Hi;
I am trying to read and write raw audio from my soundcard which is an es1371.
the code i use is as follows :
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <linux/soundcard.h>
#include <signal.h>
int breakLoop = 0; /* for breaking from soundcard reading */
void catch_interrupt(int sig_num)
{
sigset_t mask_set;
sigset_t old_set;
/* for next interrupt */
signal(SIGINT, catch_interrupt);
/* mask any further signals */
sigfillset(&mask_set);
sigprocmask(SIG_SETMASK, &mask_set, &old_set);
breakLoop = 1;
sigprocmask(SIG_SETMASK, &old_set, NULL);
}
int main()
{
int fd = 0,bytesRead=0,format=0,retVal=0,frameSize = 0;
unsigned int channel=1,samplingRate=8000;
unsigned char *soundBuffer = NULL;
FILE *fp = NULL;
/* set the Ctrl-C signal handler */
signal(SIGINT, catch_interrupt);
if ( ( fd = open("/dev/dsp",O_RDONLY) ) < 0 )
{
printf("Unable to open sound device\n");
printf("Error reason = %s\n",strerror(errno));
return(0);
}
if ( ( fp = fopen("./audiobuf","wb") ) == NULL )
{
printf("Unable to open file\n");
printf("Error reason = %s\n",strerror(errno));
if ( ( retVal = close(fd) ) < 0 )
{
printf("Error on closing sound card's descriptor\n");
printf("Error reason = %s\n",strerror(errno));
}
return(0);
}
format = AFMT_S16_LE;
retVal = ioctl(fd,SNDCTL_DSP_SETFMT,&format);
if ( ( retVal < 0 ) || ( format != AFMT_S16_LE ) )
{
printf("Unable to set ioctl for audio format\n");
if ( format == AFMT_S16_LE )
{
printf("Error reason = %s\n",strerror(errno));
errno = 0;
}
else
{
printf("Wrong Format Argument\n");
}
}
retVal = ioctl(fd,SNDCTL_DSP_CHANNELS,&channel);
if ( ( retVal < 0 ) || ( channel != 1 ) )
{
printf("Unable to set ioctl for audio channel\n");
if ( channel == 1 )
{
printf("Error reason = %s\n",strerror(errno));
errno = 0;
}
else
{
printf("Wrong channel Argument\n");
}
}
retVal = ioctl(fd,SNDCTL_DSP_SPEED,&samplingRate);
if ( ( retVal < 0 ) || ( samplingRate != 8000 ) )
{
printf("Unable to set ioctl for sampleing rate\n");
if ( samplingRate == 8000 )
{
printf("Error Reason = %s\n",strerror(errno));
}
else
{
printf("Wrong sampling rate argument\n");
}
}
/* set the frame size to be 8000 * 1 * sizeof */
/* important note : how do we know data is at 8k,8 bits/sec.where do we set it
?? */
frameSize = samplingRate * channel * sizeof(unsigned char);
printf("Frame size is %d\n",frameSize);
errno = 0;
if ( ( soundBuffer = (unsigned char *)malloc(frameSize) ) == NULL )
{
printf("Unable to allocate memory\n");
printf("Error reason = %s\n",strerror(errno));
return(1);
}
printf("Going to read from soundcard.press Ctrl+C to stop\n");
retVal = 0;
memset(soundBuffer,'\0',frameSize);
while(breakLoop == 0)/* read frame by frame till ctrl+c */
{
bytesRead = 0;
bytesRead = read(fd,soundBuffer,frameSize);
if ( ( bytesRead < frameSize ) && ( breakLoop != 1 ) )
{
printf("Bad sound card read \n");
}
else
if ( breakLoop != 1 )
{
retVal = fwrite(soundBuffer,sizeof(unsigned char),frameSize,fp);
if ( (retVal != frameSize ) || ( retVal != ( sizeof(unsigned char)
* frameSize ) ) )
{
printf("Not All bytes were written to file\n");
}
}
/* clean the buffer */
memset(soundBuffer,'\0',frameSize);
}
printf("All done cleaning up\n");
if ( ( retVal = close(fd) ) < 0 )
{
printf("Error on closing sound card's descriptor\n");
printf("Error reason = %s\n",strerror(errno));
