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pcmjob.c

/*
 *  A simple PCM loopback utility
 *  Copyright (c) 2010 by Jaroslav Kysela <perex@perex.cz>
 *
 *     Author: Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <errno.h>
#include <getopt.h>
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <math.h>
#include <syslog.h>
#include <pthread.h>
#include "alsaloop.h"

#define XRUN_PROFILE_UNKNOWN (-10000000)

static int set_rate_shift(struct loopback_handle *lhandle, double pitch);
static int get_rate(struct loopback_handle *lhandle);

#define SYNCTYPE(v) [SYNC_TYPE_##v] = #v

static const char *sync_types[] = {
      SYNCTYPE(NONE),
      SYNCTYPE(SIMPLE),
      SYNCTYPE(CAPTRATESHIFT),
      SYNCTYPE(PLAYRATESHIFT),
      SYNCTYPE(SAMPLERATE),
      SYNCTYPE(AUTO)
};

#define SRCTYPE(v) [SRC_##v] = "SRC_" #v

#ifdef USE_SAMPLERATE
static const char *src_types[] = {
      SRCTYPE(SINC_BEST_QUALITY),
      SRCTYPE(SINC_MEDIUM_QUALITY),
      SRCTYPE(SINC_FASTEST),
      SRCTYPE(ZERO_ORDER_HOLD),
      SRCTYPE(LINEAR)
};
#endif

static pthread_mutex_t pcm_open_mutex =
                                PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;

static inline void pcm_open_lock(void)
{
      if (workarounds & WORKAROUND_SERIALOPEN)
              pthread_mutex_lock(&pcm_open_mutex);
}
 
static inline void pcm_open_unlock(void)
{
      if (workarounds & WORKAROUND_SERIALOPEN)
              pthread_mutex_unlock(&pcm_open_mutex);
}

static inline snd_pcm_uframes_t get_whole_latency(struct loopback *loop)
{
      return loop->latency;
}

static inline unsigned long long
                  frames_to_time(unsigned int rate,
                               snd_pcm_uframes_t frames)
{
      return (frames * 1000000ULL) / rate;
}

static inline snd_pcm_uframes_t time_to_frames(unsigned int rate,
                                     unsigned long long time)
{
      return (time * rate) / 1000000ULL;
}

static int setparams_stream(struct loopback_handle *lhandle,
                      snd_pcm_hw_params_t *params)
{
      snd_pcm_t *handle = lhandle->handle;
      int err;
      unsigned int rrate;

      err = snd_pcm_hw_params_any(handle, params);
      if (err < 0) {
            logit(LOG_CRIT, "Broken configuration for %s PCM: no configurations available: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_pcm_hw_params_set_rate_resample(handle, params, lhandle->resample);
      if (err < 0) {
            logit(LOG_CRIT, "Resample setup failed for %s (val %i): %s\n", lhandle->id, lhandle->resample, snd_strerror(err));
            return err;
      }
      err = snd_pcm_hw_params_set_access(handle, params, lhandle->access);
      if (err < 0) {
            logit(LOG_CRIT, "Access type not available for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_pcm_hw_params_set_format(handle, params, lhandle->format);
      if (err < 0) {
            logit(LOG_CRIT, "Sample format not available for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_pcm_hw_params_set_channels(handle, params, lhandle->channels);
      if (err < 0) {
            logit(LOG_CRIT, "Channels count (%i) not available for %s: %s\n", lhandle->channels, lhandle->id, snd_strerror(err));
            return err;
      }
      rrate = lhandle->rate_req;
      err = snd_pcm_hw_params_set_rate_near(handle, params, &rrate, 0);
      if (err < 0) {
            logit(LOG_CRIT, "Rate %iHz not available for %s: %s\n", lhandle->rate_req, lhandle->id, snd_strerror(err));
            return err;
      }
      rrate = 0;
      snd_pcm_hw_params_get_rate(params, &rrate, 0);
      lhandle->rate = rrate;
      if (
#ifdef USE_SAMPLERATE
          !lhandle->loopback->src_enable &&
#endif
          (int)rrate != lhandle->rate) {
            logit(LOG_CRIT, "Rate does not match (requested %iHz, got %iHz, resample %i)\n", lhandle->rate, rrate, lhandle->resample);
            return -EINVAL;
      }
      lhandle->pitch = (double)lhandle->rate_req / (double)lhandle->rate;
      return 0;
}

static int setparams_bufsize(struct loopback_handle *lhandle,
                       snd_pcm_hw_params_t *params,
                       snd_pcm_hw_params_t *tparams,
                       snd_pcm_uframes_t bufsize)
{
      snd_pcm_t *handle = lhandle->handle;
      int err;
      snd_pcm_uframes_t periodsize;
      snd_pcm_uframes_t buffersize;
      snd_pcm_uframes_t last_bufsize = 0;

      if (lhandle->buffer_size_req > 0) {
            bufsize = lhandle->buffer_size_req;
            last_bufsize = bufsize;
            goto __set_it;
      }
      __again:
      if (lhandle->buffer_size_req > 0) {
            logit(LOG_CRIT, "Unable to set buffer size %li for %s\n", (long)lhandle->buffer_size, lhandle->id);
            return -EIO;
      }
      if (last_bufsize == bufsize)
            bufsize += 4;
      last_bufsize = bufsize;
      if (bufsize > 10*1024*1024) {
            logit(LOG_CRIT, "Buffer size too big\n");
            return -EIO;
      }
      __set_it:
      snd_pcm_hw_params_copy(params, tparams);
      periodsize = bufsize * 8;
      err = snd_pcm_hw_params_set_buffer_size_near(handle, params, &periodsize);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set buffer size %li for %s: %s\n", periodsize, lhandle->id, snd_strerror(err));
            goto __again;
      }
      snd_pcm_hw_params_get_buffer_size(params, &periodsize);
      if (verbose > 6)
            snd_output_printf(lhandle->loopback->output, "%s: buffer_size=%li\n", lhandle->id, periodsize);
      if (lhandle->period_size_req > 0)
            periodsize = lhandle->period_size_req;
      else
            periodsize /= 8;
      err = snd_pcm_hw_params_set_period_size_near(handle, params, &periodsize, 0);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set period size %li for %s: %s\n", periodsize, lhandle->id, snd_strerror(err));
            goto __again;
      }
      snd_pcm_hw_params_get_period_size(params, &periodsize, NULL);
      if (verbose > 6)
            snd_output_printf(lhandle->loopback->output, "%s: period_size=%li\n", lhandle->id, periodsize);
      if (periodsize != bufsize)
            bufsize = periodsize;
      snd_pcm_hw_params_get_buffer_size(params, &buffersize);
      if (periodsize * 2 > buffersize)
            goto __again;
      lhandle->period_size = periodsize;
      lhandle->buffer_size = buffersize;
      return 0;
}

static int setparams_set(struct loopback_handle *lhandle,
                   snd_pcm_hw_params_t *params,
                   snd_pcm_sw_params_t *swparams,
                   snd_pcm_uframes_t bufsize)
{
      snd_pcm_t *handle = lhandle->handle;
      int err;
      snd_pcm_uframes_t val, period_size, buffer_size;

      err = snd_pcm_hw_params(handle, params);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set hw params for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_pcm_sw_params_current(handle, swparams);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to determine current swparams for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_pcm_sw_params_set_start_threshold(handle, swparams, 0x7fffffff);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set start threshold mode for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      snd_pcm_hw_params_get_period_size(params, &period_size, NULL);
      snd_pcm_hw_params_get_buffer_size(params, &buffer_size);
      if (lhandle->nblock) {
            if (lhandle == lhandle->loopback->play) {
                  val = buffer_size - (2 * period_size - 4);
            } else {
                  val = 4;
            }
            if (verbose > 6)
                  snd_output_printf(lhandle->loopback->output, "%s: avail_min1=%li\n", lhandle->id, val);
      } else {
            if (lhandle == lhandle->loopback->play) {
                  val = bufsize + bufsize / 2;
                  if (val < (period_size * 3) / 4)
                        val = (period_size * 3) / 4;
                  if (val > (buffer_size * 3) / 4)
                        val = (buffer_size * 3) / 4;
                  val = buffer_size - val;
            } else {
                  val = bufsize / 2;
                  if (val < period_size / 2)
                        val = period_size / 2;
                  if (val > buffer_size / 4)
                        val = buffer_size / 4;
            }
            if (verbose > 6)
                  snd_output_printf(lhandle->loopback->output, "%s: avail_min2=%li\n", lhandle->id, val);
      }
      err = snd_pcm_sw_params_set_avail_min(handle, swparams, val);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set avail min for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      snd_pcm_sw_params_get_avail_min(swparams, &lhandle->avail_min);
      err = snd_pcm_sw_params(handle, swparams);
      if (err < 0) {
            logit(LOG_CRIT, "Unable to set sw params for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return 0;
}

