MediaFileHandle.hpp

#pragma once
#include <Media/AudioDecoder.hpp>
#include <Media/SndfileDecoder.hpp>
 
#include <score/tools/std/StringHash.hpp>
 
#include <ossia/audio/drwav_handle.hpp>
#include <ossia/detail/hash_map.hpp>
#include <ossia/detail/nullable_variant.hpp>
#include <ossia/detail/small_vector.hpp>
 
#include <QFile>
 
#include <nano_signal_slot.hpp>
#include <score_plugin_media_export.h>
 
#include <array>
#include <verdigris>
namespace ossia
{
struct libav_handle;
}
namespace score
{
struct DocumentContext;
}
namespace Media
{
// Remove the compile time overhead of std::pair for this
struct FloatPair
{
  float first, second;
};
struct RMSData;
class SoundComponentSetup;
static constexpr inline int64_t abs_max(int64_t f1, int64_t f2) noexcept
{
  return f2 >= 0 ? f1 < f2 ? f2 : f1 : f1 < -f2 ? f2 : f1;
}
#if defined(__clang__)
static constexpr inline float abs_max(float f1, float f2) noexcept
{
  const int mul = (f2 >= 0.f) ? 1 : -1;
  if(f1 < mul * f2)
    return f2;
  else
    return f1;
}
#else
static constexpr inline float abs_max(float f1, float f2) noexcept
{
  return f2 >= 0.f ? f1 < f2 ? f2 : f1 : f1 < -f2 ? f2 : f1;
}
#endif
 
enum class DecodingMethod
{
  Invalid,
  Mmap,
  Libav,
  Sndfile,
  LibavStream
};
 
struct DecodingSetup
{
  QString filePath;
  QString absoluteFilePath;
  DecodingMethod method{};
  int track{-1};
};
 
struct SCORE_PLUGIN_MEDIA_EXPORT AudioFile final : public QObject
{
public:
  static bool isSupported(const QFile& f);
 
  AudioFile();
  ~AudioFile() override;
 
  void load(DecodingSetup opts);
 
  QString originalFile() const { return m_originalFile; }
 
  QString fileName() const { return m_fileName; }
 
  QString absoluteFileName() const { return m_file; }
 
  int sampleRate() const { return m_sampleRate; }
 
  int64_t decodedSamples() const;
 
  // Number of samples in a channel.
  int64_t samples() const;
  int64_t channels() const;
 
  bool empty() const { return channels() == 0 || samples() == 0; }
  bool finishedDecoding() const noexcept { return m_fullyDecoded; }
 
  const RMSData& rms() const;
 
  ossia::audio_array getAudioArray() const;
 
  Nano::Signal<void()> on_mediaChanged;
  Nano::Signal<void()> on_newData;
  Nano::Signal<void()> on_finishedDecoding;
 
  struct MmapReader
  {
    std::shared_ptr<QFile> file;
    void* data{};
    ossia::drwav_handle wav;
  };
 
  struct RAMReader
  {
    ossia::audio_handle handle;
    ossia::small_vector<ossia::audio_sample*, 8> data;
  };
 
  struct LibavReader : RAMReader
  {
    explicit LibavReader(int rate) noexcept
        : decoder{rate}
    {
    }
    AudioDecoder decoder;
  };
  struct LibavStreamReader
  {
    std::string path;
    int stream{-1};
    int64_t samples{};
    int channels{};
  };
  struct SndfileReader : RAMReader
  {
    SndfileDecoder decoder;
  };
 
  using libav_ptr = std::shared_ptr<LibavReader>;
  using libav_stream_ptr = LibavStreamReader;
  using mmap_ptr = MmapReader;
  using sndfile_ptr = SndfileReader;
  using impl_t
      = ossia::nullable_variant<mmap_ptr, libav_ptr, sndfile_ptr, libav_stream_ptr>;
 
  struct MmapView
  {
    // Copy for thread-safety reasons
    ossia::drwav_handle wav;
  };
 
  struct StreamView
  {
    std::shared_ptr<ossia::libav_handle> handle;
  };
 
  struct RAMView
  {
    ossia::small_vector<audio_sample*, 8> data;
  };
 
