_kit_acodecPCM.h as of 2023-10-12

/**
 * \file _kit_acodecPCM.h
 * \brief Header file that contains stuff related to PCM data (used by both acodec and kmixer)
 */
#ifndef __KIT_ACODECPCM_H
#define __KIT_ACODECPCM_H


#include <SDL2/SDL.h>

#ifdef __cplusplus
extern "C" {
#endif




//using the extension ".kpm" is preferred
 //when saving kit_acodecPCM to a file
#define KPCM_MAGIC (0x4D43506B) //= "kPCM"



/**
 * \brief Stereo Uint8 samples
 */
typedef struct kit_acodecPCM_U_8S {
  Uint8 l; ///< \brief Left audio channel
  Uint8 r; ///< \brief Right audio channel
} kit_acodecPCM_U_8S;

/**
 * \brief Stereo Sint16 samples
 */
typedef struct kit_acodecPCM_I16S {
  Sint16 l; ///< \brief Left audio channel
  Sint16 r; ///< \brief Right audio channel
} kit_acodecPCM_I16S;

/**
 * \brief Stereo Sint32 samples
 */
typedef struct kit_acodecPCM_I32S {
  Sint32 l; ///< \brief Left audio channel
  Sint32 r; ///< \brief Right audio channel
} kit_acodecPCM_I32S;

/**
 * \brief Stereo float samples
 */
typedef struct kit_acodecPCM_F32S {
  float l; ///< \brief Left audio channel
  float r; ///< \brief Right audio channel
} kit_acodecPCM_F32S;


/**
 * \brief A union of supported sample formats
 */
typedef union kit_acodecPCMSamples {
  void*  data; ///< \brief Generic pointer
  Uint8*  u_8; ///< \brief Mono Uint8 Samples
  Sint16* i16; ///< \brief Mono Sint16 Samples
  Sint32* i32; ///< \brief Mono Sint32 Samples
  float*  f32; ///< \brief Mono float Samples
  kit_acodecPCM_U_8S* u_8s; ///< \brief Stereo Uint8 samples
  kit_acodecPCM_I16S* i16s; ///< \brief Stereo Sint16 samples
  kit_acodecPCM_I32S* i32s; ///< \brief Stereo Sint32 samples
  kit_acodecPCM_F32S* f32s; ///< \brief Stereo float samples
} kit_acodecPCMSamples;


/**
 * \brief The struct that contains info about a PCM audio stream. \n
 *        When saved as a file (usually as ".kpm"), the header's size will be 72 (0x48).
 */
typedef struct kit_acodecPCM {
  Uint32           magic; ///< \brief (0x00) = 0x4D43506B = "kPCM" (no null terminator)
  SDL_AudioFormat format; ///< \brief (0x04) The data format of the stream
  Uint16      headerSize; ///< \brief (0x06) = sizeof(kit_acodecPCM)
  Uint64        dataSize; ///< \brief (0x08) The size of the PCM buffer, in bytes
  Uint64       loopStart; ///< \brief (0x10) Which sample to loop back to
  Uint64         loopEnd; ///< \brief (0x18) Which sample to restart the loop on
  Uint64      numSamples; ///< \brief (0x20) The number of sample frames in the stream
  Uint32      sampleRate; ///< \brief (0x28) The stream's sample rate, in Hz
  Uint32         bitRate; ///< \brief (0x2C) The audio's bit rate per second
  Uint16       loopCount; ///< \brief (0x30) # of times to loop audio (65535 for infinite loop)
  Uint16        channels; ///< \brief (0x32) # of interlaced channels in the stream (L&R for stereo)
  Uint8     bitRemainder; ///< \brief (0x34) = bitsPerSample%8
  Uint8        userflags; ///< \brief (0x35) User-defined (is just padding otherwise)
  Uint16       uservalue; ///< \brief (0x36) User-defined (is just padding otherwise)
  //while userdata and data are technically included in a .kpm file,
   //they should appear as 0 within that file
  void*         userdata; ///< \brief (0x38) User-defined pointer
  union {
    void*  data; ///< \brief = (void*)pcm_struct_pointer + pcm_struct_pointer->headerSize
    Uint8*  u_8; ///< \brief Mono Uint8 Samples
    Sint16* i16; ///< \brief Mono Sint16 Samples
    Sint32* i32; ///< \brief Mono Sint32 Samples
    float*  f32; ///< \brief Mono float Samples
    kit_acodecPCM_U_8S* u_8s; ///< \brief Stereo Uint8 samples
    kit_acodecPCM_I16S* i16s; ///< \brief Stereo Sint16 samples
    kit_acodecPCM_I32S* i32s; ///< \brief Stereo Sint32 samples
    kit_acodecPCM_F32S* f32s; ///< \brief Stereo float samples
  }; ///< \brief (0x40) Sample data (PCM data should be contiguous with the struct itself)
} kit_acodecPCM;




#ifdef __cplusplus
}
#endif

#endif /* __KIT_ACODECPCM_H */