C++ PortAudio示例代码问题

我想制作一个吉他特效程序，所以我尝试运行PortaudioAPI中的示例代码pa_fuzz.c

它在paWDMKS主机api上工作。但是，当我使用Behringer ucg 102（无lantency）连接吉他时，主机api更改为paMME，我得到错误代码1和消息：“未定义外部错误”。 在visual studio输出控制台中，我还收到大量消息，如：

'ConsoleApplication4.exe' (Win32): Unloaded 'C:\Windows\SysWOW64\SHCore.dll'
'ConsoleApplication4.exe' (Win32): Unloaded 'C:\Windows\SysWOW64\shlwapi.dll'
'ConsoleApplication4.exe' (Win32): Unloaded 'C:\Windows\SysWOW64\shell32.dll'
'ConsoleApplication4.exe' (Win32): Unloaded 'C:\Windows\SysWOW64\dbgcore.dll'
'ConsoleApplication4.exe' (Win32): Unloaded 'C:\Program Files\Native Instruments\Rig Kontrol 3 Driver\asio\rig3asio32.dll'

下面是“PaHostErrorInfo”对象的代码段

以下是源代码：

#include <stdio.h>
#include <math.h>
#include "portaudio.h"
/*
** Note that many of the older ISA sound cards on PCs do NOT support
** full duplex audio (simultaneous record and playback).
** And some only support full duplex at lower sample rates.
*/
#define SAMPLE_RATE         (8000)
#define PA_SAMPLE_TYPE      paFloat32
#define FRAMES_PER_BUFFER   (64)

typedef float SAMPLE;

float CubicAmplifier( float input );
static int fuzzCallback( const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo* timeInfo,
                         PaStreamCallbackFlags statusFlags,
                         void *userData );

/* Non-linear amplifier with soft distortion curve. */
float CubicAmplifier( float input )
{
    float output, temp;
    if( input < 0.0 )
    {
        temp = input + 1.0f;
        output = (temp * temp * temp) - 1.0f;
    }
    else
    {
        temp = input - 1.0f;
        output = (temp * temp * temp) + 1.0f;
    }

    return output;
}
#define FUZZ(x) CubicAmplifier(CubicAmplifier(CubicAmplifier(CubicAmplifier(x))))

static int gNumNoInputs = 0;
/* This routine will be called by the PortAudio engine when audio is needed.
** It may be called at interrupt level on some machines so don't do anything
** that could mess up the system like calling malloc() or free().
*/
static int fuzzCallback( const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo* timeInfo,
                         PaStreamCallbackFlags statusFlags,
                         void *userData )
{
    SAMPLE *out = (SAMPLE*)outputBuffer;
    const SAMPLE *in = (const SAMPLE*)inputBuffer;
    unsigned int i;
    (void) timeInfo; /* Prevent unused variable warnings. */
    (void) statusFlags;
    (void) userData;

    if( inputBuffer == NULL )
    {
        for( i=0; i<framesPerBuffer; i++ )
        {
            *out++ = 0;  /* left - silent */
            *out++ = 0;  /* right - silent */
        }
        gNumNoInputs += 1;
    }
    else
    {
        for( i=0; i<framesPerBuffer; i++ )
        {
            *out++ = FUZZ(*in++);  /* left - distorted */
            *out++ = *in++;          /* right - clean */
        }
    }

    return paContinue;
}

/*******************************************************************/
int main(void);
int main(void)
{
    PaStreamParameters inputParameters, outputParameters;
    PaStream *stream;
    PaError err;
    PaDeviceInfo *info;
    err = Pa_Initialize();

    if( err != paNoError ) goto error;
    info = Pa_GetDeviceInfo(1);
    inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */
    if (inputParameters.device == paNoDevice) {
      fprintf(stderr,"Error: No default input device.\n");
      goto error;
    }
    inputParameters.channelCount = 2;       /* stereo input */
    inputParameters.sampleFormat = PA_SAMPLE_TYPE;
    inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency;
    inputParameters.hostApiSpecificStreamInfo = NULL;
    info = Pa_GetDeviceInfo(4);
    outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
    if (outputParameters.device == paNoDevice) {
      fprintf(stderr,"Error: No default output device.\n");
      goto error;
    }
    outputParameters.channelCount = 2;       /* stereo output */
    outputParameters.sampleFormat = PA_SAMPLE_TYPE;
    outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
    outputParameters.hostApiSpecificStreamInfo = NULL;

