t

audio.py

@@ -42,33 +42,70 @@ class AudioPlayer:
             self.i2s = None
 
     def play_tone(self, frequency, duration_ms, volume=0.5):
-        """播放指定频率的音调"""
+        """播放指定频率的音调 (优化内存版)"""
         if self.i2s is None: return
         
         sample_rate = self.config.get('sample_rate', 24000)
-        n_samples = int(sample_rate * duration_ms / 1000)
+        
+        if frequency <= 0:
+            # 静音处理
+            time.sleep_ms(duration_ms)
+            return
+
+        # 振幅
         amplitude = int(32767 * volume)
         
-        # STEREO: 每个采样 2 个声道 (L+R)，每个声道 2 字节 (16-bit) -> 4 字节/帧
-        buffer = bytearray(n_samples * 4)
-        if frequency > 0:
-            period = sample_rate // frequency
-            half_period = period // 2
+        # 计算单周期采样数
+        period = sample_rate // frequency
+        
+        # 目标 buffer 大小约 2048 字节 (防止 buffer 只有几字节导致 underrun)
+        target_size = 2048
+        frame_size = 4 # 16bit stereo
+        
+        # 计算 buffer 中包含多少个完整周期
+        period_bytes = period * frame_size
+        repeats = max(1, target_size // period_bytes)
+        buffer_bytes = repeats * period_bytes
+        
+        buffer = bytearray(buffer_bytes)
+        
+        # 填充 buffer
+        half_period = period // 2
+        
+        # 预计算采样值的高低字节
+        pos_val = amplitude
+        neg_val = -amplitude
+        
+        pos_low = pos_val & 0xFF
+        pos_high = (pos_val >> 8) & 0xFF
+        neg_low = neg_val & 0xFF
+        neg_high = (neg_val >> 8) & 0xFF
+        
+        for i in range(period * repeats):
+            # 方波：前半周期高电平，后半周期低电平
+            if (i % period) < half_period:
+                low, high = pos_low, pos_high
+            else:
+                low, high = neg_low, neg_high
             
-            for i in range(n_samples):
-                # 方波：前半周期高电平，后半周期低电平
-                sample = amplitude if (i % period) < half_period else -amplitude
-                # 左声道
-                struct.pack_into('<h', buffer, i * 4, sample)
-                # 右声道
-                struct.pack_into('<h', buffer, i * 4 + 2, sample)
-        else:
-            # 静音，缓冲区默认为0
-            pass
+            idx = i * 4
+            buffer[idx] = low
+            buffer[idx+1] = high
+            buffer[idx+2] = low
+            buffer[idx+3] = high
 
+        # 计算总共需要写入的数据量
+        total_bytes = int((sample_rate * duration_ms / 1000) * frame_size)
+        
+        written = 0
         try:
-            # 写入多次以确保缓冲区填满并开始播放
-            self.i2s.write(buffer) 
+            while written < total_bytes:
+                to_write = min(len(buffer), total_bytes - written)
+                if to_write == len(buffer):
+                    self.i2s.write(buffer)
+                else:
+                    self.i2s.write(buffer[:to_write])
+                written += to_write
         except Exception as e:
             print(f"Write error: {e}")