重编译 microsip 和 pjsip 支持 mp3 录音

前言

使用 MicroSip 源码编译后，在录音配置界面虽然有 mp3 格式选项，但是实际录音后不会生成mp3 文件夹，而选择wav格式却可以正常生成 wav 文件。

经测试发现需要重新编译 pjsip 工程，加入 mp3 编码才可以。

操作步骤大概如下：

1.pjmedia 项目加入如下 pjsip2.12.1版本 third_party/mp3 文件夹中的3个文件

2.在pjmedia.h 文件中包含刚引入的 mp3_port.h

//...
#include <pjmedia/wav_port.h>
#include <pjmedia/wave.h>
#include <pjmedia/wsola.h>
//增加mp3编码 [2022-7-28 By Pafey]
#include "../../third_party/mp3/mp3_port.h"
//...

3.修改 pjsua_lib 项目的 pjsua_aud.c 文件中的 pjsua_recorder_create 函数

在录音格式判断那里，源码只有处理wav格式，需要多加个mp3格式进去。

需要注意的是第七个参数 pjmedia_mp3_encoder_option param_option;

主要是跟mp3文件的质量有关：

vbr：指定是否应使用可变比特率。可变比特率通常会产生更好的质量，但代价可能是文件更大。

bit_rate：目标比特率，单位为bps。如果启用了VBR，此设置指定请求的平均比特率，并将使编码器忽略质量设置。对于CBR，这指定了实际的比特率，如果该选项为零，它将被设置为采样率乘以通道数量。

quality：编码质量，0-9，以0为最高质量。对于VBR，质量设置只在bit_rate设置为零时生效。

关键代码如下：

    if (file_format == FMT_WAV) {status = pjmedia_wav_writer_port_create(pool, path,pjsua_var.media_cfg.clock_rate,pjsua_var.mconf_cfg.channel_count,pjsua_var.mconf_cfg.samples_per_frame,pjsua_var.mconf_cfg.bits_per_sample,options, 0, &port);}else if (file_format == FMT_MP3){//增加mp3编码 [2022-7-28 By Pafey]pjmedia_mp3_encoder_option param_option;param_option.vbr = PJ_TRUE;param_option.bit_rate = 0;param_option.quality = 6;//0-9,0质量最高，vbr启用时，仅bit_rate为0时有效status = pjmedia_mp3_writer_port_create(pool, path,pjsua_var.media_cfg.clock_rate,pjsua_var.mconf_cfg.channel_count,pjsua_var.mconf_cfg.samples_per_frame,pjsua_var.mconf_cfg.bits_per_sample,&param_option, &port);} else {PJ_UNUSED_ARG(enc_param);port = NULL;status = PJ_ENOTSUP;}

