app.subprocess_run import run_subprocess_with_log
 from loguru import logger
 
+# 视频切片配置
+DEFAULT_SLICE_DURATION = 10.0  # 每10秒切一个片段
+DEFAULT_MIN_DURATION_FOR_SLICE = 15.0  # 视频超过15秒才切片
+
 BEHAVIOR_EN_TO_ZH = {
     "feeding": "吃饵",
     "normal": "正常游行",
@@ -100,8 +106,95 @@ def run_action_subprocess(mp4_path: Path, settings: Settings) -> str:
         Path(out_json).unlink(missing_ok=True)
 
 
-def run_full_action(mp4_path: Path, settings: Settings) -> HealthSnapshot:
+def run_full_action(mp4_path: Path, settings: Settings) -> tuple[HealthSnapshot, list[HealthSnapshot]]:
+    """运行 FishAction 健康检测。如果视频较长，会自动切片后分别检测。
+
+    每个切片被视为独立的视频，返回所有切片的结果列表。
+
+    Args:
+        mp4_path: 输入视频路径
+        settings: 应用配置
+
+    Returns:
+        tuple[HealthSnapshot, list[HealthSnapshot]]: (第一个切片/完整视频的快照, 所有切片快照列表)
+            - 如果视频被切片：返回 (第一个切片, 所有切片列表)
+            - 如果视频未被切片：返回 (完整视频快照, [完整视频快照])
+    """
     logger.info("[FishAction] start mp4={}", mp4_path.resolve())
+
+    # 检查视频时长
+    duration = get_video_duration(mp4_path)
+    should_slice = duration > DEFAULT_MIN_DURATION_FOR_SLICE
+
+    if should_slice:
+        # 视频较长，需要切片处理
+        logger.info(
+            "[FishAction] video duration {}s > {}s, slicing into {}s segments",
+            duration,
+            DEFAULT_MIN_DURATION_FOR_SLICE,
+            DEFAULT_SLICE_DURATION,
+        )
+
+        slice_files, slice_dir = slice_video(mp4_path, DEFAULT_SLICE_DURATION)
+
+        if len(slice_files) > 1:
+            logger.info(
+                "[FishAction] processing {} slices for {}",
+                len(slice_files),
+                mp4_path.name,
+            )
+
+            # 处理每个切片
+            all_snaps: list[HealthSnapshot] = []
+            for i, slice_file in enumerate(slice_files):
+                start_time = i * DEFAULT_SLICE_DURATION
+                end_time = min(start_time + DEFAULT_SLICE_DURATION, duration)
+
+                try:
+                    pred_en = run_action_subprocess(slice_file, settings)
+                    zh = BEHAVIOR_EN_TO_ZH[pred_en]
+                    health = behavior_to_health(pred_en)
+
+                    snap = HealthSnapshot(
+                        behavior_result=zh,
+                        health_result=health,
+                        updated_at=datetime.now(timezone.utc),
+                        raw_class_en=pred_en,
+                    )
+
+                    logger.info(
+                        "[FishAction] slice {} ({}s-{}s): pred={} behavior={} health={}",
+                        i, start_time, end_time, pred_en, zh, health,
+                    )
+
+                    all_snaps.append(snap)
+                except Exception as e:
+                    logger.error("[FishAction] failed to process slice {}: {}", i, e)
+                    # 创建一个表示失败的快照
+                    error_snap = HealthSnapshot(
+                        behavior_result="处理失败",
+                        health_result="未知",
+                        updated_at=datetime.now(timezone.utc),
+                        raw_class_en="error",
+                        error=str(e),
+                    )
+                    all_snaps.append(error_snap)
+
+            logger.info(
+                "[FishAction] done mp4={} total_slices={}",
+                mp4_path.name,
+                len(slice_files),
+            )
+
+            # 返回第一个切片的结果和所有切片列表
+            first_snap = all_snaps[0] if all_snaps else HealthSnapshot(
+                behavior_result="",
+                health_result="",
+                updated_at=datetime.now(timezone.utc),
+            )
+            return first_snap, all_snaps
+
+    # 视频较短，直接处理（原有逻辑）
     pred_en = run_action_subprocess(mp4_path, settings)
     zh = BEHAVIOR_EN_TO_ZH[pred_en]
     health = behavior_to_health(pred_en)
@@ -112,9 +205,10 @@ def run_full_action(mp4_path: Path, settings: Settings) -> HealthSnapshot:
         zh,
         health,
     )
-    return HealthSnapshot(
+    snap = HealthSnapshot(
         behavior_result=zh,
         health_result=health,
         updated_at=datetime.now(timezone.utc),
         raw_class_en=pred_en,
     )
+    return snap, [snap]

