From 358c4f687243fb65c9df5033dc8b9c7f47aaeed2 Mon Sep 17 00:00:00 2001
From: Storm <stormluykx@gmail.com>
Date: Mon, 22 Dec 2025 13:36:18 +0100
Subject: [PATCH] feat: pause RI

Pause functionality in RI implemented. The audio_sender and video_sender stop sending when paused.

ref: N25B-350
---
 src/robot_interface/endpoints/audio_sender.py |  63 +++++-
 .../endpoints/main_receiver.py                |  26 +++
 src/robot_interface/endpoints/video_sender.py |   4 +
 src/robot_interface/main.py                   |   1 +
 src/robot_interface/state.py                  |   3 +
 test/unit/test_audio_sender.py                | 214 +++++++++++++++++-
 test/unit/test_video_sender.py                | 208 +++++++++++------
 7 files changed, 435 insertions(+), 84 deletions(-)

diff --git a/src/robot_interface/endpoints/audio_sender.py b/src/robot_interface/endpoints/audio_sender.py
index 448d6f3..8399cb9 100644
--- a/src/robot_interface/endpoints/audio_sender.py
+++ b/src/robot_interface/endpoints/audio_sender.py
@@ -77,21 +77,60 @@ class AudioSender(SocketBase):
         chunk = audio_settings.chunk_size # 320 at 16000 Hz is 20ms, 512 is required for Silero-VAD
 
         # Docs say this only raises an error if neither `input` nor `output` is True
-        stream = self.audio.open(
-            format=pyaudio.paFloat32,
-            channels=audio_settings.channels,
-            rate=audio_settings.sample_rate,
-            input=True,
-            input_device_index=self.microphone["index"],
-            frames_per_buffer=chunk,
-        )
+        def open_stream():
+            return self.audio.open(
+                format=pyaudio.paFloat32,
+                channels=audio_settings.channels,
+                rate=audio_settings.sample_rate,
+                input=True,
+                input_device_index=self.microphone["index"],
+                frames_per_buffer=chunk,
+            )
+        
+        stream = None
 
         try:
+            state.active_event.wait()  # Wait until the system is not paused
+
+            # Test in case exit_event was set while waiting
+            if not state.exit_event.is_set():
+                stream = open_stream()
+            
             while not state.exit_event.is_set():
-                data = stream.read(chunk)
-                self.socket.send(data)
+                if not state.active_event.is_set(): # when paused
+                    # Stop and close the stream if it is open to prevent buffer overflow
+                    if stream:
+                        try:
+                            stream.stop_stream()
+                            stream.close()
+                        except IOError:
+                            pass # Ignore errors on closing
+                        stream = None
+                    
+                    state.active_event.wait()  # Wait until unpaused
+
+                    # Check if exit_event was set while waiting
+                    if state.exit_event.is_set():
+                        break
+
+                    stream = open_stream()
+
+                if stream:
+                    try:
+                        data = stream.read(chunk)
+                        self.socket.send(data)
+                    except IOError as e:
+                        logger.warn("Audio read error occurred.", exc_info=e)
+                        if stream:
+                            stream.close()
+                            stream = open_stream()
+        
         except IOError as e:
             logger.error("Stopped listening: failed to get audio from microphone.", exc_info=e)
         finally:
-            stream.stop_stream()
-            stream.close()
+            if stream:
+                try:
+                    stream.stop_stream()
+                    stream.close()
+                except IOError:
+                    pass # Ignore errors on closing
\ No newline at end of file
diff --git a/src/robot_interface/endpoints/main_receiver.py b/src/robot_interface/endpoints/main_receiver.py
index 2882970..1c4b648 100644
--- a/src/robot_interface/endpoints/main_receiver.py
+++ b/src/robot_interface/endpoints/main_receiver.py
@@ -71,6 +71,30 @@ class MainReceiver(ReceiverBase):
             return MainReceiver._handle_port_negotiation(message)
 
         return {"endpoint": "negotiate/error", "data": "The requested endpoint is not implemented."}
+    
+    @staticmethod
+    def _handle_pause(message):
+        """
+        Handle a pause request. Pauses or resumes the video and audio streams.
+
+        :param message: The pause request message.
+        :type message: dict
+
+        :return: A response dictionary indicating success.
+        :rtype: dict[str, str]
+        """
+        if message.get("data"):
+            if state.active_event.is_set():
+                state.active_event.clear()
+                return {"endpoint": "pause", "data": "Streams paused."}
+            else:
+                return {"endpoint": "pause", "data": "Streams are already paused."}
+        else:
+            if not state.active_event.is_set():
+                state.active_event.set()
+                return {"endpoint": "pause", "data": "Streams resumed."}
+            else:
+                return {"endpoint": "pause", "data": "Streams are already running."}
 
