freeswitch的呼叫方式（FreeSwitch学习一）

目前在互联网上和生活中，存在大量的智能语音的应用场景，比如智能语音交互机器人，智能电话系统。在这些应用中，VAD和ASR作为这些应用的底层模块，起到了关键的作用，可以说这两个模块的性能直接决定了用户体验。而FreeSwitch作为一款强大的电话交换平台，毫无疑问将会涉及到这一类的智能语音应用。通过插件模块的方式也很好了为FreeSwitch扩展了这两个功能。首选关于FreeSwitch插件本身，因为VAD和ASR均需要从系统中获取RTP语音流，所以采取了FreeSwitch的mediabug技术。

FreeSWITCH的是一个跨平台的开源电话交换平台，具有很强的伸缩性。旨在为音频、视频、文字或任何其他形式的媒体，提供路由和互连通信协议。它创建于2006年，填补了许多商业解决方案的空白。FreeSWITCH也提供了一个稳定的电话平台，许多广泛使用的免费电话就是在使用它开发的。

FreeSwitch软交换系统

从软件架构层面，FreeSwitch是一个微内核驱动，结合mod插件技术的非常灵活的架构模式，在保证稳定性的基础上最大化的实现了各种扩展功能，本文不打算详细的介绍FreeSwitch的详细架构，仅应用它的扩展模块技术开发一款支持vad（语音检测）和ASR（语音识别）功能的插件。

其实FreeSwitch源码内部已经存在了VAD和ASR的相关代码，但是它的性能很准确度并不高，作为学习研究非常合适，要真正的结合商业应用，效果并不是很理想，尤其是在中文环境下。而本文采用的方案均为高性能的设计，稍加改动便可以用于真实的用户环境，本着开源精神，模块的详细代码均已上传至著名的开源平台，请大家耐心看完本文。下面就一些基本的设计做一些文字性的描述，具体的内容均可以在代码中找到。

首选关于FreeSwitch插件本身，因为VAD和ASR均需要从系统中获取RTP语音流，所以采取了FreeSwitch的media bug技术。FreeSwitch使用media bug来实现旁路输出媒体，在录音、监听、ASR、信号检测等等场景都使用到它。使用它，首先要创建一个bug：

status = switch_core_media_bug_add(session, "vmd", NULL, robot_callback, robot_info, 0, SMBF_READ_REPLACE, &bug);if (status != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Robot Failure hooking to stream\n");return;}

然后要创建media bug的回调函数，在回调函数中可以获取音频流进行处理，回调函数的示例如下：

static switch_bool_t robot_callback(switch_media_bug_t *bug, void *user_data, switch_abc_type_t type){robot_session_info_t *robot_info;switch_frame_t *frame;switch_channel_t *channel;robot_info = (robot_session_info_t *)user_data;if (robot_info == NULL) { return SWITCH_FALSE; }channel = switch_core_session_get_channel(robot_info->session);switch (type) {case SWITCH_ABC_TYPE_INIT:break; case SWITCH_ABC_TYPE_READ_REPLACE://获取语音数据frame = switch_core_media_bug_get_read_replace_frame(bug);//静音检测flag = silk_VAD_Get((const short*)frame->data);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "vad result %d\n", flag);break;case SWITCH_ABC_TYPE_CLOSE:break;default:break;}switch_safe_free(recorddir);return SWITCH_TRUE;}

其次，VAD模块采用的是著名的OPUS编码器内置的VAD功能，全部采用C语言编写，运行速度快，识别灵敏，使用也非常简单，对于一个语音包，只需以下代码便可以进行判定：

flag = silk_VAD_Get((const short*)frame->data);

最后再来看看门槛相对较高的ASR功能的实现，ASR的效果主要体现在识别速度和识别准确率两方便，为了能使其具有良好的表现，我们采用了目前国内最先进的科大讯飞的在线实时语音识别接口。科大讯飞的实时语音转写（Real-time ASR）基于深度全序列卷积神经网络框架，通过 WebSocket 协议，建立应用与语言转写核心引擎的长连接，开发者可实现将连续的音频流内容，实时识别返回对应的文字流内容。