fish_api/app/services/action_watch.py

@@ -56,20 +56,38 @@ async def _run_inference_and_state(
     async with app_state.action_lock:
         app_state.action_status = "running"
         try:
-            snap = await asyncio.to_thread(action_svc.run_full_action, mp4, settings)
-            if health_snapshot_deliverable(snap):
-                save_health_snapshot(settings, snap, source_path=key)
-            else:
+            # 返回 (第一个快照, 所有切片快照列表)
+            first_snap, all_snaps = await asyncio.to_thread(
+                action_svc.run_full_action, mp4, settings
+            )
+
+            # 将所有切片作为独立视频保存到数据库
+            saved_count = 0
+            for i, snap in enumerate(all_snaps):
+                if health_snapshot_deliverable(snap):
+                    # 为每个切片生成独立的 source_path
+                    slice_key = f"{key}#slice{i}"
+                    save_health_snapshot(settings, snap, source_path=slice_key)
+                    saved_count += 1
+
+            if saved_count == 0:
                 logger.warning(
                     "[action-watch] no deliverable health snapshot for {}, skip SQLite",
                     mp4.name,
                 )
+
             app_state.action_status = "idle"
             processed.add(key)
             if settings.action_watch_use_state_file:
                 add_watch_processed(settings, key, "action")
-            pred = (snap.raw_class_en or "").strip()
-            logger.info("[action-watch] done: {} -> {}", mp4.name, pred)
+
+            pred = (first_snap.raw_class_en or "").strip()
+            logger.info(
+                "[action-watch] done: {} -> {} (saved {} slices)",
+                mp4.name,
+                pred,
+                saved_count,
+            )
         except Exception as e:
             logger.exception("[action-watch] error on {}: {}", mp4, e)
             app_state.action_status = "idle"

fish_api/app/services/measure.py

@@ -11,6 +11,8 @@ from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple
 
+import numpy as np
+
 from app.logging_config import format_json_pretty
 from app.settings import Settings
 from app.state import MeasureSnapshot
@@ -187,12 +189,15 @@ def _safe_media_prefix(stem: str) -> str:
 
