我想制作一个吉他效果程序,所以我试图从PORTAUDIO API运行示例代码pa_fuzz.c。
它适用于paWDMKS主机api。但是当我使用Behringer ucg 102连接吉他时(没有朗读),主机api变为paMME,我得到errorCode 1和消息:“未定义的外部错误”。 同样在visual studio输出控制台中,我收到了大量的消息,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'
以下是“PaHostErrorInfo”对象的代码段;
PaHostErrorInfo *err2 = Pa_GetLastHostErrorInfo();
printf(err2->errorText);
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;
}
你们可以看一下可能出现的问题吗?我安装了BEHRINGER USB WDM AUDIO 2.8.40驱动程序。 (我使用这个带吉他装置的usb接口)
答案 0 :(得分:1)
我切换到另一个USB端口,它工作正常。我认为这是portaudio的一个错误。我会在这里留下这个答案。现在我有另一个问题。 LATENCY :(用延迟来弹吉他是如此令人沮丧。 造成这种延迟的原因是什么?我将我的吉他与behringer ucg102连接起来(因无延迟而闻名)。再次,我使用它与Guitar Rig,我有接近0延迟。这是portaudio库的问题吗?此代码来自他们的示例&#34; pa_fuzz.c&#34;
新编辑:通过选择所需的输入和输出设备来解决延迟问题。