libsent/src/adin/adin_mic_linux_alsa.c

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/*
 * Copyright (c) 1991-2007 Kawahara Lab., Kyoto University
 * Copyright (c) 2000-2005 Shikano Lab., Nara Institute of Science and Technology
 * Copyright (c) 2005-2007 Julius project team, Nagoya Institute of Technology
 * All rights reserved
 */

#include <sent/stddefs.h>
#include <sent/adin.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifdef HAS_ALSA

#if defined(HAVE_ALSA_ASOUNDLIB_H)
#include <alsa/asoundlib.h>
#elif defined(HAVE_SYS_ASOUNDLIB_H)
#include <sys/asoundlib.h>
#endif

static snd_pcm_t *handle;       
static char *pcm_name = "default"; 
static int latency = 32;        
static boolean need_swap;       

#if (SND_LIB_MAJOR == 0)
static struct pollfd *ufds;     
static int count;               
#endif

#define MAXPOLLINTERVAL 300     

#endif /* HAS_ALSA */

#ifdef HAS_ALSA

static void
output_card_info(char *pcm_name, snd_pcm_t *handle)
{
  int err;
  snd_ctl_t *ctl;
  snd_ctl_card_info_t *info;
  snd_pcm_info_t *pcminfo;
  snd_ctl_card_info_alloca(&info);
  snd_pcm_info_alloca(&pcminfo);
  char ctlname[30];
  int card;
  
  /* get PCM information to set current device and subdevice name */
  if ((err = snd_pcm_info(handle, pcminfo)) < 0) {
    jlog("Warning: adin_alsa: failed to obtain pcm info\n");
    jlog("Warning: adin_alsa: skip output of detailed audio device info\n");
    return;
  }
  /* open control associated with the pcm device name */
  card = snd_pcm_info_get_card(pcminfo);
  if (card < 0) {
    strcpy(ctlname, "default");
  } else {
    snprintf(ctlname, 30, "hw:%d", card);
  }
  if ((err = snd_ctl_open(&ctl, ctlname, 0)) < 0) {
    jlog("Warning: adin_alsa: failed to open control device \"%s\", \n", ctlname);
    jlog("Warning: adin_alsa: skip output of detailed audio device info\n");
    return;
  }
  /* get its card info */
  if ((err = snd_ctl_card_info(ctl, info)) < 0) {
    jlog("Warning: adin_alsa: unable to get card info for %s\n", ctlname);
    jlog("Warning: adin_alsa: skip output of detailed audio device info\n");
    snd_ctl_close(ctl);
    return;
  }

  /* get detailed PCM information of current device from control */
  if ((err = snd_ctl_pcm_info(ctl, pcminfo)) < 0) {
    jlog("Error: adin_alsa: unable to get pcm info from card control\n");
    jlog("Warning: adin_alsa: skip output of detailed audio device info\n");
    snd_ctl_close(ctl);
    return;
  }
  /* output */
  jlog("Stat: \"%s\": %s [%s] device %s [%s] %s\n",
       pcm_name,
       snd_ctl_card_info_get_id(info),
       snd_ctl_card_info_get_name(info),
       snd_pcm_info_get_id(pcminfo),
       snd_pcm_info_get_name(pcminfo),
       snd_pcm_info_get_subdevice_name(pcminfo));

  /* close controller */
  snd_ctl_close(ctl);

}
#endif /* HAS_ALSA */

boolean
adin_alsa_standby(int sfreq, void *dummy)
{
#ifndef HAS_ALSA
  jlog("Error: ALSA not compiled in\n");
  return FALSE;
#else
  int err;
  snd_pcm_hw_params_t *hwparams; 
#if (SND_LIB_MAJOR == 0)
  int actual_rate;              /* sample rate returned by hardware */
#else
  unsigned int actual_rate;             /* sample rate returned by hardware */
#endif
  int dir = 0;                  /* comparison result of exact rate and given rate */
  char *p;

  /* check $ALSADEV for device name */
  if ((p = getenv("ALSADEV")) != NULL) {
    pcm_name = p;
    jlog("Stat: adin_alsa: device name from ALSADEV: \"%s\"\n", pcm_name);
  }

  /* open device in non-block mode) */
  if ((err = snd_pcm_open(&handle, pcm_name, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK)) < 0) {
    jlog("Error: adin_alsa: cannot open PCM device \"%s\" (%s)\n", pcm_name, snd_strerror(err));
    return(FALSE);
  }
  /* set device to non-block mode */
  if ((err = snd_pcm_nonblock(handle, 1)) < 0) {
    jlog("Error: adin_alsa: cannot set PCM device to non-blocking mode\n");
    return(FALSE);
  }