 
 def _result_from_weight_prediction(data: Dict[str, Any]) -> List[Dict[str, Any]]:
-    """按 track_id 聚合：体重取 max(predicted_weight_g)，体长取达到 max 的那条 PLY 的 length_input (mm)。"""
+    """按 track_id 聚合：对每个 track_id 的点云，取 predicted_weight_g 最大的 top5 平均值作为体重，
+    体长取这 top5 点云的平均 length_input (mm)。只使用通过点云分类器的好点云（used_for_prediction=True）。"""
     items = data.get("per_cloud") or data.get("per_file") or []
     if not isinstance(items, list):
         return []
-    # tid -> (max_weight_g, length_mm at max weight)
-    best: Dict[int, Tuple[float, float]] = {}
+
+    # tid -> list of (weight_g, length_mm) for this track
+    track_predictions: Dict[int, List[Tuple[float, float]]] = {}
+
     for it in items:
         if not isinstance(it, dict):
             continue
@@ -202,24 +207,55 @@ def _result_from_weight_prediction(data: Dict[str, Any]) -> List[Dict[str, Any]]
         tid = _parse_tid_from_ply_name(Path(str(ply)).name)
         if tid is None:
             continue
+
+        # 只使用通过点云分类器的好点云
+        if not it.get("used_for_prediction", True):
+            continue
+
         try:
             wg = float(it.get("predicted_weight_g", float("nan")))
         except (TypeError, ValueError):
             continue
         if not math.isfinite(wg):
             continue
+
         try:
             ln = float(it.get("length_input", float("nan")))
         except (TypeError, ValueError):
             ln = float("nan")
-        if tid not in best or wg > best[tid][0]:
-            best[tid] = (wg, ln)
+
+        if tid not in track_predictions:
+            track_predictions[tid] = []
+        track_predictions[tid].append((wg, ln))
+
     out: List[Dict[str, Any]] = []
-    for tid in sorted(best.keys()):
-        wg, ln = best[tid]
-        if not math.isfinite(ln):
+    TOP_K = 5
+
+    for tid in sorted(track_predictions.keys()):
+        predictions = track_predictions[tid]
+        if not predictions:
             continue
-        out.append({"id": tid, "weight": wg, "length": ln})
+
+        # 按重量降序排序，取 top5
+        predictions_sorted = sorted(predictions, key=lambda x: x[0], reverse=True)
+        top5 = predictions_sorted[:min(TOP_K, len(predictions_sorted))]
+
+        # 计算 top5 平均重量和平均长度
+        avg_weight = float(np.mean([p[0] for p in top5]))
+        valid_lengths = [p[1] for p in top5 if math.isfinite(p[1])]
+        avg_length = float(np.mean(valid_lengths)) if valid_lengths else float("nan")
+
+        if not math.isfinite(avg_length):
+            continue
+
+        out.append({
+            "id": tid,
+            "type": "大黄鱼",
+            "weight": str(round(avg_weight)),
+            "length": str(round(avg_length)),
+            "date": datetime.now(timezone.utc).strftime("%Y-%m-%d"),
+        })
+
     return out
 
 

fish_api/app/services/video_slice.py

@@ -0,0 +1,148 @@
+"""视频切片工具：将长视频按固定时长切分为多个片段。"""
+
+from __future__ import annotations
+
+import subprocess
+import tempfile
+from pathlib import Path
+from typing import List, Tuple
+
+from loguru import logger
+
+
+def _get_ffmpeg_path() -> str:
+    """获取可用的 ffmpeg 路径。"""
+    project_ffmpeg = Path("/home/ubuntu/projects/FishServer/tools/ffmpeg/bin/ffmpeg")
+    if project_ffmpeg.is_file():
+        return str(project_ffmpeg)
+    system_paths = ["/usr/bin/ffmpeg", "/usr/local/bin/ffmpeg"]
+    for path in system_paths:
+        if Path(path).is_file():
+            return path
+    return "ffmpeg"
+
+
+def _get_ffprobe_path() -> str:
+    """获取可用的 ffprobe 路径。"""
+    ffmpeg_path = Path(_get_ffmpeg_path())
+    ffprobe = ffmpeg_path.parent / "ffprobe"
+    if ffprobe.is_file():
+        return str(ffprobe)
+    return "ffprobe"
+
+
+def get_video_duration(video_path: Path) -> float:
+    """获取视频时长（秒）。"""
+    ffprobe_path = _get_ffprobe_path()
+    try:
+        result = subprocess.run(
+            [
+                ffprobe_path,
+                "-v", "error",
+                "-show_entries", "format=duration",
+                "-of", "default=noprint_wrappers=1:nokey=1",
+                str(video_path),
+            ],
+            capture_output=True,
+            text=True,
+            timeout=30,
+        )
+        if result.returncode == 0:
+            duration = float(result.stdout.strip())
+            return duration
+    except Exception as e:
+        logger.warning("[video_slice] failed to get duration: {}", e)
+    return 0.0
+
+
+def slice_video(
+    video_path: Path,
+    slice_duration: float = 10.0,
+    output_dir: Path | None = None,
+) -> Tuple[List[Path], Path]:
+    """将视频按固定时长切分为多个片段。
+
+    Args:
+        video_path: 源视频路径
+        slice_duration: 每个切片的时长（秒），默认10秒
+        output_dir: 输出目录，默认使用临时目录
+
+    Returns:
+        (切片文件列表, 输出目录路径)
+    """
+    duration = get_video_duration(video_path)
+    if duration <= slice_duration:
+        # 视频太短，无需切片
+        return [video_path], video_path.parent
+
+    if output_dir is None:
+        output_dir = Path(tempfile.mkdtemp(prefix="video_slices_"))
+    output_dir.mkdir(parents=True, exist_ok=True)
+
+    ffmpeg_path = _get_ffmpeg_path()
+    base_name = video_path.stem
+
+    # 计算需要切多少片
+    num_slices = int(duration / slice_duration)
+    if duration % slice_duration > 1.0:  # 剩余超过1秒才多切一片
+        num_slices += 1
+
+    logger.info(
+        "[video_slice] slicing {} ({}s) into {} slices of {}s each",
+        video_path.name,
+        duration,
+        num_slices,
+        slice_duration,
+    )
+
+    slice_files: List[Path] = []
+    for i in range(num_slices):
+        start_time = i * slice_duration
+        slice_file = output_dir / f"{base_name}_slice_{i:03d}.mp4"
+
+        # 使用 ffmpeg 切片，-c copy 快速复制，避免重新编码
+        cmd = [
+            ffmpeg_path,
+            "-y",
+            "-ss", str(start_time),
+            "-t", str(slice_duration),
+            "-i", str(video_path),
+            "-c", "copy",
+            "-avoid_negative_ts", "make_zero",
+            str(slice_file),
+        ]
+
+        try:
+            result = subprocess.run(
+                cmd,
+                capture_output=True,
+                text=True,
+                timeout=60,
+            )
+            if result.returncode == 0 and slice_file.is_file():
+                slice_files.append(slice_file)
+                logger.debug(
+                    "[video_slice] created slice {}: {} (start={}s)",
+                    i,
+                    slice_file.name,
+                    start_time,
+                )
+            else:
+                logger.warning(
+                    "[video_slice] failed to create slice {}: {}",
+                    i,
+                    result.stderr[-200:] if result.stderr else "unknown",
+                )
+        except Exception as e:
+            logger.warning("[video_slice] exception creating slice {}: {}", i, e)
+
+    if not slice_files:
+        # 切片失败，返回原视频
+        return [video_path], video_path.parent
+
+    logger.info(
+        "[video_slice] created {} slices for {}",
+        len(slice_files),
+        video_path.name,
+    )
+    return slice_files, output_dir

