cras/src/tests/mix_unittest.cc

// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <gtest/gtest.h>
#include <stdio.h>

extern "C" {
#include "cras_mix.h"
#include "cras_shm.h"
#include "cras_types.h"
}

namespace {

static const size_t kBufferFrames = 8192;
static const size_t kNumChannels = 2;
static const size_t kNumSamples = kBufferFrames * kNumChannels;
static const float kMaxVolumeToScale = 0.9999999;
static const float kMinVolumeToScale = 0.0000001;

static inline int need_to_scale(float scaler) {
  return (scaler < 0.99 || scaler > 1.01);
}

class MixTestSuiteS16_LE : public testing::Test {
 protected:
  virtual void SetUp() {
    fmt_ = SND_PCM_FORMAT_S16_LE;
    mix_buffer_ = (int16_t*)malloc(kBufferFrames * 4);
    src_buffer_ = static_cast<int16_t*>(
        calloc(1, kBufferFrames * 4 + sizeof(cras_audio_shm_header)));

    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = i;
      mix_buffer_[i] = -i;
    }

    compare_buffer_ = (int16_t*)malloc(kBufferFrames * 4);
  }

  virtual void TearDown() {
    free(mix_buffer_);
    free(compare_buffer_);
    free(src_buffer_);
  }

  void _SetupBuffer() {
    for (size_t i = 0; i < kBufferFrames; i++) {
      src_buffer_[i] = i + (INT16_MAX >> 2);
      mix_buffer_[i] = i + (INT16_MAX >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
    for (size_t i = kBufferFrames; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = i - (INT16_MAX >> 2);
      mix_buffer_[i] = i - (INT16_MAX >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
  }

  void TestScaleStride(float scaler) {
    _SetupBuffer();
    for (size_t i = 0; i < kBufferFrames * 2; i += 2) {
      int32_t tmp;
      if (need_to_scale(scaler))
        tmp = mix_buffer_[i] + src_buffer_[i / 2] * scaler;
      else
        tmp = mix_buffer_[i] + src_buffer_[i / 2];
      if (tmp > INT16_MAX)
        tmp = INT16_MAX;
      else if (tmp < INT16_MIN)
        tmp = INT16_MIN;
      compare_buffer_[i] = tmp;
    }

    cras_mix_add_scale_stride(fmt_, (uint8_t*)mix_buffer_,
                              (uint8_t*)src_buffer_, kBufferFrames, 4, 2,
                              scaler);

    EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
  }

  void ScaleIncrement(float start_scaler, float increment, float target) {
    float scaler = start_scaler;
    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      float applied_scaler = scaler;

      if ((applied_scaler > target && increment > 0) ||
          (applied_scaler < target && increment < 0))
        applied_scaler = target;

      if (applied_scaler > kMaxVolumeToScale) {
      } else if (applied_scaler < kMinVolumeToScale) {
        compare_buffer_[i] = 0;
      } else {
        compare_buffer_[i] = mix_buffer_[i] * applied_scaler;
      }

      if (i % 2 == 1)
        scaler += increment;
    }
  }

  int16_t* mix_buffer_;
  int16_t* src_buffer_;
  int16_t* compare_buffer_;
  snd_pcm_format_t fmt_;
};

TEST_F(MixTestSuiteS16_LE, MixFirst) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  EXPECT_EQ(0, memcmp(mix_buffer_, src_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixTwo) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 2;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixTwoClip) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    src_buffer_[i] = INT16_MAX;
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = INT16_MAX;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixFirstMuted) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 1, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixFirstZeroVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixFirstHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 0.5;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, MixTwoSecondHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] + (int16_t)(src_buffer_[i] * 0.5);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleFullVolumeIncrement) {
  float increment = 0.01;
  int step = 2;
  float start_scaler = 0.999999999;
  float target = 1.0;

  _SetupBuffer();
  // Scale full volume with positive increment will not change buffer.
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * 4);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleMinVolumeIncrement) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.000000001;
  float target = 0.0;

