Duckstation/src/frontend-common/cubeb_audio_stream.cpp

#include "cubeb_audio_stream.h"
#include "common/assert.h"
#include "common/log.h"
Log_SetChannel(CubebAudioStream);

#ifdef WIN32
#include "common/windows_headers.h"
#include <objbase.h>
#pragma comment(lib, "Ole32.lib")
#endif

CubebAudioStream::CubebAudioStream() = default;

CubebAudioStream::~CubebAudioStream()
{
  if (IsOpen())
    CubebAudioStream::CloseDevice();
}

bool CubebAudioStream::OpenDevice()
{
  Assert(!IsOpen());

#ifdef WIN32
  HRESULT hr = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
  m_com_initialized_by_us = SUCCEEDED(hr);
  if (FAILED(hr) && hr != RPC_E_CHANGED_MODE && hr != S_FALSE)
  {
    Log_ErrorPrintf("Failed to initialize COM");
    return false;
  }
#endif

  int rv = cubeb_init(&m_cubeb_context, "DuckStation", nullptr);
  if (rv != CUBEB_OK)
  {
    Log_ErrorPrintf("Could not initialize cubeb context: %d", rv);
    return false;
  }

  cubeb_stream_params params = {};
  params.format = CUBEB_SAMPLE_S16LE;
  params.rate = m_output_sample_rate;
  params.channels = m_channels;
  params.layout = CUBEB_LAYOUT_UNDEFINED;
  params.prefs = CUBEB_STREAM_PREF_NONE;

  u32 latency_frames = 0;
  rv = cubeb_get_min_latency(m_cubeb_context, &params, &latency_frames);
  if (rv == CUBEB_ERROR_NOT_SUPPORTED)
  {
    Log_WarningPrintf("Cubeb backend does not support latency queries, using buffer size of %u.", m_buffer_size);
    latency_frames = m_buffer_size;
  }
  else
  {
    if (rv != CUBEB_OK)
    {
      Log_ErrorPrintf("Could not get minimum latency: %d", rv);
      DestroyContext();
      return false;
    }

    Log_InfoPrintf("Minimum latency in frames: %u", latency_frames);
    if (latency_frames > m_buffer_size)
    {
      Log_WarningPrintf("Minimum latency is above buffer size: %u vs %u, adjusting to compensate.", latency_frames,
                        m_buffer_size);

      if (!SetBufferSize(latency_frames))
      {
        Log_ErrorPrintf("Failed to set new buffer size of %u frames", latency_frames);
        DestroyContext();
        return false;
      }
    }
    else
    {
      latency_frames = m_buffer_size;
    }
  }

  char stream_name[32];
  std::snprintf(stream_name, sizeof(stream_name), "AudioStream_%p", this);

  rv = cubeb_stream_init(m_cubeb_context, &m_cubeb_stream, stream_name, nullptr, nullptr, nullptr, &params,
                         latency_frames, DataCallback, StateCallback, this);
  if (rv != CUBEB_OK)
  {
    Log_ErrorPrintf("Could not create stream: %d", rv);
    DestroyContext();
    return false;
  }

  cubeb_stream_set_volume(m_cubeb_stream, static_cast<float>(m_output_volume) / 100.0f);
  return true;
}

void CubebAudioStream::PauseDevice(bool paused)
{
  if (paused == m_paused)
    return;

  int rv = paused ? cubeb_stream_stop(m_cubeb_stream) : cubeb_stream_start(m_cubeb_stream);
  if (rv != CUBEB_OK)
  {
    Log_ErrorPrintf("cubeb_stream_%s failed: %d", paused ? "stop" : "start", rv);
    return;
  }
}

void CubebAudioStream::CloseDevice()
{
  Assert(IsOpen());

  if (!m_paused)
    cubeb_stream_stop(m_cubeb_stream);

  cubeb_stream_destroy(m_cubeb_stream);
  m_cubeb_stream = nullptr;

  DestroyContext();
}

long CubebAudioStream::DataCallback(cubeb_stream* stm, void* user_ptr, const void* input_buffer, void* output_buffer,
                                    long nframes)
{
  CubebAudioStream* const this_ptr = static_cast<CubebAudioStream*>(user_ptr);
  this_ptr->ReadFrames(reinterpret_cast<SampleType*>(output_buffer), static_cast<u32>(nframes), true);
  return nframes;
}

void CubebAudioStream::StateCallback(cubeb_stream* stream, void* user_ptr, cubeb_state state)
{
  CubebAudioStream* const this_ptr = static_cast<CubebAudioStream*>(user_ptr);

  this_ptr->m_paused = (state != CUBEB_STATE_STARTED);
}

void CubebAudioStream::FramesAvailable() {}

void CubebAudioStream::DestroyContext()
{
  cubeb_destroy(m_cubeb_context);
  m_cubeb_context = nullptr;

#ifdef WIN32
  if (m_com_initialized_by_us)
    CoUninitialize();
#endif
}

std::unique_ptr<AudioStream> CubebAudioStream::Create()
{
  return std::make_unique<CubebAudioStream>();
}