    err = Pa_OpenStream(
              &stream,
              &inputParameters,
              &outputParameters,
              SAMPLE_RATE,
              FRAMES_PER_BUFFER,
              0, /* paClipOff, */  /* we won't output out of range samples so don't bother clipping them */
              fuzzCallback,
              NULL );
    PaHostErrorInfo *err2 = Pa_GetLastHostErrorInfo();
    printf(err2->errorText);
    if( err != paNoError ) goto error;

    err = Pa_StartStream( stream );
    if( err != paNoError ) goto error;

    printf("Hit ENTER to stop program.\n");
    getchar();
    err = Pa_CloseStream( stream );
    if( err != paNoError ) goto error;

    printf("Finished. gNumNoInputs = %d\n", gNumNoInputs );
    Pa_Terminate();
    return 0;

error:
    Pa_Terminate();
    fprintf( stderr, "An error occured while using the portaudio stream\n" );
    fprintf( stderr, "Error number: %d\n", err );
    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
    return -1;
}

#包括
#包括
#包括“portaudio.h”
/*
**请注意，PC上的许多旧ISA声卡不支持
**全双工音频（同时录制和播放）。
**有些仅支持低采样率的全双工。
*/
#定义抽样率（8000）
#定义PAU样本类型PA32
#为每个缓冲区定义帧（64）
typedef浮样；
浮点数输入；
静态int fuzzCallback（const void*inputBuffer，void*outputBuffer，
未签名的长帧缓冲，
const Pastream CallbackTimeInfo*timeInfo，
PaStreamCallbackFlags状态标志，
void*用户数据）；
/*具有软失真曲线的非线性放大器*/
浮点输入（浮点输入）
{
浮子输出，温度；
如果（输入<0.0）
{
温度=输入+1.0f；
输出=（温度*温度*温度）-1.0f；
}
其他的
{
温度=输入-1.0f；
输出=（温度*温度*温度）+1.0f；
}
返回输出；
}
#定义FUZZ（x）CubicAmplifier（CubicAmplifier（x）））
静态int gNumNoInputs=0；
/*当需要音频时，PortAudio引擎将调用此例程。
**在某些机器上，它可能在中断级别被调用，所以不要做任何事情
**这可能会像调用malloc（）或free（）一样扰乱系统。
*/
静态int fuzzCallback（const void*inputBuffer，void*outputBuffer，
未签名的长帧缓冲，
const Pastream CallbackTimeInfo*timeInfo，
PaStreamCallbackFlags状态标志，
void*用户数据）
{
样本*输出=（样本*）输出缓冲区；
常量样本*输入=（常量样本*）输入缓冲区；
无符号整数i；
（void）timeInfo；/*防止未使用的变量警告*/
（作废）状态标志；
（作废）用户数据；
如果（inputBuffer==NULL）
{
对于（i=0；idefaultLowOutputLatency；
outputParameters.hostApiSpecificStreamInfo=NULL；
err=Pa_OpenStream(
&溪流，
&输入参数，
&输出参数，
抽样率，
每个缓冲区的帧数，
0、/*paClipOff、*/*我们不会输出超出范围的样本，因此不必费心剪裁它们*/
回拨,，
无效）；
PaHostErrorInfo*err2=Pa_GetLastHostErrorInfo（）；
printf（err2->errertext）；
如果（err！=paNoError）转到错误；
err=Pa_开始流（流）；
如果（err！=paNoError）转到错误；
printf（“按回车键停止程序。\n”）；
getchar（）；
err=Pa_CloseStream（流）；
如果（err！=paNoError）转到错误；
printf（“Finished.gNumNoInputs=%d\n”，gNumNoInputs）；
Pa_Terminate（）；
返回0；
错误：
Pa_Terminate（）；
fprintf（stderr，“使用portaudio流时出错\n”）；
fprintf（标准，“错误号：%d\n”，错误）；
fprintf（标准，“错误消息：%s\n”，Pa_GetErrorText（err））；
返回-1；
}

---

你们能看看是什么问题吗？我已经安装了BEHRINGER USB WDM AUDIO 2.8.40驱动程序。（我使用这个USB接口和吉他装备）

我切换到另一个USB端口，它工作了。我想这是portaudio的错误。我将在这里留下这个答案。现在我有另一个问题。延迟：（用延迟弹吉他太令人沮丧了。 延迟的原因是什么？我正在将我的吉他与behringer ucg102（以无延迟而闻名）连接。同样，我将它与吉他装备一起使用，我的延迟接近0。这是portaudio库的问题吗？此代码来自他们的示例“pa_fuzz.c”

