drwav_write_handle.hpp

#pragma once
#include <ossia/dataflow/float_to_sample.hpp>
 
#include <boost/container/vector.hpp>
 
#include <dr_wav.h>
 
#include <ossia-config.hpp>
namespace ossia
{
 
struct drwav_write_handle
{
  drwav_data_format format;
  static constexpr auto static_cutoff = 4096 * 2;
 
public:
  drwav_write_handle()
      : impl{new drwav}
  {
  }
 
  ~drwav_write_handle()
  {
    close();
    delete impl;
  }
 
  void open(std::string_view path, int channels, int rate, int bits)
  {
    close();
 
    if(channels <= 0)
      return;
    if(rate <= 0)
      return;
    if(path.empty())
      return;
 
    format.container = drwav_container_riff;
    format.format = DR_WAVE_FORMAT_PCM;
    format.channels = channels;
    format.sampleRate = rate;
    format.bitsPerSample = bits;
 
    bool ok = drwav_init_file_write(impl, path.data(), &format, nullptr);
 
    buffer.reserve(channels * 8192 * (bits / 8));
    m_started = ok;
    m_written_frames = 0;
  }
 
  void close()
  {
    if(impl)
    {
      if(m_started)
      {
        drwav_uninit(impl);
      }
    }
    m_started = false;
    m_written_frames = 0;
  }
 
  drwav_uint64 write_pcm_frames(drwav_uint64 frames, const double* const* in)
  {
    if(!m_started)
      return 0;
 
    this->buffer.clear();
    this->buffer.resize(
        frames * format.channels * (format.bitsPerSample / 8),
        boost::container::default_init);
 
    switch(format.bitsPerSample)
    {
      case 16:
        m_written_frames += frames;
        interleave<int16_t, 16, 2>(
            in, reinterpret_cast<int16_t*>(buffer.data()), format.channels, frames);
 
        return drwav_write_raw(impl, frames * 2 * format.channels, buffer.data());
      case 24:
        m_written_frames += frames;
        interleave<int32_t, 24, 3>(
            in, reinterpret_cast<int32_t*>(buffer.data()), format.channels, frames);
 
        return drwav_write_raw(impl, frames * 3 * format.channels, buffer.data());
      case 32:
        m_written_frames += frames;
        interleave<int32_t, 32, 4>(
            in, reinterpret_cast<int32_t*>(buffer.data()), format.channels, frames);
 
        return drwav_write_raw(impl, frames * 4 * format.channels, buffer.data());
        break;
    }
    return 0;
  }
 
  bool is_open() const noexcept { return m_started; }
  int64_t written_frames() const noexcept { return m_written_frames; }
 
private:
  ::drwav* impl{};
  ossia::pod_vector<char> buffer;
  bool m_started{};
  int64_t m_written_frames = 0;
};
}