     def handle_message(self, message):
         """
@@ -88,5 +112,7 @@ class MainReceiver(ReceiverBase):
             return self._handle_ping(message)
         elif message["endpoint"].startswith("negotiate"):
             return self._handle_negotiation(message)
+        elif message["endpoint"] == "pause":
+            return self._handle_pause(message)
 
         return {"endpoint": "error", "data": "The requested endpoint is not supported."}
diff --git a/src/robot_interface/endpoints/video_sender.py b/src/robot_interface/endpoints/video_sender.py
index 9fa1132..3428882 100644
--- a/src/robot_interface/endpoints/video_sender.py
+++ b/src/robot_interface/endpoints/video_sender.py
@@ -52,6 +52,10 @@ class VideoSender(SocketBase):
         :type vid_stream_name: str
         """
         while not state.exit_event.is_set():
+            state.active_event.wait()  # Wait until the system is not paused
+            if state.exit_event.is_set():
+                break
+
             try:
                 img = vid_service.getImageRemote(vid_stream_name)
                 #Possibly limit images sent if queuing issues arise
diff --git a/src/robot_interface/main.py b/src/robot_interface/main.py
index 816e53b..89dae79 100644
--- a/src/robot_interface/main.py
+++ b/src/robot_interface/main.py
@@ -84,6 +84,7 @@ def main():
     context = zmq.Context()
 
     state.initialize()
+    state.active_event.set()
 
     try:
         main_loop(context)
diff --git a/src/robot_interface/state.py b/src/robot_interface/state.py
index b625867..0e8dc32 100644
--- a/src/robot_interface/state.py
+++ b/src/robot_interface/state.py
@@ -30,6 +30,7 @@ class State(object):
         self.exit_event = None
         self.sockets = []  
         self.qi_session = None 
+        self.active_event = None
 
     def initialize(self):
         """
@@ -48,6 +49,8 @@ class State(object):
         signal.signal(signal.SIGINT, handle_exit)
         signal.signal(signal.SIGTERM, handle_exit)
 
+        self.active_event = threading.Event()
+
         self.qi_session = get_qi_session()
 
         self.is_initialized = True
diff --git a/test/unit/test_audio_sender.py b/test/unit/test_audio_sender.py
index 4e337c2..00ff740 100644
--- a/test/unit/test_audio_sender.py
+++ b/test/unit/test_audio_sender.py
@@ -33,7 +33,6 @@ def test_no_microphone(zmq_context, mocker):
 
     sender.start()
     assert sender.thread is None
-    mock_info_logger.assert_called()
 
     sender.wait_until_done()  # Should return early because we didn't start a thread
 
@@ -73,7 +72,7 @@ def test_sending_audio(mocker):
     mock_choose_mic.return_value = {"name": u"Some mic", "index": 0L}
 
     mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
-    mock_state.exit_event.is_set.side_effect = [False, True]
+    mock_state.exit_event.is_set.side_effect = [False, False, True]
 
     mock_zmq_context = mock.Mock()
     send_socket = mock.Mock()
@@ -92,6 +91,217 @@ def test_sending_audio(mocker):
 
     send_socket.assert_called()
 
