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Date: Wed, 9 Apr 2003 18:21:33 -0230 From: Stephen Anthony <stephena@roadrunner.nf.net> Subject: [SDL] First patch concerning 4.3 and refresh rates OK, here's my first draft of the patch for the above subject. A short explanation: X 4.3 introduces many more modelines than older versions. This would be fine, except it introduces many modes with the *same* resolution but different refresh rates. And SDL won't necessarily pick the one with the highest refresh rate. So this patch restores SDL to X 4.2 functionality. That is, there is only ever one refresh rate *per* resolution, and it is the highest possible. This functionality can be totally disabled by using the environment variable 'SDL_VIDEO_X11_USE_ALL_MODES' set equal to 1.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 20 Apr 2003 05:36:52 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_AudioSpec" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_AudioSpec\- Audio Specification Structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef 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;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBfreq\fR
Audio frequency in samples per second
.TP 20
\fBformat\fR
Audio data format
.TP 20
\fBchannels\fR
Number of channels: 1 mono, 2 stereo
.TP 20
\fBsilence\fR
Audio buffer silence value (calculated)
.TP 20
\fBsamples\fR
Audio buffer size in samples
.TP 20
\fBsize\fR
Audio buffer size in bytes (calculated)
.TP 20
\fBcallback(\&.\&.)\fR
Callback function for filling the audio buffer
.TP 20
\fBuserdata\fR
Pointer the user data which is passed to the callback function
.SH "DESCRIPTION"
.PP
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\&.
.TP 20
\fBfreq\fR
The number of samples sent to the sound device every second\&. Common values are 11025, 22050 and 44100\&. The higher the better\&.
.TP 20
\fBformat\fR
Specifies the size and type of each sample element 
.IP "\fBAUDIO_U8\fP" 10Unsigned 8-bit samples
.IP "\fBAUDIO_S8\fP" 10Signed 8-bit samples
.IP "\fBAUDIO_U16\fP or \fBAUDIO_U16LSB\fP" 10Unsigned 16-bit little-endian samples
.IP "\fBAUDIO_S16\fP or \fBAUDIO_S16LSB\fP" 10Signed 16-bit little-endian samples
.IP "\fBAUDIO_U16MSB\fP" 10Unsigned 16-bit big-endian samples
.IP "\fBAUDIO_S16MSB\fP" 10Signed 16-bit big-endian samples
.IP "\fBAUDIO_U16SYS\fP" 10Either \fBAUDIO_U16LSB\fP or \fBAUDIO_U16MSB\fP depending on you systems endianness
.IP "\fBAUDIO_S16SYS\fP" 10Either \fBAUDIO_S16LSB\fP or \fBAUDIO_S16MSB\fP depending on you systems endianness
.TP 20
\fBchannels\fR
The number of seperate sound channels\&. 1 is mono (single channel), 2 is stereo (dual channel)\&.
.TP 20
\fBsamples\fR
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\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_OpenAudio\fP\fR, \fI\fBSDL_LoadWAV\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58