text: /***
    This file is part of PulseAudio.
  
    Copyright 2004-2006 Lennart Poettering
  
    PulseAudio is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation; either version 2.1 of the License,
    or (at your option) any later version.
  
    PulseAudio 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 Lesser General Public License
    along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
  ***/
  
  #ifdef HAVE_CONFIG_H
  #include <config.h>
  #endif
  
  #include <stdio.h>
  #include <string.h>
  #include <math.h>
  
  #include <pulse/volume.h>
  
  #include "internal.h"
  #include "sample-util.h"
  
  SPA_EXPORT
  int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) {
      int i;
      pa_assert(a);
      pa_assert(b);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), 0);
  
      if (PA_UNLIKELY(a == b))
          return 1;
  
      pa_return_val_if_fail(pa_cvolume_valid(b), 0);
  
      if (a->channels != b->channels)
          return 0;
  
      for (i = 0; i < a->channels; i++)
          if (a->values[i] != b->values[i])
              return 0;
  
      return 1;
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_init(pa_cvolume *a) {
      unsigned c;
  
      pa_assert(a);
  
      a->channels = 0;
  
      for (c = 0; c < PA_CHANNELS_MAX; c++)
          a->values[c] = PA_VOLUME_INVALID;
  
      return a;
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v) {
      int i;
  
      pa_assert(a);
      pa_assert(pa_channels_valid(channels));
  
      a->channels = (uint8_t) channels;
  
      for (i = 0; i < a->channels; i++)
          /* Clamp in case there is stale data that exceeds the current
           * PA_VOLUME_MAX */
          a->values[i] = PA_CLAMP_VOLUME(v);
  
      return a;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_avg(const pa_cvolume *a) {
      uint64_t sum = 0;
      unsigned c;
  
      pa_assert(a);
      pa_return_val_if_fail(pa_cvolume_valid(a), PA_VOLUME_MUTED);
  
      for (c = 0; c < a->channels; c++)
          sum += a->values[c];
  
      sum /= a->channels;
  
      return (pa_volume_t) sum;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_avg_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
      uint64_t sum = 0;
      unsigned c, n;
  
      pa_assert(a);
  
      if (!cm)
          return pa_cvolume_avg(a);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(a, cm), PA_VOLUME_MUTED);
  
      for (c = n = 0; c < a->channels; c++) {
  
          if (!(PA_CHANNEL_POSITION_MASK(cm->map[c]) & mask))
              continue;
  
          sum += a->values[c];
          n ++;
      }
  
      if (n > 0)
          sum /= n;
  
      return (pa_volume_t) sum;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_max(const pa_cvolume *a) {
      pa_volume_t m = PA_VOLUME_MUTED;
      unsigned c;
  
      pa_assert(a);
      pa_return_val_if_fail(pa_cvolume_valid(a), PA_VOLUME_MUTED);
  
      for (c = 0; c < a->channels; c++)
          if (a->values[c] > m)
              m = a->values[c];
  
      return m;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_min(const pa_cvolume *a) {
      pa_volume_t m = PA_VOLUME_MAX;
      unsigned c;
  
      pa_assert(a);
      pa_return_val_if_fail(pa_cvolume_valid(a), PA_VOLUME_MUTED);
  
      for (c = 0; c < a->channels; c++)
          if (a->values[c] < m)
              m = a->values[c];
  
      return m;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
      pa_volume_t m = PA_VOLUME_MUTED;
      unsigned c;
  
      pa_assert(a);
  
      if (!cm)
          return pa_cvolume_max(a);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(a, cm), PA_VOLUME_MUTED);
  
      for (c = 0; c < a->channels; c++) {
  
          if (!(PA_CHANNEL_POSITION_MASK(cm->map[c]) & mask))
              continue;
  
          if (a->values[c] > m)
              m = a->values[c];
      }
  
      return m;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
      pa_volume_t m = PA_VOLUME_MAX;
      unsigned c;
  
      pa_assert(a);
  
      if (!cm)
          return pa_cvolume_min(a);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(a, cm), PA_VOLUME_MUTED);
  
      for (c = 0; c < a->channels; c++) {
  
          if (!(PA_CHANNEL_POSITION_MASK(cm->map[c]) & mask))
              continue;
  
          if (a->values[c] < m)
              m = a->values[c];
      }
  
      return m;
  }
  
  SPA_EXPORT
  pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) {
      uint64_t result;
  