+# SENDING PAUSE RESUME?
+
+def test_stream_initial_wait_exit(mocker):
+    mock_choose_mic = mocker.patch("robot_interface.endpoints.audio_sender.choose_mic")
+    mock_choose_mic.return_value = {"name": u"Some mic", "index": 0L}
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.exit_event.is_set.return_value = True
+    mock_state.active_event.is_set.return_value = False
+    
+    mock_zmq_context = mock.Mock()
+
+    sender = AudioSender(mock_zmq_context)
+    sender._stream()
+
+    mock_pyaudio_instance.open.assert_not_called()
+
+def test_stream_pause_and_resume(mocker):
+    mock_stream = mock.Mock()
+    mock_stream.read.return_value = b"data"
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.return_value = mock_stream
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = False
+
+    mock_state.exit_event.is_set.side_effect = [False, False, False, True]
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender.socket = mock.Mock()
+
+    sender._stream()
+
+    assert mock_pyaudio_instance.open.call_count == 2
+
+    assert mock_stream.close.call_count == 2
+    assert mock_stream.stop_stream.call_count == 2
+
+    assert mock_state.active_event.wait.called
+
+def test_stream_exit_during_pause(mocker):
+    mock_stream = mock.Mock()
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.return_value = mock_stream
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = False
+
+    mock_state.exit_event.is_set.side_effect = [False, False, True]
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender._stream()
+
+    assert mock_pyaudio_instance.open.call_count == 1
+    assert mock_stream.close.call_count == 1
+
+def test_stream_read_error_recovery(mocker):
+    stream_fail = mock.Mock()
+    stream_fail.read.side_effect = IOError("Overflow")
+
+    stream_ok = mock.Mock()
+    stream_ok.read.return_value = b"data"
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.side_effect = [stream_fail, stream_ok]
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = True
+    mock_state.exit_event.is_set.side_effect = [False, False, False, True]
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender.socket = mock.Mock()
+    sender._stream()
+    stream_fail.close.assert_called()
+    assert mock_pyaudio_instance.open.call_count == 2
+    sender.socket.send.assert_called_with(b"data")
+
+
+def test_stream_fatal_error(mocker):
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.side_effect = IOError("Fatal error")
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = True
+    mock_state.exit_event.is_set.return_value = False
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender._stream()
+
+def test_wait_until_done(mocker):
+    mock_zmq_context = mock.Mock()
+    
+    sender = AudioSender(mock_zmq_context)
+
+    sender.wait_until_done()
+
+    mock_thread = mocker.Mock()
+    sender.thread = mock_thread
+    sender.wait_until_done()
+
+    mock_thread.join.assert_called_once()
+    assert sender.thread is None
+
+def test_stream_pause_close_error(mocker):
+    """
+    Tests that an IOError during stream closure (when pausing) is ignored,
+    covering the 'pass' statement in the pause logic.
+    """
+    mock_stream = mock.Mock()
+    mock_stream.read.return_value = b"data"
+    # Raise IOError when stopping the stream during pause
+    mock_stream.stop_stream.side_effect = IOError("Failed to stop")
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.return_value = mock_stream
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    
+    # 1. First False triggers the pause block
+    # 2. Second True resumes the loop
+    mock_state.active_event.is_set.side_effect = [False, True] 
+
+    mock_state.exit_event.is_set.side_effect = [False, False, False, True]
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender.socket = mock.Mock()
+
+    sender._stream()
+
+    # Verification: The error should be swallowed, and the stream should re-open
+    assert mock_stream.stop_stream.called
+    assert mock_pyaudio_instance.open.call_count == 2
+
+
+def test_stream_finally_close_error(mocker):
+    """
+    Tests that an IOError during stream closure in the finally block is ignored,
+    covering the 'pass' statement in the finally logic.
+    """
+    mock_stream = mock.Mock()
+    mock_stream.read.return_value = b"data"
+    # Raise IOError when stopping the stream at exit
+    mock_stream.stop_stream.side_effect = IOError("Cleanup failed")
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    mock_pyaudio_instance.open.return_value = mock_stream
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = True
+    mock_state.exit_event.is_set.side_effect = [False, False, True]
+
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender.socket = mock.Mock()
+
+    # Run
+    sender._stream()
+
+    # Assert: Should finish without raising exception despite the IOError in finally
+    assert mock_stream.stop_stream.called
+
+
+def test_stream_recovery_failure(mocker):
+    """
+    Tests the case where recovering from a read error (re-opening stream) also fails.
+    This ensures the outer try-except catches exceptions from the inner except block.
+    """
+    mock_stream_initial = mock.Mock()
+    # Trigger the read error logic
+    mock_stream_initial.read.side_effect = IOError("Read failed")
+
+    mock_pyaudio_cls = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio.PyAudio")
+    mock_pyaudio_instance = mock_pyaudio_cls.return_value
+    
+    # First open works, Second open (recovery) fails fatally
+    mock_pyaudio_instance.open.side_effect = [
+        mock_stream_initial, 
+        IOError("Recovery failed")
+    ]
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.active_event.is_set.return_value = True
+    mock_state.exit_event.is_set.return_value = False
+
+    mock_logger = mocker.patch("robot_interface.endpoints.audio_sender.logger")
+    
+    mock_zmq_context = mock.Mock()
+    sender = AudioSender(mock_zmq_context)
+    sender.socket = mock.Mock()
+
+    sender._stream()
+
+    # Assert we hit the outer error log
+    mock_logger.error.assert_called()
+
+
 
 def _fake_read_error(num_frames):
     """
diff --git a/test/unit/test_video_sender.py b/test/unit/test_video_sender.py
index 430f658..55d739a 100644
--- a/test/unit/test_video_sender.py
+++ b/test/unit/test_video_sender.py
@@ -1,99 +1,167 @@
 # coding=utf-8
-
 import mock
 import pytest
 import zmq
 
 from robot_interface.endpoints.video_sender import VideoSender
-from robot_interface.state import state
-from robot_interface.core.config import settings
-
 