static int setparams(struct loopback *loop, snd_pcm_uframes_t bufsize)
{
      int err;
      snd_pcm_hw_params_t *pt_params, *ct_params;     /* templates with rate, format and channels */
      snd_pcm_hw_params_t *p_params, *c_params;
      snd_pcm_sw_params_t *p_swparams, *c_swparams;

      snd_pcm_hw_params_alloca(&p_params);
      snd_pcm_hw_params_alloca(&c_params);
      snd_pcm_hw_params_alloca(&pt_params);
      snd_pcm_hw_params_alloca(&ct_params);
      snd_pcm_sw_params_alloca(&p_swparams);
      snd_pcm_sw_params_alloca(&c_swparams);
      if ((err = setparams_stream(loop->play, pt_params)) < 0) {
            logit(LOG_CRIT, "Unable to set parameters for %s stream: %s\n", loop->play->id, snd_strerror(err));
            return err;
      }
      if ((err = setparams_stream(loop->capt, ct_params)) < 0) {
            logit(LOG_CRIT, "Unable to set parameters for %s stream: %s\n", loop->capt->id, snd_strerror(err));
            return err;
      }

      if ((err = setparams_bufsize(loop->play, p_params, pt_params, bufsize / loop->play->pitch)) < 0) {
            logit(LOG_CRIT, "Unable to set buffer parameters for %s stream: %s\n", loop->play->id, snd_strerror(err));
            return err;
      }
      if ((err = setparams_bufsize(loop->capt, c_params, ct_params, bufsize / loop->capt->pitch)) < 0) {
            logit(LOG_CRIT, "Unable to set buffer parameters for %s stream: %s\n", loop->capt->id, snd_strerror(err));
            return err;
      }

      if ((err = setparams_set(loop->play, p_params, p_swparams, bufsize / loop->play->pitch)) < 0) {
            logit(LOG_CRIT, "Unable to set sw parameters for %s stream: %s\n", loop->play->id, snd_strerror(err));
            return err;
      }
      if ((err = setparams_set(loop->capt, c_params, c_swparams, bufsize / loop->capt->pitch)) < 0) {
            logit(LOG_CRIT, "Unable to set sw parameters for %s stream: %s\n", loop->capt->id, snd_strerror(err));
            return err;
      }

#if 0
      if (!loop->linked)
            if (snd_pcm_link(loop->capt->handle, loop->play->handle) >= 0)
                  loop->linked = 1;
#endif
      if ((err = snd_pcm_prepare(loop->play->handle)) < 0) {
            logit(LOG_CRIT, "Prepare %s error: %s\n", loop->play->id, snd_strerror(err));
            return err;
      }
      if (!loop->linked && (err = snd_pcm_prepare(loop->capt->handle)) < 0) {
            logit(LOG_CRIT, "Prepare %s error: %s\n", loop->capt->id, snd_strerror(err));
            return err;
      }

      if (verbose) {
            snd_pcm_dump(loop->play->handle, loop->output);
            snd_pcm_dump(loop->capt->handle, loop->output);
      }
      return 0;
}

static void showlatency(snd_output_t *out, size_t latency, unsigned int rate,
                  char *prefix)
{
      double d;
      d = (double)latency / (double)rate;
      snd_output_printf(out, "%s %li frames, %.3fus, %.6fms (%.4fHz)\n", prefix, (long)latency, d * 1000000, d * 1000, (double)1 / d);
}

static long timediff(snd_timestamp_t t1, snd_timestamp_t t2)
{
      signed long l;

      t1.tv_sec -= t2.tv_sec;
      if (t1.tv_usec < t2.tv_usec) {
            l = ((t1.tv_usec + 1000000) - t2.tv_usec) % 1000000;
            t1.tv_sec--;
      } else {
            l = t1.tv_usec - t2.tv_usec;
      }
      return (t1.tv_sec * 1000000) + l;
}

static int getcurtimestamp(snd_timestamp_t *ts)
{
      struct timeval tv;
      gettimeofday(&tv, NULL);
      ts->tv_sec = tv.tv_sec;
      ts->tv_usec = tv.tv_usec;
      return 0;
}

static void xrun_profile0(struct loopback *loop)
{
      snd_pcm_sframes_t pdelay, cdelay;

      if (snd_pcm_delay(loop->play->handle, &pdelay) >= 0 &&
          snd_pcm_delay(loop->capt->handle, &cdelay) >= 0) {
            getcurtimestamp(&loop->xrun_last_update);
            loop->xrun_last_pdelay = pdelay;
            loop->xrun_last_cdelay = cdelay;
            loop->xrun_buf_pcount = loop->play->buf_count;
            loop->xrun_buf_ccount = loop->capt->buf_count;
#ifdef USE_SAMPLERATE
            loop->xrun_out_frames = loop->src_out_frames;
#endif
      }
}

static inline void xrun_profile(struct loopback *loop)
{
      if (loop->xrun)
            xrun_profile0(loop);
}

static void xrun_stats0(struct loopback *loop)
{
      snd_timestamp_t t;
      double expected, last, wake, check, queued = -1, proc, missing = -1;
      double maxbuf, pfilled, cfilled, cqueued = -1, avail_min;
      double sincejob;

      expected = ((double)loop->latency /
                        (double)loop->play->rate_req) * 1000;
      getcurtimestamp(&t);
      last = (double)timediff(t, loop->xrun_last_update) / 1000;
      wake = (double)timediff(t, loop->xrun_last_wake) / 1000;
      check = (double)timediff(t, loop->xrun_last_check) / 1000;
      sincejob = (double)timediff(t, loop->tstamp_start) / 1000;
      if (loop->xrun_last_pdelay != XRUN_PROFILE_UNKNOWN)
            queued = ((double)loop->xrun_last_pdelay /
                        (double)loop->play->rate) * 1000;
      if (loop->xrun_last_cdelay != XRUN_PROFILE_UNKNOWN)
            cqueued = ((double)loop->xrun_last_cdelay /
                        (double)loop->capt->rate) * 1000;
      maxbuf = ((double)loop->play->buffer_size /
                        (double)loop->play->rate) * 1000;
      proc = (double)loop->xrun_max_proctime / 1000;
      pfilled = ((double)(loop->xrun_buf_pcount + loop->xrun_out_frames) /
                        (double)loop->play->rate) * 1000;
      cfilled = ((double)loop->xrun_buf_ccount /
                        (double)loop->capt->rate) * 1000;
      avail_min = (((double)loop->play->buffer_size - 
                        (double)loop->play->avail_min ) / 
                        (double)loop->play->rate) * 1000;
      avail_min = expected - avail_min;
      if (queued >= 0)
            missing = last - queued;
      if (missing >= 0 && loop->xrun_max_missing < missing)
            loop->xrun_max_missing = missing;
      loop->xrun_max_proctime = 0;
      getcurtimestamp(&t);
      logit(LOG_INFO, "  last write before %.4fms, queued %.4fms/%.4fms -> missing %.4fms\n", last, queued, cqueued, missing);
      logit(LOG_INFO, "  expected %.4fms, processing %.4fms, max missing %.4fms\n", expected, proc, loop->xrun_max_missing);
      logit(LOG_INFO, "  last wake %.4fms, last check %.4fms, avail_min %.4fms\n", wake, check, avail_min);
      logit(LOG_INFO, "  max buf %.4fms, pfilled %.4fms, cfilled %.4fms\n", maxbuf, pfilled, cfilled);
      logit(LOG_INFO, "  job started before %.4fms\n", sincejob);
}

static inline void xrun_stats(struct loopback *loop)
{
      if (loop->xrun)
            xrun_stats0(loop);
}

static inline snd_pcm_uframes_t buf_avail(struct loopback_handle *lhandle)
{
      return lhandle->buf_size - lhandle->buf_count;
}

static void buf_remove(struct loopback *loop, snd_pcm_uframes_t count)
{
      /* remove samples from the capture buffer */
      if (count <= 0)
            return;
      if (loop->play->buf == loop->capt->buf) {
            if (count < loop->capt->buf_count)
                  loop->capt->buf_count -= count;
            else
                  loop->capt->buf_count = 0;
      }
}

#if 0
static void buf_add_copy(struct loopback *loop)
{
      struct loopback_handle *capt = loop->capt;
      struct loopback_handle *play = loop->play;
      snd_pcm_uframes_t count, count1, cpos, ppos;

      count = capt->buf_count;
      cpos = capt->buf_pos - count;
      if (cpos > capt->buf_size)
            cpos += capt->buf_size;
      ppos = (play->buf_pos + play->buf_count) % play->buf_size;
      while (count > 0) {
            count1 = count;
            if (count1 + cpos > capt->buf_size)
                  count1 = capt->buf_size - cpos;
            if (count1 > buf_avail(play))
                  count1 = buf_avail(play);
            if (count1 + ppos > play->buf_size)
                  count1 = play->buf_size - ppos;
            if (count1 == 0)
                  break;
            memcpy(play->buf + ppos * play->frame_size,
                   capt->buf + cpos * capt->frame_size,
                   count1 * capt->frame_size);
            play->buf_count += count1;
            capt->buf_count -= count1;
            ppos += count1;
            ppos %= play->buf_size;
            cpos += count1;
            cpos %= capt->buf_size;
            count -= count1;
      }
}
#endif