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(a), PA_VOLUME_INVALID);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(b), PA_VOLUME_INVALID);
  
      /* cbrt((a/PA_VOLUME_NORM)^3*(b/PA_VOLUME_NORM)^3)*PA_VOLUME_NORM = a*b/PA_VOLUME_NORM */
  
      result = ((uint64_t) a * (uint64_t) b + (uint64_t) PA_VOLUME_NORM / 2ULL) / (uint64_t) PA_VOLUME_NORM;
  
      if (result > (uint64_t)PA_VOLUME_MAX)
          pa_log_warn("pa_sw_volume_multiply: Volume exceeds maximum allowed value and will be clipped. Please check your volume settings.");
  
      return (pa_volume_t) PA_CLAMP_VOLUME(result);
  }
  
  SPA_EXPORT
  pa_volume_t pa_sw_volume_divide(pa_volume_t a, pa_volume_t b) {
      uint64_t result;
  
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(a), PA_VOLUME_INVALID);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(b), PA_VOLUME_INVALID);
  
      if (b <= PA_VOLUME_MUTED)
          return 0;
  
      result = ((uint64_t) a * (uint64_t) PA_VOLUME_NORM + (uint64_t) b / 2ULL) / (uint64_t) b;
  
      if (result > (uint64_t)PA_VOLUME_MAX)
          pa_log_warn("pa_sw_volume_divide: Volume exceeds maximum allowed value and will be clipped. Please check your volume settings.");
  
      return (pa_volume_t) PA_CLAMP_VOLUME(result);
  }
  
  /* Amplitude, not power */
  static double linear_to_dB(double v) {
      return 20.0 * log10(v);
  }
  
  static double dB_to_linear(double v) {
      return pow(10.0, v / 20.0);
  }
  
  SPA_EXPORT
  pa_volume_t pa_sw_volume_from_dB(double dB) {
      if (isinf(dB) < 0 || dB <= PA_DECIBEL_MININFTY)
          return PA_VOLUME_MUTED;
  
      return pa_sw_volume_from_linear(dB_to_linear(dB));
  }
  
  SPA_EXPORT
  double pa_sw_volume_to_dB(pa_volume_t v) {
  
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(v), PA_DECIBEL_MININFTY);
  
      if (v <= PA_VOLUME_MUTED)
          return PA_DECIBEL_MININFTY;
  
      return linear_to_dB(pa_sw_volume_to_linear(v));
  }
  
  SPA_EXPORT
  pa_volume_t pa_sw_volume_from_linear(double v) {
  
      if (v <= 0.0)
          return PA_VOLUME_MUTED;
  
      /*
       * We use a cubic mapping here, as suggested and discussed here:
       *
       * http://www.robotplanet.dk/audio/audio_gui_design/
       * http://lists.linuxaudio.org/pipermail/linux-audio-dev/2009-May/thread.html#23151
       *
       * We make sure that the conversion to linear and back yields the
       * same volume value! That's why we need the lround() below!
       */
  
      return (pa_volume_t) PA_CLAMP_VOLUME((uint64_t) lround(cbrt(v) * PA_VOLUME_NORM));
  }
  
  SPA_EXPORT
  double pa_sw_volume_to_linear(pa_volume_t v) {
      double f;
  