  /* allocate hwparam structure */
  snd_pcm_hw_params_alloca(&hwparams);

  /* initialize hwparam structure */
  if ((err = snd_pcm_hw_params_any(handle, hwparams)) < 0) {
    jlog("Error: adin_alsa: cannot initialize PCM device parameter structure (%s)\n", snd_strerror(err));
    return(FALSE);
  }

  /* set interleaved read/write format */
  if ((err = snd_pcm_hw_params_set_access(handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
    jlog("Error: adin_alsa: cannot set PCM device access mode (%s)\n", snd_strerror(err));
    return(FALSE);
  }

  /* set sample format */
#ifdef WORDS_BIGENDIAN
  /* try big endian, then little endian with byte swap */
  if ((err = snd_pcm_hw_params_set_format(handle, hwparams, SND_PCM_FORMAT_S16_BE)) >= 0) {
    need_swap = FALSE;
  } else if ((err = snd_pcm_hw_params_set_format(handle, hwparams, SND_PCM_FORMAT_S16_LE)) >= 0) {
    need_swap = TRUE;
  } else {
    jlog("Error: adin_alsa: cannot set PCM device format to signed 16bit (%s)\n", snd_strerror(err));
    return(FALSE);
  }
#else  /* LITTLE ENDIAN */
  /* try little endian, then big endian with byte swap */
  if ((err = snd_pcm_hw_params_set_format(handle, hwparams, SND_PCM_FORMAT_S16_LE)) >= 0) {
    need_swap = FALSE;
  } else if ((err = snd_pcm_hw_params_set_format(handle, hwparams, SND_PCM_FORMAT_S16_BE)) >= 0) {
    need_swap = TRUE;
  } else {
    jlog("Error: adin_alsa: cannot set PCM device format to signed 16bit (%s)\n", snd_strerror(err));
    return(FALSE);
  }
#endif
  /* set number of channels */
  if ((err = snd_pcm_hw_params_set_channels(handle, hwparams, 1)) < 0) {
    jlog("Error: adin_alsa: cannot set PCM channel to %d (%s)\n", 1, snd_strerror(err));
    return(FALSE);
  }
  
  /* set sample rate (if the exact rate is not supported by the hardware, use nearest possible rate */
#if (SND_LIB_MAJOR == 0)
  actual_rate = snd_pcm_hw_params_set_rate_near(handle, hwparams, sfreq, &dir);
  if (actual_rate < 0) {
    jlog("Error: adin_alsa: cannot set PCM device sample rate to %d (%s)\n", sfreq, snd_strerror(actual_rate));
    return(FALSE);
  }
#else
  actual_rate = sfreq;
  err = snd_pcm_hw_params_set_rate_near(handle, hwparams, &actual_rate, &dir);
  if (err < 0) {
    jlog("Error: adin_alsa: cannot set PCM device sample rate to %d (%s)\n", sfreq, snd_strerror(err));
    return(FALSE);
  }
#endif
  if (actual_rate != sfreq) {
    jlog("Warning: adin_alsa: the exact rate %d Hz is not available by your PCM hardware.\n", sfreq);
    jlog("Warning: adin_alsa: using %d Hz instead.\n", actual_rate);
  }
  jlog("Stat: capture audio at %dHz\n", actual_rate);

  /* set period size */
  {
#if (SND_LIB_MAJOR == 0)
    int periodsize;             /* period size (bytes) */
    int actual_size;
    int maxsize, minsize;
#else
    unsigned int period_time, period_time_current;
    snd_pcm_uframes_t chunk_size;
    boolean has_current_period;
#endif
    boolean force = FALSE;
    
    /* set apropriate period size */
    if ((p = getenv("LATENCY_MSEC")) != NULL) {
      latency = atoi(p);
      jlog("Stat: adin_alsa: trying to set latency to %d msec from LATENCY_MSEC)\n", latency);
      force = TRUE;
    }

    /* get hardware max/min size */
#if (SND_LIB_MAJOR == 0)
    if ((maxsize = snd_pcm_hw_params_get_period_size_max(hwparams, &dir)) < 0) {
      jlog("Error: adin_alsa: cannot get maximum period size\n");
      return(FALSE);
    }
    if ((minsize = snd_pcm_hw_params_get_period_size_min(hwparams, &dir)) < 0) {
      jlog("Error: adin_alsa: cannot get minimum period size\n");
      return(FALSE);
    }
#else    
    has_current_period = TRUE;
    if ((err = snd_pcm_hw_params_get_period_time(hwparams, &period_time_current, &dir)) < 0) {
      has_current_period = FALSE;
    }
    if (has_current_period) {
      jlog("Stat: adin_alsa: current latency time: %d msec\n", period_time_current / 1000);
    }
#endif

