update

demo/ac_sound_capture1/ac_sound_capture1.cpp

@@ -91,6 +91,7 @@ class WAVHeader {
     header.subchunk2_size = wavbinsize;
   }
 
+
   void dump() {
     printf("chunk_id:         %s\n", string(header.chunk_id, 4).c_str());
     printf("chunk_size:       %d\n", header.chunk_size);
@@ -153,7 +154,11 @@ void wavWriteVoice(string filename, uint32_t sample_rate, uint16_t bits_per_samp
 void sound_capture_callback(int32_t* voicedata, uint32_t len) {
   printf("sound_capture_callback:%d\n", len);
   for (size_t i = 0; i < len; i++) {
-    voicedata[i] = voicedata[i] << 8; //底层采集的数据是24位，左移8位转换成32位
+    voicedata[i] = voicedata[i] << 8;  // 底层采集的数据是24位，左移8位转换成32位
+  }
+
+  for (size_t i = 0; i < len; i++) {
+    voicedata[i] = voicedata[i] - 421600000;  // 减去声望AC输出的直流偏量
   }
 
   wavWriteVoice("record.wav", 64000, 32, 1, (char*)voicedata, len * sizeof(int32_t));