ICodec.h

/*
 *  Copyright (C) 2005-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */

#pragma once

#include "cores/AudioEngine/Utils/AEAudioFormat.h"
#include "filesystem/File.h"
#include "music/tags/MusicInfoTag.h"

#include <string>

#define READ_EOF      -1
#define READ_SUCCESS   0
#define READ_ERROR     1

class CFileItem;

class ICodec
{
public:
  ICodec()
  {
    m_TotalTime = 0;
    m_bitRate = 0;
    m_bitsPerSample = 0;
    m_bitsPerCodedSample = 0;
  };
  virtual ~ICodec() = default;

  // Virtual functions that all codecs should implement.  Note that these may need
  // enhancing and or refactoring at a later date.  It works currently well for MP3 and
  // APE codecs.

  // Init(filename)
  // This routine should handle any initialization necessary.  At a minimum it needs to:
  // 1.  Load any dlls and make sure any buffers etc. are allocated.
  // 2.  Load the file (or at least attempt to load it)
  // 3.  Fill in the m_TotalTime, m_SampleRate, m_BitsPerSample and m_Channels parameters.
  virtual bool Init(const CFileItem &file, unsigned int filecache)=0;

  virtual bool CanSeek() {return true;}

  // Seek()
  // Should seek to the appropriate time (in ms) in the file, and return the
  // time to which we managed to seek (in the case where seeking is problematic)
  // This is used in FFwd/Rewd so can be called very often.
  virtual bool Seek(int64_t iSeekTime)=0;

  // ReadPCM()
  // Decodes audio into pBuffer up to size bytes.  The actual amount of returned data
  // is given in actualsize.  Returns READ_SUCCESS on success.  Returns READ_EOF when
  // the data has been exhausted, and READ_ERROR on error.
  virtual int ReadPCM(uint8_t* pBuffer, size_t size, size_t* actualsize) = 0;

  virtual int ReadRaw(uint8_t **pBuffer, int *bufferSize) { return READ_ERROR; }

  // CanInit()
  // Should return true if the codec can be initialized
  // eg. check if a dll needed for the codec exists
  virtual bool CanInit()=0;

  // set the total time - useful when info comes from a preset tag
  virtual void SetTotalTime(int64_t totaltime) {}

  virtual bool IsCaching()    const    {return false;}
  virtual int GetCacheLevel() const    {return -1;}

  int64_t m_TotalTime;  // time in ms
  int m_bitRate;
  int m_bitsPerSample;
  int m_bitsPerCodedSample;
  std::string m_CodecName;
  MUSIC_INFO::CMusicInfoTag m_tag;
  XFILE::CFile m_file;
  AEAudioFormat m_format;
};