Mercurial > sdl-ios-xcode
annotate docs/html/sdlconvertaudio.html @ 934:af585d6efec8
Date: Thu, 17 Jun 2004 11:38:51 -0700 (PDT)
From: Eric Wing <ewing2121@yahoo.com>
Subject: New OS X patch (was Re: [SDL] Bug with inverted mouse coordinates in
I have a new patch for OS X I would like to submit.
First, it appears no further action has been taken on
my fix from Apple on the OpenGL windowed mode mouse
inversion problem. The fix would reunify the code, and
no longer require case checking for which version of
the OS you are running. This is probably a good fix
because the behavior with the old code could change
again with future versions of the OS, so those fixes
are included in this new patch.
But in addition, when I was at Apple, I asked them
about the ability to distinguish between the modifier
keys on the left and right sides of the keyboard (e.g.
Left Shift, Right Shift, Left/Right Alt, L/R Cmd, L/R
Ctrl). They told me that starting with Panther, the OS
began supporting this feature. This has always been a
source of annoyance for me when bringing a program
that comes from Windows or Linux to OS X when the
keybindings happened to need distinguishable left-side
and right-side keys. So the rest of the patch I am
submitting contains new code to support this feature
on Panther (and presumably later versions of the OS).
So after removing the OS version checks for the mouse
inversion problem, I reused the OS version checks to
activate the Left/Right detection of modifier keys. If
you are running Panther (or above), the new code will
attempt to distinguish between sides. For the older
OS's, the code path reverts to the original code.
I've tested with Panther on a G4 Cube, G5 dual
processor, and Powerbook Rev C. The Cube and G5
keyboards demonstrated the ability to distinguish
between sides. The Powerbook seems to only have
left-side keys, but the patch was still able to handle
it by producing the same results as before the patch.
I also wanted to test a non-Apple keyboard.
Unfortunately, I don't have any PC USB keyboards.
However, I was able to borrow a Sun Microsystems USB
keyboard, so I tried that out on the G5, and I got the
correct behavior for left and right sides. I'm
expecting that if it worked with a Sun keyboard, most
other keyboards should work with no problems.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 20 Aug 2004 22:35:23 +0000 |
| parents | 355632dca928 |
| children |
| rev | line source |
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| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >SDL_ConvertAudio</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ |
| 0 | 8 "><LINK |
| 9 REL="HOME" | |
| 10 TITLE="SDL Library Documentation" | |
| 11 HREF="index.html"><LINK | |
| 12 REL="UP" | |
| 13 TITLE="Audio" | |
| 14 HREF="audio.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_BuildAudioCVT" | |
| 17 HREF="sdlbuildaudiocvt.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_MixAudio" | |
| 20 HREF="sdlmixaudio.html"></HEAD | |
| 21 ><BODY | |
| 22 CLASS="REFENTRY" | |
| 23 BGCOLOR="#FFF8DC" | |
| 24 TEXT="#000000" | |
| 25 LINK="#0000ee" | |
| 26 VLINK="#551a8b" | |
| 27 ALINK="#ff0000" | |
| 28 ><DIV | |
| 29 CLASS="NAVHEADER" | |
| 30 ><TABLE | |
|
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31 SUMMARY="Header navigation table" |
| 0 | 32 WIDTH="100%" |
| 33 BORDER="0" | |
| 34 CELLPADDING="0" | |
| 35 CELLSPACING="0" | |
| 36 ><TR | |
| 37 ><TH | |
| 38 COLSPAN="3" | |
| 39 ALIGN="center" | |
| 40 >SDL Library Documentation</TH | |
| 41 ></TR | |
| 42 ><TR | |
| 43 ><TD | |
| 44 WIDTH="10%" | |
| 45 ALIGN="left" | |
| 46 VALIGN="bottom" | |
| 47 ><A | |
| 48 HREF="sdlbuildaudiocvt.html" | |
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49 ACCESSKEY="P" |
| 0 | 50 >Prev</A |
| 51 ></TD | |
| 52 ><TD | |
| 53 WIDTH="80%" | |
| 54 ALIGN="center" | |
| 55 VALIGN="bottom" | |
| 56 ></TD | |
| 57 ><TD | |
| 58 WIDTH="10%" | |
| 59 ALIGN="right" | |
| 60 VALIGN="bottom" | |
| 61 ><A | |
| 62 HREF="sdlmixaudio.html" | |
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63 ACCESSKEY="N" |
| 0 | 64 >Next</A |
| 65 ></TD | |
| 66 ></TR | |
| 67 ></TABLE | |
| 68 ><HR | |
| 69 ALIGN="LEFT" | |
| 70 WIDTH="100%"></DIV | |
| 71 ><H1 | |
| 72 ><A | |
| 73 NAME="SDLCONVERTAUDIO" | |
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74 ></A |
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75 >SDL_ConvertAudio</H1 |
| 0 | 76 ><DIV |
| 77 CLASS="REFNAMEDIV" | |
| 78 ><A | |
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79 NAME="AEN7048" |
| 0 | 80 ></A |
| 81 ><H2 | |
| 82 >Name</H2 | |
| 83 >SDL_ConvertAudio -- Convert audio data to a desired audio format.</DIV | |
| 84 ><DIV | |
| 85 CLASS="REFSYNOPSISDIV" | |
| 86 ><A | |
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87 NAME="AEN7051" |
| 0 | 88 ></A |
| 89 ><H2 | |
| 90 >Synopsis</H2 | |
| 91 ><DIV | |
| 92 CLASS="FUNCSYNOPSIS" | |
| 93 ><A | |
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94 NAME="AEN7052" |
| 0 | 95 ></A |
| 96 ><P | |
| 97 ></P | |
| 98 ><PRE | |
| 99 CLASS="FUNCSYNOPSISINFO" | |
| 100 >#include "SDL.h"</PRE | |
| 101 ><P | |
| 102 ><CODE | |
| 103 ><CODE | |
| 104 CLASS="FUNCDEF" | |
| 105 >int <B | |
| 106 CLASS="FSFUNC" | |
| 107 >SDL_ConvertAudio</B | |
| 108 ></CODE | |
| 109 >(SDL_AudioCVT *cvt);</CODE | |
| 110 ></P | |
| 111 ><P | |
| 112 ></P | |
| 113 ></DIV | |
| 114 ></DIV | |
| 115 ><DIV | |
| 116 CLASS="REFSECT1" | |
| 117 ><A | |
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118 NAME="AEN7058" |
| 0 | 119 ></A |
| 120 ><H2 | |
| 121 >Description</H2 | |
| 122 ><P | |
| 123 ><TT | |
| 124 CLASS="FUNCTION" | |
| 125 >SDL_ConvertAudio</TT | |
| 126 > takes one parameter, <TT | |
| 127 CLASS="PARAMETER" | |
| 128 ><I | |
| 129 >cvt</I | |
| 130 ></TT | |
| 131 >, which was previously initilized. Initilizing a <A | |
| 132 HREF="sdlaudiocvt.html" | |
| 133 ><SPAN | |
| 134 CLASS="STRUCTNAME" | |
| 135 >SDL_AudioCVT</SPAN | |
| 136 ></A | |
| 137 > is a two step process. First of all, the structure must be passed to <A | |
| 138 HREF="sdlbuildaudiocvt.html" | |
| 139 ><TT | |
| 140 CLASS="FUNCTION" | |
| 141 >SDL_BuildAudioCVT</TT | |
| 142 ></A | |
| 143 > along with source and destination format parameters. Secondly, the <SPAN | |
| 144 CLASS="STRUCTNAME" | |
| 145 >cvt</SPAN | |
| 146 >-><TT | |
| 147 CLASS="STRUCTFIELD" | |
| 148 ><I | |
| 149 >buf</I | |
| 150 ></TT | |
| 151 > and <SPAN | |
| 152 CLASS="STRUCTNAME" | |
| 153 >cvt</SPAN | |
| 154 >-><TT | |
| 155 CLASS="STRUCTFIELD" | |
| 156 ><I | |
| 157 >len</I | |
| 158 ></TT | |
| 159 > fields must be setup. <SPAN | |
| 160 CLASS="STRUCTNAME" | |
| 161 >cvt</SPAN | |
| 162 >-><TT | |
| 163 CLASS="STRUCTFIELD" | |
| 164 ><I | |
| 165 >buf</I | |
| 166 ></TT | |