    /* set period time (near value will be used) */
#if (SND_LIB_MAJOR == 0)
    periodsize = actual_rate * latency / 1000 * sizeof(SP16);
    if (periodsize < minsize) {
      jlog("Stat: adin_alsa: PCM latency of %d ms (%d bytes) too small, use device minimum %d bytes\n", latency, periodsize, minsize);
      periodsize = minsize;
    } else if (periodsize > maxsize) {
      jlog("Stat: adin_alsa: PCM latency of %d ms (%d bytes) too large, use device maximum %d bytes\n", latency, periodsize, maxsize);
      periodsize = maxsize;
    }
    actual_size = snd_pcm_hw_params_set_period_size_near(handle, hwparams, periodsize, &dir);
    if (actual_size < 0) {
      jlog("Error: adin_alsa: cannot set PCM record period size to %d (%s)\n", periodsize, snd_strerror(actual_size));
      return(FALSE);
    }
    if (actual_size != periodsize) {
      jlog("Stat: adin_alsa: PCM period size: %d bytes (%dms) -> %d bytes\n", periodsize, latency, actual_size);
    }
    jlog("Stat: Audio I/O Latency = %d msec (data fragment = %d frames)\n", actual_size * 1000 / (actual_rate * sizeof(SP16)), actual_size / sizeof(SP16));
#else
    period_time = latency * 1000;
    if (!force && has_current_period && period_time > period_time_current) {
        jlog("Stat: adin_alsa: current latency (%dms) is shorter than %dms, leave it\n", period_time_current / 1000, latency);
        period_time = period_time_current;
    } else {
      if ((err = snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, 0)) < 0) {
        jlog("Error: adin_alsa: cannot set PCM record period time to %d msec (%s)\n", period_time / 1000, snd_strerror(err));
        return(FALSE);
      }
      snd_pcm_hw_params_get_period_size(hwparams, &chunk_size, 0);
      jlog("Stat: adin_alsa: latency set to %d msec (chunk = %d bytes)\n", period_time / 1000, chunk_size);
    }
#endif

#if (SND_LIB_MAJOR == 0)
    /* set number of periods ( = 2) */
    if ((err = snd_pcm_hw_params_set_periods(handle, hwparams, sizeof(SP16), 0)) < 0) {
      jlog("Error: adin_alsa: cannot set PCM number of periods to %d (%s)\n", sizeof(SP16), snd_strerror(err));
      return(FALSE);
    }
#endif
  }

  /* apply the configuration to the PCM device */
  if ((err = snd_pcm_hw_params(handle, hwparams)) < 0) {
    jlog("Error: adin_alsa: cannot set PCM hardware parameters (%s)\n", snd_strerror(err));
    return(FALSE);
  }

  /* prepare for recording */
  if ((err = snd_pcm_prepare(handle)) < 0) {
    jlog("Error: adin_alsa: failed to prepare audio interface (%s)\n", snd_strerror(err));
  }

#if (SND_LIB_MAJOR == 0)
  /* prepare for polling */
  count = snd_pcm_poll_descriptors_count(handle);
  if (count <= 0) {
    jlog("Error: adin_alsa: invalid PCM poll descriptors count\n");
    return(FALSE);
  }
  ufds = mymalloc(sizeof(struct pollfd) * count);
  if ((err = snd_pcm_poll_descriptors(handle, ufds, count)) < 0) {
    jlog("Error: adin_alsa: unable to obtain poll descriptors for PCM recording (%s)\n", snd_strerror(err));
    return(FALSE);
  }
#endif

  /* output status */
  output_card_info(pcm_name, handle);

  return(TRUE);
#endif /* HAS_ALSA */
}

#ifdef HAS_ALSA

static int
xrun_recovery(snd_pcm_t *handle, int err)
{
  if (err == -EPIPE) {    /* under-run */
    err = snd_pcm_prepare(handle);
    if (err < 0)
      jlog("Error: adin_alsa: can't recovery from PCM buffer underrun, prepare failed: %s\n", snd_strerror(err));
    return 0;
  } else if (err == -ESTRPIPE) {
    while ((err = snd_pcm_resume(handle)) == -EAGAIN)
      sleep(1);       /* wait until the suspend flag is released */
    if (err < 0) {
      err = snd_pcm_prepare(handle);
      if (err < 0)
        jlog("Error: adin_alsa: can't recovery from PCM buffer suspend, prepare failed: %s\n", snd_strerror(err));
    }
    return 0;
  }
  return err;
}
#endif /* HAS_ALSA */

boolean
adin_alsa_begin()
{
#ifndef HAS_ALSA
  return FALSE;
#else
  int err;
  snd_pcm_state_t status;

