linux下使用PulseAudio获取扬声器的音量和是否静音（C++）

一、source device和sink device的概念

source device：source可以理解为源泉，表示声音的源，即声音产生的地方

sink device：sink可以理解为水槽，表示声音的接受一方

那么就可以理解为声音从source device流出，流到sink device里面

二、获取sink device的音量和是不是静音

#include <iostream>
#include <memory>
#include <vector>
#include <string>#include <pulse/error.h>
#include <pulse/pulseaudio.h>
#include <pulse/simple.h>enum class PulseAudioContextState {PULSE_CONTEXT_INITIALIZING,PULSE_CONTEXT_READY,PULSE_CONTEXT_FINISHED
};struct SinkInfo {pa_cvolume volume;  //音量int mute;           //是不是静音，1表示静音，0表示非静音
};void DisconnectPulseAudioContext(pa_mainloop** pa_ml, pa_context** pa_ctx) {assert(pa_ml);assert(pa_ctx);if (*pa_ctx) {pa_context_set_state_callback(*pa_ctx, NULL, NULL);pa_context_disconnect(*pa_ctx);pa_context_unref(*pa_ctx);}if (*pa_ml) pa_mainloop_free(*pa_ml);*pa_ml = NULL;*pa_ctx = NULL;
}void PaContextStateCallback(pa_context* pa_ctx, void* userdata) {PulseAudioContextState* context_state = (PulseAudioContextState*)userdata;switch (pa_context_get_state(pa_ctx)) {case PA_CONTEXT_FAILED:case PA_CONTEXT_TERMINATED:*context_state = PulseAudioContextState::PULSE_CONTEXT_FINISHED;break;case PA_CONTEXT_READY:*context_state = PulseAudioContextState::PULSE_CONTEXT_READY;break;default:break;}
}int ConnectPulseAudioContext(pa_mainloop** pa_ml, pa_context** pa_ctx,const char* server, const char* description) {int ret;*pa_ml = NULL;*pa_ml = pa_mainloop_new();if (!(*pa_ml)) { return -1; }pa_mainloop_api* pa_mlapi = NULL;pa_mlapi = pa_mainloop_get_api(*pa_ml);if (!pa_mlapi) { return -1; }*pa_ctx = NULL;*pa_ctx = pa_context_new(pa_mlapi, description);if (!(*pa_ctx)) { return -1; }PulseAudioContextState context_state =PulseAudioContextState::PULSE_CONTEXT_INITIALIZING;pa_context_set_state_callback(*pa_ctx, PaContextStateCallback,&context_state);if (pa_context_connect(*pa_ctx, server, PA_CONTEXT_NOFLAGS, NULL) < 0) {return -1;}while (context_state == PulseAudioContextState::PULSE_CONTEXT_INITIALIZING)pa_mainloop_iterate(*pa_ml, 1, NULL);if (context_state == PulseAudioContextState::PULSE_CONTEXT_FINISHED) {return -1;}return 0;
}void PulseAudioSinkDeviceInfoCallback(pa_context* c, const pa_sink_info* info,int eol, void* userdata) {SinkInfo* sink_info = (SinkInfo*)userdata;if (info != nullptr) {sink_info->volume = info->volume;sink_info->mute = info->mute;for (int i = 0; i < info->volume.channels; ++i) {// 打印各个声道的音量std::cout << (info->volume.values[i]*1.0 / info->base_volume)*100 << std::endl;}std::cout << "mute:" << info->mute << std::endl;}
}SinkInfo GetPulseAudioSinkDeviceInfo(const std::string& sink_device) {SinkInfo sink_info;pa_mainloop* pa_ml = nullptr;pa_operation* pa_op = nullptr;pa_context* pa_ctx = nullptr;ConnectPulseAudioContext(&pa_ml, &pa_ctx, nullptr, "audio recorder");std::shared_ptr<void> raii_connect(nullptr, [&](void*) {DisconnectPulseAudioContext(&pa_ml, &pa_ctx);});if (pa_ctx == nullptr) { return sink_info; }pa_op = pa_context_get_sink_info_by_name(pa_ctx, sink_device.c_str(),PulseAudioSinkDeviceInfoCallback,&sink_info);while (pa_operation_get_state(pa_op) == PA_OPERATION_RUNNING) {pa_mainloop_iterate(pa_ml, 1, nullptr);}pa_operation_unref(pa_op);return sink_info;
}void PulseAudioSinkDeviceCallback(pa_context* c, const pa_sink_info* dev,int eol, void* userdata) {std::vector<std::string>* devices = (std::vector<std::string>*)userdata;if (dev != nullptr) { devices->push_back(dev->name); }
}std::vector<std::string> GetPulseAudioSinkDevice() {std::vector<std::string> sink_devices_vec;pa_mainloop* pa_ml = nullptr;pa_operation* pa_op = nullptr;pa_context* pa_ctx = nullptr;ConnectPulseAudioContext(&pa_ml, &pa_ctx, nullptr, "audio recorder");std::shared_ptr<void> raii_connect(nullptr, [&](void*) {DisconnectPulseAudioContext(&pa_ml, &pa_ctx);});if (pa_ctx == nullptr) { return sink_devices_vec; }pa_op = pa_context_get_sink_info_list(pa_ctx, PulseAudioSinkDeviceCallback,&sink_devices_vec);while (pa_operation_get_state(pa_op) == PA_OPERATION_RUNNING) {pa_mainloop_iterate(pa_ml, 1, nullptr);}pa_operation_unref(pa_op);return sink_devices_vec;
}int main(void) {std::vector<std::string> sink_devices_vec = GetPulseAudioSinkDevice();SinkInfo sink_info = GetPulseAudioSinkDeviceInfo(sink_devices_vec[0]);return 0;
}

