Ticket #323: pulse-audio-alsa-threaded.c

#include <stdlib.h>

#include <poll.h>
#include <stdio.h>
#include <sys/types.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <pthread.h>
#include <asoundlib.h>

#include <stdint.h>
#include <limits.h>
#include <glib.h>

#define bool int
#define false 0
#define true 1

snd_pcm_t *pcm = NULL;

bool init_audio_bug ()
{   
    bool result = false;
    snd_pcm_hw_params_t *params = NULL;
    uint32_t buffer_time = 500000; // request 0.5 seconds of buffer time.
    int err = 0;
    int dir = 0;
    int channels = 1;
    unsigned int rate = 44100;
    unsigned int actual_rate = rate;

    // Open a pcm device
    result = snd_pcm_open (&pcm, "default", SND_PCM_STREAM_PLAYBACK, 0);
    if (result != 0) {
        fprintf (stderr, "AudioNode::Initialize (): cannot open audio device: %s\n", snd_strerror (result));
        pcm = NULL;
        return false;
    }

    snd_output_t *output = NULL;
    err = snd_output_stdio_attach (&output, stdout, 0);
    if (err < 0) {
        fprintf(stderr, "AudioNode::SetupHW (): Could not create alsa output: %s\n", snd_strerror (err));
    }

    err = snd_pcm_hw_params_malloc (&params);
    if (err < 0) {
        fprintf(stderr, "AudioNode::SetupHW (): Audio HW setup failed (malloc): %s\n", snd_strerror (err));
        return false;
    }

    // choose all parameters
    err = snd_pcm_hw_params_any (pcm, params);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (no configurations available): %s\n", snd_strerror (err));
        goto cleanup;
    }
    
    if (output != NULL) {
        printf ("AudioNode::SetupHW (): hw configurations:\n");
        snd_pcm_hw_params_dump (params, output);
    }
    
    // enable software resampling
    err = snd_pcm_hw_params_set_rate_resample (pcm, params, 1);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (could not enable resampling): %s\n", snd_strerror (err));
        goto cleanup;
    }
    
    // set transfer mode (mmap in our case)
    err = snd_pcm_hw_params_set_access (pcm, params, SND_PCM_ACCESS_RW_INTERLEAVED);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (access type not available for playback): %s\n", snd_strerror(err));
        goto cleanup;
    }

    // set audio format
    err = snd_pcm_hw_params_set_format (pcm, params, SND_PCM_FORMAT_S16);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (sample format not available for playback): %s\n", snd_strerror(err));
        goto cleanup;
    }
    
    // set channel count
    err = snd_pcm_hw_params_set_channels (pcm, params, channels);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (channels count %i not available for playback): %s\n", channels, snd_strerror (err));
        goto cleanup;
    }
    
    // set sample rate
    err = snd_pcm_hw_params_set_rate_near (pcm, params, &actual_rate, 0);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (sample rate %i Hz not available for playback): %s\n", rate, snd_strerror (err));
        goto cleanup;
    } else if (actual_rate != rate) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (sample rate %i Hz not available for playback, only got %i Hz).\n", rate, actual_rate);
        goto cleanup;
    }
    
    // set the buffer time
    err = snd_pcm_hw_params_set_buffer_time_near (pcm, params, &buffer_time, &dir);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (unable to set buffer time %i for playback: %s\n", buffer_time, snd_strerror (err));
        goto cleanup;
    }

    // write the parameters to device
    err = snd_pcm_hw_params (pcm, params);
    if (err < 0) {
        fprintf (stderr, "AudioNode::SetupHW (): Audio HW setup failed (unable to set hw params for playback: %s)\n", snd_strerror (err));
        goto cleanup;
    }
    
    printf ("AudioNode::SetupHW (): succeeded\n");
    if (output != NULL) {
        snd_pcm_hw_params_dump (params, output);
    }

    printf ("AudioNode::SetupHW (): hardware pause support: %s\n", snd_pcm_hw_params_can_pause (params) == 0 ? "no" : "yes"); 

    result = true;
    
cleanup:
    snd_pcm_hw_params_free (params);
    
    return result;
}

void *loop (void *context)
{
    printf ("Started loop\n");

    if (!init_audio_bug ())
        return NULL;

    int result;
    int size = 8568;
    void *silence = g_malloc0 (size);
    int i;
    snd_pcm_sframes_t delay;    
    int fd;

    fd = open ("mini.wav", O_RDONLY);
    if (fd < 0)
        printf ("Open failed: %s\n", strerror (errno));
    if (read (fd, silence, 8568) <= 0)
        printf ("Read failed: %s\n", strerror (errno));
    snd_pcm_writei (pcm, silence, size / 2);
    close (fd);

//  snd_pcm_delay (pcm);
    if ((result = snd_pcm_start (pcm)) < 0) {
        printf ("start failed: %s\n", snd_strerror (result));
    }
    printf ("Sleeping...\n");
    sleep (1);
    printf ("Slept\n");

    //snd_pcm_drop (pcm);
    snd_pcm_close (pcm);

    printf ("Exited loop\n");
}


int main ()
{
    pthread_t thread;
    pthread_create (&thread, NULL, loop, NULL);
    printf ("About to join\n");
    pthread_join (thread, NULL);
    printf ("Joined\n");
    return 0;
}