Hello, I've been looking for a way to play and record audio on a Linux (preferably Ubuntu) system. I'm currently working on a front-end to a voice recognition toolkit that'll automate a few steps required to adapt a voice model for PocketSphinx and Julius.

欢迎提出音频输入/输出替代方法的建议，并修复如下所示的错误。

这是我目前用来播放 .WAV 文件的代码:

void Engine::sayText ( const string OutputText ) {
    string audioUri = "temp.wav";
    string requestUri = this->getRequestUri( OPENMARY_PROCESS , OutputText.c_str( ) );
    int error , audioStream;
    pa_simple *pulseConnection;
    pa_sample_spec simpleSpecs;
    simpleSpecs.format = PA_SAMPLE_S16LE;
    simpleSpecs.rate = 44100;
    simpleSpecs.channels = 2;

    eprintf( E_MESSAGE , "Generating audio for '%s' from '%s'..." , OutputText.c_str( ) , requestUri.c_str( ) );
    FILE* audio = this->getHttpFile( requestUri , audioUri );
    fclose(audio);
    eprintf( E_MESSAGE , "Generated audio.");

    if ( ( audioStream = open( audioUri.c_str( ) , O_RDONLY ) ) < 0 ) {
        fprintf( stderr , __FILE__": open() failed: %s\n" , strerror( errno ) );
        goto finish;
    }

    if ( dup2( audioStream , STDIN_FILENO ) < 0 ) {
        fprintf( stderr , __FILE__": dup2() failed: %s\n" , strerror( errno ) );
        goto finish;
    }

    close( audioStream );

    pulseConnection = pa_simple_new( NULL , "AudioPush" , PA_STREAM_PLAYBACK , NULL , "openMary C++" , &simpleSpecs , NULL , NULL , &error );

    for (int i = 0;;i++ ) {
        const int bufferSize = 1024;
        uint8_t audioBuffer[bufferSize];
        ssize_t r;
        eprintf( E_MESSAGE , "Buffering %d..",i);
        /* Read some data ... */
        if ( ( r = read( STDIN_FILENO , audioBuffer , sizeof (audioBuffer ) ) ) <= 0 ) {
            if ( r == 0 ) /* EOF */
                break;

            eprintf( E_ERROR , __FILE__": read() failed: %s\n" , strerror( errno ) );
    if ( pulseConnection )
        pa_simple_free( pulseConnection );

        }

        /* ... and play it */
        if ( pa_simple_write( pulseConnection , audioBuffer , ( size_t ) r , &error ) < 0 ) {
            fprintf( stderr , __FILE__": pa_simple_write() failed: %s\n" , pa_strerror( error ) );
    if ( pulseConnection )
        pa_simple_free( pulseConnection );

        }

        usleep(2);

    }
    /* Make sure that every single sample was played */
    if ( pa_simple_drain( pulseConnection , &error ) < 0 ) {
        fprintf( stderr , __FILE__": pa_simple_drain() failed: %s\n" , pa_strerror( error ) );
    if ( pulseConnection )
        pa_simple_free( pulseConnection );
    }    
}

注意:如果你想要这个文件的其余代码，你可以下载它here直接从 Launchpad。

更新:我尝试使用 GStreamermm，但这行不通:

    Glib::RefPtr<Pipeline> pipeline;
    Glib::RefPtr<Element> sink, filter, source;
    Glib::RefPtr<Gio::File> audioSrc = Gio::File::create_for_path(uri);

    pipeline = Pipeline::create("audio-playback");
    source = ElementFactory::create_element("alsasrc","source");
    filter = ElementFactory::create_element("identity","filter");
    sink = ElementFactory::create_element("alsasink","sink");
    //sink->get_property("file",audioSrc);
    if (!source || !filter || !sink){
        showErrorDialog("Houston!","We got a problem.");
        return;
    }
    pipeline->add(source)->add(filter)->add(sink);
    source->link(sink);

    pipeline->set_state(Gst::STATE_PLAYING);
    showInformation("Close this to stop recording");
    pipeline->set_state(Gst::STATE_PAUSED);

最佳答案

The "Hello World" application in the GStreamer documentation显示如何播放 Ogg/Vorbis 文件。要使它适用于 WAV 文件，您只需将“oggdemux”替换为“wavparse”并将“vorbisdec”替换为“identity”(身份插件不执行任何操作——它只是一个占位符)。

为 GStreamer 安装开发支持(在 Ubuntu 上)...

sudo apt-get install libgstreamer0.10-dev

您需要在 gcc 命令行上执行以下操作才能启用 GStreamer 库...

$(pkg-config --cflags --libs gstreamer-0.10)

顺便说一句，您可能会发现在编写代码之前使用“gst-launch”对 GStreamer 管道进行原型(prototype)设计很有用。

## recording
gst-launch-0.10 autoaudiosrc ! wavenc ! filesink location=temp.wav

## playback
gst-launch-0.10 filesrc location=temp.wav ! wavparse ! autoaudiosink

GStreamer 的一项可能对语音识别有用的功能是可以轻松地将音频质量过滤器插入管道中——例如，这样您就可以减少录音中可能存在的噪音。指向 GStreamer“好”插件列表的指针是 here .

同样有趣的是，“PocketSphinx”(似乎与您的项目有关)已经集成了一些 GStreamer。参见 Using PocketSphinx with GStreamer and Python

关于c++ - 你如何在 Linux 上用 C++ 播放或录制音频(到 .WAV)？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4934074/