Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_ConvertAudio.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reference is no longer valid.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 |
rev | line source |
---|---|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_ConvertAudio" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
4107
4e3b250c950e
Erik Heckers fixed bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
3 SDL_ConvertAudio \- Convert audio data to a desired audio format\&. |
0 | 4 .SH "SYNOPSIS" |
5 .PP | |
6 \fB#include "SDL\&.h" | |
7 .sp | |
8 \fBint \fBSDL_ConvertAudio\fP\fR(\fBSDL_AudioCVT *cvt\fR); | |
9 .SH "DESCRIPTION" | |
10 .PP | |
11 \fBSDL_ConvertAudio\fP takes one parameter, \fBcvt\fR, which was previously initilized\&. Initilizing a \fI\fBSDL_AudioCVT\fR\fR is a two step process\&. First of all, the structure must be passed to \fI\fBSDL_BuildAudioCVT\fP\fR along with source and destination format parameters\&. Secondly, the \fBcvt\fR->\fBbuf\fR and \fBcvt\fR->\fBlen\fR fields must be setup\&. \fBcvt\fR->\fBbuf\fR should point to the audio data and \fBcvt\fR->\fBlen\fR should be set to the length of the audio data in bytes\&. Remember, the length of the buffer pointed to by \fBbuf\fR show be \fBlen\fR*\fBlen_mult\fR bytes in length\&. | |
12 .PP | |
13 Once the \fBSDL_AudioCVT\fRstructure is initilized then we can pass it to \fBSDL_ConvertAudio\fP, which will convert the audio data pointer to by \fBcvt\fR->\fBbuf\fR\&. If \fBSDL_ConvertAudio\fP returned \fB0\fR then the conversion was completed successfully, otherwise \fB-1\fR is returned\&. | |
14 .PP | |
15 If the conversion completed successfully then the converted audio data can be read from \fBcvt\fR->\fBbuf\fR\&. The amount of valid, converted, audio data in the buffer is equal to \fBcvt\fR->\fBlen\fR*\fBcvt\fR->\fBlen_ratio\fR\&. | |
16 .SH "EXAMPLES" | |
17 .PP | |
18 .nf | |
19 \f(CW/* Converting some WAV data to hardware format */ | |
20 void my_audio_callback(void *userdata, Uint8 *stream, int len); | |
21 | |
22 SDL_AudioSpec *desired, *obtained; | |
23 SDL_AudioSpec wav_spec; | |
24 SDL_AudioCVT wav_cvt; | |
25 Uint32 wav_len; | |
26 Uint8 *wav_buf; | |
27 int ret; | |
28 | |
29 /* Allocated audio specs */ | |
30 desired=(SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); | |
31 obtained=(SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); | |
32 | |
33 /* Set desired format */ | |
34 desired->freq=22050; | |
35 desired->format=AUDIO_S16LSB; | |
36 desired->samples=8192; | |
37 desired->callback=my_audio_callback; | |
38 desired->userdata=NULL; | |
39 | |
40 /* Open the audio device */ | |
41 if ( SDL_OpenAudio(desired, obtained) < 0 ){ | |
42 fprintf(stderr, "Couldn\&'t open audio: %s | |
43 ", SDL_GetError()); | |
44 exit(-1); | |
45 } | |
46 | |
47 free(desired); | |
48 | |
49 /* Load the test\&.wav */ | |
50 if( SDL_LoadWAV("test\&.wav", &wav_spec, &wav_buf, &wav_len) == NULL ){ | |
51 fprintf(stderr, "Could not open test\&.wav: %s | |
52 ", SDL_GetError()); | |
53 SDL_CloseAudio(); | |
54 free(obtained); | |
55 exit(-1); | |
56 } | |
57 | |
58 /* Build AudioCVT */ | |
59 ret = SDL_BuildAudioCVT(&wav_cvt, | |
60 wav_spec\&.format, wav_spec\&.channels, wav_spec\&.freq, | |
61 obtained->format, obtained->channels, obtained->freq); | |
62 | |
63 /* Check that the convert was built */ | |
64 if(ret==-1){ | |
65 fprintf(stderr, "Couldn\&'t build converter! | |
66 "); | |
67 SDL_CloseAudio(); | |
68 free(obtained); | |
69 SDL_FreeWAV(wav_buf); | |
70 } | |
71 | |
72 /* Setup for conversion */ | |
73 wav_cvt\&.buf=(Uint8 *)malloc(wav_len*wav_cvt\&.len_mult); | |
74 wav_cvt\&.len=wav_len; | |
75 memcpy(wav_cvt\&.buf, wav_buf, wav_len); | |
76 | |
77 /* We can delete to original WAV data now */ | |
78 SDL_FreeWAV(wav_buf); | |
79 | |
80 /* And now we\&'re ready to convert */ | |
81 SDL_ConvertAudio(&wav_cvt); | |
82 | |
83 /* do whatever */ | |
84 \&. | |
85 \&. | |
86 \&. | |
87 \&. | |
88 | |
89 \fR | |
90 .fi | |
91 .PP | |
92 .SH "SEE ALSO" | |
93 .PP | |
94 \fI\fBSDL_BuildAudioCVT\fP\fR, \fI\fBSDL_AudioCVT\fP\fR | |
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
95 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58 |