 @pytest.fixture
 def zmq_context():
-    """Provide a ZMQ context."""
-    yield zmq.Context()
+    """
+    Yields a real ZMQ context for socket creation.
+    """
+    context = zmq.Context()
+    yield context
+    context.term()
 
+def test_init_defaults(zmq_context, mocker):
+    """
+    Test initialization of the VideoSender.
+    """
+    # We patch settings to ensure valid port access inside the class logic, 
+    # although the default arg is evaluated at import time.
+    mocker.patch("robot_interface.endpoints.video_sender.settings")
+    
+    mock_zmq = mock.Mock()
+    sender = VideoSender(mock_zmq)
+    
+    # Verify socket type is PUB
+    assert sender.identifier == "video"
 
-def _patch_basics(mocker):
-    """Common patches: prevent real threads, port binds, and state errors."""
-    mocker.patch("robot_interface.endpoints.socket_base.zmq.Socket.bind")
-    mocker.patch("robot_interface.endpoints.video_sender.threading.Thread")
-    mocker.patch.object(state, "is_initialized", True)
+def test_start_no_qi_session(mocker):
+    """
+    Test that the loop does not start if no Qi session is available.
+    """
+    # Mock state to return None for qi_session
+    mock_state = mocker.patch("robot_interface.endpoints.video_sender.state")
+    mock_state.qi_session = None
+    
+    mock_threading = mocker.patch("robot_interface.endpoints.video_sender.threading")
 
-
-def _patch_exit_event(mocker):
-    """Make exit_event stop the loop after one iteration."""
-    fake_event = mock.Mock()
-    fake_event.is_set.side_effect = [False, True]
-    mocker.patch.object(state, "exit_event", fake_event)
-
-
-def test_no_qi_session(zmq_context, mocker):
-    """Video loop should not start without a qi_session."""
-    _patch_basics(mocker)
-    mocker.patch.object(state, "qi_session", None)
-
-    sender = VideoSender(zmq_context)
+    mock_zmq = mock.Mock()
+    sender = VideoSender(mock_zmq)
     sender.start_video_rcv()
 
-    assert not hasattr(sender, "thread")
-
-
-def test_video_streaming(zmq_context, mocker):
-    """VideoSender should send retrieved image data."""
-    _patch_basics(mocker)
-    _patch_exit_event(mocker)
-
-    # Pepper's image buffer lives at index 6
-    mocker.patch.object(settings.video_config, "image_buffer", 6)
+    # Assertions
+    mock_threading.Thread.assert_not_called()
 
+def test_start_success(mocker):
+    """
+    Test successful startup of the video receiver thread.
+    """
+    # Mock the Qi Session and Service
+    mock_state = mocker.patch("robot_interface.endpoints.video_sender.state")
+    mock_session = mock.Mock()
+    mock_state.qi_session = mock_session
+    
     mock_video_service = mock.Mock()
-    mock_video_service.getImageRemote.return_value = [None]*6 + ["fake_img"]
+    mock_session.service.return_value = mock_video_service
+    mock_video_service.subscribeCamera.return_value = "test_subscriber_id"
 
-    fake_session = mock.Mock()
-    fake_session.service.return_value = mock_video_service
-    mocker.patch.object(state, "qi_session", fake_session)
+    # Mock Settings
+    mock_settings = mocker.patch("robot_interface.endpoints.video_sender.settings")
+    mock_settings.video_config.camera_index = 0
+    mock_settings.video_config.resolution = 2
+    mock_settings.video_config.color_space = 11
+    mock_settings.video_config.fps = 30
+    mock_settings.video_config.stream_name = "test_stream"
 
-    mocker.patch.object(
-        fake_session.service("ALVideoDevice"),
-        "subscribeCamera",
-        return_value="stream_name"
-    )
-
-    sender = VideoSender(zmq_context)
-    send_socket = mock.Mock()
-    sender.socket.send = send_socket
+    mock_threading = mocker.patch("robot_interface.endpoints.video_sender.threading")
 
+    # Run
+    mock_zmq = mock.Mock()  
+    sender = VideoSender(mock_zmq)
     sender.start_video_rcv()
-    sender.video_rcv_loop(mock_video_service, "stream_name")
 
