Mercurial > sdl-ios-xcode
view docs/man3/SDL_AudioSpec.3 @ 4223:63fd67e17705 SDL-1.2
Fixed bug #727
Lorenzo Desole 2009-04-19 07:36:10 PDT
I am one of the developers of a multimedia application (My Media System MMS),
which uses SDL.
MMS is normally running in fullscreen mode but it switches it off before
launching external applications (mplayer, xine, etc.).
The problem with fullscreen is that when the latter is switched off either via
SDL_WM_ToggleFullScreen() or SDL_SetVideoMode(), SDL compares the current
screen sizes with the ones saved when the video system was initted, and if they
don't match, it calls XF86VidModeSwitchToMode() to switch to the old modeline.
This makes it impossible for external programs and for MMS itself to use RandR
to change the screen size, because next time fullscreen mode is turned off, it
bombs out with the following error:
X Error of failed request: BadValue (integer parameter out of range for
operation)
Major opcode of failed request: 136 (XFree86-VidModeExtension)
Minor opcode of failed request: 10 (XF86VidModeSwitchToMode)
[...]
Obviously this happens only if the new screen resolution is smaller than the
original one and XF86VidModeSwitchToMode() can't succeed.
I couldn't find any way to inform SDL that the screen resolution it uses as
reference is no longer valid.
This can be fixed by adding "save_mode(this)" to
./src/video/x11/SDL_x11modes.c, API X11_EnterFullScreen(_THIS), like this:
int X11_EnterFullScreen(_THIS)
{
int okay;
+ save_mode(this);
I can't rule out possible side effects, but I don't see any.
While I admit this is a minor issue for the general users, it is a major
showstopper for our program where the ability to change screen resolution and
refresh rate according to the movie being played, is very important.
Thanks in advance.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 21 Sep 2009 11:14:36 +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