---

新建编辑：通过选择所需的输入和输出设备修复延迟问题。

请不要发布文本图像。按原样将文本复制并粘贴到帖子中。用于代码和错误。dll卸载发生在错误消息之前还是之后？卸载发生在Pa_Terminate（）时；调用时，我将发布代码。我认为这不是问题所在

#include <stdio.h>
#include <math.h>
#include "portaudio.h"
/*
** Note that many of the older ISA sound cards on PCs do NOT support
** full duplex audio (simultaneous record and playback).
** And some only support full duplex at lower sample rates.
*/
#define SAMPLE_RATE         (8000)
#define PA_SAMPLE_TYPE      paFloat32
#define FRAMES_PER_BUFFER   (64)

typedef float SAMPLE;

float CubicAmplifier( float input );
static int fuzzCallback( const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo* timeInfo,
                         PaStreamCallbackFlags statusFlags,
                         void *userData );

/* Non-linear amplifier with soft distortion curve. */
float CubicAmplifier( float input )
{
    float output, temp;
    if( input < 0.0 )
    {
        temp = input + 1.0f;
        output = (temp * temp * temp) - 1.0f;
    }
    else
    {
        temp = input - 1.0f;
        output = (temp * temp * temp) + 1.0f;
    }

    return output;
}
#define FUZZ(x) CubicAmplifier(CubicAmplifier(CubicAmplifier(CubicAmplifier(x))))

static int gNumNoInputs = 0;
/* This routine will be called by the PortAudio engine when audio is needed.
** It may be called at interrupt level on some machines so don't do anything
** that could mess up the system like calling malloc() or free().
*/
static int fuzzCallback( const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo* timeInfo,
                         PaStreamCallbackFlags statusFlags,
                         void *userData )
{
    SAMPLE *out = (SAMPLE*)outputBuffer;
    const SAMPLE *in = (const SAMPLE*)inputBuffer;
    unsigned int i;
    (void) timeInfo; /* Prevent unused variable warnings. */
    (void) statusFlags;
    (void) userData;

    if( inputBuffer == NULL )
    {
        for( i=0; i<framesPerBuffer; i++ )
        {
            *out++ = 0;  /* left - silent */
            *out++ = 0;  /* right - silent */
        }
        gNumNoInputs += 1;
    }
    else
    {
        for( i=0; i<framesPerBuffer; i++ )
        {
            *out++ = FUZZ(*in++);  /* left - distorted */
            *out++ = *in++;          /* right - clean */
        }
    }

    return paContinue;
}

/*******************************************************************/
int main(void);
int main(void)
{
    PaStreamParameters inputParameters, outputParameters;
    PaStream *stream;
    PaError err;
    PaDeviceInfo *info;
    err = Pa_Initialize();

    if( err != paNoError ) goto error;
    info = Pa_GetDeviceInfo(1);
    inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */
    if (inputParameters.device == paNoDevice) {
      fprintf(stderr,"Error: No default input device.\n");
      goto error;
    }
    inputParameters.channelCount = 2;       /* stereo input */
    inputParameters.sampleFormat = PA_SAMPLE_TYPE;
    inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency;
    inputParameters.hostApiSpecificStreamInfo = NULL;
    info = Pa_GetDeviceInfo(4);
    outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
    if (outputParameters.device == paNoDevice) {
      fprintf(stderr,"Error: No default output device.\n");
      goto error;
    }
    outputParameters.channelCount = 2;       /* stereo output */
    outputParameters.sampleFormat = PA_SAMPLE_TYPE;
    outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
    outputParameters.hostApiSpecificStreamInfo = NULL;

    err = Pa_OpenStream(
              &stream,
              &inputParameters,
              &outputParameters,
              SAMPLE_RATE,
              FRAMES_PER_BUFFER,
              0, /* paClipOff, */  /* we won't output out of range samples so don't bother clipping them */
              fuzzCallback,
              NULL );
    PaHostErrorInfo *err2 = Pa_GetLastHostErrorInfo();
    printf(err2->errorText);
    if( err != paNoError ) goto error;

    err = Pa_StartStream( stream );
    if( err != paNoError ) goto error;

    printf("Hit ENTER to stop program.\n");
    getchar();
    err = Pa_CloseStream( stream );
    if( err != paNoError ) goto error;

    printf("Finished. gNumNoInputs = %d\n", gNumNoInputs );
    Pa_Terminate();
    return 0;

error:
    Pa_Terminate();
    fprintf( stderr, "An error occured while using the portaudio stream\n" );
    fprintf( stderr, "Error number: %d\n", err );
    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
    return -1;
}