src/audio/audio_source.cpp

#include "rive/audio/audio_source.hpp"
#ifdef WITH_RIVE_AUDIO
#include "rive/audio/audio_engine.hpp"
#include "rive/audio/audio_sound.hpp"
#include "rive/audio/audio_reader.hpp"
#include <algorithm>
#endif

using namespace rive;

#ifdef WITH_RIVE_AUDIO
// Both of these should be make_rcp but it is currently getting refed directy
// somewhere else so until we refactor that we have to not ref here.
rcp<AudioSource> AudioSource::MakeAudioSource(rive::Span<uint8_t> fileBytes)
{
  ma_decoder decoder;
  ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 0, 0);
  if (ma_decoder_init_memory(
          fileBytes.data(),
          fileBytes.size(),
          &config,
          &decoder) != MA_SUCCESS)
  {
    return nullptr;
  }
  ma_decoder_uninit(&decoder);
  return rcp<AudioSource>(new AudioSource(std::move(fileBytes)));
}

rcp<AudioSource> AudioSource::MakeAudioSource(
    rive::SimpleArray<uint8_t> fileBytes)
{
  ma_decoder decoder;
  ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 0, 0);
  auto result = ma_decoder_init_memory(
      fileBytes.data(),
      fileBytes.size(),
      &config,
      &decoder);
  if (result != MA_SUCCESS)
  {
    fprintf(
        stderr,
        "Failed to decode audio with error %s\n",
        ma_result_description(result));
    return nullptr;
  }

  ma_decoder_uninit(&decoder);
  return rcp<AudioSource>(new AudioSource(std::move(fileBytes)));
}

AudioSource::AudioSource(
    rive::Span<float> samples,
    uint32_t numChannels,
    uint32_t sampleRate)
    : m_isBuffered(true)
    , m_channels(numChannels)
    , m_sampleRate(sampleRate)
    , m_duration(-1.0f)
    , m_ownedBytes((uint8_t*)samples.data(), samples.size() * sizeof(float))
{
  assert(numChannels != 0);
  assert(sampleRate != 0);
}

AudioSource::AudioSource(rive::Span<uint8_t> fileBytes)
    : m_isBuffered(false)
    , m_channels(0)
    , m_sampleRate(0)
    , m_duration(-1.0f)
    , m_fileBytes(fileBytes)
{}

AudioSource::AudioSource(rive::SimpleArray<uint8_t> fileBytes)
    : m_isBuffered(false)
    , m_channels(0)
    , m_sampleRate(0)
    , m_duration(-1.0f)
    , m_fileBytes(fileBytes.data(), fileBytes.size())
    , m_ownedBytes(std::move(fileBytes))
{}

const rive::Span<float> AudioSource::bufferedSamples() const
{
  assert(m_isBuffered);
  return rive::Span<float>(
      (float*)m_ownedBytes.data(),
      m_ownedBytes.size() / sizeof(float));
}

class AudioSourceDecoder
{
public:
  AudioSourceDecoder(rive::Span<uint8_t> fileBytes) : m_decoder({})
  {
    ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 0, 0);
    if (ma_decoder_init_memory(
            fileBytes.data(),
            fileBytes.size(),
            &config,
            &m_decoder) != MA_SUCCESS)
    {
      fprintf(stderr, "AudioSourceDecoder - Failed to initialize decoder.\n");
    }
  }

  ~AudioSourceDecoder() { ma_decoder_uninit(&m_decoder); }

  uint32_t channels() { return (uint32_t)m_decoder.outputChannels; }

  uint32_t sampleRate() { return (uint32_t)m_decoder.outputSampleRate; }

private:
  ma_decoder m_decoder;
};

uint32_t AudioSource::channels()
{
  if (m_channels != 0)
  {
    return m_channels;
  }
  AudioSourceDecoder audioDecoder(m_fileBytes);
  return m_channels = audioDecoder.channels();
}

