fix: fixing issue with microphone channels numbering and status recovery on stop_recording

lerobot/common/robot_devices/microphones/microphone.py

@@ -207,7 +207,7 @@ class Microphone:
         else:
             self.sample_rate = int(actual_microphone["default_samplerate"])
 
-        if self.channels is not None:
+        if self.channels is not None and len(self.channels) > 0:
             if any(c > actual_microphone["max_input_channels"] for c in self.channels):
                 raise OSError(
                     f"Some of the provided channels {self.channels} are outside the maximum channel range of the microphone {actual_microphone['max_input_channels']}."
@@ -216,13 +216,13 @@ class Microphone:
             self.channels = np.arange(1, actual_microphone["max_input_channels"] + 1)
         
         # Get channels index instead of number for slicing
-        self.channels = np.array(self.channels) - 1
+        self.channels_index = np.array(self.channels) - 1
 
         # Create the audio stream
         self.stream = sd.InputStream(
             device=self.microphone_index,
             samplerate=self.sample_rate,
-            channels=max(self.channels) + 1,
+            channels=max(self.channels),
             dtype="float32",
             callback=self._audio_callback,
         )
@@ -240,8 +240,8 @@ class Microphone:
         # Slicing makes copy unnecessary
         # Two separate queues are necessary because .get() also pops the data from the queue
         if self.is_writing:
-            self.record_queue.put(indata[:, self.channels])
-        self.read_queue.put(indata[:, self.channels])
+            self.record_queue.put(indata[:, self.channels_index])
+        self.read_queue.put(indata[:, self.channels_index])
 
     @staticmethod
     def _record_loop(queue, event: Event, sample_rate: int, channels: list[int], output_file: Path) -> None:
@@ -253,7 +253,7 @@ class Microphone:
             output_file,
             mode="x",
             samplerate=sample_rate,
-            channels=max(channels) + 1,
+            channels=max(channels),
             subtype=sf.default_subtype(output_file.suffix[1:]),
         ) as file:
             while not event.is_set():