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(v), 0.0);
  
      if (v <= PA_VOLUME_MUTED)
          return 0.0;
  
      if (v == PA_VOLUME_NORM)
          return 1.0;
  
      f = ((double) v / PA_VOLUME_NORM);
  
      return f*f*f;
  }
  
  SPA_EXPORT
  char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c) {
      unsigned channel;
      bool first = true;
      char *e;
  
      pa_assert(s);
      pa_assert(l > 0);
      pa_assert(c);
  
      pa_init_i18n();
  
      if (!pa_cvolume_valid(c)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      *(e = s) = 0;
  
      for (channel = 0; channel < c->channels && l > 1; channel++) {
          l -= pa_snprintf(e, l, "%s%u: %3u%%",
                        first ? "" : " ",
                        channel,
                        (unsigned)(((uint64_t)c->values[channel] * 100 + (uint64_t)PA_VOLUME_NORM / 2) / (uint64_t)PA_VOLUME_NORM));
  
          e = strchr(e, 0);
          first = false;
      }
  
      return s;
  }
  
  SPA_EXPORT
  char *pa_volume_snprint(char *s, size_t l, pa_volume_t v) {
      pa_assert(s);
      pa_assert(l > 0);
  
      pa_init_i18n();
  
      if (!PA_VOLUME_IS_VALID(v)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      pa_snprintf(s, l, "%3u%%", (unsigned)(((uint64_t)v * 100 + (uint64_t)PA_VOLUME_NORM / 2) / (uint64_t)PA_VOLUME_NORM));
      return s;
  }
  
  SPA_EXPORT
  char *pa_sw_cvolume_snprint_dB(char *s, size_t l, const pa_cvolume *c) {
      unsigned channel;
      bool first = true;
      char *e;
  
      pa_assert(s);
      pa_assert(l > 0);
      pa_assert(c);
  
      pa_init_i18n();
  
      if (!pa_cvolume_valid(c)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      *(e = s) = 0;
  
      for (channel = 0; channel < c->channels && l > 1; channel++) {
          double f = pa_sw_volume_to_dB(c->values[channel]);
  
          l -= pa_snprintf(e, l, "%s%u: %0.2f dB",
                           first ? "" : " ",
                           channel,
                           isinf(f) < 0 || f <= PA_DECIBEL_MININFTY ? -INFINITY : f);
  
          e = strchr(e, 0);
          first = false;
      }
  
      return s;
  }
  
  SPA_EXPORT
  char *pa_cvolume_snprint_verbose(char *s, size_t l, const pa_cvolume *c, const pa_channel_map *map, int print_dB) {
      char *current = s;
      bool first = true;
  
      pa_assert(s);
      pa_assert(l > 0);
      pa_assert(c);
  
      pa_init_i18n();
  
      if (!pa_cvolume_valid(c)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      pa_assert(!map || (map->channels == c->channels));
      pa_assert(!map || pa_channel_map_valid(map));
  
      current[0] = 0;
  
      for (unsigned channel = 0; channel < c->channels && l > 1; channel++) {
          char channel_position[32];
          size_t bytes_printed;
          char buf[PA_VOLUME_SNPRINT_VERBOSE_MAX];
  
          if (map)
              pa_snprintf(channel_position, sizeof(channel_position), "%s", pa_channel_position_to_string(map->map[channel]));
          else
              pa_snprintf(channel_position, sizeof(channel_position), "%u", channel);
  
          bytes_printed = pa_snprintf(current, l, "%s%s: %s",
                                      first ? "" : ",   ",
                                      channel_position,
                                      pa_volume_snprint_verbose(buf, sizeof(buf), c->values[channel], print_dB));
          l -= bytes_printed;
          current += bytes_printed;
          first = false;
      }
  
      return s;
  }
  
  SPA_EXPORT
  char *pa_sw_volume_snprint_dB(char *s, size_t l, pa_volume_t v) {
      double f;
  
      pa_assert(s);
      pa_assert(l > 0);
  
      pa_init_i18n();
  