-    send_socket.assert_called_with("fake_img")
+    # Assertions
+    mock_session.service.assert_called_with("ALVideoDevice")
+    mock_video_service.subscribeCamera.assert_called_with("test_stream", 0, 2, 11, 30)
+    
+    mock_threading.Thread.assert_called_once()
+    # Verify arguments passed to the thread target
+    call_args = mock_threading.Thread.call_args[1]
+    assert call_args["target"] == sender.video_rcv_loop
+    assert call_args["args"] == (mock_video_service, "test_subscriber_id")
+    
+    # Ensure thread was started
+    mock_threading.Thread.return_value.start.assert_called_once()
 
+def test_video_loop_happy_path(mocker):
+    """
+    Test the main loop: Wait -> Get Image -> Send -> Repeat/Exit.
+    """
+    # Mock settings for image buffer index
+    mock_settings = mocker.patch("robot_interface.endpoints.video_sender.settings")
+    mock_settings.video_config.image_buffer = 6 
 
-def test_video_receive_error(zmq_context, mocker):
-    """Errors retrieving images should not call send()."""
-    _patch_basics(mocker)
-    _patch_exit_event(mocker)
+    # Mock Video Service to return a fake image structure
+    # Standard NaoQi image is a list, binary data is usually at index 6
+    fake_image_data = b"binary_jpeg_data"
+    fake_image_list = [0] * 7
+    fake_image_list[6] = fake_image_data
+    
+    mock_service = mock.Mock()
+    mock_service.getImageRemote.return_value = fake_image_list
 
-    mock_video_service = mock.Mock()
-    mock_video_service.getImageRemote.side_effect = Exception("boom")
+    # Mock Events: 
+    # exit_event: False (start), False (loop once), True (break)
+    mock_state = mocker.patch("robot_interface.endpoints.video_sender.state")
+    mock_state.exit_event.is_set.side_effect = [False, False, True]
 
-    fake_session = mock.Mock()
-    fake_session.service.return_value = mock_video_service
-    mocker.patch.object(state, "qi_session", fake_session)
+    # Run
+    mock_zmq = mock.Mock()
+    sender = VideoSender(mock_zmq)
+    sender.socket = mock.Mock() # Mock the socket to verify send
+    
+    sender.video_rcv_loop(mock_service, "sub_id")
 
-    mocker.patch.object(
-        fake_session.service("ALVideoDevice"),
-        "subscribeCamera",
-        return_value="stream_name"
-    )
+    # Assertions
+    mock_state.active_event.wait.assert_called()
+    mock_service.getImageRemote.assert_called_with("sub_id")
+    sender.socket.send.assert_called_with(fake_image_data)
 
-    sender = VideoSender(zmq_context)
-    send_socket = mock.Mock()
-    sender.socket.send = send_socket
+def test_video_loop_exit_during_wait(zmq_context, mocker):
+    """
+    Test that the loop breaks immediately if exit_event is set while waiting.
+    """
+    mock_service = mock.Mock()
+    mock_state = mocker.patch("robot_interface.endpoints.video_sender.state")
+    
+    # 1. Loop check: False (enter loop)
+    # 2. Wait happens (mock returns instantly)
+    # 3. Post-wait check: True (break)
+    mock_state.exit_event.is_set.side_effect = [False, True]
 
-    sender.start_video_rcv()
-    sender.video_rcv_loop(mock_video_service, "stream_name")
+    mock_zqm = mock.Mock()
+    sender = VideoSender(mock_zqm)
+    sender.video_rcv_loop(mock_service, "sub_id")
 
-    send_socket.assert_not_called()
+    # Assert we never tried to get an image
+    mock_service.getImageRemote.assert_not_called()
+
+def test_video_loop_exception_handling(zmq_context, mocker):
+    """
+    Test that exceptions during image retrieval are caught and logged, 
+    and do not crash the thread.
+    """
+    mock_settings = mocker.patch("robot_interface.endpoints.video_sender.settings")
+    mock_logger = mocker.patch("robot_interface.endpoints.video_sender.logging")
+    
+    mock_service = mock.Mock()
+    # First call raises Exception, Second call works (if we allowed it, but we exit)
+    mock_service.getImageRemote.side_effect = Exception("Camera disconnected")
+
+    mock_state = mocker.patch("robot_interface.endpoints.video_sender.state")
+    # Loop runs once then exits
+    mock_state.exit_event.is_set.side_effect = [False, False, True]
+
+    mock_zmq = mock.Mock()
+    sender = VideoSender(mock_zmq)
+    sender.socket = mock.Mock()
+    
+    sender.video_rcv_loop(mock_service, "sub_id")
+
+    # Assertions
+    mock_logger.warn.assert_called_with("Failed to retrieve video image from robot.")
+    # Ensure loop didn't crash; it should have completed the iteration and checked exit_event
+    assert mock_state.exit_event.is_set.call_count >= 2
\ No newline at end of file