diff --git a/fish_api/app/services/measure.py b/fish_api/app/services/measure.py
index 666756e..2bc4390 100644
--- a/fish_api/app/services/measure.py
+++ b/fish_api/app/services/measure.py
@@ -71,10 +71,10 @@ def _load_weight_json(svo_path: Path, settings: Settings) -> Dict[str, Any]:
 
 
 def _find_preview_videos(output_dir: Path) -> Tuple[Optional[Path], Optional[Path]]:
-    previews = sorted(output_dir.glob("*preview*.mp4"))
+    previews = sorted(output_dir.rglob("*preview*.mp4"))
     if len(previews) >= 2:
         return previews[0], previews[1]
-    all_mp4 = sorted(output_dir.glob("*.mp4"))
+    all_mp4 = sorted(output_dir.rglob("*.mp4"))
     if len(all_mp4) >= 2:
         return all_mp4[0], all_mp4[1]
     if len(all_mp4) == 1:
@@ -84,6 +84,46 @@ def _find_preview_videos(output_dir: Path) -> Tuple[Optional[Path], Optional[Pat
     return None, None
 
 
+def _split_sbs_video(src: Path, left_dst: Path, right_dst: Path) -> bool:
+    """Split a side-by-side stereo video (W x H where W == 2*H_single) into left/right halves.
+
+    Returns True if split succeeded, False otherwise (caller should fall back to copy).
+    """
+    probe = subprocess.run(
+        [
+            "ffprobe", "-v", "quiet", "-print_format", "json",
+            "-show_streams", str(src),
+        ],
+        capture_output=True, text=True,
+    )
+    if probe.returncode != 0:
+        return False
+    import json as _json
+    try:
+        streams = _json.loads(probe.stdout).get("streams", [])
+        vstream = next((s for s in streams if s.get("codec_type") == "video"), None)
+        if vstream is None:
+            return False
+        w, h = int(vstream["width"]), int(vstream["height"])
+    except Exception:
+        return False
+    half_w = w // 2
+    if half_w < 1 or w < h:
+        return False
+
+    for crop, dst in [
+        (f"crop={half_w}:{h}:{half_w}:0", left_dst),
+        (f"crop={half_w}:{h}:0:0", right_dst),
+    ]:
+        r = subprocess.run(
+            ["ffmpeg", "-y", "-i", str(src), "-vf", crop, "-an", "-q:v", "5", str(dst)],
+            capture_output=True, text=True,
+        )
+        if r.returncode != 0:
+            return False
+    return True
+
+
 def _publish_media(
     left: Optional[Path],
     right: Optional[Path],
@@ -94,6 +134,13 @@ def _publish_media(
     right_dst = settings.media_root / "latest_right.mp4"
     base = settings.public_base_url.rstrip("/")
 
+    if left is not None and left == right and left.is_file():
+        if _split_sbs_video(left, left_dst, right_dst):
+            return (
+                f"{base}/media/{left_dst.name}",
+                f"{base}/media/{right_dst.name}",
+            )
+
     def publish(src: Optional[Path], dst: Path) -> str:
         if src is None or not src.is_file():
             return ""
diff --git a/scripts/biomass_poller.py b/scripts/biomass_poller.py
index 87678cc..6ecf59e 100755
--- a/scripts/biomass_poller.py
+++ b/scripts/biomass_poller.py
@@ -29,22 +29,39 @@ def _fmt_body(resp: httpx.Response) -> Any:
         return resp.text
 
 
+_last_camera: dict | None = None
+_last_health: dict | None = None
+
+
+def _has_data(body: Any) -> bool:
+    """非空业务数据：code==200 且 data 里至少有一个非空字段。"""
+    if not isinstance(body, dict):
+        return False
+    if body.get("code") != 200:
+        return True  # 错误也算"新信息"
+    data = body.get("data", {})
+    if not isinstance(data, dict):
+        return bool(data)
+    return any(bool(v) for v in data.values())
+
+
 async def poll_once(client: httpx.AsyncClient, base: str) -> None:
+    global _last_camera, _last_health
     base = base.rstrip("/")
     camera_url = f"{base}/api/v1/biomass/real/camera/"
     health_url = f"{base}/api/v1/biomass/health/result/"
     r1 = await client.get(camera_url)
     r2 = await client.get(health_url)
-    logger.info(
-        "[real/camera/] HTTP {} | {}",
-        r1.status_code,
-        json.dumps(_fmt_body(r1), ensure_ascii=False),
-    )
-    logger.info(
-        "[health/result/] HTTP {} | {}",
-        r2.status_code,
-        json.dumps(_fmt_body(r2), ensure_ascii=False),
-    )
+    b1 = _fmt_body(r1)
+    b2 = _fmt_body(r2)
+    changed1 = b1 != _last_camera
+    changed2 = b2 != _last_health
+    if changed1 and _has_data(b1):
+        logger.info("[real/camera/] HTTP {} | {}", r1.status_code, json.dumps(b1, ensure_ascii=False))
+    if changed2 and _has_data(b2):
+        logger.info("[health/result/] HTTP {} | {}", r2.status_code, json.dumps(b2, ensure_ascii=False))
+    _last_camera = b1
+    _last_health = b2
 
 
 async def poll_loop(base: str, interval: float) -> None: