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"SDL_AudioSpec" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference"
"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"

20 freq Audio frequency in samples per second

20 format Audio data format

20 channels Number of channels: 1 mono, 2 stereo

20 silence Audio buffer silence value (calculated)

20 samples Audio buffer size in samples

20 size Audio buffer size in bytes (calculated)

20 callback(..) Callback function for filling the audio buffer

20 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.

20 freq The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.

20 format Specifies the size and type of each sample element

"AUDIO_U8" 10Unsigned 8-bit samples
"AUDIO_S8" 10Signed 8-bit samples
"AUDIO_U16 or AUDIO_U16LSB" 10Unsigned 16-bit little-endian samples
"AUDIO_S16 or AUDIO_S16LSB" 10Signed 16-bit little-endian samples
"AUDIO_U16MSB" 10Unsigned 16-bit big-endian samples
"AUDIO_S16MSB" 10Signed 16-bit big-endian samples
"AUDIO_U16SYS" 10Either AUDIO_U16LSB or AUDIO_U16MSB depending on you systems endianness
"AUDIO_S16SYS" 10Either AUDIO_S16LSB or AUDIO_S16MSB depending on you systems endianness

20 channels The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).

20 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 created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58