Add MJPEG camera server with systemd deployment

- camera/capture.py: V4L2 mmap-based MJPEG frame capture with background thread - camera/mjpeg.py: MJPEG streaming server (multipart/x-mixed-replace) + minimal web UI - camera/app.py: Entry point with argument parsing and signal handling - pyproject.toml: uv project config (no external dependencies) - camera-webui.service: systemd unit for native Pi deployment - README.md: Updated for systemd-only direction with install instructions
2026-08-06 01:17:26 +09:00
parent ceccdcc211
commit d4eebf79f6
7 changed files with 440 additions and 77 deletions
@@ -0,0 +1,130 @@
+"""MJPEG streaming handler for HTTP multipart/x-mixed-replace.
+
+Each client gets its own handler thread. Frames are pulled from the shared
+camera capture singleton — no queuing, just the latest frame.
+"""
+
+import io
+import threading
+import time
+import socketserver
+from http import server
+
+BOUNDARY = b"--myboundary"
+
+# HTML template for the web UI
+INDEX_HTML = (
+    "<!DOCTYPE html>"
+    "<html lang='en'>"
+    "<head>"
+    "<meta charset='utf-8'>"
+    "<meta name='viewport' content='width=device-width,initial-scale=1'>"
+    "<title>Camera Feed</title>"
+    "<style>"
+    "* { margin: 0; padding: 0; box-sizing: border-box; }"
+    "html, body { width: 100%; height: 100%; background: #111; overflow: hidden; }"
+    "#feed { display: block; width: 100vw; height: 100vh; object-fit: contain; }"
+    "#status { position: fixed; top: 12px; left: 12px; z-index: 10;"
+    "  color: #ccc; font: 13px/1 system-ui, sans-serif; display: flex;"
+    "  align-items: center; gap: 6px; opacity: 1; transition: opacity 0.3s; }"
+    "#status.hidden { opacity: 0; }"
+    "#spinner { width: 12px; height: 12px; border: 2px solid #555;"
+    "  border-top-color: #fff; border-radius: 50%; animation: spin 0.6s linear infinite;"
+    "  flex-shrink: 0; }"
+    "@keyframes spin { to { transform: rotate(360deg); } }"
+    "</style>"
+    "</head>"
+    "<body>"
+    "<div id='status'><div id='spinner'></div><span id='label'>Connecting...</span></div>"
+    "<img id='feed' src='/stream' onerror='document.getElementById(\"label\").textContent=\"Stream error\"' />"
+    "</body>"
+    "</html>"
+)
+
+
+class MJPEGHandler(server.BaseHTTPRequestHandler):
+    """Serve a single MJPEG stream to one HTTP client."""
+
+    server_version = "CameraWebUI/0.1"
+
+    def log_message(self, format, *args):  # noqa: A002
+        """Suppress per-request logging to reduce noise."""
+        pass
+
+    def do_GET(self):
+        if self.path == "/" or self.path == "":
+            self._serve_index()
+        elif self.path == "/stream":
+            self._serve_stream()
+        else:
+            self.send_error(404)
+
+    def _serve_index(self):
+        self.send_response(200)
+        self.send_header("Content-Type", "text/html; charset=utf-8")
+        self.end_headers()
+        self.wfile.write(INDEX_HTML.encode("utf-8"))
+
+    def _serve_stream(self):
+        self.send_response(200)
+        self.send_header(
+            "Content-Type", "multipart/x-mixed-replace; boundary=%s" % BOUNDARY.decode()
+        )
+        self.send_header("Cache-Control", "no-cache")
+        self.send_header("Connection", "close")
+        self.end_headers()
+
+        from camera.capture import get_camera
+
+        cam = get_camera()
+        try:
+            last_frame = None
+            while True:
+                frame = cam.frame()
+                if frame is not None and frame is not last_frame:
+                    self._write_frame(frame)
+                    last_frame = frame
+                else:
+                    time.sleep(0.05)
+        except (BrokenPipeError, ConnectionResetError, OSError):
+            pass
+
+    def _write_frame(self, frame: bytes) -> None:
+        """Write one MJPEG frame with boundary and headers."""
+        w = self.wfile
+        w.write(BOUNDARY)
+        w.write(b"\r\n")
+        w.write(b"Content-Type: image/jpeg\r\n")
+        w.write(b"Content-Length: %d\r\n\r\n" % len(frame))
+        w.write(frame)
+        w.write(b"\r\n")
+        w.flush()
+
+
+class ThreadedServer(socketserver.ThreadingMixIn, server.HTTPServer):
+    """HTTP server that handles each request in a new thread."""
+
+    daemon_threads = True
+    allow_reuse_address = True
+
+
+def run(host: str = "0.0.0.0", port: int = 8080):
+    """Start the HTTP server and block."""
+    from camera.capture import get_camera
+
+    cam = get_camera()
+    try:
+        cam.start()
+    except FileNotFoundError:
+        print(f"Error: {cam._device} not found — is the camera connected?")
+        raise SystemExit(1)
+
+    server = ThreadedServer((host, port), MJPEGHandler)
+    print(f"Server running on http://{host}:{port}")
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        cam.stop()
+        server.server_close()