/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "AudioMixer.h"

#include "gtest/gtest.h"

using mozilla::AudioDataValue;

using mozilla::AudioSampleFormat;

namespace audio_mixer {

struct MixerConsumer : public mozilla::MixerCallbackReceiver

{

/* In this test, the different audio stream and channels are always created to

 * cancel each other. */

  void MixerCallback(AudioDataValue* aData, AudioSampleFormat aFormat, uint32_t aChannels, uint32_t aFrames, uint32_t aSampleRate)

  {

    bool silent = true;

    for (uint32_t i = 0; i < aChannels * aFrames; i++) {

      if (aData[i] != 0.0) {

        if (aFormat == mozilla::AUDIO_FORMAT_S16) {

          fprintf(stderr, "Sample at %d is not silent: %d\n", i, (short)aData[i]);

        } else {

          fprintf(stderr, "Sample at %d is not silent: %f\n", i, (float)aData[i]);

        }

        silent = false;

      }

    }

    ASSERT_TRUE(silent);

  }

};

/* Helper function to give us the maximum and minimum value that don't clip,

 * for a given sample format (integer or floating-point). */

template<typename T>

T GetLowValue();

template<typename T>

T GetHighValue();

template<>

float GetLowValue<float>() {

  return -1.0;

}

template<>

short GetLowValue<short>() {

  return -INT16_MAX;

}

template<>

float GetHighValue<float>() {

  return 1.0;

}

template<>

short GetHighValue<short>() {

  return INT16_MAX;

}

void FillBuffer(AudioDataValue* aBuffer, uint32_t aLength, AudioDataValue aValue)

{

  AudioDataValue* end = aBuffer + aLength;

  while (aBuffer != end) {

    *aBuffer++ = aValue;

  }

}

TEST(AudioMixer, Test)

{

  const uint32_t CHANNEL_LENGTH = 256;

  const uint32_t AUDIO_RATE = 44100;

  MixerConsumer consumer;

  AudioDataValue a[CHANNEL_LENGTH * 2];

  AudioDataValue b[CHANNEL_LENGTH * 2];

  FillBuffer(a, CHANNEL_LENGTH, GetLowValue<AudioDataValue>());

  FillBuffer(a + CHANNEL_LENGTH, CHANNEL_LENGTH, GetHighValue<AudioDataValue>());

  FillBuffer(b, CHANNEL_LENGTH, GetHighValue<AudioDataValue>());

  FillBuffer(b + CHANNEL_LENGTH, CHANNEL_LENGTH, GetLowValue<AudioDataValue>());

  {

    int iterations = 2;

    mozilla::AudioMixer mixer;

    mixer.AddCallback(&consumer);

    fprintf(stderr, "Test AudioMixer constant buffer length.\n");

    while (iterations--) {

      mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

      mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

      mixer.FinishMixing();

    }

  }

  {

    mozilla::AudioMixer mixer;

    mixer.AddCallback(&consumer);

    fprintf(stderr, "Test AudioMixer variable buffer length.\n");

    FillBuffer(a, CHANNEL_LENGTH / 2, GetLowValue<AudioDataValue>());

    FillBuffer(a + CHANNEL_LENGTH / 2, CHANNEL_LENGTH / 2, GetLowValue<AudioDataValue>());

    FillBuffer(b, CHANNEL_LENGTH / 2, GetHighValue<AudioDataValue>());

    FillBuffer(b + CHANNEL_LENGTH / 2, CHANNEL_LENGTH / 2, GetHighValue<AudioDataValue>());

    mixer.Mix(a, 2, CHANNEL_LENGTH / 2, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH / 2, AUDIO_RATE);

    mixer.FinishMixing();

    FillBuffer(a, CHANNEL_LENGTH, GetLowValue<AudioDataValue>());

    FillBuffer(a + CHANNEL_LENGTH, CHANNEL_LENGTH, GetHighValue<AudioDataValue>());

    FillBuffer(b, CHANNEL_LENGTH, GetHighValue<AudioDataValue>());

    FillBuffer(b + CHANNEL_LENGTH, CHANNEL_LENGTH, GetLowValue<AudioDataValue>());

    mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

    FillBuffer(a, CHANNEL_LENGTH / 2, GetLowValue<AudioDataValue>());

    FillBuffer(a + CHANNEL_LENGTH / 2, CHANNEL_LENGTH / 2, GetLowValue<AudioDataValue>());

    FillBuffer(b, CHANNEL_LENGTH / 2, GetHighValue<AudioDataValue>());

    FillBuffer(b + CHANNEL_LENGTH / 2, CHANNEL_LENGTH / 2, GetHighValue<AudioDataValue>());

    mixer.Mix(a, 2, CHANNEL_LENGTH / 2, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH / 2, AUDIO_RATE);

    mixer.FinishMixing();

  }

  FillBuffer(a, CHANNEL_LENGTH, GetLowValue<AudioDataValue>());

  FillBuffer(b, CHANNEL_LENGTH, GetHighValue<AudioDataValue>());

  {

    mozilla::AudioMixer mixer;

    mixer.AddCallback(&consumer);

    fprintf(stderr, "Test AudioMixer variable channel count.\n");

    mixer.Mix(a, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

    mixer.Mix(a, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

    mixer.Mix(a, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 1, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

  }

  {

    mozilla::AudioMixer mixer;

    mixer.AddCallback(&consumer);

    fprintf(stderr, "Test AudioMixer variable stream count.\n");

    mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

    mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

    mixer.Mix(a, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.Mix(b, 2, CHANNEL_LENGTH, AUDIO_RATE);

    mixer.FinishMixing();

  }

}

} // namespace audio_mixer