Add ability to restream birdseye (#4761)

* Try using RTSP for restream

* Add ability to get snapshot of birdseye when birdseye restream is enabled

* Write to pipe instead of encoding mpeg1

* Write to cache instead

* Use const for location

* Formatting

* Add hardware encoding for birdseye based on ffmpeg preset

* Provide framerate

* Adjust args

* Fix order

* Delete pipe file if it exists

* Cleanup spacing

* Fix spacing

frigate/http.py

@@ -825,6 +825,24 @@ def latest_frame(camera_name):
 
         frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
 
+        ret, jpg = cv2.imencode(
+            ".jpg", frame, [int(cv2.IMWRITE_JPEG_QUALITY), resize_quality]
+        )
+        response = make_response(jpg.tobytes())
+        response.headers["Content-Type"] = "image/jpeg"
+        response.headers["Cache-Control"] = "no-store"
+        return response
+    elif camera_name == "birdseye" and current_app.frigate_config.restream.birdseye:
+        frame = cv2.cvtColor(
+            current_app.detected_frames_processor.get_current_frame(camera_name),
+            cv2.COLOR_YUV2BGR_I420,
+        )
+
+        height = int(request.args.get("h", str(frame.shape[0])))
+        width = int(height * frame.shape[1] / frame.shape[0])
+
+        frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
+
         ret, jpg = cv2.imencode(
             ".jpg", frame, [int(cv2.IMWRITE_JPEG_QUALITY), resize_quality]
         )