SDL_AudioSpec (3) - Linux Manuals

SDL_AudioSpec: Audio Specification Structure

Command to display SDL_AudioSpec manual in Linux: $ man 3 SDL_AudioSpec

NAME

SDL_AudioSpec - Audio Specification Structure

STRUCTURE DEFINITION

typedef struct{
  int freq;
  Uint16 format;
  Uint8 channels;
  Uint8 silence;
  Uint16 samples;
  Uint32 size;
  void (*callback)(void *userdata, Uint8 *stream, int len);
  void *userdata;
} SDL_AudioSpec;

STRUCTURE DATA

freq: Audio frequency in samples per second
format: Audio data format
channels: Number of channels: 1 mono, 2 stereo
silence: Audio buffer silence value (calculated)
samples: Audio buffer size in samples
size: Audio buffer size in bytes (calculated)
callback(..): Callback function for filling the audio buffer
userdata: Pointer the user data which is passed to the callback function

DESCRIPTION

The SDL_AudioSpec structure is used to describe the format of some audio data. This structure is used by SDL_OpenAudio and SDL_LoadWAV. While all fields are used by SDL_OpenAudio only freq, format, samples and channels are used by SDL_LoadWAV. We will detail these common members here.

freq: The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.
format: Specifies the size and type of each sample element
AUDIO_U8
AUDIO_S8
AUDIO_U16 or AUDIO_U16LSB
AUDIO_S16 or AUDIO_S16LSB
AUDIO_U16MSB
AUDIO_S16MSB
AUDIO_U16SYS
AUDIO_S16SYS
channels: The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).
samples: When used with SDL_OpenAudio this refers to the size of the audio buffer in samples. A sample a chunk of audio data of the size specified in format mulitplied by the number of channels. When the SDL_AudioSpec is used with SDL_LoadWAV samples is set to 4096.