SDL_AudioCVT man page

typedef struct{
  int needed;
  Uint16 src_format;
  Uint16 dest_format;
  double rate_incr;
  Uint8 *buf;
  int len;
  int len_cvt;
  int len_mult;
  double len_ratio;
  void (*filters[10])(struct SDL_AudioCVT *cvt, Uint16 format);
  int filter_index;
} SDL_AudioCVT;

needed

Set to one if the conversion is possible

src_format

Audio format of the source

dest_format

Audio format of the destination

rate_incr

Rate conversion increment

buf

Audio buffer

len

Length of the original audio buffer in bytes

len_cvt

Length of converted audio buffer in bytes (calculated)

len_mult

buf must be len*len_mult bytes in size(calculated)

len_ratio

Final audio size is len*len_ratio

filters[10](..)

Pointers to functions needed for this conversion

filter_index

Current conversion function

The SDL_AudioCVT is used to convert audio data between different formats. A SDL_AudioCVT structure is created with the SDL_BuildAudioCVT function, while the actual conversion is done by the SDL_ConvertAudio function.

Many of the fields in the SDL_AudioCVT structure should be considered private and their function will not be discussed here.

Uint8 *buf

int len

int len_mult

double len_ratio

SDL_BuildAudioCVT, SDL_ConvertAudio, SDL_AudioSpec