机械臂摄像头

arm_server/arm_server.py

@@ -45,6 +45,7 @@ def _ensure_ffmpeg():
                 "ffmpeg",
                 "-f", "v4l2",
                 "-input_format", "mjpeg",
+                "-re",
                 "-i", f"/dev/video{ARM_CAMERA_INDEX}",
                 "-vf", "rotate=PI",
                 "-q:v", "8",
@@ -103,6 +104,40 @@ def arm_camera_restart():
     _ensure_ffmpeg()
     return jsonify({"ok": True})
 
+@arm_video_app.route("/api/camera/snapshot")
+def arm_camera_snapshot():
+    """机械臂摄像头单帧 JPEG — pkill -9 强杀旧 ffmpeg，再临时抓一帧"""
+    import subprocess
+    global _ffmpeg_proc
+    # 用 pkill -9 强杀所有 ffmpeg 进程，释放 /dev/video0
+    subprocess.run(["pkill", "-9", "-f", "ffmpeg"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=3)
+    time.sleep(0.3)
+    _ffmpeg_proc = None
+    proc = subprocess.run(
+        [
+            "ffmpeg",
+            "-f", "v4l2",
+            "-input_format", "mjpeg",
+            "-i", f"/dev/video{ARM_CAMERA_INDEX}",
+            "-vf", "rotate=PI",
+            "-vframes", "1",
+            "-q:v", "8",
+            "-f", "mjpeg",
+            "pipe:1"
+        ],
+        stdout=subprocess.PIPE,
+        timeout=5,
+        stderr=subprocess.DEVNULL
+    )
+    if proc.returncode == 0 and proc.stdout:
+        r = Response(proc.stdout, mimetype="image/jpeg")
+        r.headers["Cache-Control"] = "no-cache, no-store, must-revalidate, max-age=0"
+        r.headers["Pragma"] = "no-cache"
+        r.headers["Expires"] = "0"
+        return r
+    logger.warning(f"ffmpeg snapshot failed: rc={proc.returncode}")
+    return "", 500
+
 
 # ========== RoboFlow 630 Socket API 客户端 ==========
 class RoboFlowClient: