Remove variable audio recordings data types (will be converted to float32 anyway)

src/lerobot/microphones/configs.py

@@ -23,7 +23,6 @@ class MicrophoneConfig(draccus.ChoiceRegistry, abc.ABC):
     microphone_index: int
     sampling_rate: int | None = None
     channels: list[int] | None = None
-    data_type: str | None = None
 
     @property
     def type(self) -> str:

src/lerobot/microphones/microphone.py

@@ -109,7 +109,7 @@ class Microphone:
     ```python
     from lerobot.common.robot_devices.microphones.configs import MicrophoneConfig
 
-    config = MicrophoneConfig(microphone_index=0, sampling_rate=16000, channels=[1], data_type="int16")
+    config = MicrophoneConfig(microphone_index=0, sampling_rate=16000, channels=[1])
     microphone = Microphone(config)
 
     microphone.connect()
@@ -131,7 +131,6 @@ class Microphone:
         # Store the recording sampling rate and channels
         self.sampling_rate = config.sampling_rate
         self.channels = config.channels
-        self.data_type = config.data_type
 
         # Input audio stream
         self.stream = None
@@ -192,7 +191,7 @@ class Microphone:
             device=self.microphone_index,
             samplerate=self.sampling_rate,
             channels=max(self.channels) + 1,
-            dtype=self.data_type,
+            dtype="float32",
             callback=self._audio_callback,
         )
         # Remark : the blocksize parameter could be passed to the stream to ensure that audio_callback always receive same length buffers.
@@ -209,6 +208,7 @@ class Microphone:
         self.read_queue.put(indata[:, self.channels])
 
     def _record_loop(self, output_file: Path) -> None:
+        # Can only be run on a single process/thread for file writing safety
         with sf.SoundFile(
             output_file,
             mode="x",