#ifdef USE_SAMPLERATE
static void buf_add_src(struct loopback *loop)
{
      struct loopback_handle *capt = loop->capt;
      struct loopback_handle *play = loop->play;
      float *old_data_out;
      snd_pcm_uframes_t count, pos, count1, pos1;
      count = capt->buf_count;
      pos = 0;
      pos1 = capt->buf_pos - count;
      if (pos1 > capt->buf_size)
            pos1 += capt->buf_size;
      while (count > 0) {
            count1 = count;
            if (count1 + pos1 > capt->buf_size)
                  count1 = capt->buf_size - pos1;
            if (capt->format == SND_PCM_FORMAT_S32)
                  src_int_to_float_array((int *)(capt->buf +
                                    pos1 * capt->frame_size),
                               loop->src_data.data_in +
                                 pos * capt->channels,
                               count1 * capt->channels);
            else
                  src_short_to_float_array((short *)(capt->buf +
                                    pos1 * capt->frame_size),
                               loop->src_data.data_in +
                                 pos * capt->channels,
                               count1 * capt->channels);
            count -= count1;
            pos += count1;
            pos1 += count1;
            pos1 %= capt->buf_size;
      }
      loop->src_data.input_frames = pos;
      loop->src_data.output_frames = play->buf_size -
                                    loop->src_out_frames;
      loop->src_data.end_of_input = 0;
      old_data_out = loop->src_data.data_out;
      loop->src_data.data_out = old_data_out + loop->src_out_frames;
      src_process(loop->src_state, &loop->src_data);
      loop->src_data.data_out = old_data_out;
      capt->buf_count -= loop->src_data.input_frames_used;
      count = loop->src_data.output_frames_gen +
            loop->src_out_frames;
      pos = 0;
      pos1 = (play->buf_pos + play->buf_count) % play->buf_size;
      while (count > 0) {
            count1 = count;
            if (count1 + pos1 > play->buf_size)
                  count1 = play->buf_size - pos1;
            if (count1 > buf_avail(play))
                  count1 = buf_avail(play);
            if (count1 == 0)
                  break;
            if (capt->format == SND_PCM_FORMAT_S32)
                  src_float_to_int_array(loop->src_data.data_out +
                                 pos * play->channels,
                               (int *)(play->buf +
                                 pos1 * play->frame_size),
                               count1 * play->channels);
            else
                  src_float_to_short_array(loop->src_data.data_out +
                                 pos * play->channels,
                               (short *)(play->buf +
                                 pos1 * play->frame_size),
                               count1 * play->channels);
            play->buf_count += count1;
            count -= count1;
            pos += count1;
            pos1 += count1;
            pos1 %= play->buf_size;
      }
#if 0
      printf("src: pos = %li, gen = %li, out = %li, count = %li\n",
            (long)pos, (long)loop->src_data.output_frames_gen,
            (long)loop->src_out_frames, play->buf_count);
#endif
      loop->src_out_frames = (loop->src_data.output_frames_gen +
                              loop->src_out_frames) - pos;
      if (loop->src_out_frames > 0) {
            memmove(loop->src_data.data_out,
                  loop->src_data.data_out + pos * play->channels,
                  loop->src_out_frames * play->channels * sizeof(float));
      }
}
#else
static void buf_add_src(struct loopback *loop)
{
}
#endif

static void buf_add(struct loopback *loop, snd_pcm_uframes_t count)
{
      /* copy samples from capture to playback buffer */
      if (count <= 0)
            return;
      if (loop->play->buf == loop->capt->buf) {
            loop->play->buf_count += count;
      } else {
            buf_add_src(loop);
      }
}

static int xrun(struct loopback_handle *lhandle)
{
      int err;

      if (lhandle == lhandle->loopback->play) {
            logit(LOG_DEBUG, "underrun for %s\n", lhandle->id);
            xrun_stats(lhandle->loopback);
            if ((err = snd_pcm_prepare(lhandle->handle)) < 0)
                  return err;
            lhandle->xrun_pending = 1;
      } else {
            logit(LOG_DEBUG, "overrun for %s\n", lhandle->id);
            xrun_stats(lhandle->loopback);
            if ((err = snd_pcm_prepare(lhandle->handle)) < 0)
                  return err;
            lhandle->xrun_pending = 1;
      }
      return 0;
}

static int suspend(struct loopback_handle *lhandle)
{
      int err;

      while ((err = snd_pcm_resume(lhandle->handle)) == -EAGAIN)
            usleep(1);
      if (err < 0)
            return xrun(lhandle);
      return 0;
}

static int readit(struct loopback_handle *lhandle)
{
      snd_pcm_sframes_t r, res = 0;
      snd_pcm_sframes_t avail;
      int err;

      avail = snd_pcm_avail_update(lhandle->handle);
      if (avail == -EPIPE) {
            return xrun(lhandle);
      } else if (avail == -ESTRPIPE) {
            if ((err = suspend(lhandle)) < 0)
                  return err;
      }
      if (avail > buf_avail(lhandle)) {
            lhandle->buf_over += avail - buf_avail(lhandle);
            avail = buf_avail(lhandle);
      } else if (avail == 0) {
            if (snd_pcm_state(lhandle->handle) == SND_PCM_STATE_DRAINING) {
                  lhandle->loopback->reinit = 1;
                  return 0;
            }
      }
      while (avail > 0) {
            r = buf_avail(lhandle);
            if (r + lhandle->buf_pos > lhandle->buf_size)
                  r = lhandle->buf_size - lhandle->buf_pos;
            if (r > avail)
                  r = avail;
            r = snd_pcm_readi(lhandle->handle,
                          lhandle->buf +
                          lhandle->buf_pos *
                          lhandle->frame_size, r);
            if (r == 0)
                  return res;
            if (r < 0) {
                  if (r == -EPIPE) {
                        err = xrun(lhandle);
                        return res > 0 ? res : err;
                  } else if (r == -ESTRPIPE) {
                        if ((err = suspend(lhandle)) < 0)
                              return res > 0 ? res : err;
                        r = 0;
                  } else {
                        return res > 0 ? res : r;
                  }
            }
#ifdef FILE_CWRITE
            if (lhandle->loopback->cfile)
                  fwrite(lhandle->buf + lhandle->buf_pos * lhandle->frame_size,
                         r, lhandle->frame_size, lhandle->loopback->cfile);
#endif
            res += r;
            if (lhandle->max < res)
                  lhandle->max = res;
            lhandle->counter += r;
            lhandle->buf_count += r;
            lhandle->buf_pos += r;
            lhandle->buf_pos %= lhandle->buf_size;
            avail -= r;
      }
      return res;
}

static int writeit(struct loopback_handle *lhandle)
{
      snd_pcm_sframes_t avail;
      snd_pcm_sframes_t r, res = 0;
      int err;

      __again:
      avail = snd_pcm_avail_update(lhandle->handle);
      if (avail == -EPIPE) {
            if ((err = xrun(lhandle)) < 0)
                  return err;
            return res;
      } else if (avail == -ESTRPIPE) {
            if ((err = suspend(lhandle)) < 0)
                  return err;
            goto __again;
      }
      while (avail > 0 && lhandle->buf_count > 0) {
            r = lhandle->buf_count;
            if (r + lhandle->buf_pos > lhandle->buf_size)
                  r = lhandle->buf_size - lhandle->buf_pos;
            if (r > avail)
                  r = avail;
            r = snd_pcm_writei(lhandle->handle,
                           lhandle->buf +
                           lhandle->buf_pos *
                           lhandle->frame_size, r);
            if (r <= 0) {
                  if (r == -EPIPE) {
                        if ((err = xrun(lhandle)) < 0)
                              return err;
                        return res;
                  } else if (r == -ESTRPIPE) {
                  }
                  return res > 0 ? res : r;
            }
#ifdef FILE_PWRITE
            if (lhandle->loopback->pfile)
                  fwrite(lhandle->buf + lhandle->buf_pos * lhandle->frame_size,
                         r, lhandle->frame_size, lhandle->loopback->pfile);
#endif
            res += r;
            lhandle->counter += r;
            lhandle->buf_count -= r;
            lhandle->buf_pos += r;
            lhandle->buf_pos %= lhandle->buf_size;
            xrun_profile(lhandle->loopback);
            if (lhandle->loopback->stop_pending) {
                  lhandle->loopback->stop_count += r;
                  if (lhandle->loopback->stop_count * lhandle->pitch >
                      lhandle->loopback->latency * 3) {
                        lhandle->loopback->stop_pending = 0;
                        lhandle->loopback->reinit = 1;
                        break;
                  }
            }
      }
      return res;
}

static snd_pcm_sframes_t remove_samples(struct loopback *loop,
                              int capture_preferred,
                              snd_pcm_sframes_t count)
{
      struct loopback_handle *play = loop->play;
      struct loopback_handle *capt = loop->capt;

      if (loop->play->buf == loop->capt->buf) {
            if (count > loop->play->buf_count)
                  count = loop->play->buf_count;
            if (count > loop->capt->buf_count)
                  count = loop->capt->buf_count;
            capt->buf_count -= count;
            play->buf_pos += count;
            play->buf_pos %= play->buf_size;
            play->buf_count -= count;
            return count;
      }
      if (capture_preferred) {
            if (count > capt->buf_count)
                  count = capt->buf_count;
            capt->buf_count -= count;
      } else {
            if (count > play->buf_count)
                  count = play->buf_count;
            play->buf_count -= count;
      }
      return count;
}

static int xrun_sync(struct loopback *loop)
{
      struct loopback_handle *play = loop->play;
      struct loopback_handle *capt = loop->capt;
      snd_pcm_uframes_t fill = get_whole_latency(loop);
      snd_pcm_sframes_t pdelay, cdelay, delay1, pdelay1, cdelay1, diff;
      int err;