pjsua_recorder_create 函数完整代码：

/** Create a file recorder, and automatically connect this recorder to* the conference bridge.*/
PJ_DEF(pj_status_t) pjsua_recorder_create( const pj_str_t *filename,unsigned enc_type,void *enc_param,pj_ssize_t max_size,unsigned options,pjsua_recorder_id *p_id)
{enum Format{FMT_UNKNOWN,FMT_WAV,FMT_MP3,};unsigned slot, file_id;char path[PJ_MAXPATH];pj_str_t ext;int file_format;pj_pool_t *pool = NULL;pjmedia_port *port;pj_status_t status = PJ_SUCCESS;/* Filename must present */PJ_ASSERT_RETURN(filename != NULL, PJ_EINVAL);/* Don't support max_size at present */PJ_ASSERT_RETURN(max_size == 0 || max_size == -1, PJ_EINVAL);/* Don't support encoding type at present */PJ_ASSERT_RETURN(enc_type == 0, PJ_EINVAL);if (filename->slen >= PJ_MAXPATH)return PJ_ENAMETOOLONG;if (filename->slen < 4)return PJ_EINVALIDOP;PJ_LOG(4,(THIS_FILE, "Creating recorder %.*s..",(int)filename->slen, filename->ptr));pj_log_push_indent();if (pjsua_var.rec_cnt >= PJ_ARRAY_SIZE(pjsua_var.recorder)) {pj_log_pop_indent();return PJ_ETOOMANY;}/* Determine the file format */ext.ptr = filename->ptr + filename->slen - 4;ext.slen = 4;if (pj_stricmp2(&ext, ".wav") == 0)file_format = FMT_WAV;else if (pj_stricmp2(&ext, ".mp3") == 0)file_format = FMT_MP3;else {PJ_LOG(1,(THIS_FILE, "pjsua_recorder_create() error: unable to ""determine file format for %.*s",(int)filename->slen, filename->ptr));pj_log_pop_indent();return PJ_ENOTSUP;}PJSUA_LOCK();for (file_id=0; file_id<PJ_ARRAY_SIZE(pjsua_var.recorder); ++file_id) {if (pjsua_var.recorder[file_id].port == NULL)break;}if (file_id == PJ_ARRAY_SIZE(pjsua_var.recorder)) {/* This is unexpected */pj_assert(0);status = PJ_EBUG;goto on_return;}pj_memcpy(path, filename->ptr, filename->slen);path[filename->slen] = '\0';pool = pjsua_pool_create(get_basename(path, (unsigned)filename->slen), 1000, 1000);if (!pool) {status = PJ_ENOMEM;goto on_return;}if (file_format == FMT_WAV) {status = pjmedia_wav_writer_port_create(pool, path,pjsua_var.media_cfg.clock_rate,pjsua_var.mconf_cfg.channel_count,pjsua_var.mconf_cfg.samples_per_frame,pjsua_var.mconf_cfg.bits_per_sample,options, 0, &port);}else if (file_format == FMT_MP3){pjmedia_mp3_encoder_option param_option;param_option.vbr = PJ_TRUE;param_option.bit_rate = 0;param_option.quality = 6;//0-9,0质量最高，vbr启用时，仅bit_rate为0时有效//增加mp3编码 [2022-7-28 By Pafey]status = pjmedia_mp3_writer_port_create(pool, path,pjsua_var.media_cfg.clock_rate,pjsua_var.mconf_cfg.channel_count,pjsua_var.mconf_cfg.samples_per_frame,pjsua_var.mconf_cfg.bits_per_sample,&param_option, &port);} else {PJ_UNUSED_ARG(enc_param);port = NULL;status = PJ_ENOTSUP;}if (status != PJ_SUCCESS) {pjsua_perror(THIS_FILE, "Unable to open file for recording", status);goto on_return;}status = pjmedia_conf_add_port(pjsua_var.mconf, pool,port, filename, &slot);if (status != PJ_SUCCESS) {pjmedia_port_destroy(port);goto on_return;}pjsua_var.recorder[file_id].port = port;pjsua_var.recorder[file_id].slot = slot;pjsua_var.recorder[file_id].pool = pool;if (p_id) *p_id = file_id;++pjsua_var.rec_cnt;PJSUA_UNLOCK();PJ_LOG(4,(THIS_FILE, "Recorder created, id=%d, slot=%d", file_id, slot));pj_log_pop_indent();return PJ_SUCCESS;on_return:PJSUA_UNLOCK();if (pool) pj_pool_release(pool);pj_log_pop_indent();return status;
}

4.编译 libpjproject 项目

生成 libpjproject-i386-Win32-vc14-Release.lib 库文件。就可以被sip软电话引入使用了。我这里用的是MicroSip，在配置界面录音选择 mp3

打个电话就可以生成mp3文件了，搞了一天终于完美收工。

问题记录

pjsip编译完成后，引入库文件依然不能生成mp3文件，后面调试进

pjmedia_mp3_writer_port_create -> init_blade_dll

这个初始化需要加载 LAME_ENC.DLL
去 microsip 安装文件夹内拷一个出来放到自己编译的microsip exe所在路径就成功了
文末放了下载地址

#include <windows.h>
#define DLL_NAME    PJ_T("LAME_ENC.DLL")/** Load BladeEncoder DLL.*/
static pj_status_t init_blade_dll(void)
{if (BladeDLL.refCount == 0) {#define GET_PROC(type, name)  \BladeDLL.name = (type)GetProcAddress(BladeDLL.hModule, PJ_T(#name)); \if (BladeDLL.name == NULL) { \PJ_LOG(1,(THIS_FILE, "Unable to find %s in %s", #name, DLL_NAME)); \return PJ_RETURN_OS_ERROR(GetLastError()); \}BE_VERSION beVersion;BladeDLL.hModule = (void*)LoadLibrary(DLL_NAME);if (BladeDLL.hModule == NULL) {pj_status_t status = PJ_RETURN_OS_ERROR(GetLastError());char errmsg[PJ_ERR_MSG_SIZE];pj_strerror(status, errmsg, sizeof(errmsg));PJ_LOG(1,(THIS_FILE, "Unable to load %s: %s", DLL_NAME, errmsg));return status;}
//...}

编译的库文件

库文件和编码dll下载地址