Mercurial > SDL_sound_CoreAudio
annotate decoders/wav.c @ 47:ea58bc3b15d7
Added init() and quit() methods.
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Sat, 22 Sep 2001 14:41:38 +0000 |
parents | c15396fc0e55 |
children | b13fafb976be |
rev | line source |
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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 | |
47
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44 static int WAV_init(void); |
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45 static void WAV_quit(void); |
17 | 46 static int WAV_open(Sound_Sample *sample, const char *ext); |
47 static void WAV_close(Sound_Sample *sample); | |
48 static Uint32 WAV_read(Sound_Sample *sample); | |
49 | |
50 const Sound_DecoderFunctions __Sound_DecoderFunctions_WAV = | |
51 { | |
52 { | |
53 "WAV", | |
54 "Microsoft WAVE audio format", | |
55 "Ryan C. Gordon <icculus@clutteredmind.org>", | |
56 "http://www.icculus.org/SDL_sound/" | |
57 }, | |
58 | |
47
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59 WAV_init, /* init() method */ |
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60 WAV_quit, /* quit() method */ |
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61 WAV_open, /* open() method */ |
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62 WAV_close, /* close() method */ |
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63 WAV_read /* read() method */ |
17 | 64 }; |
65 | |
66 | |
67 /* this is what we store in our internal->decoder_private field... */ | |
68 typedef struct | |
69 { | |
70 Sint32 bytesLeft; | |
71 } wav_t; | |
72 | |
73 | |
74 /* Chunk management code... */ | |
75 | |
76 #define riffID 0x46464952 /* "RIFF", in ascii. */ | |
77 #define waveID 0x45564157 /* "WAVE", in ascii. */ | |
78 | |
79 | |
80 #define fmtID 0x20746D66 /* "fmt ", in ascii. */ | |
81 | |
82 #define FMT_NORMAL 1 /* Uncompressed waveform data. */ | |
83 | |
84 typedef struct | |
85 { | |
86 Uint32 chunkID; | |
87 Sint32 chunkSize; | |
88 Sint16 wFormatTag; | |
89 Uint16 wChannels; | |
90 Uint32 dwSamplesPerSec; | |
91 Uint32 dwAvgBytesPerSec; | |
92 Uint16 wBlockAlign; | |
93 Uint16 wBitsPerSample; | |
94 } fmt_t; | |
95 | |
96 | |
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97 static int WAV_init(void) |
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98 { |
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99 return(1); /* always succeeds. */ |
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100 } /* WAV_init */ |
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101 |
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102 |
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103 static void WAV_quit(void) |
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104 { |
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105 /* it's a no-op. */ |
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106 } /* WAV_quit */ |
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107 |
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108 |
17 | 109 /* |
110 * Read in a fmt_t from disk. This makes this process safe regardless of | |
111 * the processor's byte order or how the fmt_t structure is packed. | |
112 */ | |
113 static int read_fmt_chunk(SDL_RWops *rw, fmt_t *fmt) | |
114 { | |
115 /* skip reading the chunk ID, since it was already read at this point... */ | |
116 fmt->chunkID = fmtID; | |
117 | |
118 if (SDL_RWread(rw, &fmt->chunkSize, sizeof (fmt->chunkSize), 1) != 1) | |
119 return(0); | |
120 fmt->chunkSize = SDL_SwapLE32(fmt->chunkSize); | |
121 | |
122 if (SDL_RWread(rw, &fmt->wFormatTag, sizeof (fmt->wFormatTag), 1) != 1) | |
123 return(0); | |
124 fmt->wFormatTag = SDL_SwapLE16(fmt->wFormatTag); | |
125 | |
126 if (SDL_RWread(rw, &fmt->wChannels, sizeof (fmt->wChannels), 1) != 1) | |
127 return(0); | |
128 fmt->wChannels = SDL_SwapLE16(fmt->wChannels); | |
129 | |
130 if (SDL_RWread(rw, &fmt->dwSamplesPerSec, | |
131 sizeof (fmt->dwSamplesPerSec), 1) != 1) | |
132 return(0); | |
133 fmt->dwSamplesPerSec = SDL_SwapLE32(fmt->dwSamplesPerSec); | |
134 | |
135 if (SDL_RWread(rw, &fmt->dwAvgBytesPerSec, | |
136 sizeof (fmt->dwAvgBytesPerSec), 1) != 1) | |
137 return(0); | |
138 fmt->dwAvgBytesPerSec = SDL_SwapLE32(fmt->dwAvgBytesPerSec); | |
139 | |
140 if (SDL_RWread(rw, &fmt->wBlockAlign, sizeof (fmt->wBlockAlign), 1) != 1) | |
141 return(0); | |
142 fmt->wBlockAlign = SDL_SwapLE16(fmt->wBlockAlign); | |
143 | |
144 if (SDL_RWread(rw, &fmt->wBitsPerSample, | |
145 sizeof (fmt->wBitsPerSample), 1) != 1) | |
146 return(0); | |
147 fmt->wBitsPerSample = SDL_SwapLE16(fmt->wBitsPerSample); | |
148 | |