| 167 > should point to the audio data and <SPAN | |
| 168 CLASS="STRUCTNAME" | |
| 169 >cvt</SPAN | |
| 170 >-><TT | |
| 171 CLASS="STRUCTFIELD" | |
| 172 ><I | |
| 173 >len</I | |
| 174 ></TT | |
| 175 > should be set to the length of the audio data in bytes. Remember, the length of the buffer pointed to by <TT | |
| 176 CLASS="STRUCTFIELD" | |
| 177 ><I | |
| 178 >buf</I | |
| 179 ></TT | |
| 180 > show be <TT | |
| 181 CLASS="STRUCTFIELD" | |
| 182 ><I | |
| 183 >len</I | |
| 184 ></TT | |
| 185 >*<TT | |
| 186 CLASS="STRUCTFIELD" | |
| 187 ><I | |
| 188 >len_mult</I | |
| 189 ></TT | |
| 190 > bytes in length.</P | |
| 191 ><P | |
| 192 >Once the <SPAN | |
| 193 CLASS="STRUCTNAME" | |
| 194 >SDL_AudioCVT</SPAN | |
| 195 >structure is initilized then we can pass it to <TT | |
| 196 CLASS="FUNCTION" | |
| 197 >SDL_ConvertAudio</TT | |
| 198 >, which will convert the audio data pointer to by <SPAN | |
| 199 CLASS="STRUCTNAME" | |
| 200 >cvt</SPAN | |
| 201 >-><TT | |
| 202 CLASS="STRUCTFIELD" | |
| 203 ><I | |
| 204 >buf</I | |
| 205 ></TT | |
| 206 >. If <TT | |
| 207 CLASS="FUNCTION" | |
| 208 >SDL_ConvertAudio</TT | |
| 209 > returned <SPAN | |
| 210 CLASS="RETURNVALUE" | |
| 211 >0</SPAN | |
| 212 > then the conversion was completed successfully, otherwise <SPAN | |
| 213 CLASS="RETURNVALUE" | |
| 214 >-1</SPAN | |
| 215 > is returned.</P | |
| 216 ><P | |
| 217 >If the conversion completed successfully then the converted audio data can be read from <SPAN | |
| 218 CLASS="STRUCTNAME" | |
| 219 >cvt</SPAN | |
| 220 >-><TT | |
| 221 CLASS="STRUCTFIELD" | |
| 222 ><I | |
| 223 >buf</I | |
| 224 ></TT | |
| 225 >. The amount of valid, converted, audio data in the buffer is equal to <SPAN | |
| 226 CLASS="STRUCTNAME" | |
| 227 >cvt</SPAN | |
| 228 >-><TT | |
| 229 CLASS="STRUCTFIELD" | |
| 230 ><I | |
| 231 >len</I | |
| 232 ></TT | |
| 233 >*<TT | |
| 234 CLASS="STRUCTFIELD" | |
| 235 ><I | |
| 236 >cvt</I | |
| 237 ></TT | |
| 238 >-><SPAN | |
| 239 CLASS="STRUCTNAME" | |
| 240 >len_ratio</SPAN | |
| 241 >.</P | |
| 242 ></DIV | |
| 243 ><DIV | |
| 244 CLASS="REFSECT1" | |
| 245 ><A | |
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246 NAME="AEN7093" |
| 0 | 247 ></A |
| 248 ><H2 | |
| 249 >Examples</H2 | |
| 250 ><PRE | |
| 251 CLASS="PROGRAMLISTING" | |
| 252 >/* Converting some WAV data to hardware format */ | |
| 253 void my_audio_callback(void *userdata, Uint8 *stream, int len); | |
| 254 | |
| 255 SDL_AudioSpec *desired, *obtained; | |
| 256 SDL_AudioSpec wav_spec; | |
| 257 SDL_AudioCVT wav_cvt; | |
| 258 Uint32 wav_len; | |
| 259 Uint8 *wav_buf; | |
| 260 int ret; | |
| 261 | |
| 262 /* Allocated audio specs */ | |
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263 desired = malloc(sizeof(SDL_AudioSpec)); |
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264 obtained = malloc(sizeof(SDL_AudioSpec)); |
| 0 | 265 |
| 266 /* Set desired format */ | |
| 267 desired->freq=22050; | |
| 268 desired->format=AUDIO_S16LSB; | |
| 269 desired->samples=8192; | |
| 270 desired->callback=my_audio_callback; | |
| 271 desired->userdata=NULL; | |
| 272 | |
| 273 /* Open the audio device */ | |
| 274 if ( SDL_OpenAudio(desired, obtained) < 0 ){ | |
| 275 fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError()); | |
| 276 exit(-1); | |
| 277 } | |
| 278 | |
| 279 free(desired); | |
| 280 | |
| 281 /* Load the test.wav */ | |
