// 全局 file path：
char debug_recording_path_[256];

  // locate file path on ios in debug mode
  NSArray  *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *documentsDirectory = [paths objectAtIndex:0];
  NSString* pcmPath = [NSString stringWithFormat: @"%@/testL.pcm", documentsDirectory];
  strcpy(debug_recording_path_, [pcmPath UTF8String]);
  RTC_LOG(LS_INFO) << "debug_recording_path_:"  << debug_recording_path_;


=========== c++ 文件  ==============
//pcm debug
FILE *fp = nullptr;

// file path
extern char debug_recording_path_[256];


// open file
if(fp == NULL){
    fp = fopen(debug_recording_path_, "wb");
}

//write
 if(fp) {
       fwrite(reinterpret_cast<const int8_t*>(audio_frame->data()), 1, audio_frame->samples_per_channel_ * audio_frame->num_channels_ * 2, fp);
      }


或者

int8_t* datas = reinterpret_cast<int8_t*>(const_cast<int16_t*>(audio_frame->data()));
  if(fp && datas != NULL) {
    fwrite(datas, 1, audio_frame->samples_per_channel_*audio_frame->num_channels_*2, fp);
  }

//close
if(fp) fclose(fp);

if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)

extern char global_debug_recording_path_[256];

endif

if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)

// open file
if(fp == NULL){
fp = fopen(global_debug_recording_path_, "wb");
}

swift 获取文件路径

 let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
 var pcmFilePath = documentsPath + "/tl.pcm"
  print("pcmFilePath:", pcmFilePath)