149 return(1); | |
150 } /* read_fmt_chunk */ | |
151 | |
152 | |
153 #define dataID 0x61746164 /* "data", in ascii. */ | |
154 | |
155 typedef struct | |
156 { | |
157 Uint32 chunkID; | |
158 Sint32 chunkSize; | |
159 /* Then, (chunkSize) bytes of waveform data... */ | |
160 } data_t; | |
161 | |
162 | |
163 /* | |
164 * Read in a fmt_t from disk. This makes this process safe regardless of | |
165 * the processor's byte order or how the fmt_t structure is packed. | |
166 */ | |
167 static int read_data_chunk(SDL_RWops *rw, data_t *data) | |
168 { | |
169 /* skip reading the chunk ID, since it was already read at this point... */ | |
170 data->chunkID = dataID; | |
171 | |
172 if (SDL_RWread(rw, &data->chunkSize, sizeof (data->chunkSize), 1) != 1) | |
173 return(0); | |
174 data->chunkSize = SDL_SwapLE32(data->chunkSize); | |
175 | |
176 return(1); | |
40
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177 } /* read_data_chunk */ |
17 | 178 |
179 | |
180 static int find_chunk(SDL_RWops *rw, Uint32 id) | |
181 { | |
182 Sint32 siz = 0; | |
183 Uint32 _id = 0; | |
184 | |
185 while (1) | |
186 { | |
187 BAIL_IF_MACRO(SDL_RWread(rw, &_id, sizeof (_id), 1) != 1, NULL, 0); | |
188 if (SDL_SwapLE32(_id) == id) | |
189 return(1); | |
190 | |
191 BAIL_IF_MACRO(SDL_RWread(rw, &siz, sizeof (siz), 1) != 1, NULL, 0); | |
192 siz = SDL_SwapLE32(siz); | |
193 assert(siz > 0); | |
194 BAIL_IF_MACRO(SDL_RWseek(rw, siz, SEEK_SET) != siz, NULL, 0); | |
195 } /* while */ | |
196 | |
197 return(0); /* shouldn't hit this, but just in case... */ | |
198 } /* find_chunk */ | |
199 | |
200 | |
201 static int WAV_open(Sound_Sample *sample, const char *ext) | |
202 { | |
203 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
204 SDL_RWops *rw = internal->rw; | |
205 fmt_t f; | |
206 data_t d; | |
207 wav_t *w; | |
208 | |
209 BAIL_IF_MACRO(SDL_ReadLE32(rw) != riffID, "WAV: Not a RIFF file.", 0); | |
210 SDL_ReadLE32(rw); /* throw the length away; we get this info later. */ | |
211 BAIL_IF_MACRO(SDL_ReadLE32(rw) != waveID, "WAV: Not a WAVE file.", 0); | |
212 BAIL_IF_MACRO(!find_chunk(rw, fmtID), "WAV: No format chunk.", 0); | |
213 BAIL_IF_MACRO(!read_fmt_chunk(rw, &f), "WAV: Can't read format chunk.", 0); | |
214 | |
215 /* !!! FIXME: This will have to change for compression types... */ | |
216 BAIL_IF_MACRO(f.wFormatTag != FMT_NORMAL, "WAV: Unsupported encoding.", 0); | |
217 | |
218 sample->actual.channels = (Uint8) f.wChannels; | |
219 sample->actual.rate = f.dwSamplesPerSec; | |
220 | |
221 if (f.wBitsPerSample <= 8) | |
222 sample->actual.format = AUDIO_U8; | |
223 else if (f.wBitsPerSample <= 16) | |
224 sample->actual.format = AUDIO_S16LSB; | |
225 else | |
226 BAIL_MACRO("WAV: Unsupported sample size.", 0); | |
227 | |
228 BAIL_IF_MACRO(!find_chunk(rw, dataID), "WAV: No data chunk.", 0); | |
229 BAIL_IF_MACRO(!read_data_chunk(rw, &d), "WAV: Can't read data chunk.", 0); | |
230 | |
231 w = (wav_t *) malloc(sizeof(wav_t)); | |
232 BAIL_IF_MACRO(w == NULL, ERR_OUT_OF_MEMORY, 0); | |
233 w->bytesLeft = d.chunkSize; | |
234 internal->decoder_private = (void *) w; | |
235 | |
236 sample->flags = SOUND_SAMPLEFLAG_NONE; | |
237 | |
238 _D(("WAV: Accepting data stream.\n")); | |
239 return(1); /* we'll handle this data. */ | |
240 } /* WAV_open */ | |
241 | |
242 | |
243 static void WAV_close(Sound_Sample *sample) | |
244 { | |
245 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
246 free(internal->decoder_private); | |
247 } /* WAV_close */ | |
248 | |
249 | |
250 static Uint32 WAV_read(Sound_Sample *sample) | |
251 { | |
252 Uint32 retval; | |
253 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
254 wav_t *w = (wav_t *) internal->decoder_private; | |
255 Uint32 max = (internal->buffer_size < (Uint32) w->bytesLeft) ? | |
256 internal->buffer_size : (Uint32) w->bytesLeft; | |
257 | |
258 assert(max > 0); | |
259 | |
260 /* | |
261 * We don't actually do any decoding, so we read the wav data | |
262 * directly into the internal buffer... | |
263 */ | |
264 retval = SDL_RWread(internal->rw, internal->buffer, 1, max); | |
265 | |
266 w->bytesLeft -= retval; | |
267 | |
268 /* Make sure the read went smoothly... */ | |
269 if ((retval == 0) || (w->bytesLeft == 0)) | |
270 sample->flags |= SOUND_SAMPLEFLAG_EOF; | |
271 | |
272 else if (retval == -1) | |
273 sample->flags |= SOUND_SAMPLEFLAG_ERROR; | |
274 | |
275 /* (next call this EAGAIN may turn into an EOF or error.) */ | |
276 else if (retval < internal->buffer_size) | |
277 sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; | |
278 | |
279 return(retval); | |
280 } /* WAV_read */ | |
281 | |
282 | |
283 /* end of wav.c ... */ | |
284 |