科大讯飞ASR接口

贴下完整的插件主代码： mod_vadasr.cpp

/** FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application* Copyright (C) 2005/2012, Anthony Minessale II <anthm@freeswitch.org>** Version: MPL 1.1** The contents of this file are subject to the Mozilla Public License Version* 1.1 (the "License"); you may not use this file except in compliance with* the License. You may obtain a copy of the License at* http://www.mozilla.org/MPL/** Software distributed under the License is distributed on an "AS IS" basis,* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License* for the specific language governing rights and limitations under the* License.** The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application** The Initial Developer of the Original Code is* Anthony Minessale II <anthm@freeswitch.org>* Portions created by the Initial Developer are Copyright (C) * the Initial Developer. All Rights Reserved.** Contributor(s):** Anthony Minessale II <anthm@freeswitch.org>* Neal Horman <neal at wanlink dot com>*** mod_vadasr.c -- Freeswitch asr Module**/#define DR_WAV_IMPLEMENTATION#include <switch.h>#include "dr_wav.h"#include "opusvad.h"#include "queue.h"#include "xfasr.h"#define VAD_EVENT_START "vad::start"#define VAD_EVENT_STOP "vad::stop"#define VAD_EVENT_ASR "vad::asr"static switch_bool_t robot_callback(switch_media_bug_t *bug, void *user_data, switch_abc_type_t type);#define MAX_VOICE_LEN 240000#define MAX_VOICE_LEN_BASE64 645000#define MAXFILES 8#define TTS_MAX_SIZE 900#define MAX_HZ_SIZE 240#define VAD_VOICE_FRAMES 5 #define VAD_SILINCE_FRAMES 50#define VAD_HIS_LEN 100#define VAD_ADD_FRAME_SIZE 5static struct {char* appid;char* appkey;} globals;typedef struct robot_session_info {int index;int filetime;int fileplaytime;int nostoptime;int asrtimeout;int asr;int play, pos;int sos, eos, ec, count;int eos_silence_threshold;int final_timeout_ms;int silence_threshold; int harmonic;int monitor;int lanid;int vadvoicems;int vadsilencems;int nslevel;switch_core_session_t *session;char taskid[32];char groupid[32];char telno[32];char userid[64];char callid[64];char orgi[64];char extid[64];char uuid[64];char uuidbak[64];char recordfilename[128];char para1[256];char para2[256];char para3[256];char filename[TTS_MAX_SIZE];char vadfilename[TTS_MAX_SIZE];short buffer[MAX_VOICE_LEN];drwav *fwav;drwav *fvadwav; int state; // 0:silence 1:voicequeue *vadqueue;int16_t *vadbuffer;int16_t framecount;switch_audio_resampler_t*resampler;asr_session_t *asrsession;} robot_session_info_t;SWITCH_BEGIN_EXTERN_CSWITCH_MODULE_SHUTDOWN_FUNCTION(mod_vadasr_shutdown);SWITCH_MODULE_LOAD_FUNCTION(mod_vadasr_load);SWITCH_MODULE_DEFINITION(mod_vadasr, mod_vadasr_load, mod_vadasr_shutdown, NULL);SWITCH_STANDARD_APP(robotasr_start_function);SWITCH_MODULE_LOAD_FUNCTION(mod_vadasr_load){switch_application_interface_t *app_interface;char *cf = "asr.conf";switch_xml_t cfg, xml, settings, param;memset(&globals, 0, sizeof(globals));globals.appid = NULL;globals.appkey = NULL;if (switch_event_reserve_subclass(VAD_EVENT_START) != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Robot Couldn't register subclass %s!\n",VAD_EVENT_START);return SWITCH_STATUS_TERM;}if (switch_event_reserve_subclass(VAD_EVENT_STOP) != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Robot Couldn't register subclass %s!\n",VAD_EVENT_STOP);return SWITCH_STATUS_TERM;}if (switch_event_reserve_subclass(VAD_EVENT_ASR) != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Robot Couldn't register subclass %s!