Error while running simple C Program from Pulse Audio - c++

Question

I have used the simple C code of pulse audio for playback and record and it worked fine. But when I converted it to C++ it doesn't work. I am pasting both the codes. Please help. The C++ code doesn't show any error but doesn't playback any sound. But C++ code plays the recorded sound.
N.B: I am using 64 bit CentOS 6.2
C++ Code:
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <iostream>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include "pulse/simple.h"
#include "pulse/error.h"
using namespace std;
#define BUFSIZE 32
int error;
/* The Sample format to use */
class AudioCapt
{
public:
AudioCapt();
void RecordSound(int argc,char *argv[],pa_simple *s_in,pa_sample_spec &ss,pa_simple *s_out,uint8_t buf[],ssize_t r);
void PlaybackSound(int argc, char*argv[],pa_simple *s_out,pa_sample_spec &ss,uint8_t buf[],ssize_t r);
};
void AudioCapt::RecordSound(int argc, char*argv[],pa_simple *s_in,pa_sample_spec &ss,pa_simple *s_out,uint8_t buf[],ssize_t r)
{
printf("Audio Capturing \n");
if (!(s_in = pa_simple_new(NULL, argv[0], PA_STREAM_RECORD, NULL, "record", &ss, NULL, NULL, &error))) {
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
}
if (pa_simple_read(s_in, buf, sizeof(buf), &error) < 0) {
fprintf(stderr, __FILE__": read() failed: %s\n", strerror(errno));
}
printf("Buffer :::: %d\n",buf[0]);
}
void AudioCapt::PlaybackSound(int argc, char*argv[],pa_simple *s_out,pa_sample_spec &ss,uint8_t buf[],ssize_t r)
{
printf("Audio PlayBack \n");
printf("Play Buffer::: %d\n",buf[0]);
if (!(s_out = pa_simple_new(NULL, argv[0], PA_STREAM_PLAYBACK, NULL, "playback", &ss, NULL, NULL, &error))) {
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
}
/* ... and play it (Modified) */
if (pa_simple_write(s_out, buf, sizeof(buf), &error) < 0) {
fprintf(stderr, __FILE__": pa_simple_write() failed: %s\n", pa_strerror(error));
}
/* Make sure that every single sample was played */
if (pa_simple_drain(s_out, &error) < 0) {
fprintf(stderr, __FILE__": pa_simple_drain() failed: %s\n", pa_strerror(error));
}
}
int main(int argc, char * argv[])
{
pa_sample_spec ss;
ss.format = PA_SAMPLE_S16LE;
ss.rate = 44100;
ss.channels = 2;
pa_simple *s_in, *s_out = NULL;
AudioCapt *m_pMyObject;
for(;;)
{
uint8_t buf[BUFSIZE];
ssize_t r;
m_pMyObject->RecordSound(argc,argv,s_in,ss,s_out,buf,r);
m_pMyObject->PlaybackSound(argc,argv,s_out,ss,buf,r);
}
return 0;
}
C Code:
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <pulse/simple.h>
#include <pulse/error.h>
#define BUFSIZE 32
int main(int argc, char*argv[]) {
/* The Sample format to use */
static const pa_sample_spec ss = {
.format = PA_SAMPLE_S16LE,
.rate = 44100,
.channels = 2
};
pa_simple *s_in, *s_out = NULL;
int ret = 1;
int error;
/* Create a new playback stream */
if (!(s_out = pa_simple_new(NULL, argv[0], PA_STREAM_PLAYBACK, NULL, "playback", &ss, NULL, NULL, &error))) {
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
goto finish;
}
if (!(s_in = pa_simple_new(NULL, argv[0], PA_STREAM_RECORD, NULL, "record", &ss, NULL, NULL, &error))) {
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
goto finish;
}
for (;;) {
uint8_t buf[BUFSIZE];
ssize_t r;
#if 1
pa_usec_t latency;
if ((latency = pa_simple_get_latency(s_in, &error)) == (pa_usec_t) -1) {
fprintf(stderr, __FILE__": pa_simple_get_latency() failed: %s\n", pa_strerror(error));
goto finish;
}
fprintf(stderr, "In: %0.0f usec \r\n", (float)latency);
if ((latency = pa_simple_get_latency(s_out, &error)) == (pa_usec_t) -1) {
fprintf(stderr, __FILE__": pa_simple_get_latency() failed: %s\n", pa_strerror(error));
goto finish;
}
fprintf(stderr, "Out: %0.0f usec \r\n", (float)latency);
#endif
if (pa_simple_read(s_in, buf, sizeof(buf), &error) < 0) {
fprintf(stderr, __FILE__": read() failed: %s\n", strerror(errno));
goto finish;
}
printf("Buffer :::: %d\n",buf[0]);
/* ... and play it */
if (pa_simple_write(s_out, buf, sizeof(buf), &error) < 0) {
fprintf(stderr, __FILE__": pa_simple_write() failed: %s\n", pa_strerror(error));
goto finish;
}
}
/* Make sure that every single sample was played */
if (pa_simple_drain(s_out, &error) < 0) {
fprintf(stderr, __FILE__": pa_simple_drain() failed: %s\n", pa_strerror(error));
goto finish;
}
ret = 0;
finish:
if (s_in)
pa_simple_free(s_in);
if (s_out)
pa_simple_free(s_out);
return ret;
}

Answer 1

In RecordSound and PlaybackSound you're initializing temporary variables with pa_simple_new. This value is lost once function returns, and you passing NULL to next one.

Answer 2

I would suggest turning on compiler checks and fixing all errors and warnings issued by your compiler on this code.
To start, m_pMyObject is never initialized, so using it in the call to RecordSound will mean passing an uninitialized value as "this" to the method. This is generally a bad thing to do.
In RecordSound and PlaybackSound, you use size(buf) to tell the library how many bytes to read/write. The parameter buf is a pointer to uint8_t. So the compiler fills in the size of the pointer (probably 8 on a 64-bit machine). In these methods you should use the parameter you have for the size. In the calls, pass sizeof(buf) to that parameter.
I don't know how many streams the library can create before running out of memory/resources. Each call to RecordSound creates a recording stream, and the PlaybackSound creates a playback stream. These streams are never freed.
So to summarize, If using the uninitialized value to call the RecordSound method does not cause the program to crash, it will create a recording stream and record a couple samples, then it will create a playback stream and play back those two samples. Then it will try doing all this again.