      __again:
      if (verbose > 5)
            snd_output_printf(loop->output, "%s: xrun sync %i %i\n", loop->id, capt->xrun_pending, play->xrun_pending);
      if (capt->xrun_pending) {
            __pagain:
            capt->xrun_pending = 0;
            if ((err = snd_pcm_prepare(capt->handle)) < 0) {
                  logit(LOG_CRIT, "%s prepare failed: %s\n", capt->id, snd_strerror(err));
                  return err;
            }
            if ((err = snd_pcm_start(capt->handle)) < 0) {
                  logit(LOG_CRIT, "%s start failed: %s\n", capt->id, snd_strerror(err));
                  return err;
            }
      } else {
            diff = readit(capt);
            buf_add(loop, diff);
            if (capt->xrun_pending)
                  goto __pagain;
      }
      /* skip additional playback samples */
      if ((err = snd_pcm_delay(capt->handle, &cdelay)) < 0) {
            if (err == -EPIPE) {
                  capt->xrun_pending = 1;
                  goto __again;
            }
            if (err == -ESTRPIPE) {
                  err = suspend(capt);
                  if (err < 0)
                        return err;
                  goto __again;
            }
            logit(LOG_CRIT, "%s capture delay failed: %s\n", capt->id, snd_strerror(err));
            return err;
      }
      if ((err = snd_pcm_delay(play->handle, &pdelay)) < 0) {
            if (err == -EPIPE) {
                  pdelay = 0;
                  play->xrun_pending = 1;
            } else if (err == -ESTRPIPE) {
                  err = suspend(play);
                  if (err < 0)
                        return err;
                  goto __again;
            } else {
                  logit(LOG_CRIT, "%s playback delay failed: %s\n", play->id, snd_strerror(err));
                  return err;
            }
      }
      capt->counter = cdelay;
      play->counter = pdelay;
      if (play->buf != capt->buf)
            cdelay += capt->buf_count;
      pdelay += play->buf_count;
#ifdef USE_SAMPLERATE
      pdelay += loop->src_out_frames;
#endif
      cdelay1 = cdelay * capt->pitch;
      pdelay1 = pdelay * play->pitch;
      delay1 = cdelay1 + pdelay1;
      capt->total_queued = 0;
      play->total_queued = 0;
      loop->total_queued_count = 0;
      loop->pitch_diff = loop->pitch_diff_min = loop->pitch_diff_max = 0;
      if (verbose > 6) {
            snd_output_printf(loop->output,
                  "sync: cdelay=%li(%li), pdelay=%li(%li), fill=%li (delay=%li)"
#ifdef USE_SAMPLERATE
                  ", src_out=%li"
#endif
                  "\n",
                  (long)cdelay, (long)cdelay1, (long)pdelay, (long)pdelay1,
                  (long)fill, (long)delay1
#ifdef USE_SAMPLERATE
                  , (long)loop->src_out_frames
#endif
                  );
            snd_output_printf(loop->output,
                  "sync: cbufcount=%li, pbufcount=%li\n",
                  (long)capt->buf_count, (long)play->buf_count);
      }
      if (delay1 > fill && capt->counter > 0) {
            if ((err = snd_pcm_drop(capt->handle)) < 0)
                  return err;
            if ((err = snd_pcm_prepare(capt->handle)) < 0)
                  return err;
            if ((err = snd_pcm_start(capt->handle)) < 0)
                  return err;
            diff = remove_samples(loop, 1, (delay1 - fill) / capt->pitch);
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: capt stop removed %li samples\n", (long)diff);
            goto __again;
      }
      if (delay1 > fill) {
            diff = (delay1 - fill) / play->pitch;
            if (diff > play->buf_count)
                  diff = play->buf_count;
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: removing %li playback samples, delay1=%li\n", (long)diff, (long)delay1);
            diff = remove_samples(loop, 0, diff);
            pdelay -= diff;
            pdelay1 = pdelay * play->pitch;
            delay1 = cdelay1 + pdelay1;
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: removed %li playback samples, delay1=%li\n", (long)diff, (long)delay1);
      }
      if (delay1 > fill) {
            diff = (delay1 - fill) / capt->pitch;
            if (diff > capt->buf_count)
                  diff = capt->buf_count;
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: removing %li captured samples, delay1=%li\n", (long)diff, (long)delay1);
            diff -= remove_samples(loop, 1, diff);
            cdelay -= diff;
            cdelay1 = cdelay * capt->pitch;
            delay1 = cdelay1 + pdelay1;         
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: removed %li captured samples, delay1=%li\n", (long)diff, (long)delay1);
      }
      if (play->xrun_pending) {
            play->xrun_pending = 0;
            diff = (fill - delay1) / play->pitch;
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: xrun_pending, silence filling %li / buf_count=%li\n", (long)diff, play->buf_count);
            if (fill > delay1 && play->buf_count < diff) {
                  diff = diff - play->buf_count;
                  if (verbose > 6)
                        snd_output_printf(loop->output,
                              "sync: playback silence added %li samples\n", (long)diff);
                  play->buf_pos -= diff;
                  play->buf_pos %= play->buf_size;
                  if ((err = snd_pcm_format_set_silence(play->format, play->buf + play->buf_pos * play->channels, diff)) < 0)
                        return err;
                  play->buf_count += diff;
            }
            if ((err = snd_pcm_prepare(play->handle)) < 0) {
                  logit(LOG_CRIT, "%s prepare failed: %s\n", play->id, snd_strerror(err));

                  return err;
            }
            delay1 = writeit(play);
            if (verbose > 6)
                  snd_output_printf(loop->output,
                        "sync: playback wrote %li samples\n", (long)delay1);
            if (delay1 > diff) {
                  buf_remove(loop, delay1 - diff);
                  if (verbose > 6)
                        snd_output_printf(loop->output,
                              "sync: playback buf_remove %li samples\n", (long)(delay1 - diff));
            }
            if ((err = snd_pcm_start(play->handle)) < 0) {
                  logit(LOG_CRIT, "%s start failed: %s\n", play->id, snd_strerror(err));
                  return err;
            }
      }
      if (verbose > 5) {
            snd_output_printf(loop->output, "%s: xrun sync ok\n", loop->id);
            if (verbose > 6) {
                  if (snd_pcm_delay(capt->handle, &cdelay) < 0)
                        cdelay = -1;
                  if (snd_pcm_delay(play->handle, &pdelay) < 0)
                        pdelay = -1;
                  if (play->buf != capt->buf)
                        cdelay += capt->buf_count;
                  pdelay += play->buf_count;
#ifdef USE_SAMPLERATE
                  pdelay += loop->src_out_frames;
#endif
                  cdelay1 = cdelay * capt->pitch;
                  pdelay1 = pdelay * play->pitch;
                  delay1 = cdelay1 + pdelay1;
                  snd_output_printf(loop->output, "%s: sync verify: %li\n", loop->id, delay1);
            }
      }
      loop->xrun_max_proctime = 0;
      return 0;
}

static int set_notify(struct loopback_handle *lhandle, int enable)
{
      int err;

      if (lhandle->ctl_notify == NULL)
            return 0;
      snd_ctl_elem_value_set_boolean(lhandle->ctl_notify, 0, enable);
      err = snd_ctl_elem_write(lhandle->ctl, lhandle->ctl_notify);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot set PCM Notify element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      err = snd_ctl_elem_read(lhandle->ctl, lhandle->ctl_notify);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot get PCM Notify element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return 0;
}

static int set_rate_shift(struct loopback_handle *lhandle, double pitch)
{
      int err;

      if (lhandle->ctl_rate_shift == NULL)
            return 0;
      snd_ctl_elem_value_set_integer(lhandle->ctl_rate_shift, 0, pitch * 100000);
      err = snd_ctl_elem_write(lhandle->ctl, lhandle->ctl_rate_shift);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot set PCM Rate Shift element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return 0;
}

void update_pitch(struct loopback *loop)
{
      double pitch = loop->pitch;

