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annotate docs/man3/SDL_ConvertAudio.3 @ 2429:2c55b72ba46e gsoc2008_iphone
testdyngles is exactly what it sounds like -- a version of testdyngl that uses OpenGL ES calls instead of OpenGL. Was necessary to create because glOrtho is called glOrthof in OpenGL ES, and OpenGL ES doesn't have glBegin() type semantics for specifying geometry.
| author | Holmes Futrell <hfutrell@umail.ucsb.edu> |
|---|---|
| date | Fri, 15 Aug 2008 00:52:52 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| rev | line source |
|---|---|
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181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
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1 .TH "SDL_ConvertAudio" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
|
2283
546f7c1eb755
Merged revision 3472 from SDL 1.2, fixing bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
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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
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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 |