Mercurial > SDL_sound_CoreAudio
annotate decoders/wav.c @ 40:c15396fc0e55
Fixed incorrect comment, by Torbj�rn Andersson. :)
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Thu, 20 Sep 2001 07:57:52 +0000 |
| parents | 102cf61c0816 |
| children | ea58bc3b15d7 |
| rev | line source |
|---|---|
| 17 | 1 /* |
| 2 * SDL_sound -- An abstract sound format decoding API. | |
| 3 * Copyright (C) 2001 Ryan C. Gordon. | |
| 4 * | |
| 5 * This library is free software; you can redistribute it and/or | |
| 6 * modify it under the terms of the GNU Lesser General Public | |
| 7 * License as published by the Free Software Foundation; either | |
| 8 * version 2.1 of the License, or (at your option) any later version. | |
| 9 * | |
| 10 * This library is distributed in the hope that it will be useful, | |
| 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 * Lesser General Public License for more details. | |
| 14 * | |
| 15 * You should have received a copy of the GNU Lesser General Public | |
| 16 * License along with this library; if not, write to the Free Software | |
| 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 */ | |
| 19 | |
| 20 /* | |
| 21 * WAV decoder for SDL_sound. | |
| 22 * | |
| 23 * This driver handles Microsoft .WAVs, in as many of the thousands of | |
| 24 * variations as we can. | |
| 25 * | |
| 26 * Please see the file LICENSE in the source's root directory. | |
| 27 * | |
| 28 * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) | |
| 29 */ | |
| 30 | |
| 31 #include <stdio.h> | |
| 32 #include <stdlib.h> | |
| 33 #include <string.h> | |
| 34 #include <assert.h> | |
| 35 #include "SDL_sound.h" | |
| 36 | |
| 37 #define __SDL_SOUND_INTERNAL__ | |
| 38 #include "SDL_sound_internal.h" | |
| 39 | |
| 40 #if (!defined SOUND_SUPPORTS_WAV) | |
| 41 #error SOUND_SUPPORTS_WAV must be defined. | |
| 42 #endif | |
| 43 | |
| 44 static int WAV_open(Sound_Sample *sample, const char *ext); | |
| 45 static void WAV_close(Sound_Sample *sample); | |
| 46 static Uint32 WAV_read(Sound_Sample *sample); | |
| 47 | |
| 48 const Sound_DecoderFunctions __Sound_DecoderFunctions_WAV = | |
| 49 { | |
| 50 { | |
| 51 "WAV", | |
| 52 "Microsoft WAVE audio format", | |
| 53 "Ryan C. Gordon <icculus@clutteredmind.org>", | |
| 54 "http://www.icculus.org/SDL_sound/" | |
| 55 }, | |
| 56 | |
| 57 WAV_open, /* open() method */ | |
| 58 WAV_close, /* close() method */ | |
| 59 WAV_read /* read() method */ | |
| 60 }; | |
| 61 | |
| 62 | |
| 63 /* this is what we store in our internal->decoder_private field... */ | |
| 64 typedef struct | |
| 65 { | |
| 66 Sint32 bytesLeft; | |
| 67 } wav_t; | |
| 68 | |
| 69 | |
| 70 /* Chunk management code... */ | |
| 71 | |
| 72 #define riffID 0x46464952 /* "RIFF", in ascii. */ | |
| 73 #define waveID 0x45564157 /* "WAVE", in ascii. */ | |
| 74 | |
| 75 | |
| 76 #define fmtID 0x20746D66 /* "fmt ", in ascii. */ | |
| 77 | |
| 78 #define FMT_NORMAL 1 /* Uncompressed waveform data. */ | |
| 79 | |
| 80 typedef struct | |
| 81 { | |
| 82 Uint32 chunkID; | |
| 83 Sint32 chunkSize; | |
| 84 Sint16 wFormatTag; | |
| 85 Uint16 wChannels; | |
| 86 Uint32 dwSamplesPerSec; | |
| 87 Uint32 dwAvgBytesPerSec; | |
| 88 Uint16 wBlockAlign; | |
| 89 Uint16 wBitsPerSample; | |
| 90 } fmt_t; | |
| 91 | |
| 92 | |
| 93 /* | |