  _SetupBuffer();
  // Scale min volume with negative increment will change buffer to zeros.
  memset(compare_buffer_, 0, kBufferFrames * 4);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumePositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumeNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumeStartFullNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 1.0;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumeStartZeroPositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.0;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumePositiveIncrementCappedByTarget) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleVolumeNegativeIncrementCappedByTarget) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleFullVolume) {
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * 4);
  cras_scale_buffer(fmt_, (uint8_t*)mix_buffer_, kNumSamples, 0.999999999);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleMinVolume) {
  memset(compare_buffer_, 0, kBufferFrames * 4);
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.0000000001);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, ScaleHalfVolume) {
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 0.5;
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.5);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS16_LE, StrideCopy) {
  TestScaleStride(1.0);
  TestScaleStride(100);
  TestScaleStride(0.5);
}

class MixTestSuiteS24_LE : public testing::Test {
 protected:
  virtual void SetUp() {
    fmt_ = SND_PCM_FORMAT_S24_LE;
    fr_bytes_ = 4 * kNumChannels;
    mix_buffer_ = (int32_t*)malloc(kBufferFrames * fr_bytes_);
    src_buffer_ = static_cast<int32_t*>(
        calloc(1, kBufferFrames * fr_bytes_ + sizeof(cras_audio_shm_header)));

    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = i;
      mix_buffer_[i] = -i;
    }

    compare_buffer_ = (int32_t*)malloc(kBufferFrames * fr_bytes_);
  }

  virtual void TearDown() {
    free(mix_buffer_);
    free(compare_buffer_);
    free(src_buffer_);
  }

  void _SetupBuffer() {
    for (size_t i = 0; i < kBufferFrames; i++) {
      src_buffer_[i] = i + (0x007fffff >> 2);
      mix_buffer_[i] = i + (0x007fffff >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
    for (size_t i = kBufferFrames; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = -i - (0x007fffff >> 2);
      mix_buffer_[i] = -i - (0x007fffff >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
  }

  void TestScaleStride(float scaler) {
    _SetupBuffer();
    for (size_t i = 0; i < kBufferFrames * 2; i += 2) {
      int32_t tmp;
      if (need_to_scale(scaler))
        tmp = mix_buffer_[i] + Scale(src_buffer_[i / 2], scaler);
      else
        tmp = mix_buffer_[i] + src_buffer_[i / 2];
      if (tmp > 0x007fffff)
        tmp = 0x007fffff;
      else if (tmp < (int32_t)0xff800000)
        tmp = (int32_t)0xff800000;
      compare_buffer_[i] = tmp;
    }

    cras_mix_add_scale_stride(fmt_, (uint8_t*)mix_buffer_,
                              (uint8_t*)src_buffer_, kBufferFrames, 8, 4,
                              scaler);

    EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 8));
  }

  void ScaleIncrement(float start_scaler, float increment, float target) {
    float scaler = start_scaler;

    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      float applied_scaler = scaler;

      if ((applied_scaler > target && increment > 0) ||
          (applied_scaler < target && increment < 0))
        applied_scaler = target;

      if (applied_scaler > kMaxVolumeToScale) {
      } else if (applied_scaler < kMinVolumeToScale) {
        compare_buffer_[i] = 0;
      } else {
        compare_buffer_[i] = Scale(mix_buffer_[i], applied_scaler);
      }

      if (i % 2 == 1)
        scaler += increment;
    }
  }

  int32_t Scale(int32_t value, float scaler) {
    value = ((uint32_t)(value & 0x00ffffff)) << 8;
    value *= scaler;
    return (value >> 8) & 0x00ffffff;
  }

  int32_t* mix_buffer_;
  int32_t* src_buffer_;
  int32_t* compare_buffer_;
  snd_pcm_format_t fmt_;
  unsigned int fr_bytes_;
};

TEST_F(MixTestSuiteS24_LE, MixFirst) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  EXPECT_EQ(0, memcmp(mix_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixTwo) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = Scale(src_buffer_[i], 2);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixTwoClip) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    src_buffer_[i] = 0x007fffff;
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0x007fffff;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixFirstMuted) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 1, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixFirstZeroVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixFirstHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = Scale(src_buffer_[i], 0.5);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, MixTwoSecondHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] + Scale(src_buffer_[i], 0.5);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleFullVolumeIncrement) {
  float increment = 0.01;
  int step = 2;
  float start_scaler = 0.999999999;
  float target = 1.0;