\n",VAD_EVENT_ASR);return SWITCH_STATUS_TERM;}/* connect my internal structure to the blank pointer passed to me */*module_interface = switch_loadable_module_create_module_interface(pool, modname);if (!(xml = switch_xml_open_cfg(cf, &cfg, NULL))) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Open of %s failed\n", cf);}else {if ((settings = switch_xml_child(cfg, "settings"))) {for (param = switch_xml_child(settings, "param"); param; param = param->next) {char *var = (char *)switch_xml_attr_soft(param, "name");char *val = (char *)switch_xml_attr_soft(param, "value");if (!strcmp(var, "appid")) {globals.appid = val;}if (!strcmp(var, "appkey")) {globals.appkey = val;}}}switch_xml_free(xml);}switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Robot enabled,appid=%s,appkey=%s\n", globals.appid, globals.appkey);// 为此模块增加app，调用名称即为 vadSWITCH_ADD_APP(app_interface, "vad", "vad", "ai robot", robotasr_start_function, "[<ACTION ><VAD_VOICE_FRAMES> <VAD_SILINCE_FRAMES> <NS_LEVEL>]", SAF_NONE);/* indicate that the module should continue to be loaded */return SWITCH_STATUS_SUCCESS;}//Called when the system shuts downSWITCH_MODULE_SHUTDOWN_FUNCTION(mod_vadasr_shutdown){switch_event_free_subclass(VAD_EVENT_START);switch_event_free_subclass(VAD_EVENT_STOP);switch_event_free_subclass(VAD_EVENT_ASR);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "myapplication disabled\n");return SWITCH_STATUS_SUCCESS;}SWITCH_STANDARD_APP(robotasr_start_function){switch_media_bug_t *bug;switch_status_t status;switch_channel_t *channel;robot_session_info_t *robot_info;// switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_INFO, "robot_start_function start\n");if (session == NULL) {switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR,"FreeSWITCH is NULL! Please report to developers\n");return;}channel = switch_core_session_get_channel(session);if (channel == NULL) {switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR,"No channel for FreeSWITCH session! Please report this ""to the developers.\n");return;}/* Is this channel already set? */bug = (switch_media_bug_t *)switch_channel_get_private(channel, "_robot_");/* If yes */if (bug != NULL) {/* If we have a stop remove audio bug */if (strcasecmp(data, "stop") == 0) {// robot_info = (robot_session_info_t *)switch_channel_get_private(channel, "_robotinfo_");switch_channel_set_private(channel, "_robot_", NULL);// process_close(robot_info);switch_core_media_bug_remove(session, &bug);return;}/* We have already started */switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_WARNING,"Robot Cannot run 2 at once on the same channel!\n");return;}const char *action = NULL, *vadvoicems = NULL, *vadsilencems = NULL, *nslevel = NULL;char *argv[4] = { 0 };char *mycmd = NULL;if (!zstr(data)) {mycmd = switch_core_session_strdup(session, data);switch_separate_string(mycmd, ' ', argv, (sizeof(argv) / sizeof(argv[0])));}if (argv[0]) action = argv[0];if (argv[1]) vadvoicems = argv[1];if (argv[2]) vadsilencems = argv[2];if (argv[3]) nslevel = argv[3];if (!action || !vadvoicems || !vadsilencems || !nslevel) {switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "-ERR Missing Arguments\n");return;}switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_INFO,"action %s vadvoicems %s vadsilencems %s nslevel %s\n", action, vadvoicems, vadsilencems,nslevel);// 初始化变量，一定记得要 free掉robot_info = (robot_session_info_t *)malloc(sizeof(robot_session_info_t));if (robot_info == NULL) return;robot_info->session = session;strcpy(robot_info->uuid, switch_core_session_get_uuid(robot_info->session));robot_info->vadvoicems = atoi(vadvoicems);robot_info->vadsilencems = atoi(vadsilencems);robot_info->nslevel = atoi(nslevel);status = switch_core_media_bug_add(session, "vmd", NULL, robot_callback, robot_info, 0, SMBF_READ_REPLACE, &bug);if (status != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Robot Failure hooking to stream\n");return;}switch_channel_set_private(channel, "_robot_", bug);}SWITCH_END_EXTERN_Cstatic switch_bool_t process_close(robot_session_info_t *rh){switch_channel_t *channel;rh->uuid[0] = 0;rh->index = -1;if (NULL != rh->fwav) { drwav_uninit(rh->fwav); }if (NULL != rh->fvadwav) { drwav_uninit(rh->fvadwav); }destroy_queue(rh->vadqueue);channel = switch_core_session_get_channel(rh->session);switch_channel_set_private(channel, "_robot_", NULL);delete rh->asrsession;free(rh);return SWITCH_TRUE;}void handle_event(const std::string & message, void *arg){switch_event_t *event;switch_status_t status;switch_event_t *event_copy;switch_channel_t *channel;robot_session_info_t *robot_info = (robot_session_info_t *)arg;channel = switch_core_session_get_channel(robot_info->session);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "eventAsrText:%s\n", message.c_str());status = switch_event_create_subclass(&event, SWITCH_EVENT_CUSTOM, VAD_EVENT_ASR);if (status != SWITCH_STATUS_SUCCESS) { return; }switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Asr-Text", message.c_str());switch_channel_event_set_data(channel, event);switch_event_fire(&event);}void handle_message(const std::string & message, void *arg){char middleText[500] = { 0 };//printf(">>> %s\n", message.c_str());cJSON* cjson_test = NULL;cJSON* cjson_action = NULL;cJSON* cjson_code = NULL;cJSON* cjson_data = NULL;cJSON* cjson_desc = NULL;cJSON* cjson_sid = NULL;cJSON* cjson_text = NULL;cJSON* cjson_segid = NULL;cJSON* cjson_cn = NULL;cJSON* cjson_st = NULL;cJSON* cjson_rt = NULL;cJSON* cjson_rt_item = NULL;cJSON* cjson_cw_item = NULL;cJSON* cjson_w_item = NULL;cJSON* cjson_type = NULL;cJSON* cjson_ws = NULL;cJSON* cjson_cw = NULL;cJSON* cjson_w = NULL;asr_session_t *asr = (asr_session_t *)arg;cjson_test = cJSON_Parse(message.c_str());cjson_action = cJSON_GetObjectItem(cjson_test, "action");cjson_code = cJSON_GetObjectItem(cjson_test, "code");cjson_data = cJSON_GetObjectItem(cjson_test, "data");cjson_desc = cJSON_GetObjectItem(cjson_test, "desc");cjson_sid = cJSON_GetObjectItem(cjson_test, "sid");if (strcmp(cjson_action->valuestring, "result") == 0 && strcmp(cjson_code->valuestring, "0") == 0 && strlen(cjson_data->valuestring) > 0){cjson_text = cJSON_Parse(cjson_data->valuestring);cjson_segid = cJSON_GetObjectItem(cjson_text, "seg_id");cjson_cn = cJSON_GetObjectItem(cjson_text, "cn");cjson_st = cJSON_GetObjectItem(cjson_cn, "st");cjson_rt = cJSON_GetObjectItem(cjson_st, "rt");cjson_type = cJSON_GetObjectItem(cjson_st, "type");if (strcmp(cjson_type->valuestring, "0") == 0){int rt_array_size = cJSON_GetArraySize(cjson_rt);//printf("rt_array_size:%d", rt_array_size);for (int i = 0; i < rt_array_size; i){cjson_rt_item = cJSON_GetArrayItem(cjson_rt, i);cjson_ws = cJSON_GetObjectItem(cjson_rt_item, "ws");int ws_array_size = cJSON_GetArraySize(cjson_ws);for (int j = 0; j < ws_array_size; j){cjson_cw_item = cJSON_GetArrayItem(cjson_ws, j);cjson_cw = cJSON_GetObjectItem(cjson_cw_item, "cw");int cw_array_size = cJSON_GetArraySize(cjson_cw);for (int k = 0; k < cw_array_size; k){cjson_w_item = cJSON_GetArrayItem(cjson_cw, k);cjson_w = cJSON_GetObjectItem(cjson_w_item, "w");//printf("w:%s", cjson_w->valuestring);if (strlen(asr->asr_text) <= BFLEN - 20){strcat(asr->asr_text, cjson_w->valuestring);}else{switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "content too long!!!!!!