  /* check hardware status */
  while(1) {                    /* wait till prepared */
    status = snd_pcm_state(handle);
    switch(status) {
    case SND_PCM_STATE_PREPARED: /* prepared for operation */
      if ((err = snd_pcm_start(handle)) < 0) {
        jlog("Error: adin_alsa: cannot start PCM (%s)\n", snd_strerror(err));
        return (FALSE);
      }
      return(TRUE);
      break;
    case SND_PCM_STATE_RUNNING: /* capturing the samples of other application */
      if ((err = snd_pcm_drop(handle)) < 0) { /* discard the existing samples */
        jlog("Error: adin_alsa: cannot drop PCM (%s)\n", snd_strerror(err));
        return (FALSE);
      }
      break;
    case SND_PCM_STATE_XRUN:    /* buffer overrun */
      if ((err = xrun_recovery(handle, -EPIPE)) < 0) {
        jlog("Error: adin_alsa: PCM XRUN recovery failed (%s)\n", snd_strerror(err));
        return(FALSE);
      }
      break;
    case SND_PCM_STATE_SUSPENDED:       /* suspended by power management system */
      if ((err = xrun_recovery(handle, -ESTRPIPE)) < 0) {
        jlog("Error: adin_alsa: PCM XRUN recovery failed (%s)\n", snd_strerror(err));
        return(FALSE);
      }
      break;
    default:
      /* do nothing */
      break;
    }
  }

  return(TRUE);
#endif /* HAS_ALSA */
}
  
boolean
adin_alsa_end()
{
  return(TRUE);
}

int
adin_alsa_read(SP16 *buf, int sampnum)
{
#ifndef HAS_ALSA
  return -2;
#else
  int cnt;

#if (SND_LIB_MAJOR == 0)

  snd_pcm_sframes_t avail;

  while ((avail = snd_pcm_avail_update(handle)) <= 0) {
    usleep(latency * 1000);
  }
  if (avail < sampnum) {
    cnt = snd_pcm_readi(handle, buf, avail);
  } else {
    cnt = snd_pcm_readi(handle, buf, sampnum);
  }

#else

  int ret;
  snd_pcm_status_t *status;
  int res;
  struct timeval now, diff, tstamp;

  ret = snd_pcm_wait(handle, MAXPOLLINTERVAL);
  switch (ret) {
  case 0:                       /* timeout */
    jlog("Warning: adin_alsa: no data fragment after %d msec?\n", MAXPOLLINTERVAL);
    cnt = 0;
    break;
  case 1:                       /* has data */
    cnt = snd_pcm_readi(handle, buf, sampnum); /* read available (non-block) */
    break;
  case -EPIPE:                  /* pipe error */
    /* try to recover the broken pipe */
    snd_pcm_status_alloca(&status);
    if ((res = snd_pcm_status(handle, status))<0) {
      jlog("Error: adin_alsa: broken pipe: status error (%s)\n", snd_strerror(res));
      return -2;
    }
    if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
      gettimeofday(&now, 0);
      snd_pcm_status_get_trigger_tstamp(status, &tstamp);
      timersub(&now, &tstamp, &diff);
      jlog("Warning: adin_alsa: overrun!!! (at least %.3f ms long)\n",
           diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
      if ((res = snd_pcm_prepare(handle))<0) {
        jlog("Error: adin_alsa: overrun: prepare error (%s)", snd_strerror(res));
        return -2;
      }
      break;         /* ok, data should be accepted again */
    } else if (snd_pcm_status_get_state(status) == SND_PCM_STATE_DRAINING) {
      jlog("Warning: adin_alsa: draining: capture stream format change? attempting recover...\n");
      if ((res = snd_pcm_prepare(handle))<0) {
        jlog("Error: adin_alsa: draining: prepare error (%s)", snd_strerror(res));
        return -2;
      }
      break;
    }
    jlog("Error: adin_alsa: error in snd_pcm_wait() (%s)\n", snd_pcm_state_name(snd_pcm_status_get_state(status)));
    return -2;

  default:                      /* other poll error */
    jlog("Error: adin_alsa: error in snd_pcm_wait() (%s)\n", snd_strerror(ret));
    return(-2);                 /* error */
  }
#endif
  if (cnt < 0) {
    jlog("Error: adin_alsa: failed to read PCM (%s)\n", snd_strerror(cnt));
    return(-2);
  }
  if (need_swap) {
    swap_sample_bytes(buf, cnt);
  }

  return(cnt);
#endif /* HAS_ALSA */
}

/* end of file */

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