| 94 * Read in a fmt_t from disk. This makes this process safe regardless of | |
| 95 * the processor's byte order or how the fmt_t structure is packed. | |
| 96 */ | |
| 97 static int read_fmt_chunk(SDL_RWops *rw, fmt_t *fmt) | |
| 98 { | |
| 99 /* skip reading the chunk ID, since it was already read at this point... */ | |
| 100 fmt->chunkID = fmtID; | |
| 101 | |
| 102 if (SDL_RWread(rw, &fmt->chunkSize, sizeof (fmt->chunkSize), 1) != 1) | |
| 103 return(0); | |
| 104 fmt->chunkSize = SDL_SwapLE32(fmt->chunkSize); | |
| 105 | |
| 106 if (SDL_RWread(rw, &fmt->wFormatTag, sizeof (fmt->wFormatTag), 1) != 1) | |
| 107 return(0); | |
| 108 fmt->wFormatTag = SDL_SwapLE16(fmt->wFormatTag); | |
| 109 | |
| 110 if (SDL_RWread(rw, &fmt->wChannels, sizeof (fmt->wChannels), 1) != 1) | |
| 111 return(0); | |
| 112 fmt->wChannels = SDL_SwapLE16(fmt->wChannels); | |
| 113 | |
| 114 if (SDL_RWread(rw, &fmt->dwSamplesPerSec, | |
| 115 sizeof (fmt->dwSamplesPerSec), 1) != 1) | |
| 116 return(0); | |
| 117 fmt->dwSamplesPerSec = SDL_SwapLE32(fmt->dwSamplesPerSec); | |
| 118 | |
| 119 if (SDL_RWread(rw, &fmt->dwAvgBytesPerSec, | |
| 120 sizeof (fmt->dwAvgBytesPerSec), 1) != 1) | |
| 121 return(0); | |
| 122 fmt->dwAvgBytesPerSec = SDL_SwapLE32(fmt->dwAvgBytesPerSec); | |
| 123 | |
| 124 if (SDL_RWread(rw, &fmt->wBlockAlign, sizeof (fmt->wBlockAlign), 1) != 1) | |
| 125 return(0); | |
| 126 fmt->wBlockAlign = SDL_SwapLE16(fmt->wBlockAlign); | |
| 127 | |
| 128 if (SDL_RWread(rw, &fmt->wBitsPerSample, | |
| 129 sizeof (fmt->wBitsPerSample), 1) != 1) | |
| 130 return(0); | |
| 131 fmt->wBitsPerSample = SDL_SwapLE16(fmt->wBitsPerSample); | |
| 132 | |
| 133 return(1); | |
| 134 } /* read_fmt_chunk */ | |
| 135 | |
| 136 | |
| 137 #define dataID 0x61746164 /* "data", in ascii. */ | |
| 138 | |
| 139 typedef struct | |
| 140 { | |
| 141 Uint32 chunkID; | |
| 142 Sint32 chunkSize; | |
| 143 /* Then, (chunkSize) bytes of waveform data... */ | |
| 144 } data_t; | |
| 145 | |
| 146 | |
| 147 /* | |
| 148 * Read in a fmt_t from disk. This makes this process safe regardless of | |
| 149 * the processor's byte order or how the fmt_t structure is packed. | |
| 150 */ | |
| 151 static int read_data_chunk(SDL_RWops *rw, data_t *data) | |
| 152 { | |
| 153 /* skip reading the chunk ID, since it was already read at this point... */ | |
| 154 data->chunkID = dataID; | |
| 155 | |
| 156 if (SDL_RWread(rw, &data->chunkSize, sizeof (data->chunkSize), 1) != 1) | |
| 157 return(0); | |
| 158 data->chunkSize = SDL_SwapLE32(data->chunkSize); | |
| 159 | |
| 160 return(1); | |
|
40
c15396fc0e55
Fixed incorrect comment, by Torbj�rn Andersson. :)
Ryan C. Gordon <icculus@icculus.org>
parents:
17
diff
changeset
|
161 } /* read_data_chunk */ |
| 17 | 162 |
| 163 | |
| 164 static int find_chunk(SDL_RWops *rw, Uint32 id) | |
| 165 { | |
| 166 Sint32 siz = 0; | |
| 167 Uint32 _id = 0; | |
| 168 | |
| 169 while (1) | |
| 170 { | |
| 171 BAIL_IF_MACRO(SDL_RWread(rw, &_id, sizeof (_id), 1) != 1, NULL, 0); | |
| 172 if (SDL_SwapLE32(_id) == id) | |
| 173 return(1); | |
| 174 | |
| 175 BAIL_IF_MACRO(SDL_RWread(rw, &siz, sizeof (siz), 1) != 1, NULL, 0); | |
| 176 siz = SDL_SwapLE32(siz); | |
| 177 assert(siz > 0); | |
| 178 BAIL_IF_MACRO(SDL_RWseek(rw, siz, SEEK_SET) != siz, NULL, 0); | |
| 179 } /* while */ | |
| 180 | |