uint32_t AudioSource::sampleRate()
{
  if (m_sampleRate != 0)
  {
    return m_sampleRate;
  }
  AudioSourceDecoder audioDecoder(m_fileBytes);
  return m_sampleRate = audioDecoder.sampleRate();
}

float AudioSource::duration()
{
  if (m_duration >= 0.0f)
  {
    return m_duration;
  }
  if (m_isBuffered)
  {
    uint32_t ch = channels();
    uint32_t sr = sampleRate();
    if (ch == 0 || sr == 0)
    {
      return m_duration = 0.0f;
    }
    return m_duration = (float)bufferedSamples().size() / (float)(ch * sr);
  }
  // A reader's seek table corrects an MP3 header that miscounts its frames.
  auto reader = makeReader(0, 0);
  if (reader == nullptr || reader->sampleRate() == 0)
  {
    return m_duration = 0.0f;
  }
  return m_duration = (float)reader->lengthInFrames() /
                      (float)reader->sampleRate();
}

AudioFormat AudioSource::format() const
{
  if (m_isBuffered)
  {
    return AudioFormat::buffered;
  }
  ma_decoder decoder;
  ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 0, 0);
  if (ma_decoder_init_memory(
          m_fileBytes.data(),
          m_fileBytes.size(),
          &config,
          &decoder) != MA_SUCCESS)
  {
    fprintf(stderr, "AudioSource::format - Failed to initialize decoder.\n");
    return AudioFormat::unknown;
  }
  ma_encoding_format encodingFormat;

  AudioFormat format = AudioFormat::unknown;
  if (ma_decoder_get_encoding_format(&decoder, &encodingFormat) == MA_SUCCESS)
  {
    switch (encodingFormat)
    {
      case ma_encoding_format_mp3:
        format = AudioFormat::mp3;
        break;
      case ma_encoding_format_wav:
        format = AudioFormat::wav;
        break;
      case ma_encoding_format_vorbis:
        format = AudioFormat::vorbis;
        break;
      case ma_encoding_format_flac:
        format = AudioFormat::flac;
        break;
      default:
        format = AudioFormat::unknown;
        break;
    }
  }

  ma_decoder_uninit(&decoder);

  return format;
}

rcp<AudioReader> AudioSource::makeReader(
    uint32_t numChannels,
    uint32_t sampleRate)
{
  rive::rcp<rive::AudioSource> rcSource = rive::rcp<rive::AudioSource>(this);
  rcSource->ref();
  auto reader = rcp<AudioReader>(new AudioReader(rcSource));
  if (!m_isBuffered)
  {
    // Native format, so the reader's own converter carries across a loop.
    ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 0, 0);
    config.seekPointCount = kDecoderSeekPoints;
    if (ma_decoder_init_memory(
            m_fileBytes.data(),
            m_fileBytes.size(),
            &config,
            &reader->m_decoder) != MA_SUCCESS)
    {
      fprintf(
          stderr,
          "AudioSource::makeReader - Failed to initialize decoder.\n");
      return nullptr;
    }
    reader->m_decoding = true;
  }
  return reader->init(numChannels, sampleRate) ? reader : nullptr;
}
#else
rcp<AudioSource> AudioSource::MakeAudioSource(rive::Span<uint8_t> fileBytes)
{
  return nullptr;
}

rcp<AudioSource> AudioSource::MakeAudioSource(
    rive::SimpleArray<uint8_t> fileBytes)
{
  return nullptr;
}
AudioSource::AudioSource(rive::Span<uint8_t> fileBytes) {}
AudioSource::AudioSource(rive::SimpleArray<uint8_t> fileBytes) {}
AudioSource::AudioSource(
    rive::Span<float> samples,
    uint32_t numChannels,
    uint32_t sampleRate)
{}
uint32_t AudioSource::channels() { return 0; }
uint32_t AudioSource::sampleRate() { return 0; }
AudioFormat AudioSource::format() const { return AudioFormat::unknown; }
const rive::Span<float> AudioSource::bufferedSamples() const
{
  return rive::Span<float>(nullptr, 0);
}
#endif