Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_ConvertAudio.3 @ 1282:217f5d5a49e5
Date: Sat, 15 Jan 2005 02:01:51 +0000 (UTC)
From: jimrandomh
Subject: [SDL] Re: Modifier keys pressed during initialization stick
I wrote a simple test program which initializes SDL, prints the SDL
version number, then prints any keydown and keyup events with their
modifiers. (Source code below). Compilation was done using Visual
Studio 6, release mode.
My test sequence was:
Start a command prompt. Type the name of the test program.
shift down
enter down (program starts)
Wait for window to appear
enter up
shift up
spacebar down
spacebar up
Under Windows 98, the output was correct:
SDL 1.2.8
left shift down
shift-return down
shift-return up
left shift up
space down
space up
Under Windows 2000 and under Windows XP, the output was:
SDL 1.2.8
shift-space down
shift-space up
Since shift was not held at the time space was pressed, this is
incorrect. Similar results were observed with launching in different
ways (including double-clicking in Windows Explorer), so it does not
depend on the launching terminal.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 29 Jan 2006 07:57:13 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
| 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" |
| 3 SDL_ConvertAudio\- Convert audio data to a desired audio format\&. | |
| 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 |