From 5d9a5629f2396d1f8d4464d9efb3abe6a58d9d3f Mon Sep 17 00:00:00 2001
From: ATATC <futerry@outlook.com>
Date: Wed, 17 Jul 2024 15:14:50 +0800
Subject: [PATCH 1/2] Added `LowLatencyCamera` and `LowLatencyBase64Camera`.
 (#304)

---
 leads_video/camera.py | 51 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 45 insertions(+), 6 deletions(-)

diff --git a/leads_video/camera.py b/leads_video/camera.py
index 938b2ce9..b1eb0add 100644
--- a/leads_video/camera.py
+++ b/leads_video/camera.py
@@ -1,3 +1,4 @@
+from threading import Thread as _Thread
 from typing import override as _override
 
 from PIL.Image import fromarray as _fromarray, Image as _Image
@@ -59,18 +60,32 @@ def close(self) -> None:
         self._video_capture.release()
 
 
-class Base64Camera(Camera, _ShadowDevice):
+class LowLatencyCamera(Camera, _ShadowDevice):
     def __init__(self, port: int, resolution: tuple[int, int] | None = None) -> None:
         Camera.__init__(self, port, resolution)
         _ShadowDevice.__init__(self, port)
-        self._original: _ndarray | None = None
-        self._base64: str = ""
+        self._frame: _ndarray | None = None
 
     @_override
     def loop(self) -> None:
         if self._video_capture:
-            self._original = super().read()
-            self._base64 = base64_encode(self._original)
+            self._frame = super().read()
+
+    @_override
+    def read(self) -> _ndarray | None:
+        return self._frame
+
+
+class Base64Camera(LowLatencyCamera):
+    def __init__(self, port: int, resolution: tuple[int, int] | None = None) -> None:
+        super().__init__(port, resolution)
+        self._base64: str = ""
+
+    @_override
+    def loop(self) -> None:
+        super().loop()
+        if self._frame is not None:
+            self._base64 = base64_encode(self._frame)
 
     @_override
     def read(self) -> str:
@@ -78,4 +93,28 @@ def read(self) -> str:
 
     @_override
     def read_numpy(self) -> _ndarray | None:
-        return self._original
+        return self._frame
+
+
+class LowLatencyBase64Camera(Base64Camera):
+    def __init__(self, port: int, resolution: tuple[int, int] | None = None) -> None:
+        super().__init__(port, resolution)
+        self._shadow_thread2: _Thread | None = None
+
+    @_override
+    def loop(self) -> None:
+        LowLatencyCamera.loop(self)
+
+    def loop2(self) -> None:
+        if (local_frame := self._frame) is not None:
+            self._base64 = base64_encode(local_frame)
+
+    def run2(self) -> None:
+        while True:
+            self.loop2()
+
+    @_override
+    def initialize(self, *parent_tags: str) -> None:
+        super().initialize(*parent_tags)
+        self._shadow_thread2 = _Thread(name=f"{id(self)} shadow2", target=self.run2, daemon=True)
+        self._shadow_thread2.start()

From f1626af48bda463720489a197fe6301b0539fb0c Mon Sep 17 00:00:00 2001
From: ATATC <futerry@outlook.com>
Date: Wed, 17 Jul 2024 15:15:00 +0800
Subject: [PATCH 2/2] Using `LowLatencyBase64Camera`. (#304)

---
 leads_vec/devices_jarvis.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/leads_vec/devices_jarvis.py b/leads_vec/devices_jarvis.py
index c0a9b1e3..3971b701 100644
--- a/leads_vec/devices_jarvis.py
+++ b/leads_vec/devices_jarvis.py
@@ -3,7 +3,7 @@
 from leads import device, MAIN_CONTROLLER, mark_device, FRONT_VIEW_CAMERA, LEFT_VIEW_CAMERA, RIGHT_VIEW_CAMERA, \
     REAR_VIEW_CAMERA, require_config
 from leads_gui import Config
-from leads_video import Base64Camera
+from leads_video import LowLatencyBase64Camera
 
 import_error: ImportError | None = None
 try:
@@ -30,7 +30,7 @@
 
 
 @device(CAMERA_TAGS, MAIN_CONTROLLER, CAMERA_ARGS)
-class Cameras(Base64Camera):
+class Cameras(LowLatencyBase64Camera):
     @override
     def initialize(self, *parent_tags: str) -> None:
         mark_device(self, "Jarvis")