      if (!PA_VOLUME_IS_VALID(v)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      f = pa_sw_volume_to_dB(v);
      pa_snprintf(s, l, "%0.2f dB", isinf(f) < 0 || f <= PA_DECIBEL_MININFTY ? -INFINITY : f);
  
      return s;
  }
  
  SPA_EXPORT
  char *pa_volume_snprint_verbose(char *s, size_t l, pa_volume_t v, int print_dB) {
      char dB[PA_SW_VOLUME_SNPRINT_DB_MAX];
  
      pa_assert(s);
      pa_assert(l > 0);
  
      pa_init_i18n();
  
      if (!PA_VOLUME_IS_VALID(v)) {
          pa_snprintf(s, l, _("(invalid)"));
          return s;
      }
  
      pa_snprintf(s, l, "%" PRIu32 " / %3u%%%s%s",
                  v,
                  (unsigned)(((uint64_t)v * 100 + (uint64_t)PA_VOLUME_NORM / 2) / (uint64_t)PA_VOLUME_NORM),
                  print_dB ? " / " : "",
                  print_dB ? pa_sw_volume_snprint_dB(dB, sizeof(dB), v) : "");
  
      return s;
  }
  
  SPA_EXPORT
  int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) {
      unsigned c;
      pa_assert(a);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), 0);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(v), 0);
  
      for (c = 0; c < a->channels; c++)
          if (a->values[c] != v)
              return 0;
  
      return 1;
  }
  
  SPA_EXPORT
  pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b) {
      unsigned i;
  
      pa_assert(dest);
      pa_assert(a);
      pa_assert(b);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), NULL);
      pa_return_val_if_fail(pa_cvolume_valid(b), NULL);
  
      dest->channels = PA_MIN(a->channels, b->channels);
  
      for (i = 0; i < dest->channels; i++)
          dest->values[i] = pa_sw_volume_multiply(a->values[i], b->values[i]);
  
      return dest;
  }
  
  SPA_EXPORT
  pa_cvolume *pa_sw_cvolume_multiply_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b) {
      unsigned i;
  
      pa_assert(dest);
      pa_assert(a);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(b), NULL);
  
      for (i = 0; i < a->channels; i++)
          dest->values[i] = pa_sw_volume_multiply(a->values[i], b);
  
      dest->channels = (uint8_t) i;
  
      return dest;
  }
  
  SPA_EXPORT
  pa_cvolume *pa_sw_cvolume_divide(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b) {
      unsigned i;
  
      pa_assert(dest);
      pa_assert(a);
      pa_assert(b);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), NULL);
      pa_return_val_if_fail(pa_cvolume_valid(b), NULL);
  
      dest->channels = PA_MIN(a->channels, b->channels);
  
      for (i = 0; i < dest->channels; i++)
          dest->values[i] = pa_sw_volume_divide(a->values[i], b->values[i]);
  
      return dest;
  }
  
  SPA_EXPORT
  pa_cvolume *pa_sw_cvolume_divide_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b) {
      unsigned i;
  
      pa_assert(dest);
      pa_assert(a);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(b), NULL);
  
      for (i = 0; i < a->channels; i++)
          dest->values[i] = pa_sw_volume_divide(a->values[i], b);
  
      dest->channels = (uint8_t) i;
  
      return dest;
  }
  
  SPA_EXPORT
  int pa_cvolume_valid(const pa_cvolume *v) {
      unsigned c;
  
      pa_assert(v);
  
      if (!pa_channels_valid(v->channels))
          return 0;
  
      for (c = 0; c < v->channels; c++)
          if (!PA_VOLUME_IS_VALID(v->values[c]))
              return 0;
  
      return 1;
  }
  
  static bool on_left(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_LEFT);
  }
  
  static bool on_right(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_RIGHT);
  }
  
  static bool on_center(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_CENTER);
  }
  
  static bool on_hfe(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_HFE);
  }
  
  static bool on_lfe(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_LFE);
  }
  
  static bool on_front(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_FRONT);
  }
  
  static bool on_rear(pa_channel_position_t p) {
      return !!(PA_CHANNEL_POSITION_MASK(p) & PA_CHANNEL_POSITION_MASK_REAR);
  }
  
