tune consumption of samples

src/auracast/multicast.py

@@ -58,17 +58,8 @@ from auracast.utils.webrtc_audio_input import WebRTCAudioInput
 # Patch sounddevice.InputStream globally to use low-latency settings
 import sounddevice as sd
 from collections import deque
-import statistics
 
 
-def popleft_n(d: deque, n: int) -> bytes:
-    # pops up to n items (handles short deques)
-    # if the deque was too short, fill with 0s and print a warning
-    it = (d.popleft() for _ in range(min(n, len(d))))
-    if len(d) < n:
-        logging.warning("SoundDeviceAudioInput: deque was too short, requested %d, got %d", n, len(d))
-    return b"".join(it)
-
 class ModSoundDeviceAudioInput(audio_io.SoundDeviceAudioInput):
     """Patched SoundDeviceAudioInput with low-latency capture and adaptive resampling."""
 
@@ -94,13 +85,10 @@ class ModSoundDeviceAudioInput(audio_io.SoundDeviceAudioInput):
         # Target ~2 ms blocksize (48 kHz -> 96 frames). For other rates, keep ~2 ms.
         _sr = int(self._pcm_format.sample_rate)
 
-        self.log_counter0=0
-        self._runavg_samps = deque(maxlen=30)
-        self._runavg = 0
+        self.counter=0
         self.max_avail=0
         self.logfile_name="available_samples.txt"
-        self.blocksize = 480
-        self._frames_offset = 0
+        self.blocksize = 120
 
         if os.path.exists(self.logfile_name):
             os.remove(self.logfile_name)
@@ -111,7 +99,7 @@ class ModSoundDeviceAudioInput(audio_io.SoundDeviceAudioInput):
             channels=self._pcm_format.channels,
             dtype='int16',
             blocksize=self.blocksize,
-            latency=0.005,
+            latency=0.004,
         )
         self._stream.start()
 
@@ -123,50 +111,43 @@ class ModSoundDeviceAudioInput(audio_io.SoundDeviceAudioInput):
         )
 
     def _read(self, frame_size: int) -> bytes:
-        """Generate frames while minimally adjusting frames_offset to keep _runavg ~ blocksize/2."""
-        # Persist frames_offset across calls; clamp within 1% of blocksize
+        """Read PCM samples from the stream."""
 
-        max_offset = 30
-        target = 0.5*self.blocksize 
-        deadband = 2
+        #if self.counter % 50 == 0:
+        frame_size = frame_size + 1 # consume samples a little faster to avoid latency akkumulation
 
-        pcm_buffer, overflowed = self._stream.read(frame_size + self._frames_offset)
+        pcm_buffer, overflowed = self._stream.read(frame_size)
         if overflowed:
             logging.warning("SoundDeviceAudioInput: overflowed")
 
-        available = self._stream.read_available
-        if available > 0:
-            self.max_avail = max(self.max_avail, available)
+        n_available = self._stream.read_available
 
-        self._runavg_samps.append(available)
-        self._runavg = max(self._runavg_samps) # statistics.median(self._runavg_samps)
+        # adapt = n_available > 20
+        # if adapt:
+        #     pcm_extra, overflowed = self._stream.read(3)
+        #     logging.info('consuming extra samples, available was %d', n_available)
+        #     if overflowed:
+        #         logging.warning("SoundDeviceAudioInput: overflowed")
+            
+        #     out = bytes(pcm_buffer) +  bytes(pcm_extra)
+        # else:
+        out = bytes(pcm_buffer)     
 
-        # Minimal feedback: nudge frames_offset by 1 to target blocksize/2 with small deadband
-
-        increment = self._runavg > (target + deadband) or overflowed
-        decrement = self._runavg < (target - deadband) 
-        clipped_upper = self._frames_offset >= max_offset
-        clipped_lower = self._frames_offset <= -1 * max_offset
-
-        self._frames_offset = 0
-        if increment and not clipped_upper:
-            self._frames_offset += 1
-        elif decrement and not clipped_lower:
-            self._frames_offset -= 1
+        self.max_avail = max(self.max_avail, n_available)
 
         #Diagnostics 
-        with open(self.logfile_name, "a", encoding="utf-8") as f:
-            f.write(f"{available}, {round(self._runavg, 2)}, {self._frames_offset}, {overflowed}\n")
+        #with open(self.logfile_name, "a", encoding="utf-8") as f:
+        #    f.write(f"{n_available}, {adapt}, {round(self._runavg, 2)}, {overflowed}\n")
 
-        if self.log_counter0 % 500 == 0:
+        if self.counter % 500 == 0:
             logging.info(
-                "read available=%d, max=%d, runavg=%.3f, frames_offset=%d (max %d)",
-                available, self.max_avail, round(self._runavg, 2), self._frames_offset, max_offset
+                "read available=%d, max=%d, latency:%d", 
+                n_available, self.max_avail, self._stream.latency
             )
             self.max_avail = 0
 
-        self.log_counter0 += 1
-        return bytes(pcm_buffer)
+        self.counter += 1
+        return out
 
 audio_io.SoundDeviceAudioInput = ModSoundDeviceAudioInput
 

src/misc/asound.conf

@@ -6,8 +6,8 @@ pcm.ch1 {
         channels 2
         rate 48000
         format S16_LE
-        period_size 480    # 2.5ms
-        buffer_size 960    
+        period_size 120    
+        buffer_size 240    
     }
     bindings.0  0
 }
@@ -21,8 +21,8 @@ pcm.ch2 {
         channels 2
         rate 48000
         format S16_LE
-        period_size 480
-        buffer_size 960
+        period_size 120
+        buffer_size 240
     }    
     bindings.0  1
 }