编译：g++ main.cpp -lpulse -lpulse-simple -o audio_test

运行：./audio_test

linux下使用PulseAudio获取扬声器的音量和是否静音（C++）相关推荐

Linux下通过v4l2获取视频设备名、支持的编解码及视频size列表实现
早些时候给出了在Windows下通过dshow获取视频设备信息的实现,包括获取视频设备名.获取每种视频设备支持的编解码格式列表.每种编解码格式支持的video size列表,见:https://blo ...
java 收集系统资源_方法：Linux 下用JAVA获取CPU、内存、磁盘的系统资源信息
CPU使用率: InputStream is = null; InputStreamReader isr = null; BufferedReader brStat = null; StringTok ...
有关Linux下request.getRealPath(/)获取路径的问题
request.getRealPath("/") 在window获取的是服务器的根目录,结尾包含分隔符, 如E:\apache-tomcat-6.0.29-bak\apache-t ...
Linux下百度云盘报获取bdstoken失败
在用linux下百度云盘工具(bcloud),登录时,报获取bdstoken失败. 在网上搜了一下,解决办法如下. 找到auth.py文件 locate auth.py |grep bcloud 结果 ...
sigar如何获取linux的buffer内存,Linux 下使用Sigar 获取内存信息
上一篇文章介绍了linux下的sigar 库,并使用sigar 库来获取cpu 使用率,本文在这里介绍一下如何使用sigar 库获取内存信息. 和cpu 一样,sigar中有和内存相关的结构体siga ...
linux c 读取摄像头,Linux下onvif客户端获取ipc摄像头获取能力：GetCapabilities
getcapabilities:获取能力,主要目的获取设备能力信息(获取媒体服务地址) 鉴权:但是在调用获取设备能力之前是需要鉴权的.onvif协议规定,部分接口需要鉴权,部分接口不需要鉴权,在调用需 ...
linux dmidecode命令,linux下dmidecode命令获取硬件信息
dmidecode在 Linux 系统下获取有关硬件方面的信息.dmidecode 遵循 SMBIOS/DMI 标准,以一种可读的方式dump出机器的DMI(Desktop Management In ...
linux下从git获取有权限的代码,linux下从源代码安装git
之所以有这样的需求,是因为部分预安装的git版本太低,很多功能没有并且安全性存在问题. 比如git submodule add xxx@host:yyy.git必须在父repo的root目录安装,而新 ...
获取linux命令硬盘信息,Linux 下使用命令获取硬盘信息
本文主要是一些和硬盘相关的命令,包括如何查看硬盘的型号,容量,还有硬盘上的分区情况,来详细了解本机硬盘的状态. hdparm 如果想要在 Linux 下查看硬盘信息,可以使用命令 hdparm .这个 ...

linux下使用PulseAudio获取扬声器的音量和是否静音（C++）

linux下使用PulseAudio获取扬声器的音量和是否静音（C++）相关推荐

最新文章

热门文章