SDL_AudioSpec
Section: SDL API Reference (3)
Updated: Tue 11 Sep 2001, 22:58
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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.
SEE ALSO
SDL_OpenAudio, SDL_LoadWAV