SDL_AudioSpec - Audio Specification Structure
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;
- 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
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.
SDL_OpenAudio,
SDL_LoadWAV