| 181 return(0); /* shouldn't hit this, but just in case... */ | |
| 182 } /* find_chunk */ | |
| 183 | |
| 184 | |
| 185 static int WAV_open(Sound_Sample *sample, const char *ext) | |
| 186 { | |
| 187 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
| 188 SDL_RWops *rw = internal->rw; | |
| 189 fmt_t f; | |
| 190 data_t d; | |
| 191 wav_t *w; | |
| 192 | |
| 193 BAIL_IF_MACRO(SDL_ReadLE32(rw) != riffID, "WAV: Not a RIFF file.", 0); | |
| 194 SDL_ReadLE32(rw); /* throw the length away; we get this info later. */ | |
| 195 BAIL_IF_MACRO(SDL_ReadLE32(rw) != waveID, "WAV: Not a WAVE file.", 0); | |
| 196 BAIL_IF_MACRO(!find_chunk(rw, fmtID), "WAV: No format chunk.", 0); | |
| 197 BAIL_IF_MACRO(!read_fmt_chunk(rw, &f), "WAV: Can't read format chunk.", 0); | |
| 198 | |
| 199 /* !!! FIXME: This will have to change for compression types... */ | |
| 200 BAIL_IF_MACRO(f.wFormatTag != FMT_NORMAL, "WAV: Unsupported encoding.", 0); | |
| 201 | |
| 202 sample->actual.channels = (Uint8) f.wChannels; | |
| 203 sample->actual.rate = f.dwSamplesPerSec; | |
| 204 | |
| 205 if (f.wBitsPerSample <= 8) | |
| 206 sample->actual.format = AUDIO_U8; | |
| 207 else if (f.wBitsPerSample <= 16) | |
| 208 sample->actual.format = AUDIO_S16LSB; | |
| 209 else | |
| 210 BAIL_MACRO("WAV: Unsupported sample size.", 0); | |
| 211 | |
| 212 BAIL_IF_MACRO(!find_chunk(rw, dataID), "WAV: No data chunk.", 0); | |
| 213 BAIL_IF_MACRO(!read_data_chunk(rw, &d), "WAV: Can't read data chunk.", 0); | |
| 214 | |
| 215 w = (wav_t *) malloc(sizeof(wav_t)); | |
| 216 BAIL_IF_MACRO(w == NULL, ERR_OUT_OF_MEMORY, 0); | |
| 217 w->bytesLeft = d.chunkSize; | |
| 218 internal->decoder_private = (void *) w; | |
| 219 | |
| 220 sample->flags = SOUND_SAMPLEFLAG_NONE; | |
| 221 | |
| 222 _D(("WAV: Accepting data stream.\n")); | |
| 223 return(1); /* we'll handle this data. */ | |
| 224 } /* WAV_open */ | |
| 225 | |
| 226 | |
| 227 static void WAV_close(Sound_Sample *sample) | |
| 228 { | |
| 229 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
| 230 free(internal->decoder_private); | |
| 231 } /* WAV_close */ | |
| 232 | |
| 233 | |
| 234 static Uint32 WAV_read(Sound_Sample *sample) | |
| 235 { | |
| 236 Uint32 retval; | |
| 237 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
| 238 wav_t *w = (wav_t *) internal->decoder_private; | |
| 239 Uint32 max = (internal->buffer_size < (Uint32) w->bytesLeft) ? | |
| 240 internal->buffer_size : (Uint32) w->bytesLeft; | |
| 241 | |
| 242 assert(max > 0); | |
| 243 | |
| 244 /* | |
| 245 * We don't actually do any decoding, so we read the wav data | |
| 246 * directly into the internal buffer... | |
| 247 */ | |
| 248 retval = SDL_RWread(internal->rw, internal->buffer, 1, max); | |
| 249 | |
| 250 w->bytesLeft -= retval; | |
| 251 | |
| 252 /* Make sure the read went smoothly... */ | |
| 253 if ((retval == 0) || (w->bytesLeft == 0)) | |
| 254 sample->flags |= SOUND_SAMPLEFLAG_EOF; | |
| 255 | |
| 256 else if (retval == -1) | |
| 257 sample->flags |= SOUND_SAMPLEFLAG_ERROR; | |
| 258 | |
| 259 /* (next call this EAGAIN may turn into an EOF or error.) */ | |
| 260 else if (retval < internal->buffer_size) | |
| 261 sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; | |
| 262 | |
| 263 return(retval); | |
| 264 } /* WAV_read */ | |
| 265 | |
| 266 | |
| 267 /* end of wav.c ... */ | |
| 268 |