fish_api/app/services/water_video.py

@@ -1,19 +1,35 @@
-"""水上视频：从 FishAction 输入目录或显式路径发布 H.264 MP4 到 MEDIA_ROOT。"""
+"""水上视频：从 FishAction 输入目录或显式路径发布 H.264 MP4 到 MEDIA_ROOT。
+
+支持长视频切片：如果视频较长，会切分为多个10秒片段并分别转码发布。
+每个切片被视为独立的视频。
+
+对齐机制：使用 client_id 区分不同客户端的轮询进度，确保 health/result 和
+water/video 两个端点对齐返回同一切片。
+"""
 
 from __future__ import annotations
 
 import asyncio
 import shutil
 from pathlib import Path
+from typing import Dict, List
 
 from loguru import logger
 
 from app.services.action_watch import iter_mp4
 from app.services.measure import transcode_src_to_h264_dst
+from app.services.video_slice import get_video_duration, slice_video
 from app.settings import Settings
 
 _publish_lock = asyncio.Lock()
 
+# 视频切片配置
+SLICE_DURATION = 10.0  # 每个切片的时长（秒）
+MIN_DURATION_FOR_SLICE = 15.0  # 超过此时长才切片
+
+# 默认客户端ID（与 db.py 保持一致）
+DEFAULT_CLIENT_ID = "default"
+
 
 def _public_media_url(settings: Settings, basename: str) -> str:
     base = settings.public_base_url.rstrip("/")
@@ -27,6 +43,23 @@ def _safe_water_media_basename(raw: str) -> str:
     return Path(n).name or "biomass_water_surface.mp4"
 