#ifdef USE_SAMPLERATE
      if (loop->sync == SYNC_TYPE_SAMPLERATE) {
            loop->src_data.src_ratio = (double)1.0 / (pitch *
                        loop->play->pitch * loop->capt->pitch);
            if (verbose > 2)
                  snd_output_printf(loop->output, "%s: Samplerate src_ratio update1: %.8f\n", loop->id, loop->src_data.src_ratio);
      } else
#endif
      if (loop->sync == SYNC_TYPE_CAPTRATESHIFT) {
            set_rate_shift(loop->capt, pitch);
#ifdef USE_SAMPLERATE
            if (loop->use_samplerate) {
                  loop->src_data.src_ratio = 
                        (double)1.0 /
                              (loop->play->pitch * loop->capt->pitch);
                  if (verbose > 2)
                        snd_output_printf(loop->output, "%s: Samplerate src_ratio update2: %.8f\n", loop->id, loop->src_data.src_ratio);
            }
#endif
      }
      else if (loop->sync == SYNC_TYPE_PLAYRATESHIFT) {
            set_rate_shift(loop->play, pitch);
#ifdef USE_SAMPLERATE
            if (loop->use_samplerate) {
                  loop->src_data.src_ratio = 
                        (double)1.0 /
                              (loop->play->pitch * loop->capt->pitch);
                  if (verbose > 2)
                        snd_output_printf(loop->output, "%s: Samplerate src_ratio update3: %.8f\n", loop->id, loop->src_data.src_ratio);
            }
#endif
      }
      if (verbose)
            snd_output_printf(loop->output, "New pitch for %s: %.8f (min/max samples = %li/%li)\n", loop->id, pitch, loop->pitch_diff_min, loop->pitch_diff_max);
}

static int get_active(struct loopback_handle *lhandle)
{
      int err;

      if (lhandle->ctl_active == NULL)
            return 0;
      err = snd_ctl_elem_read(lhandle->ctl, lhandle->ctl_active);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot get PCM Slave Active element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return snd_ctl_elem_value_get_boolean(lhandle->ctl_active, 0);
}

static int get_format(struct loopback_handle *lhandle)
{
      int err;

      if (lhandle->ctl_format == NULL)
            return 0;
      err = snd_ctl_elem_read(lhandle->ctl, lhandle->ctl_format);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot get PCM Format element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return snd_ctl_elem_value_get_integer(lhandle->ctl_format, 0);
}

static int get_rate(struct loopback_handle *lhandle)
{
      int err;

      if (lhandle->ctl_rate == NULL)
            return 0;
      err = snd_ctl_elem_read(lhandle->ctl, lhandle->ctl_rate);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot get PCM Rate element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return snd_ctl_elem_value_get_integer(lhandle->ctl_rate, 0);
}

static int get_channels(struct loopback_handle *lhandle)
{
      int err;

      if (lhandle->ctl_channels == NULL)
            return 0;
      err = snd_ctl_elem_read(lhandle->ctl, lhandle->ctl_channels);
      if (err < 0) {
            logit(LOG_CRIT, "Cannot get PCM Channels element for %s: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      return snd_ctl_elem_value_get_integer(lhandle->ctl_channels, 0);
}

static void openctl_elem(struct loopback_handle *lhandle,
                   int device, int subdevice,
                   const char *name,
                   snd_ctl_elem_value_t **elem)
{
      int err;

      if (snd_ctl_elem_value_malloc(elem) < 0) {
            *elem = NULL;
      } else {
            snd_ctl_elem_value_set_interface(*elem,
                                     SND_CTL_ELEM_IFACE_PCM);
            snd_ctl_elem_value_set_device(*elem, device);
            snd_ctl_elem_value_set_subdevice(*elem, subdevice);
            snd_ctl_elem_value_set_name(*elem, name);
            err = snd_ctl_elem_read(lhandle->ctl, *elem);
            if (err < 0) {
                  snd_ctl_elem_value_free(*elem);
                  *elem = NULL;
            }
      }
}

static int openctl(struct loopback_handle *lhandle, int device, int subdevice)
{
      int err;

      lhandle->ctl_rate_shift = NULL;
      if (lhandle->loopback->play == lhandle) {
            if (lhandle->loopback->controls)
                  goto __events;
            return 0;
      }
      openctl_elem(lhandle, device, subdevice, "PCM Notify",
                  &lhandle->ctl_notify);
      openctl_elem(lhandle, device, subdevice, "PCM Rate Shift 100000",
                  &lhandle->ctl_rate_shift);
      set_rate_shift(lhandle, 1);
      openctl_elem(lhandle, device, subdevice, "PCM Slave Active",
                  &lhandle->ctl_active);
      openctl_elem(lhandle, device, subdevice, "PCM Slave Format",
                  &lhandle->ctl_format);
      openctl_elem(lhandle, device, subdevice, "PCM Slave Rate",
                  &lhandle->ctl_rate);
      openctl_elem(lhandle, device, subdevice, "PCM Slave Channels",
                  &lhandle->ctl_channels);
      if ((lhandle->ctl_active &&
           lhandle->ctl_format &&
           lhandle->ctl_rate &&
           lhandle->ctl_channels) ||
          lhandle->loopback->controls) {
            __events:
            if ((err = snd_ctl_poll_descriptors_count(lhandle->ctl)) < 0)
                  lhandle->ctl_pollfd_count = 0;
            else
                  lhandle->ctl_pollfd_count = err;
            if (snd_ctl_subscribe_events(lhandle->ctl, 1) < 0)
                  lhandle->ctl_pollfd_count = 0;
      }
      return 0;
}

static int openit(struct loopback_handle *lhandle)
{
      snd_pcm_info_t *info;
      int stream = lhandle == lhandle->loopback->play ?
                        SND_PCM_STREAM_PLAYBACK :
                        SND_PCM_STREAM_CAPTURE;
      int err, card, device, subdevice;
      pcm_open_lock();
      err = snd_pcm_open(&lhandle->handle, lhandle->device, stream, SND_PCM_NONBLOCK);
      pcm_open_unlock();
      if (err < 0) {
            logit(LOG_CRIT, "%s open error: %s\n", lhandle->id, snd_strerror(err));
            return err;
      }
      if ((err = snd_pcm_info_malloc(&info)) < 0)
            return err;
      if ((err = snd_pcm_info(lhandle->handle, info)) < 0) {
            snd_pcm_info_free(info);
            return err;
      }
      card = snd_pcm_info_get_card(info);
      device = snd_pcm_info_get_device(info);
      subdevice = snd_pcm_info_get_subdevice(info);
      snd_pcm_info_free(info);
      lhandle->card_number = card;
      lhandle->ctl = NULL;
      if (card >= 0 || lhandle->ctldev) {
            char name[16], *dev = lhandle->ctldev;
            if (dev == NULL) {
                  sprintf(name, "hw:%i", card);
                  dev = name;
            }
            pcm_open_lock();
            err = snd_ctl_open(&lhandle->ctl, dev, SND_CTL_NONBLOCK);
            pcm_open_unlock();
            if (err < 0) {
                  logit(LOG_CRIT, "%s [%s] ctl open error: %s\n", lhandle->id, dev, snd_strerror(err));
                  lhandle->ctl = NULL;
            }
            if (lhandle->ctl)
                  openctl(lhandle, device, subdevice);
      }
      return 0;
}

static int freeit(struct loopback_handle *lhandle)
{
      free(lhandle->buf);
      lhandle->buf = NULL;
      return 0;
}

static int closeit(struct loopback_handle *lhandle)
{
      int err = 0;

      set_rate_shift(lhandle, 1);
      if (lhandle->ctl_rate_shift)
            snd_ctl_elem_value_free(lhandle->ctl_rate_shift);
      lhandle->ctl_rate_shift = NULL;
      if (lhandle->ctl)
            err = snd_ctl_close(lhandle->ctl);
      lhandle->ctl = NULL;
      if (lhandle->handle)
            err = snd_pcm_close(lhandle->handle);
      lhandle->handle = NULL;
      return err;
}

static int init_handle(struct loopback_handle *lhandle, int alloc)
{
      snd_pcm_uframes_t lat;
      lhandle->frame_size = (snd_pcm_format_width(lhandle->format) / 8) *
                                             lhandle->channels;
      lhandle->sync_point = lhandle->rate * 15; /* every 15 seconds */
      lat = lhandle->loopback->latency;
      if (lhandle->buffer_size > lat)
            lat = lhandle->buffer_size;
      lhandle->buf_size = lat * 2;
      if (alloc) {
            lhandle->buf = calloc(1, lhandle->buf_size * lhandle->frame_size);
            if (lhandle->buf == NULL)
                  return -ENOMEM;
      }
      return 0;
}

int pcmjob_init(struct loopback *loop)
{
      int err;
      char id[128];

