1 前言

2 下载编译

具体构建过程参照官方文档：https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/PulseAudioFromGit/

2.1 下载代码

git clone git://anongit.freedesktop.org/pulseaudio/pulseaudio

2.2 编译

编译过程遇到太多错误了，见问题集，主要是依赖没有安装

meson build
ninja -C build
sudo ninja -C build install
sudo ldconfig

3 demo实践

PulseAudio对外api非常简单，基本就是和io操作一样：read，write，open…
pa_simple_new：创建到服务器的新连接。
pa_simple_read：从服务器读取一些数据。（阻塞）
pa_simple_write：向服务器写入一些数据。
pa_simple_free：关闭并释放与服务器的连接。
pa_simple_drain：等待守护进程播放所有已写入的数据。
pa_simple_flush：刷新播放或记录缓冲区。
pa_simple_get_latency：返回播放或记录延迟。
下面是官方demo：

/***This file is part of PulseAudio.PulseAudio is free software; you can redistribute it and/or modifyit under the terms of the GNU Lesser General Public License as publishedby the Free Software Foundation; either version 2.1 of the License,or (at your option) any later version.PulseAudio is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNUGeneral Public License for more details.You should have received a copy of the GNU Lesser General Public Licensealong with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/#ifdef HAVE_CONFIG_H
#include <config.h>
#endif#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>#include <pulse/simple.h>
#include <pulse/error.h>#define BUFSIZE 1024int main(int argc, char*argv[]) {/* The Sample format to use */static const pa_sample_spec ss = {.format = PA_SAMPLE_S16LE,.rate = 44100,.channels = 2};pa_simple *s = NULL;int ret = 1;int error;/* replace STDIN with the specified file if needed */if (argc > 1) {int fd;if ((fd = open(argv[1], O_RDONLY)) < 0) {fprintf(stderr, __FILE__": open() failed: %s\n", strerror(errno));goto finish;}if (dup2(fd, STDIN_FILENO) < 0) {fprintf(stderr, __FILE__": dup2() failed: %s\n", strerror(errno));goto finish;}close(fd);}/* Create a new playback stream */if (!(s = pa_simple_new(NULL, argv[0], PA_STREAM_PLAYBACK, NULL, "playback", &ss, NULL, NULL, &error))) {fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));goto finish;}for (;;) {uint8_t buf[BUFSIZE];ssize_t r;#if 0pa_usec_t latency;if ((latency = pa_simple_get_latency(s, &error)) == (pa_usec_t) -1) {fprintf(stderr, __FILE__": pa_simple_get_latency() failed: %s\n", pa_strerror(error));goto finish;}fprintf(stderr, "%0.0f usec    \r", (float)latency);
#endif/* Read some data ... */if ((r = read(STDIN_FILENO, buf, sizeof(buf))) <= 0) {if (r == 0) /* EOF */break;fprintf(stderr, __FILE__": read() failed: %s\n", strerror(errno));goto finish;}/* ... and play it */if (pa_simple_write(s, buf, (size_t) r, &error) < 0) {fprintf(stderr, __FILE__": pa_simple_write() failed: %s\n", pa_strerror(error));goto finish;}}/* Make sure that every single sample was played */if (pa_simple_drain(s, &error) < 0) {fprintf(stderr, __FILE__": pa_simple_drain() failed: %s\n", pa_strerror(error));goto finish;}ret = 0;finish:if (s)pa_simple_free(s);return ret;
}

4 问题集

4.1 tdb库缺失

问题描述

meson.build:595:2: ERROR: Dependency “tdb” not found, tried pkgconfig and cmake

解决方案：
下载最新版本tdb编译安装。
下载地址：https://www.samba.org/ftp/tdb/

tar -xvf tdb-1.4.5.tar.gz
cd tdb-1.4.5
./configure && make && make install

4.2 sndfile库缺失

meson.build:653:0: ERROR: Dependency “sndfile” not found, tried pkgconfig and cmake

解决方案：
下载最新版本tdb编译安装。
下载地址：http://www.mega-nerd.com/libsndfile/

tar -xvf libsndfile-1.0.28.tar.gz
cd libsndfile-1.0.28
./configure && make && make install

4.3 xtst库缺失

meson.build:686:2: ERROR: Dependency “xtst” not found, tried pkgconfig and cmake

解决方案：

sudo apt-get install libxtst-dev

4.4 check库缺失

meson.build:792:0: ERROR: Dependency “check” not found, tried pkgconfig and cmake