 
+def _slice_media_basename(base_name: str, slice_index: int) -> str:
+    """生成切片视频的媒体文件名。"""
+    base = Path(base_name).stem
+    return f"{base}_slice_{slice_index:03d}.mp4"
+
+
+# 客户端独立的状态：每个 client_id 有自己的切片队列和索引
+# _client_slice_queues[client_id] = [url0, url1, url2, ...]
+# _client_slice_indices[client_id] = 当前应该返回的索引
+_client_slice_queues: Dict[str, List[str]] = {}
+_client_slice_indices: Dict[str, int] = {}
+
+# 全局缓存的切片列表（用于检测源文件变化）
+_global_slice_urls: List[str] = []
+_last_source_mtime: float = 0.0
+
+
 def resolve_water_video_source(settings: Settings) -> Path | None:
     """优先 BIOMASS_WATER_VIDEO_SOURCE；否则取 ACTION_WATCH_DIR 中 mtime 最新的 .mp4。"""
     cfg = settings.biomass_water_video_source
@@ -51,51 +84,180 @@ def resolve_water_video_source(settings: Settings) -> Path | None:
         return None
 
 
-async def get_water_video_public_url(settings: Settings) -> str:
-    """转码并发布到 MEDIA_ROOT 后返回绝对 URL；无可用源且无已发布文件时返回空串。"""
-    settings.media_root.mkdir(parents=True, exist_ok=True)
-    basename = _safe_water_media_basename(settings.biomass_water_video_media_name)
-    dst = settings.media_root / basename
+async def _publish_video(
+    src: Path,
+    dst: Path,
+    settings: Settings,
+) -> str:
+    """发布视频到 MEDIA_ROOT。
 
-    src = resolve_water_video_source(settings)
-    if src is None:
+    Args:
+        src: 源视频路径
+        dst: 目标路径
+        settings: 应用配置
+
+    Returns:
+        发布的视频URL，失败返回空串
+    """
+    tmp = dst.with_name(dst.stem + "_tmp.mp4")
+    tmp.unlink(missing_ok=True)
+
+    try:
+        ok = await asyncio.to_thread(transcode_src_to_h264_dst, src, tmp)
+        if ok and tmp.is_file() and tmp.stat().st_size > 0:
+            tmp.replace(dst)
+            logger.info("[water-video] published H.264: {} -> {}", src.name, dst.name)
+        else:
+            tmp.unlink(missing_ok=True)
+            await asyncio.to_thread(shutil.copy2, src, dst)
+            logger.warning(
+                "[water-video] transcode failed, copied raw: {} -> {}",
+                src.name,
+                dst.name,
+            )
+        return _public_media_url(settings, dst.name)
+    except Exception:
+        logger.exception("[water-video] publish failed")
+        tmp.unlink(missing_ok=True)
         if dst.is_file():
             return _public_media_url(settings, dst.name)
         return ""
 
-    async with _publish_lock:
-        need_publish = True
-        if dst.is_file():
-            try:
-                if dst.stat().st_mtime >= src.stat().st_mtime:
-                    need_publish = False
-            except OSError:
-                pass
-        if not need_publish:
-            return _public_media_url(settings, dst.name)
 