#ifdef FILE_CWRITE
      loop->cfile = fopen(FILE_CWRITE, "w+");
#endif
#ifdef FILE_PWRITE
      loop->pfile = fopen(FILE_PWRITE, "w+");
#endif
      if ((err = openit(loop->play)) < 0)
            goto __error;
      if ((err = openit(loop->capt)) < 0)
            goto __error;
      snprintf(id, sizeof(id), "%s/%s", loop->play->id, loop->capt->id);
      id[sizeof(id)-1] = '\0';
      loop->id = strdup(id);
      if (loop->sync == SYNC_TYPE_AUTO && loop->capt->ctl_rate_shift)
            loop->sync = SYNC_TYPE_CAPTRATESHIFT;
      if (loop->sync == SYNC_TYPE_AUTO && loop->play->ctl_rate_shift)
            loop->sync = SYNC_TYPE_PLAYRATESHIFT;
#ifdef USE_SAMPLERATE
      if (loop->sync == SYNC_TYPE_AUTO && loop->src_enable)
            loop->sync = SYNC_TYPE_SAMPLERATE;
#endif
      if (loop->sync == SYNC_TYPE_AUTO)
            loop->sync = SYNC_TYPE_SIMPLE;
      if (loop->slave == SLAVE_TYPE_AUTO &&
          loop->capt->ctl_notify &&
          loop->capt->ctl_active &&
          loop->capt->ctl_format &&
          loop->capt->ctl_rate &&
          loop->capt->ctl_channels)
            loop->slave = SLAVE_TYPE_ON;
      if (loop->slave == SLAVE_TYPE_ON) {
            err = set_notify(loop->capt, 1);
            if (err < 0)
                  goto __error;
            if (loop->capt->ctl_notify == NULL ||
                snd_ctl_elem_value_get_boolean(loop->capt->ctl_notify, 0) == 0) {
                  logit(LOG_CRIT, "unable to enable slave mode for %s\n", loop->id);
                  err = -EINVAL;
                  goto __error;
            }
      }
      err = control_init(loop);
      if (err < 0)
            goto __error;
      return 0;
      __error:
      pcmjob_done(loop);
      return err;
}

static void freeloop(struct loopback *loop)
{
#ifdef USE_SAMPLERATE
      if (loop->use_samplerate) {
            if (loop->src_state)
                  src_delete(loop->src_state);
            loop->src_state = NULL;
            free(loop->src_data.data_in);
            loop->src_data.data_in = NULL;
            free(loop->src_data.data_out);
            loop->src_data.data_out = NULL;
      }
#endif
      if (loop->play->buf == loop->capt->buf)
            loop->play->buf = NULL;
      freeit(loop->play);
      freeit(loop->capt);
}

int pcmjob_done(struct loopback *loop)
{
      control_done(loop);
      closeit(loop->play);
      closeit(loop->capt);
      freeloop(loop);
      free(loop->id);
      loop->id = NULL;
#ifdef FILE_PWRITE
      if (loop->pfile) {
            fclose(loop->pfile);
            loop->pfile = NULL;
      }
#endif
#ifdef FILE_CWRITE
      if (loop->cfile) {
            fclose(loop->cfile);
            loop->cfile = NULL;
      }
#endif
      return 0;
}

static void lhandle_start(struct loopback_handle *lhandle)
{
      lhandle->buf_pos = 0;
      lhandle->buf_count = 0;
      lhandle->counter = 0;
      lhandle->total_queued = 0;
}

int pcmjob_start(struct loopback *loop)
{
      snd_pcm_uframes_t count;
      int err;

      loop->pollfd_count = loop->play->ctl_pollfd_count +
                       loop->capt->ctl_pollfd_count;
      if ((err = snd_pcm_poll_descriptors_count(loop->play->handle)) < 0)
            goto __error;
      loop->play->pollfd_count = err;
      loop->pollfd_count += err;
      if ((err = snd_pcm_poll_descriptors_count(loop->capt->handle)) < 0)
            goto __error;
      loop->capt->pollfd_count = err;
      loop->pollfd_count += err;
      if (loop->slave == SLAVE_TYPE_ON) {
            err = get_active(loop->capt);
            if (err < 0)
                  goto __error;
            if (err == 0)           /* stream is not active */
                  return 0;
            err = get_format(loop->capt);
            if (err < 0)
                  goto __error;
            loop->play->format = loop->capt->format = err;
            err = get_rate(loop->capt);
            if (err < 0)
                  goto __error;
            loop->play->rate_req = loop->capt->rate_req = err;
            err = get_channels(loop->capt);
            if (err < 0)
                  goto __error;
            loop->play->channels = loop->capt->channels = err;
      }
      loop->reinit = 0;
      loop->use_samplerate = 0;
      if (loop->latency_req) {
            loop->latency_reqtime = frames_to_time(loop->play->rate_req,
                                           loop->latency_req);
            loop->latency_req = 0;
      }
      loop->latency = time_to_frames(loop->play->rate_req, loop->latency_reqtime);
      if ((err = setparams(loop, loop->latency/2)) < 0)
            goto __error;
      if (verbose)
            showlatency(loop->output, loop->latency, loop->play->rate_req, "Latency");
      if (loop->play->access == loop->capt->access &&
          loop->play->format == loop->capt->format &&
          loop->play->rate == loop->capt->rate &&
          loop->play->channels == loop->play->channels &&
          loop->sync != SYNC_TYPE_SAMPLERATE) {
            if (verbose > 1)
                  snd_output_printf(loop->output, "shared buffer!!!\n");
            if ((err = init_handle(loop->play, 1)) < 0)
                  goto __error;
            if ((err = init_handle(loop->capt, 0)) < 0)
                  goto __error;
            if (loop->play->buf_size < loop->capt->buf_size) {
                  char *nbuf = realloc(loop->play->buf,
                                   loop->capt->buf_size *
                                     loop->capt->frame_size);
                  if (nbuf == NULL) {
                        err = -ENOMEM;
                        goto __error;
                  }
                  loop->play->buf = nbuf;
                  loop->play->buf_size = loop->capt->buf_size;
            } else if (loop->capt->buf_size < loop->play->buf_size) {
                  char *nbuf = realloc(loop->capt->buf,
                                   loop->play->buf_size *
                                     loop->play->frame_size);
                  if (nbuf == NULL) {
                        err = -ENOMEM;
                        goto __error;
                  }
                  loop->capt->buf = nbuf;
                  loop->capt->buf_size = loop->play->buf_size;
            }
            loop->capt->buf = loop->play->buf;
      } else {
            if ((err = init_handle(loop->play, 1)) < 0)
                  goto __error;
            if ((err = init_handle(loop->capt, 1)) < 0)
                  goto __error;
            if (loop->play->rate_req != loop->play->rate)
                  loop->use_samplerate = 1;
            if (loop->capt->rate_req != loop->capt->rate)
                  loop->use_samplerate = 1;
      }
#ifdef USE_SAMPLERATE
      if (loop->sync == SYNC_TYPE_SAMPLERATE)
            loop->use_samplerate = 1;
      if (loop->use_samplerate && !loop->src_enable) {
            logit(LOG_CRIT, "samplerate conversion required but disabled\n");
            loop->use_samplerate = 0;
            err = -EIO;
            goto __error;           
      }
      if (loop->use_samplerate) {
            if ((loop->capt->format != SND_PCM_FORMAT_S16 ||
                loop->play->format != SND_PCM_FORMAT_S16) &&
                (loop->capt->format != SND_PCM_FORMAT_S32 ||
                 loop->play->format != SND_PCM_FORMAT_S32)) {
                  logit(LOG_CRIT, "samplerate conversion supports only %s or %s formats (play=%s, capt=%s)\n", snd_pcm_format_name(SND_PCM_FORMAT_S16), snd_pcm_format_name(SND_PCM_FORMAT_S32), snd_pcm_format_name(loop->play->format), snd_pcm_format_name(loop->capt->format));
                  loop->use_samplerate = 0;
                  err = -EIO;
                  goto __error;           
            }
            loop->src_state = src_new(loop->src_converter_type,
                                loop->play->channels, &err);
            loop->src_data.data_in = calloc(1, sizeof(float)*loop->capt->channels*loop->capt->buf_size);
            if (loop->src_data.data_in == NULL) {
                  err = -ENOMEM;
                  goto __error;
            }
            loop->src_data.data_out =  calloc(1, sizeof(float)*loop->play->channels*loop->play->buf_size);
            if (loop->src_data.data_out == NULL) {
                  err = -ENOMEM;
                  goto __error;
            }
            loop->src_data.src_ratio = (double)loop->play->rate /
                                 (double)loop->capt->rate;
            loop->src_data.end_of_input = 0;
            loop->src_out_frames = 0;
      } else {
            loop->src_state = NULL;
      }
#else
      if (loop->sync == SYNC_TYPE_SAMPLERATE || loop->use_samplerate) {
            logit(LOG_CRIT, "alsaloop is compiled without libsamplerate support\n");
            err = -EIO;
            goto __error;
      }
#endif
      if (verbose) {
            snd_output_printf(loop->output, "%s sync type: %s", loop->id, sync_types[loop->sync]);
#ifdef USE_SAMPLERATE
            if (loop->sync == SYNC_TYPE_SAMPLERATE)
                  snd_output_printf(loop->output, " (%s)", src_types[loop->src_converter_type]);
#endif
            snd_output_printf(loop->output, "\n");
      }
      lhandle_start(loop->play);
      lhandle_start(loop->capt);
      if ((err = snd_pcm_format_set_silence(loop->play->format,
                                    loop->play->buf,
                                    loop->play->buf_size * loop->play->channels)) < 0) {
            logit(LOG_CRIT, "%s: silence error\n", loop->id);
            goto __error;
      }
      if (verbose > 4)
            snd_output_printf(loop->output, "%s: capt->buffer_size = %li, play->buffer_size = %li\n", loop->id, loop->capt->buf_size, loop->play->buf_size);
      loop->pitch = 1.0;
      update_pitch(loop);
      loop->pitch_delta = 1.0 / ((double)loop->capt->rate * 4);
      loop->total_queued_count = 0;
      loop->pitch_diff = 0;
      count = get_whole_latency(loop) / loop->play->pitch;
      loop->play->buf_count = count;
      if (loop->play->buf == loop->capt->buf)
            loop->capt->buf_pos = count;
      err = writeit(loop->play);
      if (verbose > 4)
            snd_output_printf(loop->output, "%s: silence queued %i samples\n", loop->id, err);
      if (count > loop->play->buffer_size)
            count = loop->play->buffer_size;
      if (err != count) {
            logit(LOG_CRIT, "%s: initial playback fill error (%i/%i/%i)\n", loop->id, err, (int)count, loop->play->buffer_size);
            err = -EIO;
            goto __error;
      }
      loop->running = 1;
      loop->stop_pending = 0;
      if (loop->xrun) {
            getcurtimestamp(&loop->xrun_last_update);
            loop->xrun_last_pdelay = XRUN_PROFILE_UNKNOWN;
            loop->xrun_last_cdelay = XRUN_PROFILE_UNKNOWN;
            loop->xrun_max_proctime = 0;
      }
      if ((err = snd_pcm_start(loop->capt->handle)) < 0) {
            logit(LOG_CRIT, "pcm start %s error: %s\n", loop->capt->id, snd_strerror(err));
            goto __error;
      }
      if (!loop->linked) {
            if ((err = snd_pcm_start(loop->play->handle)) < 0) {
                  logit(LOG_CRIT, "pcm start %s error: %s\n", loop->play->id, snd_strerror(err));
                  goto __error;
            }
      }
      return 0;
      __error:
      pcmjob_stop(loop);
      return err;
}