| 282 if( SDL_LoadWAV("test.wav", &wav_spec, &wav_buf, &wav_len) == NULL ){ | |
| 283 fprintf(stderr, "Could not open test.wav: %s\n", SDL_GetError()); | |
| 284 SDL_CloseAudio(); | |
| 285 free(obtained); | |
| 286 exit(-1); | |
| 287 } | |
| 288 | |
| 289 /* Build AudioCVT */ | |
| 290 ret = SDL_BuildAudioCVT(&wav_cvt, | |
| 291 wav_spec.format, wav_spec.channels, wav_spec.freq, | |
| 292 obtained->format, obtained->channels, obtained->freq); | |
| 293 | |
| 294 /* Check that the convert was built */ | |
| 295 if(ret==-1){ | |
| 296 fprintf(stderr, "Couldn't build converter!\n"); | |
| 297 SDL_CloseAudio(); | |
| 298 free(obtained); | |
| 299 SDL_FreeWAV(wav_buf); | |
| 300 } | |
| 301 | |
| 302 /* Setup for conversion */ | |
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303 wav_cvt.buf = malloc(wav_len * wav_cvt.len_mult); |
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304 wav_cvt.len = wav_len; |
| 0 | 305 memcpy(wav_cvt.buf, wav_buf, wav_len); |
| 306 | |
| 307 /* We can delete to original WAV data now */ | |
| 308 SDL_FreeWAV(wav_buf); | |
| 309 | |
| 310 /* And now we're ready to convert */ | |
| 311 SDL_ConvertAudio(&wav_cvt); | |
| 312 | |
| 313 /* do whatever */ | |
| 314 . | |
| 315 . | |
| 316 . | |
| 317 . | |
| 318 </PRE | |
| 319 ></DIV | |
| 320 ><DIV | |
| 321 CLASS="REFSECT1" | |
| 322 ><A | |
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323 NAME="AEN7096" |
| 0 | 324 ></A |
| 325 ><H2 | |
| 326 >See Also</H2 | |
| 327 ><P | |
| 328 ><A | |
| 329 HREF="sdlbuildaudiocvt.html" | |
| 330 ><TT | |
| 331 CLASS="FUNCTION" | |
| 332 >SDL_BuildAudioCVT</TT | |
| 333 ></A | |
| 334 >, | |
| 335 <A | |
| 336 HREF="sdlaudiocvt.html" | |
| 337 ><TT | |
| 338 CLASS="FUNCTION" | |
| 339 >SDL_AudioCVT</TT | |
| 340 ></A | |
| 341 ></P | |
| 342 ></DIV | |
| 343 ><DIV | |
| 344 CLASS="NAVFOOTER" | |
| 345 ><HR | |
| 346 ALIGN="LEFT" | |
| 347 WIDTH="100%"><TABLE | |
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348 SUMMARY="Footer navigation table" |
| 0 | 349 WIDTH="100%" |
| 350 BORDER="0" | |
| 351 CELLPADDING="0" | |
| 352 CELLSPACING="0" | |
| 353 ><TR | |
| 354 ><TD | |
| 355 WIDTH="33%" | |
| 356 ALIGN="left" | |
| 357 VALIGN="top" | |
| 358 ><A | |
| 359 HREF="sdlbuildaudiocvt.html" | |
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360 ACCESSKEY="P" |
| 0 | 361 >Prev</A |
| 362 ></TD | |
| 363 ><TD | |
| 364 WIDTH="34%" | |
| 365 ALIGN="center" | |
| 366 VALIGN="top" | |
| 367 ><A | |
| 368 HREF="index.html" | |
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369 ACCESSKEY="H" |
| 0 | 370 >Home</A |
| 371 ></TD | |
| 372 ><TD | |
| 373 WIDTH="33%" | |
| 374 ALIGN="right" | |
| 375 VALIGN="top" | |
| 376 ><A | |
| 377 HREF="sdlmixaudio.html" | |
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378 ACCESSKEY="N" |
| 0 | 379 >Next</A |
| 380 ></TD | |
| 381 ></TR | |
| 382 ><TR | |
| 383 ><TD | |
| 384 WIDTH="33%" | |
| 385 ALIGN="left" | |
| 386 VALIGN="top" | |
| 387 >SDL_BuildAudioCVT</TD | |
| 388 ><TD | |
| 389 WIDTH="34%" | |
| 390 ALIGN="center" | |
| 391 VALIGN="top" | |
| 392 ><A | |
| 393 HREF="audio.html" | |
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394 ACCESSKEY="U" |
| 0 | 395 >Up</A |
| 396 ></TD | |
| 397 ><TD | |
| 398 WIDTH="33%" | |
| 399 ALIGN="right" | |
| 400 VALIGN="top" | |
| 401 >SDL_MixAudio</TD | |
| 402 ></TR | |
| 403 ></TABLE | |
| 404 ></DIV | |
| 405 ></BODY | |
| 406 ></HTML | |
| 407 > |