Mercurial > sdl-ios-xcode
view docs/man3/SDL_AudioSpec.3 @ 4168:69bcba65c388 SDL-1.2
Fixed bug #526
Comment #1 From Simon Howard 2009-03-20 16:50:56
Hi,
I'm the author of Chocolate Doom, one of the other source ports that James
mentioned. This is a patch against the current SVN version of SDL 1.2 that
fixes the bug. It has been tested and hopefully should be obviously correct
from examining the changes. I'll give a brief explanation.
When the palette is set with SDL_SetPalette, the IDirectDrawPalette_SetEntries
DirectX function is invoked. However, when this happens, a WM_PALETTECHANGED
message is sent to the window.
A WM_PALETTECHANGED message can also be received if the palette is changed for
some other reason, like if the system palette is changed. Therefore, the
palette change handler (DX5_PaletteChanged) has code to deal with this case.
It distinguishes "expected" palette changes (set with SDL_SetPalette) from
"unexpected" palette changes using the colorchange_expected variable, which is
set before calling IDirectDrawPalette_SetEntries. However, the code to set
this variable is missing in the fullscreen code path. By setting this
variable, the palette change is handled properly and the freezes go away.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 13 Apr 2009 00:53:12 +0000 |
| parents | 4e3b250c950e |
| children | 1238da4a7112 |
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.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