int pcmjob_stop(struct loopback *loop)
{
      int err;

      if (loop->running) {
            if ((err = snd_pcm_drop(loop->capt->handle)) < 0)
                  logit(LOG_WARNING, "pcm drop %s error: %s\n", loop->capt->id, snd_strerror(err));
            if ((err = snd_pcm_drop(loop->play->handle)) < 0)
                  logit(LOG_WARNING, "pcm drop %s error: %s\n", loop->play->id, snd_strerror(err));
            if ((err = snd_pcm_hw_free(loop->capt->handle)) < 0)
                  logit(LOG_WARNING, "pcm hw_free %s error: %s\n", loop->capt->id, snd_strerror(err));
            if ((err = snd_pcm_hw_free(loop->play->handle)) < 0)
                  logit(LOG_WARNING, "pcm hw_free %s error: %s\n", loop->play->id, snd_strerror(err));
            loop->running = 0;
      }
      freeloop(loop);
      return 0;
}

int pcmjob_pollfds_init(struct loopback *loop, struct pollfd *fds)
{
      int err, idx = 0;

      if (loop->running) {
            err = snd_pcm_poll_descriptors(loop->play->handle, fds + idx, loop->play->pollfd_count);
            if (err < 0)
                  return err;
            idx += loop->play->pollfd_count;
            err = snd_pcm_poll_descriptors(loop->capt->handle, fds + idx, loop->capt->pollfd_count);
            if (err < 0)
                  return err;
            idx += loop->capt->pollfd_count;
      }
      if (loop->play->ctl_pollfd_count > 0 &&
          (loop->slave == SLAVE_TYPE_ON || loop->controls)) {
            err = snd_ctl_poll_descriptors(loop->play->ctl, fds + idx, loop->play->ctl_pollfd_count);
            if (err < 0)
                  return err;
            idx += loop->play->ctl_pollfd_count;
      }
      if (loop->capt->ctl_pollfd_count > 0 &&
          (loop->slave == SLAVE_TYPE_ON || loop->controls)) {
            err = snd_ctl_poll_descriptors(loop->capt->ctl, fds + idx, loop->capt->ctl_pollfd_count);
            if (err < 0)
                  return err;
            idx += loop->capt->ctl_pollfd_count;
      }
      loop->active_pollfd_count = idx;
      return idx;
}

static snd_pcm_sframes_t get_queued_playback_samples(struct loopback *loop)
{
      snd_pcm_sframes_t delay;
      int err;

      if ((err = snd_pcm_delay(loop->play->handle, &delay)) < 0)
            return 0;
      loop->play->last_delay = delay;
      delay += loop->play->buf_count;
#ifdef USE_SAMPLERATE
      delay += loop->src_out_frames;
#endif
      return delay;
}

static snd_pcm_sframes_t get_queued_capture_samples(struct loopback *loop)
{
      snd_pcm_sframes_t delay;
      int err;

      if ((err = snd_pcm_delay(loop->capt->handle, &delay)) < 0)
            return 0;
      loop->capt->last_delay = delay;
      delay += loop->capt->buf_count;
      return delay;
}

static int ctl_event_check(snd_ctl_elem_value_t *val, snd_ctl_event_t *ev)
{
      snd_ctl_elem_id_t *id1, *id2;
      snd_ctl_elem_id_alloca(&id1);
      snd_ctl_elem_id_alloca(&id2);
      snd_ctl_elem_value_get_id(val, id1);
      snd_ctl_event_elem_get_id(ev, id2);
      if (snd_ctl_event_elem_get_mask(ev) == SND_CTL_EVENT_MASK_REMOVE)
            return 0;
      if ((snd_ctl_event_elem_get_mask(ev) & SND_CTL_EVENT_MASK_VALUE) == 0)
            return 0;
      return control_id_match(id1, id2);
}

static int handle_ctl_events(struct loopback_handle *lhandle,
                       unsigned short events)
{
      struct loopback *loop = lhandle->loopback;
      snd_ctl_event_t *ev;
      int err, restart = 0;

      snd_ctl_event_alloca(&ev);
      while ((err = snd_ctl_read(lhandle->ctl, ev)) != 0 && err != -EAGAIN) {
            if (err < 0)
                  break;
            if (snd_ctl_event_get_type(ev) != SND_CTL_EVENT_ELEM)
                  continue;
            if (lhandle == loop->play)
                  goto __ctl_check;
            if (verbose > 6)
                  snd_output_printf(loop->output, "%s: ctl event!!!! %s\n", lhandle->id, snd_ctl_event_elem_get_name(ev));
            if (ctl_event_check(lhandle->ctl_active, ev)) {
                  continue;
            } else if (ctl_event_check(lhandle->ctl_format, ev)) {
                  err = get_format(lhandle);
                  if (lhandle->format != err)
                        restart = 1;
                  continue;
            } else if (ctl_event_check(lhandle->ctl_rate, ev)) {
                  err = get_rate(lhandle);
                  if (lhandle->rate != err)
                        restart = 1;
                  continue;
            } else if (ctl_event_check(lhandle->ctl_channels, ev)) {
                  err = get_channels(lhandle);
                  if (lhandle->channels != err)
                        restart = 1;
                  continue;
            }
            __ctl_check:
            control_event(lhandle, ev);
      }
      err = get_active(lhandle);
      if (verbose > 7)
            snd_output_printf(loop->output, "%s: ctl event active %i\n", lhandle->id, err);
      if (!err) {
            if (lhandle->loopback->running) {
                  loop->stop_pending = 1;
                  loop->stop_count = 0;
            }
      } else {
            loop->stop_pending = 0;
            if (loop->running == 0)
                  restart = 1;
      }
      if (restart) {
            pcmjob_stop(loop);
            err = pcmjob_start(loop);
            if (err < 0)
                  return err;
      }
      return 1;
}

int pcmjob_pollfds_handle(struct loopback *loop, struct pollfd *fds)
{
      struct loopback_handle *play = loop->play;
      struct loopback_handle *capt = loop->capt;
      unsigned short prevents, crevents, events;
      snd_pcm_uframes_t ccount, pcount;
      int err, loopcount = 10, idx;

