问题描述
我正在尝试制作一个全双工音频程序，该程序可以检测来自麦克风的音频输入，并使用portaudio库和回调函数将其实时定向到扬声器，但是我一直遇到错误。我试图打开一个完整的输入输出流，然后从麦克风开始读取并将捕获的数据发送到回调函数，该函数将开始将音频流传输到扬声器 谁能帮我这个 ？？ 错误如下：
ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) UnkNown PCM cards.pcm.rear
ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) UnkNown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) UnkNown PCM cards.pcm.side
ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map
Output device # 14.
Output LL: 0.00870748 s
Output HL: 0.0348299 s
Now recording!!
An error occured while using the portaudio stream
Error number: -9988
Error message: Invalid stream pointer
An error occured while using the portaudio stream
Error number: -9988
Error message: Invalid stream pointer
An error occured while using the portaudio stream
Error number: -9977
Error message: Can't read from a callback stream
这是我的代码：
#include "diffusion.c"
#include "confusion.c"
#include "portaudio.h"
#include "wave_file.c"
/* #define SAMPLE_RATE (17932) // Test failure to open with this value. */
#define SAMPLE_RATE (44100)
#define FRAMES_PER_BUFFER (0)
#define NUM_SECONDS (2)
#define NUM_CHANNELS (2)
/* #define DITHER_FLAG (paDitherOff) */
#define DITHER_FLAG (0) /**/
#define WRITE_TO_WAVE_FILE (1)
/* define sample format. */
#define PA_SAMPLE_TYPE paInt16
typedef short SAMPLE;
#define SAMPLE_SILENCE (0)
#define PRINTF_S_FORMAT "%d"
PaStreamParameters inputParameters,outputParameters;
PaStream *stream;
PaError err;
SAMPLE *recordedSamples,*recordedSamples2;
int i;
int totalFrames;
int numSamples;
int numBytes;
static int playCallback (const void *input,void *output,unsigned long frameCount,const PaStreamCallbackTimeInfo* timeInfo,PaStreamCallbackFlags statusFlags,void *userData
)
{
err = Pa_StartStream( stream );
if( err != paNoError ) goto error;
printf("Now recording!!\n"); fflush(stdout);
err = Pa_WriteStream( stream,userData,totalFrames );
if( err != paNoError ) goto error;
err = Pa_CloseStream( stream );
if( err != paNoError ) goto error;
free( userData );
return paContinue;
error:
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 paContinue;
}
int main(void);
int main(void)
{
PaStreamParameters inputParameters,*recordedSamples2;
int i;
int totalFrames;
int numSamples;
int numBytes;
printf("patest_read_record.c\n"); fflush(stdout);
totalFrames = NUM_SECONDS * SAMPLE_RATE; /* Record for a few seconds. */
numSamples = totalFrames * NUM_CHANNELS;
numBytes = numSamples * sizeof(SAMPLE);
recordedSamples = (SAMPLE *) malloc( numBytes );
if( recordedSamples == NULL )
{
printf("Could not allocate record array.\n");
exit(1);
}
for( i=0; i<numSamples; i++ ) recordedSamples[i] = 0;
err = Pa_Initialize();
if( err != paNoError ) goto error;
inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */
if (inputParameters.device == paNoDevice) {
fprintf(stderr,"Error: No default input device.\n");
goto error;
}
inputParameters.channelCount = NUM_CHANNELS;
inputParameters.sampleFormat = PA_SAMPLE_TYPE;
inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency;
inputParameters.hostApiSpecificStreamInfo = NULL;
outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
printf( "Output device # %d.\n",outputParameters.device );
printf( "Output LL: %g s\n",Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency );
printf( "Output HL: %g s\n",Pa_GetDeviceInfo( outputParameters.device )->defaultHighOutputLatency );
outputParameters.channelCount = NUM_CHANNELS;
outputParameters.sampleFormat = PA_SAMPLE_TYPE;
outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultHighOutputLatency;
outputParameters.hostApiSpecificStreamInfo = NULL;
/* Record some audio. -------------------------------------------- */
err = Pa_OpenStream(
&stream,&inputParameters,&outputParameters,/* &outputParameters,*/
SAMPLE_RATE,paFramesPerBufferUnspecified,paClipOff,/* we won't output out of range samples so don't bother clipping them */
playCallback,/* no callback,use blocking API */
recordedSamples ); /* no callback,so no callback userData */
if( err != paNoError ) goto error;
err = Pa_StartStream( stream );
if( err != paNoError ) goto error;
printf("Now recording!!\n"); fflush(stdout);
err = Pa_ReadStream( stream,recordedSamples,totalFrames );
if( err != paNoError ) goto error;
err = Pa_CloseStream( stream );
if( err != paNoError ) goto error;
/* save the recorded data in a wave file " recording.wav ". -------------------------- */
saveInWaveFile(recordedSamples,totalFrames,"recording.wav");
for (int i =0; i< numSamples ; i++){
recordedSamples2[i] = recordedSamples[i];
}
free( recordedSamples );
Pa_Terminate();
return 0;
error:
Pa_Terminate();
fprintf( stderr,Pa_GetErrorText( err ) );
return -1;
}
解决方法
首先请确保默认输入和输出设备正确。为此，您可以先运行examples文件夹中的pa_devs.c示例，以打印已连接到计算机的已启用音频设备的列表。确定正确的设备后，将这些行替换为设备号，例如
inputParameters.device = Pa_GetDefaultInputDevice();
为
inputParameters.device = <device number (e.g. 11)>;
和
outputParameters.device = Pa_GetDefaultOutputDevice();
为
outputParameters.device = <device number (e.g. 11)>;
您可以尝试的另一种方式是称为paex_read_write_wire.c的示例。这样可以实现与您所讨论的功能相同的功能，但是使用阻塞方法，而不是您在代码中使用的回调函数。
,我现在无法测试它，但它应该播放（监视）输入缓冲区（麦克风）：
table.column(colID).search('Tokyo').draw();