  struct Handle : impl_t
  {
    using impl_t::impl_t;
    Handle(mmap_ptr&& ptr)
        : impl_t{std::move(ptr)}
    {
    }
    Handle(libav_ptr&& ptr)
        : impl_t{std::move(ptr)}
    {
    }
    Handle(libav_stream_ptr&& ptr)
        : impl_t{std::move(ptr)}
    {
    }
    Handle(sndfile_ptr&& ptr)
        : impl_t{std::move(ptr)}
    {
    }
    Handle& operator=(mmap_ptr&& ptr)
    {
      ((impl_t&)*this) = std::move(ptr);
      return *this;
    }
    Handle& operator=(libav_ptr&& ptr)
    {
      ((impl_t&)*this) = std::move(ptr);
      return *this;
    }
    Handle& operator=(libav_stream_ptr&& ptr)
    {
      ((impl_t&)*this) = std::move(ptr);
      return *this;
    }
    Handle& operator=(sndfile_ptr&& ptr)
    {
      ((impl_t&)*this) = std::move(ptr);
      return *this;
    }
  };
 
  using view_impl_t = ossia::nullable_variant<MmapView, RAMView, StreamView>;
  struct ViewHandle : view_impl_t
  {
    using view_impl_t::view_impl_t;
    ViewHandle(const Handle&);
 
    void frame(int64_t start_frame, ossia::small_vector<float, 8>& out) noexcept;
    void absmax_frame(
        int64_t start_frame, int64_t end_frame,
        ossia::small_vector<float, 8>& out) noexcept;
    void minmax_frame(
        int64_t start_frame, int64_t end_frame,
        ossia::small_vector<FloatPair, 8>& out) noexcept;
  };
 
  // Note : this is a copy, because it's not thread safe.
  ViewHandle handle() const noexcept { return m_impl; }
 
  const Handle& unsafe_handle() const noexcept { return m_impl; }
 
  std::optional<double> knownTempo() const noexcept;
 
private:
  void load_libav(int rate);
  void load_libav_stream();
  void load_drwav();
  void load_sndfile();
 
  friend class SoundComponentSetup;
 
  QString m_originalFile;
  QString m_file;
  QString m_fileName;
  int m_track{-1};
 
  RMSData* m_rms{};
  int m_sampleRate{};
  bool m_fullyDecoded{};
 
  Handle m_impl;
};
 
class SCORE_PLUGIN_MEDIA_EXPORT AudioFileManager final : public QObject
{
public:
  AudioFileManager() noexcept;
  ~AudioFileManager() noexcept;
 
  static AudioFileManager& instance() noexcept;
  std::shared_ptr<AudioFile>
  get(const QString&, int stream, const score::DocumentContext&);
 
  std::shared_ptr<AudioFile> get(const QString& absolutePath, int stream);
 
private:
  struct StreamInfo
  {
    struct hash
    {
      std::size_t operator()(const StreamInfo& f) const noexcept
      {
        constexpr const QtPrivate::QHashCombine combine;
        std::size_t h = 0;
        h = combine(h, f.file);
        h = combine(h, f.stream);
        return h;
      }
    };
    bool operator==(const StreamInfo& other) const noexcept
    {
      return file == other.file && stream == other.stream;
    }
    QString file;
    int stream{-1};
  };
  ossia::hash_map<StreamInfo, std::shared_ptr<AudioFile>, StreamInfo::hash> m_handles;
};
 
SCORE_PLUGIN_MEDIA_EXPORT
void writeAudioArrayToFile(const QString& path, const ossia::audio_array& arr, int fs);
 
std::optional<double> estimateTempo(const AudioFile& file);
std::optional<double> estimateTempo(const QString& filePath);
 
std::optional<AudioInfo> probe(const QString& path);
 
}
 
Q_DECLARE_METATYPE(std::shared_ptr<Media::AudioFile>)
W_REGISTER_ARGTYPE(std::shared_ptr<Media::AudioFile>)
Q_DECLARE_METATYPE(const Media::AudioFile*)
W_REGISTER_ARGTYPE(const Media::AudioFile*)