  SPA_EXPORT
  pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to) {
      int a, b;
      pa_cvolume result;
  
      pa_assert(v);
      pa_assert(from);
      pa_assert(to);
  
      pa_return_val_if_fail(pa_channel_map_valid(to), NULL);
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, from), NULL);
  
      if (pa_channel_map_equal(from, to))
          return v;
  
      result.channels = to->channels;
  
      for (b = 0; b < to->channels; b++) {
          pa_volume_t k = 0;
          int n = 0;
  
          for (a = 0; a < from->channels; a++)
              if (from->map[a] == to->map[b]) {
                  k += v->values[a];
                  n ++;
              }
  
          if (n <= 0) {
              for (a = 0; a < from->channels; a++)
                  if ((on_left(from->map[a]) && on_left(to->map[b])) ||
                      (on_right(from->map[a]) && on_right(to->map[b])) ||
                      (on_center(from->map[a]) && on_center(to->map[b])) ||
                      (on_lfe(from->map[a]) && on_lfe(to->map[b]))) {
  
                      k += v->values[a];
                      n ++;
                  }
          }
  
          if (n <= 0)
              k = pa_cvolume_avg(v);
          else
              k /= n;
  
          result.values[b] = k;
      }
  
      *v = result;
      return v;
  }
  
  SPA_EXPORT
  int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) {
  
      pa_assert(v);
      pa_assert(ss);
  
      pa_return_val_if_fail(pa_cvolume_valid(v), 0);
      pa_return_val_if_fail(pa_sample_spec_valid(ss), 0);
  
      return v->channels == ss->channels;
  }
  
  SPA_EXPORT
  int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) {
      pa_assert(v);
      pa_assert(cm);
  
      pa_return_val_if_fail(pa_cvolume_valid(v), 0);
      pa_return_val_if_fail(pa_channel_map_valid(cm), 0);
  
      return v->channels == cm->channels;
  }
  
  /*
   * Returns the average volume of l and r, where l and r are two disjoint sets of channels
   * (e g left and right, or front and rear).
   */
  static void get_avg(const pa_channel_map *map, const pa_cvolume *v, pa_volume_t *l, pa_volume_t *r,
                      bool (*on_l)(pa_channel_position_t), bool (*on_r)(pa_channel_position_t)) {
      int c;
      pa_volume_t left = 0, right = 0;
      unsigned n_left = 0, n_right = 0;
  
      pa_assert(v);
      pa_assert(map);
      pa_assert(map->channels == v->channels);
      pa_assert(l);
      pa_assert(r);
  
      for (c = 0; c < map->channels; c++) {
          if (on_l(map->map[c])) {
              left += v->values[c];
              n_left++;
          } else if (on_r(map->map[c])) {
              right += v->values[c];
              n_right++;
          }
      }
  
      if (n_left <= 0)
          *l = PA_VOLUME_NORM;
      else
          *l = left / n_left;
  
      if (n_right <= 0)
          *r = PA_VOLUME_NORM;
      else
          *r = right / n_right;
  }
  
  SPA_EXPORT
  float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) {
      pa_volume_t left, right;
  
      pa_assert(v);
      pa_assert(map);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), 0.0f);
  
      if (!pa_channel_map_can_balance(map))
          return 0.0f;
  
      get_avg(map, v, &left, &right, on_left, on_right);
  
      if (left == right)
          return 0.0f;
  
