SDL_AudioSpec(3)

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

Overview

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.

Releases

11 releases since Debian 3.0 (Woody); the text changed 1 time.