\n");}}}}switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "asrFinalResult:%s\n", asr->asr_text);}else{int rt_array_size = cJSON_GetArraySize(cjson_rt);//printf("rt_array_size:%d", rt_array_size);for (int i = 0; i < rt_array_size; i){cjson_rt_item = cJSON_GetArrayItem(cjson_rt, i);cjson_ws = cJSON_GetObjectItem(cjson_rt_item, "ws");int ws_array_size = cJSON_GetArraySize(cjson_ws);for (int j = 0; j < ws_array_size; j){cjson_cw_item = cJSON_GetArrayItem(cjson_ws, j);cjson_cw = cJSON_GetObjectItem(cjson_cw_item, "cw");int cw_array_size = cJSON_GetArraySize(cjson_cw);for (int k = 0; k < cw_array_size; k){cjson_w_item = cJSON_GetArrayItem(cjson_cw, k);cjson_w = cJSON_GetObjectItem(cjson_w_item, "w");strcat(middleText, cjson_w->valuestring);}}}switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "asrTempResult:%s\n", middleText);}}else if (strcmp(cjson_action->valuestring, "error") == 0 ){switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "asrErrorInfo:%s\n", cjson_desc->valuestring);}}static switch_bool_t robot_callback(switch_media_bug_t *bug, void *user_data, switch_abc_type_t type){robot_session_info_t *robot_info;//switch_codec_t *read_codec;switch_frame_t *frame;int flag;drwav_data_format format;// = { 0 };int16_t len;int voiceflagcount;int silenceflagcount;int nslevel;switch_event_t *event;switch_status_t status;switch_event_t *event_copy;char *recorddir = NULL;switch_codec_implementation_t read_impl;switch_channel_t *channel;robot_info = (robot_session_info_t *)user_data;if (robot_info == NULL) { return SWITCH_FALSE; }channel = switch_core_session_get_channel(robot_info->session);voiceflagcount = robot_info->vadvoicems / 20;silenceflagcount = robot_info->vadsilencems / 20;nslevel = robot_info->nslevel;format.container = drwav_container_riff;format.format = DR_WAVE_FORMAT_PCM;format.channels = 1;format.sampleRate = (drwav_uint32)8000;format.bitsPerSample = 16;recorddir = switch_core_get_variable_dup("record_prefix");switch (type) {case SWITCH_ABC_TYPE_INIT:sprintf(robot_info->filename, "%s%s.wav", recorddir, robot_info->uuid);robot_info->fwav = drwav_open_file_write(robot_info->filename, &format);if (!robot_info->fwav) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "full record openfile error %s\n",robot_info->filename);}SetConsoleOutputCP(CP_UTF8); //解决windows控制台输出中文乱码robot_info->vadqueue = create_queue();robot_info->state = 0;robot_info->framecount = 0;robot_info->fvadwav = NULL;//初始话语音识别robot_info->asrsession = new asr_session_t();robot_info->asrsession->handle_message = handle_message;robot_info->asrsession->handle_event = handle_event;robot_info->asrsession->event_arg = robot_info;switch_core_session_get_read_impl(robot_info->session, &read_impl);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Read imp %u %u.