  _SetupBuffer();
  // Scale full volume with positive increment will not change buffer.
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleMinVolumeIncrement) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.000000001;
  float target = 0.0;

  _SetupBuffer();
  // Scale min volume with negative increment will change buffer to zeros.
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumePositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumeNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumeStartFullNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 1.0;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumeStartZeroPositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.0;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumePositiveIncrementCappedByTarget) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleVolumeNegativeIncrementCappedByTarget) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleFullVolume) {
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)mix_buffer_, kNumSamples, 0.999999999);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleMinVolume) {
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.0000000001);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, ScaleHalfVolume) {
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = Scale(src_buffer_[i], 0.5);
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.5);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_LE, StrideCopy) {
  TestScaleStride(1.0);
  TestScaleStride(100);
  TestScaleStride(0.1);
}

class MixTestSuiteS32_LE : public testing::Test {
 protected:
  virtual void SetUp() {
    fmt_ = SND_PCM_FORMAT_S32_LE;
    fr_bytes_ = 4 * kNumChannels;
    mix_buffer_ = (int32_t*)malloc(kBufferFrames * fr_bytes_);
    src_buffer_ = static_cast<int32_t*>(
        calloc(1, kBufferFrames * fr_bytes_ + sizeof(cras_audio_shm_header)));

    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = i;
      mix_buffer_[i] = -i;
    }

    compare_buffer_ = (int32_t*)malloc(kBufferFrames * fr_bytes_);
  }

  virtual void TearDown() {
    free(mix_buffer_);
    free(compare_buffer_);
    free(src_buffer_);
  }

  void _SetupBuffer() {
    for (size_t i = 0; i < kBufferFrames; i++) {
      src_buffer_[i] = i + (INT32_MAX >> 2);
      mix_buffer_[i] = i + (INT32_MAX >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
    for (size_t i = kBufferFrames; i < kBufferFrames * 2; i++) {
      src_buffer_[i] = i - (INT32_MAX >> 2);
      mix_buffer_[i] = i - (INT32_MAX >> 2);
      compare_buffer_[i] = mix_buffer_[i];
    }
  }

  void TestScaleStride(float scaler) {
    _SetupBuffer();
    for (size_t i = 0; i < kBufferFrames * 2; i += 2) {
      int64_t tmp;
      if (need_to_scale(scaler))
        tmp = mix_buffer_[i] + src_buffer_[i / 2] * scaler;
      else
        tmp = mix_buffer_[i] + src_buffer_[i / 2];
      if (tmp > INT32_MAX)
        tmp = INT32_MAX;
      else if (tmp < INT32_MIN)
        tmp = INT32_MIN;
      compare_buffer_[i] = tmp;
    }

    cras_mix_add_scale_stride(fmt_, (uint8_t*)mix_buffer_,
                              (uint8_t*)src_buffer_, kBufferFrames, 8, 4,
                              scaler);

    EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 8));
  }

  void ScaleIncrement(float start_scaler, float increment, float target) {
    float scaler = start_scaler;

    for (size_t i = 0; i < kBufferFrames * 2; i++) {
      float applied_scaler = scaler;

      if ((applied_scaler > target && increment > 0) ||
          (applied_scaler < target && increment < 0))
        applied_scaler = target;

      if (applied_scaler > kMaxVolumeToScale) {
      } else if (applied_scaler < kMinVolumeToScale) {
        compare_buffer_[i] = 0;
      } else {
        compare_buffer_[i] = mix_buffer_[i] * applied_scaler;
      }

      if (i % 2 == 1)
        scaler += increment;
    }
  }

  int32_t* mix_buffer_;
  int32_t* src_buffer_;
  int32_t* compare_buffer_;
  snd_pcm_format_t fmt_;
  unsigned int fr_bytes_;
};

TEST_F(MixTestSuiteS32_LE, MixFirst) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  EXPECT_EQ(0, memcmp(mix_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixTwo) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 2;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixTwoClip) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    src_buffer_[i] = INT32_MAX;
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = INT32_MAX;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixFirstMuted) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 1, 1.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixFirstZeroVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.0);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = 0;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixFirstHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 0.5;
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, MixTwoSecondHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] + (int32_t)(src_buffer_[i] * 0.5);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleFullVolumeIncrement) {
  float increment = 0.01;
  int step = 2;
  float start_scaler = 0.999999999;
  float target = 1.0;