      if (verbose > 11)
            snd_output_printf(loop->output, "%s: pollfds handle\n", loop->id);
      if (verbose > 13 || loop->xrun)
            getcurtimestamp(&loop->tstamp_start);
      if (verbose > 12) {
            snd_pcm_sframes_t pdelay, cdelay;
            if ((err = snd_pcm_delay(play->handle, &pdelay)) < 0)
                  snd_output_printf(loop->output, "%s: delay error: %s / %li / %li\n", play->id, snd_strerror(err), play->buf_size, play->buf_count);
            else
                  snd_output_printf(loop->output, "%s: delay %li / %li / %li\n", play->id, pdelay, play->buf_size, play->buf_count);
            if ((err = snd_pcm_delay(capt->handle, &cdelay)) < 0)
                  snd_output_printf(loop->output, "%s: delay error: %s / %li / %li\n", capt->id, snd_strerror(err), capt->buf_size, capt->buf_count);
            else
                  snd_output_printf(loop->output, "%s: delay %li / %li / %li\n", capt->id, cdelay, capt->buf_size, capt->buf_count);
      }
      idx = 0;
      if (loop->running) {
            err = snd_pcm_poll_descriptors_revents(play->handle, fds,
                                           play->pollfd_count,
                                           &prevents);
            if (err < 0)
                  return err;
            idx += play->pollfd_count;
            err = snd_pcm_poll_descriptors_revents(capt->handle, fds + idx,
                                           capt->pollfd_count,
                                           &crevents);
            if (err < 0)
                  return err;
            idx += capt->pollfd_count;
            if (loop->xrun) {
                  if (prevents || crevents) {
                        loop->xrun_last_wake = loop->xrun_last_wake0;
                        loop->xrun_last_wake0 = loop->tstamp_start;
                  }
                  loop->xrun_last_check = loop->xrun_last_check0;
                  loop->xrun_last_check0 = loop->tstamp_start;
            }
      } else {
            prevents = crevents = 0;
      }
      if (play->ctl_pollfd_count > 0 &&
          (loop->slave == SLAVE_TYPE_ON || loop->controls)) {
            err = snd_ctl_poll_descriptors_revents(play->ctl, fds + idx,
                                           play->ctl_pollfd_count,
                                           &events);
            if (err < 0)
                  return err;
            if (events) {
                  err = handle_ctl_events(play, events);
                  if (err == 1)
                        return 0;
                  if (err < 0)
                        return err;
            }
            idx += play->ctl_pollfd_count;
      }
      if (capt->ctl_pollfd_count > 0 &&
          (loop->slave == SLAVE_TYPE_ON || loop->controls)) {
            err = snd_ctl_poll_descriptors_revents(capt->ctl, fds + idx,
                                           capt->ctl_pollfd_count,
                                           &events);
            if (err < 0)
                  return err;
            if (events) {
                  err = handle_ctl_events(capt, events);
                  if (err == 1)
                        return 0;
                  if (err < 0)
                        return err;
            }
            idx += capt->ctl_pollfd_count;
      }
      if (verbose > 9)
            snd_output_printf(loop->output, "%s: prevents = 0x%x, crevents = 0x%x\n", loop->id, prevents, crevents);
      if (!loop->running)
            goto __pcm_end;
      do {
            ccount = readit(capt);
            buf_add(loop, ccount);
            if (capt->xrun_pending || loop->reinit)
                  break;
            /* we read new samples, if we have a room in the playback
               buffer, feed them there */
            pcount = writeit(play);
            buf_remove(loop, pcount);
            if (play->xrun_pending || loop->reinit)
                  break;
            loopcount--;
      } while ((ccount > 0 || pcount > 0) && loopcount > 0);
      if (play->xrun_pending || capt->xrun_pending) {
            if ((err = xrun_sync(loop)) < 0)
                  return err;
      }
      if (loop->reinit) {
            err = pcmjob_stop(loop);
            if (err < 0)
                  return err;
            err = pcmjob_start(loop);
            if (err < 0)
                  return err;
      }
      if (loop->sync != SYNC_TYPE_NONE &&
          play->counter >= play->sync_point &&
          capt->counter >= play->sync_point) {
            snd_pcm_sframes_t diff, lat = get_whole_latency(loop);
            diff = ((double)(((double)play->total_queued * play->pitch) +
                         ((double)capt->total_queued * capt->pitch)) /
                  (double)loop->total_queued_count) - lat;
            /* FIXME: this algorithm may be slightly better */
            if (verbose > 3)
                  snd_output_printf(loop->output, "%s: sync diff %li old diff %li\n", loop->id, diff, loop->pitch_diff);
            if (diff > 0) {
                  if (diff == loop->pitch_diff)
                        loop->pitch += loop->pitch_delta;
                  else if (diff > loop->pitch_diff)
                        loop->pitch += loop->pitch_delta*2;
            } else if (diff < 0) {
                  if (diff == loop->pitch_diff)
                        loop->pitch -= loop->pitch_delta;
                  else if (diff < loop->pitch_diff)
                        loop->pitch -= loop->pitch_delta*2;
            }
            loop->pitch_diff = diff;
            if (loop->pitch_diff_min > diff)
                  loop->pitch_diff_min = diff;
            if (loop->pitch_diff_max < diff)
                  loop->pitch_diff_max = diff;
            update_pitch(loop);
            play->counter -= play->sync_point;
            capt->counter -= play->sync_point;
            play->total_queued = 0;
            capt->total_queued = 0;
            loop->total_queued_count = 0;
      }
      if (loop->sync != SYNC_TYPE_NONE) {
            snd_pcm_sframes_t pqueued, cqueued;
            pqueued = get_queued_playback_samples(loop);
            cqueued = get_queued_capture_samples(loop);
            if (verbose > 4)
                  snd_output_printf(loop->output, "%s: queued %li/%li samples\n", loop->id, pqueued, cqueued);
            if (pqueued > 0)
                  play->total_queued += pqueued;
            if (cqueued > 0)
                  capt->total_queued += cqueued;
            if (pqueued > 0 || cqueued > 0)
                  loop->total_queued_count += 1;
      }
      if (verbose > 12) {
            snd_pcm_sframes_t pdelay, cdelay;
            if ((err = snd_pcm_delay(play->handle, &pdelay)) < 0)
                  snd_output_printf(loop->output, "%s: end delay error: %s / %li / %li\n", play->id, snd_strerror(err), play->buf_size, play->buf_count);
            else
                  snd_output_printf(loop->output, "%s: end delay %li / %li / %li\n", play->id, pdelay, play->buf_size, play->buf_count);
            if ((err = snd_pcm_delay(capt->handle, &cdelay)) < 0)
                  snd_output_printf(loop->output, "%s: end delay error: %s / %li / %li\n", capt->id, snd_strerror(err), capt->buf_size, capt->buf_count);
            else
                  snd_output_printf(loop->output, "%s: end delay %li / %li / %li\n", capt->id, cdelay, capt->buf_size, capt->buf_count);
      }
      __pcm_end:
      if (verbose > 13 || loop->xrun) {
            long diff;
            getcurtimestamp(&loop->tstamp_end);
            diff = timediff(loop->tstamp_end, loop->tstamp_start);
            if (verbose > 13)
                  snd_output_printf(loop->output, "%s: processing time %lius\n", loop->id, diff);
            if (loop->xrun && loop->xrun_max_proctime < diff)
                  loop->xrun_max_proctime = diff;
      }
      return 0;
}

#define OUT(args...) \
      snd_output_printf(loop->state, ##args)

static pthread_mutex_t state_mutex = PTHREAD_MUTEX_INITIALIZER;

static void show_handle(struct loopback_handle *lhandle, const char *id)
{
      struct loopback *loop = lhandle->loopback;

      OUT("  %s: %s:\n", id, lhandle->id);
      OUT("    device = '%s', ctldev '%s'\n", lhandle->device, lhandle->ctldev);
      OUT("    card_number = %i\n", lhandle->card_number);
      if (!loop->running)
            return;
      OUT("    access = %s, format = %s, rate = %u, channels = %u\n", snd_pcm_access_name(lhandle->access), snd_pcm_format_name(lhandle->format), lhandle->rate, lhandle->channels);
      OUT("    buffer_size = %u, period_size = %u, avail_min = %li\n", lhandle->buffer_size, lhandle->period_size, lhandle->avail_min);
      OUT("    xrun_pending = %i\n", lhandle->xrun_pending);
      OUT("    buf_size = %li, buf_pos = %li, buf_count = %li, buf_over = %li\n", lhandle->buf_size, lhandle->buf_pos, lhandle->buf_count, lhandle->buf_over);
      OUT("    pitch = %.8f\n", lhandle->pitch);
}

void pcmjob_state(struct loopback *loop)
{
      pthread_t self = pthread_self();
      pthread_mutex_lock(&state_mutex);
      OUT("State dump for thread %p job %i: %s:\n", (void *)self, loop->thread, loop->id);
      OUT("  running = %i\n", loop->running);
      OUT("  sync = %i\n", loop->sync);
      OUT("  slave = %i\n", loop->slave);
      if (!loop->running)
            goto __skip;
      OUT("  pollfd_count = %i\n", loop->pollfd_count);
      OUT("  pitch = %.8f, delta = %.8f, diff = %li, min = %li, max = %li\n", loop->pitch, loop->pitch_delta, loop->pitch_diff, loop->pitch_diff_min, loop->pitch_diff_max);
      OUT("  use_samplerate = %i\n", loop->use_samplerate);
      __skip:
      show_handle(loop->play, "playback");
      show_handle(loop->capt, "capture");
      pthread_mutex_unlock(&state_mutex);
}

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