      /*   1.0,  0.0  =>  -1.0
           0.0,  1.0  =>   1.0
           0.0,  0.0  =>   0.0
           0.5,  0.5  =>   0.0
           1.0,  0.5  =>  -0.5
           1.0,  0.25 => -0.75
           0.75, 0.25 => -0.66
           0.5,  0.25 => -0.5   */
  
      if (left > right)
          return -1.0f + ((float) right / (float) left);
      else
          return 1.0f - ((float) left / (float) right);
  }
  
  static pa_cvolume* set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance,
                                 bool (*on_l)(pa_channel_position_t), bool (*on_r)(pa_channel_position_t)) {
  
      pa_volume_t left, nleft, right, nright, m;
      unsigned c;
  
      get_avg(map, v, &left, &right, on_l, on_r);
  
      m = PA_MAX(left, right);
  
      if (new_balance <= 0) {
          nright = (new_balance + 1.0f) * m;
          nleft = m;
      } else {
          nleft = (1.0f - new_balance) * m;
          nright = m;
      }
  
      for (c = 0; c < map->channels; c++) {
          if (on_l(map->map[c])) {
              if (left == 0)
                  v->values[c] = nleft;
              else
                  v->values[c] = (pa_volume_t) PA_CLAMP_VOLUME(((uint64_t) v->values[c] * (uint64_t) nleft) / (uint64_t) left);
          } else if (on_r(map->map[c])) {
              if (right == 0)
                  v->values[c] = nright;
              else
                  v->values[c] = (pa_volume_t) PA_CLAMP_VOLUME(((uint64_t) v->values[c] * (uint64_t) nright) / (uint64_t) right);
          }
      }
  
      return v;
  }
  
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance) {
      pa_assert(map);
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), NULL);
      pa_return_val_if_fail(new_balance >= -1.0f, NULL);
      pa_return_val_if_fail(new_balance <= 1.0f, NULL);
  
      if (!pa_channel_map_can_balance(map))
          return v;
  
      return set_balance(v, map, new_balance, on_left, on_right);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max) {
      unsigned c;
      pa_volume_t t = 0;
  
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(max), NULL);
  
      t = pa_cvolume_max(v);
  
      if (t <= PA_VOLUME_MUTED)
          return pa_cvolume_set(v, v->channels, max);
  
      for (c = 0; c < v->channels; c++)
          v->values[c] = (pa_volume_t) PA_CLAMP_VOLUME(((uint64_t) v->values[c] * (uint64_t) max) / (uint64_t) t);
  
      return v;
  }
  
  SPA_EXPORT
  #if PA_CHECK_VERSION(12, 0, 0)
  pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
  #else
  pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, pa_channel_map *cm, pa_channel_position_mask_t mask) {
  #endif
      unsigned c;
      pa_volume_t t = 0;
  
      pa_assert(v);
  
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(max), NULL);
  
      if (!cm)
          return pa_cvolume_scale(v, max);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, cm), NULL);
  
      t = pa_cvolume_max_mask(v, cm, mask);
  
      if (t <= PA_VOLUME_MUTED)
          return pa_cvolume_set(v, v->channels, max);
  
      for (c = 0; c < v->channels; c++)
          v->values[c] = (pa_volume_t) PA_CLAMP_VOLUME(((uint64_t) v->values[c] * (uint64_t) max) / (uint64_t) t);
  
      return v;
  }
  
  SPA_EXPORT
  float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) {
      pa_volume_t rear, front;
  
      pa_assert(v);
      pa_assert(map);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), 0.0f);
  
      if (!pa_channel_map_can_fade(map))
          return 0.0f;
  
      get_avg(map, v, &rear, &front, on_rear, on_front);
  
      if (front == rear)
          return 0.0f;
  
      if (rear > front)
          return -1.0f + ((float) front / (float) rear);
      else
          return 1.0f - ((float) rear / (float) front);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade) {
      pa_assert(map);
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), NULL);
      pa_return_val_if_fail(new_fade >= -1.0f, NULL);
      pa_return_val_if_fail(new_fade <= 1.0f, NULL);
  
      if (!pa_channel_map_can_fade(map))
          return v;
  
