/* Copyright 2014 The ChromiumOS Authors

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#include "cras/src/server/cras_audio_area.h"

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include <sys/param.h>

#include "cras/src/server/cras_mix.h"

#include "cras_audio_format.h"

struct cras_audio_area* cras_audio_area_create(size_t num_channels) {

  struct cras_audio_area* area;

  size_t sz;

  sz = sizeof(*area) + num_channels * sizeof(struct cras_channel_area);

  area = calloc(1, sz);

  area->num_channels = num_channels;

  return area;

}

unsigned int cras_audio_area_copy(const struct cras_audio_area* dst,

                                  unsigned int dst_offset,

                                  const struct cras_audio_format* dst_fmt,

                                  const struct cras_audio_area* src,

                                  unsigned int src_offset,

                                  float software_gain_scaler) {

  unsigned int src_idx, dst_idx;

  unsigned int ncopy;

  uint8_t *schan, *dchan;

  ncopy = MIN(src->frames - src_offset, dst->frames - dst_offset);

  // TODO(dgreid) - this replaces a memcpy, it needs to be way faster.

  for (src_idx = 0; src_idx < src->num_channels; src_idx++) {

    for (dst_idx = 0; dst_idx < dst->num_channels; dst_idx++) {

      if (!(src->channels[src_idx].ch_set & dst->channels[dst_idx].ch_set)) {

        continue;

      }

      schan = src->channels[src_idx].buf +

              src_offset * src->channels[src_idx].step_bytes;

      dchan = dst->channels[dst_idx].buf +

              dst_offset * dst->channels[dst_idx].step_bytes;

      cras_mix_add_scale_stride(dst_fmt->format, dchan, schan, ncopy,

                                dst->channels[dst_idx].step_bytes,

                                src->channels[src_idx].step_bytes,

                                software_gain_scaler);

    }

  }

  return ncopy;

}

void cras_audio_area_destroy(struct cras_audio_area* area) {

  free(area);

}

void cras_audio_area_config_channels(struct cras_audio_area* area,

                                     const struct cras_audio_format* fmt) {

  unsigned int i, ch;

  /* For mono, config the channel type to match both front left and front

   * right. Notice that the stereo-mono conversion is to add up two channels so

   * the magnitude of mono is louder than stereo. We can't fix it by dividing

   * by 2 directly because it may cause the recording magnitude decreased for

   * some camera mic users.

   * TODO(hychao): add more mapping when we have like {FL, FC}

   * for mono + kb mic.

   */

  if ((fmt->num_channels == 1) && ((fmt->channel_layout[CRAS_CH_FC] == 0) ||

                                   (fmt->channel_layout[CRAS_CH_FL] == 0))) {

    channel_area_set_channel(area->channels, CRAS_CH_FL);

    channel_area_set_channel(area->channels, CRAS_CH_FR);

    return;

  }

  for (i = 0; i < fmt->num_channels; i++) {

    area->channels[i].ch_set = 0;

    for (ch = 0; ch < CRAS_CH_MAX; ch++) {

      if (fmt->channel_layout[ch] == i) {

        channel_area_set_channel(&area->channels[i], ch);

      }

    }

  }

}

void cras_audio_area_config_buf_pointers(struct cras_audio_area* area,

                                         const struct cras_audio_format* fmt,

                                         uint8_t* base_buffer) {

  int i;

  const int sample_size = snd_pcm_format_physical_width(fmt->format) / 8;

  // TODO(dgreid) - assuming interleaved audio here for now.

  for (i = 0; i < area->num_channels; i++) {

    area->channels[i].step_bytes = cras_get_format_bytes(fmt);

    area->channels[i].buf = base_buffer + i * sample_size;

  }

}