\n", read_impl.samples_per_second, read_impl.number_of_channels);status = switch_resample_create(&robot_info->resampler, read_impl.actual_samples_per_second, 16000, 640, SWITCH_RESAMPLE_QUALITY, 1);if (status != SWITCH_STATUS_SUCCESS) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to allocate resampler\n");}break; case SWITCH_ABC_TYPE_READ_REPLACE:if (robot_info->uuid[0] == 0) break;//获取语音数据frame = switch_core_media_bug_get_read_replace_frame(bug);//静音检测flag = silk_VAD_Get((const short*)frame->data);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "vad result %d\n", flag);//静音标志缓冲len = get_queue_length(robot_info->vadqueue);if (len == VAD_HIS_LEN) { delete_queue(robot_info->vadqueue); }insert_queue(robot_info->vadqueue, flag, NULL, 0);//语音检测if (getvadflagcount(robot_info->vadqueue, voiceflagcount, 1) && robot_info->state == 0) {robot_info->state = 1;switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Speech Detected!!!\n");//开启语音识别init_asr((char*)globals.appid, (char*)globals.appkey, robot_info->asrsession);sprintf(robot_info->vadfilename, "%s%s_%d.wav", recorddir, robot_info->uuid, robot_info->framecount);robot_info->fvadwav = drwav_open_file_write(robot_info->vadfilename, &format);if (!robot_info->fvadwav) {switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "vad open file error %s\n",robot_info->vadfilename);strcpy(robot_info->vadfilename, "");//break;}status = switch_event_create_subclass(&event, SWITCH_EVENT_CUSTOM, VAD_EVENT_START);if (status != SWITCH_STATUS_SUCCESS) { break; }switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Vad-Status", "start");switch_channel_event_set_data(channel, event);/*if ((switch_event_dup(&event_copy, event)) != SWITCH_STATUS_SUCCESS) { break; }switch_core_session_queue_event(robot_info->session, &event);switch_event_fire(&event_copy);*/switch_event_fire(&event);}//静音检测if (getvadflagcount(robot_info->vadqueue, silenceflagcount, 0) && robot_info->state == 1) {robot_info->state = 0;switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE,"-----Silence Detected,Stop Recording!!! FileName:%s.-----\n", robot_info->vadfilename);if (robot_info->fvadwav) { drwav_uninit(robot_info->fvadwav); }robot_info->fvadwav = NULL;status = switch_event_create_subclass(&event, SWITCH_EVENT_CUSTOM, VAD_EVENT_STOP);if (status != SWITCH_STATUS_SUCCESS) { break; }switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Vad-Status", "stop");switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Vad-RecordFile", robot_info->vadfilename);switch_channel_event_set_data(channel, event);switch_event_fire(&event);//发送Asr结束标记send_end(robot_info->asrsession);}//录音-vad部分if (robot_info->fvadwav) { drwav_write_pcm_frames(robot_info->fvadwav, frame->samples, frame->data); }//完整部分if (robot_info->fwav){ drwav_write_pcm_frames(robot_info->fwav, frame->samples, frame->data); }robot_info->framecount;//检测到语音时发送语音数据包if(robot_info->state == 1){//上采样至16Kswitch_resample_process(robot_info->resampler, (int16_t *)frame->data, frame->datalen);send_data(robot_info->asrsession, (char*)robot_info->resampler->to, robot_info->resampler->to_len);}break;case SWITCH_ABC_TYPE_CLOSE:switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "SWITCH_ABC_TYPE_CLOSE\n");send_end(robot_info->asrsession);thrd_join(robot_info->asrsession->thr, NULL);thrd_detach(robot_info->asrsession->thr);mtx_destroy(&robot_info->asrsession->mutex);switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "the asr thread closed!!!\n");if (robot_info->resampler){switch_resample_destroy(&robot_info->resampler);}process_close(robot_info);break;default:break;}switch_safe_free(recorddir);return SWITCH_TRUE;}

完成的代码已经上传到github，大家可以自行下载阅读，GitHub - shanghaimoon888/mod_vadasr: This is FreeSwitch module that can do VAD and ASR with IFLYTEK websocket api. 如果有什么问题，也欢迎私信我交流沟通。