| 1 | .TH "SDL_AudioSpec" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" |
| 2 | .SH "NAME" |
| 3 | SDL_AudioSpec \- Audio Specification Structure |
| 4 | .SH "STRUCTURE DEFINITION" |
| 5 | .PP |
| 6 | .nf |
| 7 | \f(CWtypedef struct{ |
| 8 | int freq; |
| 9 | Uint16 format; |
| 10 | Uint8 channels; |
| 11 | Uint8 silence; |
| 12 | Uint16 samples; |
| 13 | Uint32 size; |
| 14 | void (*callback)(void *userdata, Uint8 *stream, int len); |
| 15 | void *userdata; |
| 16 | } SDL_AudioSpec;\fR |
| 17 | .fi |
| 18 | .PP |
| 19 | .SH "STRUCTURE DATA" |
| 20 | .TP 20 |
| 21 | \fBfreq\fR |
| 22 | Audio frequency in samples per second |
| 23 | .TP 20 |
| 24 | \fBformat\fR |
| 25 | Audio data format |
| 26 | .TP 20 |
| 27 | \fBchannels\fR |
| 28 | Number of channels: 1 mono, 2 stereo |
| 29 | .TP 20 |
| 30 | \fBsilence\fR |
| 31 | Audio buffer silence value (calculated) |
| 32 | .TP 20 |
| 33 | \fBsamples\fR |
| 34 | Audio buffer size in samples |
| 35 | .TP 20 |
| 36 | \fBsize\fR |
| 37 | Audio buffer size in bytes (calculated) |
| 38 | .TP 20 |
| 39 | \fBcallback(\&.\&.)\fR |
| 40 | Callback function for filling the audio buffer |
| 41 | .TP 20 |
| 42 | \fBuserdata\fR |
| 43 | Pointer the user data which is passed to the callback function |
| 44 | .SH "DESCRIPTION" |
| 45 | .PP |
| 46 | The \fBSDL_AudioSpec\fR structure is used to describe the format of some audio data\&. This structure is used by \fI\fBSDL_OpenAudio\fP\fR and \fI\fBSDL_LoadWAV\fP\fR\&. While all fields are used by \fBSDL_OpenAudio\fP only \fBfreq\fR, \fBformat\fR, \fBsamples\fR and \fBchannels\fR are used by \fBSDL_LoadWAV\fP\&. We will detail these common members here\&. |
| 47 | .TP 20 |
| 48 | \fBfreq\fR |
| 49 | The number of samples sent to the sound device every second\&. Common values are 11025, 22050 and 44100\&. The higher the better\&. |
| 50 | .TP 20 |
| 51 | \fBformat\fR |
| 52 | Specifies the size and type of each sample element |
| 53 | .IP "\fBAUDIO_U8\fP" 10Unsigned 8-bit samples |
| 54 | .IP "\fBAUDIO_S8\fP" 10Signed 8-bit samples |
| 55 | .IP "\fBAUDIO_U16\fP or \fBAUDIO_U16LSB\fP" 10Unsigned 16-bit little-endian samples |
| 56 | .IP "\fBAUDIO_S16\fP or \fBAUDIO_S16LSB\fP" 10Signed 16-bit little-endian samples |
| 57 | .IP "\fBAUDIO_U16MSB\fP" 10Unsigned 16-bit big-endian samples |
| 58 | .IP "\fBAUDIO_S16MSB\fP" 10Signed 16-bit big-endian samples |
| 59 | .IP "\fBAUDIO_U16SYS\fP" 10Either \fBAUDIO_U16LSB\fP or \fBAUDIO_U16MSB\fP depending on you systems endianness |
| 60 | .IP "\fBAUDIO_S16SYS\fP" 10Either \fBAUDIO_S16LSB\fP or \fBAUDIO_S16MSB\fP depending on you systems endianness |
| 61 | .TP 20 |
| 62 | \fBchannels\fR |
| 63 | The number of seperate sound channels\&. 1 is mono (single channel), 2 is stereo (dual channel)\&. |
| 64 | .TP 20 |
| 65 | \fBsamples\fR |
| 66 | When used with \fI\fBSDL_OpenAudio\fP\fR this refers to the size of the audio buffer in samples\&. A sample a chunk of audio data of the size specified in \fBformat\fR mulitplied by the number of channels\&. When the \fBSDL_AudioSpec\fR is used with \fI\fBSDL_LoadWAV\fP\fR \fBsamples\fR is set to 4096\&. |
| 67 | .SH "SEE ALSO" |
| 68 | .PP |
| 69 | \fI\fBSDL_OpenAudio\fP\fR, \fI\fBSDL_LoadWAV\fP\fR |
| 70 | .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58 |