strawberry-audio-player-windows-mac-linux/src/engine/enginebase.h

/*
 * Strawberry Music Player
 * This file was part of Amarok / Clementine
 * Copyright 2003 Mark Kretschmann
 * Copyright 2004 - 2005 Max Howell, <max.howell@methylblue.com>
 * Copyright 2010 David Sansome <me@davidsansome.com>
 * Copyright 2017 - 2018 Jonas Kvinge <jonas@jkvinge.net>
 *
 * Strawberry is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Strawberry is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ENGINEBASE_H
#define ENGINEBASE_H

#include "config.h"

#include <sys/types.h>
#include <cstdint>
#include <vector>
#include <stdbool.h>

#include <QtGlobal>
#include <QObject>
#include <QList>
#include <QMetaType>
#include <QVariant>
#include <QString>
#include <QUrl>

#include "engine_fwd.h"
#include "enginetype.h"
#include "enginedevice.h"
#include "core/song.h"

namespace Engine {

struct SimpleMetaBundle;

typedef std::vector<int16_t> Scope;

class Base : public QObject {
  Q_OBJECT

protected:
  Base();

public:

  virtual ~Base();

  struct OutputDetails {
    QString name;
    QString description;
    QString iconname;
  };
  typedef QList<OutputDetails> OutputDetailsList;

  virtual bool Init() = 0;
  virtual State state() const = 0;
  virtual void StartPreloading(const QUrl &media_url, const QUrl &original_url, bool, qint64, qint64) {}
  virtual bool Load(const QUrl &media_url, const QUrl &original_url, TrackChangeFlags change, bool force_stop_at_end, quint64 beginning_nanosec, qint64 end_nanosec);
  virtual bool Play(quint64 offset_nanosec) = 0;
  virtual void Stop(bool stop_after = false) = 0;
  virtual void Pause() = 0;
  virtual void Unpause() = 0;
  virtual void Seek(quint64 offset_nanosec) = 0;
  virtual void SetVolumeSW(uint percent) = 0;

  virtual qint64 position_nanosec() const = 0;
  virtual qint64 length_nanosec() const = 0;

  virtual const Scope &scope(int chunk_length) { return scope_; }

  // Sets new values for the beginning and end markers of the currently playing song.
  // This doesn't change the state of engine or the stream's current position.
  virtual void RefreshMarkers(quint64 beginning_nanosec, qint64 end_nanosec) {
    beginning_nanosec_ = beginning_nanosec;
    end_nanosec_ = end_nanosec;
  }

  virtual OutputDetailsList GetOutputsList() const = 0;
  virtual bool ValidOutput(const QString &output) = 0;
  virtual QString DefaultOutput() = 0;
  virtual bool CustomDeviceSupport(const QString &output) = 0;
  virtual bool ALSADeviceSupport(const QString &output) = 0;

  // Plays a media stream represented with the URL 'u' from the given 'beginning' to the given 'end' (usually from 0 to a song's length).
  // Both markers should be passed in nanoseconds. 'end' can be negative, indicating that the real length of 'u' stream is unknown.
  bool Play(const QUrl &media_url, const QUrl &original_url, TrackChangeFlags c, bool force_stop_at_end, quint64 beginning_nanosec, qint64 end_nanosec);
  void SetVolume(uint value);
  static uint MakeVolumeLogarithmic(uint volume);

public slots:
  virtual void ReloadSettings();

protected:
  void EmitAboutToEnd();

public:

  // Simple accessors
  EngineType type() const { return type_; }
  inline uint volume() const { return volume_; }

  bool is_fadeout_enabled() const { return fadeout_enabled_; }
  bool is_crossfade_enabled() const { return crossfade_enabled_; }
  bool is_autocrossfade_enabled() const { return autocrossfade_enabled_; }
  bool crossfade_same_album() const { return crossfade_same_album_; }
  bool IsEqualizerEnabled() { return equalizer_enabled_; }

  static const int kScopeSize = 1024;

  QVariant device() { return device_; }

public slots:
  virtual void SetEqualizerEnabled(bool) {}
  virtual void SetEqualizerParameters(int preamp, const QList<int> &bandGains) {}
  virtual void SetStereoBalance(float value) {}

signals:
  // Emitted when crossfading is enabled and the track is crossfade_duration_ away from finishing
  void TrackAboutToEnd();

  void TrackEnded();

  void FadeoutFinishedSignal();

  void StatusText(const QString &text);
  void Error(const QString &text);

  // Emitted when there was a fatal error
  void FatalError();
  // Emitted when Engine was unable to play a song with the given QUrl.
  void InvalidSongRequested(const QUrl &url);
  // Emitted when Engine successfully started playing a song with the given QUrl.
  void ValidSongRequested(const QUrl &url);

  void MetaData(const Engine::SimpleMetaBundle&);

  // Signals that the engine's state has changed (a stream was stopped for example).
  // Always use the state from event, because it's not guaranteed that immediate subsequent call to state() won't return a stale value.
  void StateChanged(Engine::State);

protected:

  struct PluginDetails {
    QString name;
    QString description;
    QString iconname;
  };
  typedef QList<PluginDetails> PluginDetailsList;

  EngineType type_;
  uint volume_;
  quint64 beginning_nanosec_;
  qint64 end_nanosec_;
  QUrl media_url_;
  QUrl original_url_;
  Scope scope_;
  bool buffering_;
  bool equalizer_enabled_;

  // Settings
  QString output_;
  QVariant device_;

  // ReplayGain
  bool rg_enabled_;
  int rg_mode_;
  float rg_preamp_;
  bool rg_compression_;

  // Buffering
  quint64 buffer_duration_nanosec_;
  int buffer_min_fill_;

  bool mono_playback_;

  // Fadeout
  bool fadeout_enabled_;
  bool crossfade_enabled_;
  bool autocrossfade_enabled_;
  bool crossfade_same_album_;
  bool fadeout_pause_enabled_;
  qint64 fadeout_duration_;
  qint64 fadeout_duration_nanosec_;
  qint64 fadeout_pause_duration_;
  qint64 fadeout_pause_duration_nanosec_;

private:
  bool about_to_end_emitted_;
  Q_DISABLE_COPY(Base);

};

struct SimpleMetaBundle {
  QUrl url;
  QString title;
  QString artist;
  QString album;
  QString comment;
  QString genre;
  qlonglong length;
  int year;
  int tracknr;
  Song::FileType filetype;
  int samplerate;
  int bitdepth;
  qlonglong bitrate;
  QString lyrics;
};

}  // namespace

Q_DECLARE_METATYPE(EngineBase::OutputDetails);

#endif