  _SetupBuffer();
  // Scale full volume with positive increment will not change buffer.
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleMinVolumeIncrement) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.000000001;
  float target = 0.0;

  _SetupBuffer();
  // Scale min volume with negative increment will change buffer to zeros.
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumePositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumeNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumeStartFullNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 1.0;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumeStartZeroPositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.0;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumePositiveIncrementCappedByTarget) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleVolumeNegativeIncrementCappedByTarget) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleFullVolume) {
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)mix_buffer_, kNumSamples, 0.999999999);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleMinVolume) {
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.0000000001);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, ScaleHalfVolume) {
  for (size_t i = 0; i < kBufferFrames * 2; i++)
    compare_buffer_[i] = src_buffer_[i] * 0.5;
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.5);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS32_LE, StrideCopy) {
  TestScaleStride(1.0);
  TestScaleStride(100);
  TestScaleStride(0.1);
}

class MixTestSuiteS24_3LE : public testing::Test {
 protected:
  virtual void SetUp() {
    fmt_ = SND_PCM_FORMAT_S24_3LE;
    fr_bytes_ = 3 * kNumChannels;
    mix_buffer_ = (uint8_t*)malloc(kBufferFrames * fr_bytes_);
    src_buffer_ = static_cast<uint8_t*>(
        calloc(1, kBufferFrames * fr_bytes_ + sizeof(cras_audio_shm_header)));

    for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
      memcpy(src_buffer_ + 3 * i, &i, 3);
      int32_t tmp = -i * 256;
      memcpy(mix_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
    }

    compare_buffer_ = (uint8_t*)malloc(kBufferFrames * fr_bytes_);
  }

  virtual void TearDown() {
    free(mix_buffer_);
    free(compare_buffer_);
    free(src_buffer_);
  }

  void _SetupBuffer() {
    memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
    for (size_t i = 0; i < kBufferFrames; i++) {
      int32_t tmp = (i << 8) + (INT32_MAX >> 2);
      memcpy(src_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
      memcpy(mix_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
      memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
    }
    for (size_t i = kBufferFrames; i < kBufferFrames * 2; i++) {
      int32_t tmp = (i << 8) - (INT32_MAX >> 2);
      memcpy(src_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
      memcpy(mix_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
      memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
    }
  }

  void TestScaleStride(float scaler) {
    _SetupBuffer();
    for (size_t i = 0; i < kBufferFrames * kNumChannels; i += 2) {
      int64_t tmp;
      int32_t src_frame = 0;
      int32_t dst_frame = 0;
      memcpy((uint8_t*)&src_frame + 1, src_buffer_ + 3 * i / 2, 3);
      memcpy((uint8_t*)&dst_frame + 1, mix_buffer_ + 3 * i, 3);
      if (need_to_scale(scaler))
        tmp = (int64_t)dst_frame + (int64_t)src_frame * scaler;
      else
        tmp = (int64_t)dst_frame + (int64_t)src_frame;
      if (tmp > INT32_MAX)
        tmp = INT32_MAX;
      else if (tmp < INT32_MIN)
        tmp = INT32_MIN;
      dst_frame = (int32_t)tmp;
      memcpy(compare_buffer_ + 3 * i, (uint8_t*)&dst_frame + 1, 3);
    }

    cras_mix_add_scale_stride(fmt_, (uint8_t*)mix_buffer_,
                              (uint8_t*)src_buffer_, kBufferFrames, 6, 3,
                              scaler);

    EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 6));
  }

  void ScaleIncrement(float start_scaler, float increment, float target) {
    float scaler = start_scaler;

    for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
      float applied_scaler = scaler;
      int32_t tmp = 0;
      memcpy((uint8_t*)&tmp + 1, src_buffer_ + 3 * i, 3);

      if ((applied_scaler > target && increment > 0) ||
          (applied_scaler < target && increment < 0))
        applied_scaler = target;

      if (applied_scaler > kMaxVolumeToScale) {
      } else if (applied_scaler < kMinVolumeToScale) {
        tmp = 0;
      } else {
        tmp *= applied_scaler;
      }

      memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);

      if (i % 2 == 1)
        scaler += increment;
    }
  }

  uint8_t* mix_buffer_;
  uint8_t* src_buffer_;
  uint8_t* compare_buffer_;
  snd_pcm_format_t fmt_;
  unsigned int fr_bytes_;
};