      return set_balance(v, map, new_fade, on_rear, on_front);
  }
  
  SPA_EXPORT
  float pa_cvolume_get_lfe_balance(const pa_cvolume *v, const pa_channel_map *map) {
      pa_volume_t hfe, lfe;
  
      pa_assert(v);
      pa_assert(map);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), 0.0f);
  
      if (!pa_channel_map_can_lfe_balance(map))
          return 0.0f;
  
      get_avg(map, v, &hfe, &lfe, on_hfe, on_lfe);
  
      if (hfe == lfe)
          return 0.0f;
  
      if (hfe > lfe)
          return -1.0f + ((float) lfe / (float) hfe);
      else
          return 1.0f - ((float) hfe / (float) lfe);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_set_lfe_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance) {
      pa_assert(map);
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), NULL);
      pa_return_val_if_fail(new_balance >= -1.0f, NULL);
      pa_return_val_if_fail(new_balance <= 1.0f, NULL);
  
      if (!pa_channel_map_can_lfe_balance(map))
          return v;
  
      return set_balance(v, map, new_balance, on_hfe, on_lfe);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_set_position(
          pa_cvolume *cv,
          const pa_channel_map *map,
          pa_channel_position_t t,
          pa_volume_t v) {
  
      unsigned c;
      bool good = false;
  
      pa_assert(cv);
      pa_assert(map);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(cv, map), NULL);
      pa_return_val_if_fail(t < PA_CHANNEL_POSITION_MAX, NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(v), NULL);
  
      for (c = 0; c < map->channels; c++)
          if (map->map[c] == t) {
              cv->values[c] = v;
              good = true;
          }
  
      return good ? cv : NULL;
  }
  
  SPA_EXPORT
  pa_volume_t pa_cvolume_get_position(
          PA_CONST pa_cvolume *cv,
          const pa_channel_map *map,
          pa_channel_position_t t) {
  
      unsigned c;
      pa_volume_t v = PA_VOLUME_MUTED;
  
      pa_assert(cv);
      pa_assert(map);
  
      pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(cv, map), PA_VOLUME_MUTED);
      pa_return_val_if_fail(t < PA_CHANNEL_POSITION_MAX, PA_VOLUME_MUTED);
  
      for (c = 0; c < map->channels; c++)
          if (map->map[c] == t)
              if (cv->values[c] > v)
                  v = cv->values[c];
  
      return v;
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_merge(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b) {
      unsigned i;
  
      pa_assert(dest);
      pa_assert(a);
      pa_assert(b);
  
      pa_return_val_if_fail(pa_cvolume_valid(a), NULL);
      pa_return_val_if_fail(pa_cvolume_valid(b), NULL);
  
      dest->channels = PA_MIN(a->channels, b->channels);
  
      for (i = 0; i < dest->channels; i++)
          dest->values[i] = PA_MAX(a->values[i], b->values[i]);
  
      return dest;
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_inc_clamp(pa_cvolume *v, pa_volume_t inc, pa_volume_t limit) {
      pa_volume_t m;
  
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(inc), NULL);
  
      m = pa_cvolume_max(v);
  
      if (m >= limit - inc)
          m = limit;
      else
          m += inc;
  
      return pa_cvolume_scale(v, m);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_inc(pa_cvolume *v, pa_volume_t inc) {
      return pa_cvolume_inc_clamp(v, inc, PA_VOLUME_MAX);
  }
  
  SPA_EXPORT
  pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec) {
      pa_volume_t m;
  
      pa_assert(v);
  
      pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
      pa_return_val_if_fail(PA_VOLUME_IS_VALID(dec), NULL);
  
      m = pa_cvolume_max(v);
  
      if (m <= PA_VOLUME_MUTED + dec)
          m = PA_VOLUME_MUTED;
      else
          m -= dec;
  
      return pa_cvolume_scale(v, m);
  }
  