-        tmp = dst.with_name(dst.stem + "_tmp.mp4")
-        tmp.unlink(missing_ok=True)
-        try:
-            ok = await asyncio.to_thread(transcode_src_to_h264_dst, src, tmp)
-            if ok and tmp.is_file() and tmp.stat().st_size > 0:
-                tmp.replace(dst)
-                logger.info("[water-video] published H.264: {} -> {}", src.name, dst.name)
-            else:
-                tmp.unlink(missing_ok=True)
-                await asyncio.to_thread(shutil.copy2, src, dst)
-                logger.warning(
-                    "[water-video] transcode failed, copied raw: {} -> {}",
-                    src.name,
-                    dst.name,
-                )
-        except Exception:
-            logger.exception("[water-video] publish failed")
-            tmp.unlink(missing_ok=True)
+async def _prepare_slices(settings: Settings) -> List[str]:
+    """预处理：如果视频较长，切分为多个片段并发布到 MEDIA_ROOT。
+
+    返回切片URL列表（供各客户端使用）。
+    """
+    global _global_slice_urls, _last_source_mtime
+
+    base_basename = _safe_water_media_basename(settings.biomass_water_video_media_name)
+    src = resolve_water_video_source(settings)
+
+    if src is None:
+        return []
+
+    # 检查是否需要重新切片
+    try:
+        current_mtime = src.stat().st_mtime
+    except OSError:
+        current_mtime = 0.0
+
+    # 如果源文件未变化且已有缓存，直接返回缓存
+    if current_mtime == _last_source_mtime and _global_slice_urls:
+        return _global_slice_urls
+
+    # 检查视频时长
+    duration = get_video_duration(src)
+    should_slice = duration > MIN_DURATION_FOR_SLICE
+
+    new_urls: List[str] = []
+
+    if should_slice:
+        # 视频较长，切片处理
+        logger.info(
+            "[water-video] video duration {}s > {}s, slicing into {}s segments",
+            duration,
+            MIN_DURATION_FOR_SLICE,
+            SLICE_DURATION,
+        )
+
+        slice_files, slice_dir = slice_video(src, SLICE_DURATION)
+
+        if len(slice_files) > 1:
+            # 发布每个切片
+            for i, slice_file in enumerate(slice_files):
+                slice_basename = _slice_media_basename(base_basename, i)
+                dst = settings.media_root / slice_basename
+
+                # 检查是否需要重新发布
+                need_publish = True
+                if dst.is_file():
+                    try:
+                        if dst.stat().st_mtime >= slice_file.stat().st_mtime:
+                            need_publish = False
+                    except OSError:
+                        pass
+
+                if need_publish:
+                    url = await _publish_video(slice_file, dst, settings)
+                else:
+                    url = _public_media_url(settings, dst.name)
+
+                if url:
+                    new_urls.append(url)
+
+            logger.info(
+                "[water-video] prepared {} slices for {}",
+                len(new_urls),
+                src.name,
+            )
+
+            # 更新全局缓存
+            _global_slice_urls = new_urls
+            _last_source_mtime = current_mtime
+            return new_urls
+
+    # 视频较短，只保留完整视频
+    dst = settings.media_root / base_basename
+    url = await _publish_video(src, dst, settings)
+
+    if url:
+        new_urls = [url]
+        _global_slice_urls = new_urls
+        _last_source_mtime = current_mtime
+        return new_urls
+
+    return []
+
+
+async def get_water_video_public_url(settings: Settings, client_id: str = DEFAULT_CLIENT_ID) -> str:
+    """转码并发布到 MEDIA_ROOT 后返回绝对 URL；无可用源且无已发布文件时返回空串。
+
+    如果视频较长被切片，会根据 health/result 端点的状态返回对应的切片URL。
+
+    对齐机制：查询 health 数据库记录的切片索引，确保与 health/result 端点对齐。
+    只有当 health/result 返回了第 N 个切片的行为结果后，本端点才会返回第 N 个切片的视频。
+
+    Args:
+        settings: 应用配置
+        client_id: 客户端标识，默认为 "default"
+
+    Returns:
+        视频URL，失败返回空串
+    """
+    from app.db import get_last_health_slice_index
+
+    settings.media_root.mkdir(parents=True, exist_ok=True)
+
+    async with _publish_lock:
+        # 确保切片已准备好
+        slice_urls = await _prepare_slices(settings)
+
+        if not slice_urls:
+            # 没有切片，尝试返回已发布的文件
+            basename = _safe_water_media_basename(settings.biomass_water_video_media_name)
+            dst = settings.media_root / basename
             if dst.is_file():
                 return _public_media_url(settings, dst.name)
             return ""
 
-    if dst.is_file():
-        return _public_media_url(settings, dst.name)
-    return ""
+        # 查询 health 端点上次返回的切片索引
+        target_slice_idx = get_last_health_slice_index(client_id)
+
+        if target_slice_idx >= 0 and target_slice_idx < len(slice_urls):
+            # 返回与 health 结果对齐的切片
+            logger.debug(
+                "[water-video] client_id={} aligned to health slice {}/{}",
+                client_id,
+                target_slice_idx,
+                len(slice_urls),
+            )
+            return slice_urls[target_slice_idx]
+        else:
+            # 没有对齐的 health 结果，返回空（等待 health/result 先被调用）
+            logger.debug(
+                "[water-video] client_id={} no health index yet, returning empty",
+                client_id,
+            )
+            return ""