TEST_F(MixTestSuiteS24_3LE, MixFirst) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  EXPECT_EQ(0, memcmp(mix_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixTwo) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp = 0;
    memcpy((uint8_t*)&tmp + 1, src_buffer_ + 3 * i, 3);
    tmp *= 2;
    memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
  }
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixTwoClip) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp = INT32_MAX;
    memcpy(src_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
  }
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 1.0);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp = INT32_MAX;
    memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
  }
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixFirstMuted) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 1, 1.0);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++)
    memset(compare_buffer_ + 3 * i, 0, 3);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixFirstZeroVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.0);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++)
    memset(compare_buffer_ + 3 * i, 0, 3);
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixFirstHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp = 0;
    memcpy((uint8_t*)&tmp + 1, src_buffer_ + 3 * i, 3);
    tmp *= 0.5;
    memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
  }
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, MixTwoSecondHalfVolume) {
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               0, 0, 1.0);
  cras_mix_add(fmt_, (uint8_t*)mix_buffer_, (uint8_t*)src_buffer_, kNumSamples,
               1, 0, 0.5);

  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp1 = 0, tmp2 = 0;
    memcpy((uint8_t*)&tmp1 + 1, src_buffer_ + 3 * i, 3);
    memcpy((uint8_t*)&tmp2 + 1, src_buffer_ + 3 * i, 3);
    tmp1 = tmp1 + (int32_t)(tmp2 * 0.5);
    memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp1 + 1, 3);
  }
  EXPECT_EQ(0, memcmp(mix_buffer_, compare_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleFullVolumeIncrement) {
  float increment = 0.01;
  int step = 2;
  float start_scaler = 0.999999999;
  float target = 1.0;

  _SetupBuffer();
  // Scale full volume with positive increment will not change buffer.
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleMinVolumeIncrement) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.000000001;
  float target = 0.0;

  _SetupBuffer();
  // Scale min volume with negative increment will change buffer to zeros.
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumePositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumeNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumeStartFullNegativeIncrement) {
  float increment = -0.0001;
  int step = 2;
  float start_scaler = 1.0;
  float target = 0.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumeStartZeroPositiveIncrement) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.0;
  float target = 1.0;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);

  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * 4));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumePositiveIncrementCappedByTarget) {
  float increment = 0.0001;
  int step = 2;
  float start_scaler = 0.1;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleVolumeNegativeIncrementCappedByTarget) {
  float increment = -0.01;
  int step = 2;
  float start_scaler = 0.8;
  float target = 0.5;

  _SetupBuffer();
  ScaleIncrement(start_scaler, increment, target);

  cras_scale_buffer_increment(fmt_, (uint8_t*)mix_buffer_, kBufferFrames,
                              start_scaler, increment, target, step);
  EXPECT_EQ(0, memcmp(compare_buffer_, mix_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleFullVolume) {
  memcpy(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)mix_buffer_, kNumSamples, 0.999999999);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleMinVolume) {
  memset(compare_buffer_, 0, kBufferFrames * fr_bytes_);
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.0000000001);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, ScaleHalfVolume) {
  for (size_t i = 0; i < kBufferFrames * kNumChannels; i++) {
    int32_t tmp = 0;
    memcpy((uint8_t*)&tmp + 1, src_buffer_ + 3 * i, 3);
    tmp *= 0.5;
    memcpy(compare_buffer_ + 3 * i, (uint8_t*)&tmp + 1, 3);
  }
  cras_scale_buffer(fmt_, (uint8_t*)src_buffer_, kNumSamples, 0.5);

  EXPECT_EQ(0, memcmp(compare_buffer_, src_buffer_, kBufferFrames * fr_bytes_));
}

TEST_F(MixTestSuiteS24_3LE, StrideCopy) {
  TestScaleStride(1.0);
  TestScaleStride(100);
  TestScaleStride(0.1);
}

/* Stubs */
extern "C" {}  // extern "C"

}  //  namespace

int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}