Segmentation fault (core dumped) with pulseaudio lib on c - c

Question

I'm new to Stackoverflow and c and pulseaudio. Thanks for all help.
I get a the Segmentation fault (core dumped) error in the mainloop of a custom pulseaudiolib code. It it takes 1 to 30s to apear.
I am trying to get the audio data of a custom sink
pacmd load-module module-null-sink sink_name=MySink
pacmd update-sink-proplist MySink device.description=MySink
pacmd load-module module-loopback sink=MySink
use its data and pip it back to the speaker.
I'm pretty new at C and pulseaudio so I used the doc and https://menno.io/posts/pulseaudio_monitoring/
This is my code:
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <pulse/simple.h>
#include <pulse/error.h>
#include <pulse/context.h>
#include <pulse/def.h>
#include <pulse/format.h>
#include <pulse/introspect.h>
#include <pulse/stream.h>
#include <pulse/thread-mainloop.h>
const char * SINKNAME = "MySink";
const char * SPEAKNAME = "alsa_output.pci-0000_05_00.6.analog-stereo";
char found = 0;
const uint32_t RATE = 344;
pa_stream * gStream = NULL;
void stream_read_cb(pa_stream *stream, size_t length, void *index_incr){
printf("in read\n");
const void * samples[length];
size_t * leng;
(*leng) = length;
printf("length : %d, %d\n",length,(*leng));
int res = pa_stream_peek(stream, samples, leng);
pa_stream_drop(stream);
if(gStream != NULL){
int result = pa_stream_write( gStream, samples,length, NULL,0, PA_SEEK_RELATIVE);
}
printf("[");
if (res == 0){
for(int i = 0 ; i< length; i++){
printf("%d,",samples[i]);
}
}
printf("]\n");
}
void sink_info_cb(pa_context* context, const pa_sink_info *sink_info_p, int eol, void *userdata){
printf( "in sinkinfo\n");
const pa_sink_info* sink_info = sink_info_p;
if(found !=1){
printf( "index: %d\n", (*sink_info).index);
printf("help\n");
printf( "name: %s\n", (*sink_info).name);
printf( "description: %s\n", (*sink_info).description);
printf("searchName: %s\n",SINKNAME);
if (strcmp((*sink_info).name, SINKNAME) == 0){
found = 1;
// Found the sink we want to monitor for peak levels.
// Tell PA to call stream_read_cb with peak samples.
printf( "setting up peak recording using: %s\n ", (*sink_info).monitor_source_name);
pa_sample_spec *samplespec;
(*samplespec).channels = 1;
(*samplespec).format = PA_SAMPLE_U8;
(*samplespec).rate = RATE;
pa_stream * stream = pa_stream_new(context, "peak detect demo", samplespec, NULL);
pa_stream_set_read_callback(stream,
stream_read_cb,
( *sink_info).index);
pa_stream_connect_record(stream,
(*sink_info).monitor_source_name,
NULL,
PA_STREAM_PEAK_DETECT);
printf("settetd \n");
}/*
if((*sink_info).name[0] == 'a'){
//printf( "setting up peak recording using: %s\n ", (*sink_info).monitor_source_name);
//pa_sample_spec *samplespec;
// (*samplespec).channels = 1;
// (*samplespec).format = PA_SAMPLE_U8;
// (*samplespec).rate = RATE;
printf("set gStream");
//gStream = pa_stream_new(context, "peak detect demo", samplespec, NULL);
//printf("gSteam setted\n");
}*/
printf("out sink\n");
}
}
void context_notify_cb(pa_context *context, void *userdata){
printf("in context\n");
pa_context_state_t state = pa_context_get_state(context);
if( state == PA_CONTEXT_READY){
printf( "Pulseaudio connection ready...");
// Connected to Pulseaudio. Now request that sink_info_cb
// be called with information about the available sinks.
pa_operation * o = pa_context_get_sink_info_list(context, sink_info_cb, userdata);
pa_operation_unref(o);
}
else if( state == PA_CONTEXT_FAILED){
printf( "Connection failed");
}
else if( state == PA_CONTEXT_TERMINATED){
printf( "Connection terminated");
}
printf("out context\n");
}
void init(){
// Wrap callback methods in appropriate ctypefunc instances so
// that the Pulseaudio C API can call them
printf("in init\n");
pa_context_notify_cb_t _context_notify_cb;
//context_notify_cb(context_notify_cb void ** userdata);
pa_sink_info_cb_t(sink_info_cb);
pa_stream_request_cb_t(stream_read_cb);
// Create the mainloop thread and set our context_notify_cb
// method to be called when there's updates relating to the
// connection to Pulseaudio
pa_threaded_mainloop* _mainloop = pa_threaded_mainloop_new();
pa_mainloop_api* _mainloop_api = pa_threaded_mainloop_get_api(_mainloop);
pa_context *context = pa_context_new(_mainloop_api, "peak_demo");
pa_context_set_state_callback(context, context_notify_cb,NULL);
pa_context_connect(context, NULL, 0, NULL);
pa_threaded_mainloop_start(_mainloop);
printf("out intit\n");
}
int main(int argc, char*argv[]) {
init();
printf("Hello World\n");
while(1){
;
}
printf("end World\n");
return 0;
}
if I try to uncomment
/*
if((*sink_info).name[0] == 'a'){
//printf( "setting up peak recording using: %s\n ", (*sink_info).monitor_source_name);
//pa_sample_spec *samplespec;
// (*samplespec).channels = 1;
// (*samplespec).format = PA_SAMPLE_U8;
// (*samplespec).rate = RATE;
printf("set gStream");
//gStream = pa_stream_new(context, "peak detect demo", samplespec, NULL);
//printf("gSteam setted\n");
}
*/
the error shots like directly.
the output:
...
in read
length : 1, 1
[-1261830080,]
in read
length : 6, 6
[-1246625728,-1017902384,0,0,-1017902304,591610535,]
in read
length : 1, 1
[-1259864000,]
in read
length : 6, 6
[-1227227072,-1017902384,0,0,-1017902304,591610535,]
in read
length : 1, 1
[-1255800768,]
in read
length : 6, 6
[-1234960320,-1017902384,0,0,-1017902304,591610535,]
in read
length : 7, 7
[-1249247168,-939474438,-1017902512,-1017902384,0,0,-1017902304,]
in read
length : 7, 7
[-1242693568,-939474438,-1017902464,-1017902336,0,0,-1017902256,]
Segmentation fault (core dumped)
the uncomment output:
in init
in context
out context
out intit
Hello World
in context
out context
in context
out context
in context
Pulseaudio connection ready...out context
in sinkinfo
index: 0
help
name: alsa_output.pci-0000_05_00.6.analog-stereo
description: Family 17h (Models 10h-1fh) HD Audio Controller Analog Stereo
searchName: MySink
set gStreamout sink
in sinkinfo
index: 1
help
name: MySink
description: MySink
searchName: MySink
setting up peak recording using: MySink.monitor
settetd
Segmentation fault (core dumped)