}
free(soundBuffer);
soundBuffer = NULL;
fclose(fp);
printf("Trying to write back to the sound card\n");
errno = 0;
if ( ( fd = open("/dev/dsp",O_WRONLY) ) < 0 )
{
printf("Unable to opne sound card for writing\n");
printf("Error reason = %s\n",strerror(errno));
return(1);
}
if ( ( fp = fopen("./audiobuf","r") ) == NULL )
{
printf("Unable to open the audio file\n");
printf("Error reason = %s\n",strerror(errno));
return(1);
}
if ( ( fp = fopen("./audiobuf","r") ) == NULL )
{
printf("Unable to open the audio file\n");
printf("Error reason = %s\n",strerror(errno));
if ( ( retVal = close(fd) ) < 0 )
{
printf("Error on closing sound card's descriptor\n");
printf("Error reason = %s\n",strerror(errno));
}
return(1);
}
format = AFMT_S16_LE;
retVal = ioctl(fd,SNDCTL_DSP_SETFMT,&format);
if ( ( retVal < 0 ) || ( format != AFMT_S16_LE ) )
{
printf("Unable to set ioctl for audio format\n");
if ( format == AFMT_S16_LE )
{
printf("Error reason = %s\n",strerror(errno));
errno = 0;
}
else
{
printf("Wrong Format Argument\n");
}
}
retVal = ioctl(fd,SNDCTL_DSP_CHANNELS,&channel);
if ( ( retVal < 0 ) || ( channel != 1 ) )
{
printf("Unable to set ioctl for audio channel\n");
if ( channel == 1 )
{
printf("Error reason = %s\n",strerror(errno));
errno = 0;
}
else
{
printf("Wrong channel Argument\n");
}
}
retVal = ioctl(fd,SNDCTL_DSP_SPEED,&samplingRate);
if ( ( retVal < 0 ) || ( samplingRate != 8000 ) )
{
printf("Unable to set ioctl for sampleing rate\n");
if ( samplingRate == 8000 )
{
printf("Error Reason = %s\n",strerror(errno));
}
else
{
printf("Wrong sampling rate argument\n");
}
}
frameSize = samplingRate * channel * sizeof(unsigned char);
errno = 0;
if ( ( soundBuffer = (unsigned char *)malloc(frameSize) ) == NULL )
{
printf("Unable to allocate memory\n");
printf("Error reason = %s\n",strerror(errno));
return(1);
}
errno = 0;
/* clean the buffer */
memset(soundBuffer,'\0',frameSize);
while( ! feof(fp) )
{
fread(soundBuffer,sizeof(unsigned char),frameSize,fp);
if ( ! feof(fp) )
{
errno = 0;
if ( write(fd,soundBuffer,frameSize) != frameSize )
{
printf("Error occurred during writing\n");
printf("Error reason = %s\n",strerror(errno));
}
/* clean the buffer */
memset(soundBuffer,'\0',frameSize);
}
}
if ( ( retVal = close(fd) ) < 0 )
{
printf("Error on closing sound card's descriptor\n");
printf("Error reason = %s\n",strerror(errno));
}
printf("All Done\n");
free(soundBuffer);
soundBuffer = NULL;
fclose(fp);
return(0);
}
ya i know the code is not optimized but then i was just testing it anyway.
the catch is i want to know whether i can read data from the soundcard and write back
to it without doing any encoding.
the above code is not working.
any clues/pointers would be greatly appreciated.
Thanks
K.Shyam
________________________________________________________
Outgrown your current e-mail service?
Get a 25MB Inbox, POP3 Access, No Ads and No Taglines with LYCOS MAIL PLUS.
http://login.mail.lycos.com/brandPage.shtml?pageId=plus
_______________________________________________________________
Don't miss the 2002 Sprint PCS Application Developer's Conference
August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm
_______________________________________________
Alsa-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/alsa-devel
