1 /*
2 SDL_mixer: An audio mixer library based on the SDL library
3 Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20
21 This is the source needed to decode an AIFF file into a waveform.
22 It's pretty straightforward once you get going. The only
23 externally-callable function is Mix_LoadAIFF_RW(), which is meant to
24 act as identically to SDL_LoadWAV_RW() as possible.
25
26 This file by Torbj�rn Andersson (torbjorn.andersson@eurotime.se)
27 8SVX file support added by Marc Le Douarain (mavati@club-internet.fr)
28 in december 2002.
29 */
30
31 /* $Id$ */
32
33 #include <stdlib.h>
34 #include <string.h>
35
36 #include "SDL_endian.h"
37 #include "SDL_mixer.h"
38 #include "load_aiff.h"
39
40 /*********************************************/
41 /* Define values for AIFF (IFF audio) format */
42 /*********************************************/
43 #define FORM 0x4d524f46 /* "FORM" */
44
45 #define AIFF 0x46464941 /* "AIFF" */
46 #define SSND 0x444e5353 /* "SSND" */
47 #define COMM 0x4d4d4f43 /* "COMM" */
48
49 #define _8SVX 0x58565338 /* "8SVX" */
50 #define VHDR 0x52444856 /* "VHDR" */
51 #define BODY 0x59444F42 /* "BODY" */
52
53 /* This function was taken from libsndfile. I don't pretend to fully
54 * understand it.
55 */
56
SANE_to_Uint32(Uint8 * sanebuf)57 static Uint32 SANE_to_Uint32 (Uint8 *sanebuf)
58 {
59 /* Is the frequency outside of what we can represent with Uint32? */
60 if ( (sanebuf[0] & 0x80) || (sanebuf[0] <= 0x3F) || (sanebuf[0] > 0x40)
61 || (sanebuf[0] == 0x40 && sanebuf[1] > 0x1C) )
62 return 0;
63
64 return ((sanebuf[2] << 23) | (sanebuf[3] << 15) | (sanebuf[4] << 7)
65 | (sanebuf[5] >> 1)) >> (29 - sanebuf[1]);
66 }
67
68 /* This function is based on SDL_LoadWAV_RW(). */
69
Mix_LoadAIFF_RW(SDL_RWops * src,int freesrc,SDL_AudioSpec * spec,Uint8 ** audio_buf,Uint32 * audio_len)70 SDL_AudioSpec *Mix_LoadAIFF_RW (SDL_RWops *src, int freesrc,
71 SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
72 {
73 int was_error;
74 int found_SSND;
75 int found_COMM;
76 int found_VHDR;
77 int found_BODY;
78 long start = 0;
79
80 Uint32 chunk_type;
81 Uint32 chunk_length;
82 long next_chunk;
83
84 /* AIFF magic header */
85 Uint32 FORMchunk;
86 Uint32 AIFFmagic;
87
88 /* SSND chunk */
89 Uint32 offset;
90 Uint32 blocksize;
91
92 /* COMM format chunk */
93 Uint16 channels = 0;
94 Uint32 numsamples = 0;
95 Uint16 samplesize = 0;
96 Uint8 sane_freq[10];
97 Uint32 frequency = 0;
98
99 /* Make sure we are passed a valid data source */
100 was_error = 0;
101 if ( src == NULL ) {
102 was_error = 1;
103 goto done;
104 }
105
106 FORMchunk = SDL_ReadLE32(src);
107 chunk_length = SDL_ReadBE32(src);
108 if ( chunk_length == AIFF ) { /* The FORMchunk has already been read */
109 AIFFmagic = chunk_length;
110 chunk_length = FORMchunk;
111 FORMchunk = FORM;
112 } else {
113 AIFFmagic = SDL_ReadLE32(src);
114 }
115 if ( (FORMchunk != FORM) || ( (AIFFmagic != AIFF) && (AIFFmagic != _8SVX) ) ) {
116 SDL_SetError("Unrecognized file type (not AIFF nor 8SVX)");
117 was_error = 1;
118 goto done;
119 }
120
121 /* TODO: Better santity-checking. */
122
123 found_SSND = 0;
124 found_COMM = 0;
125 found_VHDR = 0;
126 found_BODY = 0;
127
128 do {
129 chunk_type = SDL_ReadLE32(src);
130 chunk_length = SDL_ReadBE32(src);
131 next_chunk = SDL_RWtell(src) + chunk_length;
132 /* Paranoia to avoid infinite loops */
133 if (chunk_length == 0)
134 break;
135
136 switch (chunk_type) {
137 case SSND:
138 found_SSND = 1;
139 offset = SDL_ReadBE32(src);
140 blocksize = SDL_ReadBE32(src);
141 start = SDL_RWtell(src) + offset;
142 break;
143
144 case COMM:
145 found_COMM = 1;
146 channels = SDL_ReadBE16(src);
147 numsamples = SDL_ReadBE32(src);
148 samplesize = SDL_ReadBE16(src);
149 SDL_RWread(src, sane_freq, sizeof(sane_freq), 1);
150 frequency = SANE_to_Uint32(sane_freq);
151 if (frequency == 0) {
152 SDL_SetError("Bad AIFF sample frequency");
153 was_error = 1;
154 goto done;
155 }
156 break;
157
158 case VHDR:
159 found_VHDR = 1;
160 SDL_ReadBE32(src);
161 SDL_ReadBE32(src);
162 SDL_ReadBE32(src);
163 frequency = SDL_ReadBE16(src);
164 channels = 1;
165 samplesize = 8;
166 break;
167
168 case BODY:
169 found_BODY = 1;
170 numsamples = chunk_length;
171 start = SDL_RWtell(src);
172 break;
173
174 default:
175 break;
176 }
177 /* a 0 pad byte can be stored for any odd-length chunk */
178 if (chunk_length&1)
179 next_chunk++;
180 } while ( ( ( (AIFFmagic == AIFF) && ( !found_SSND || !found_COMM ) )
181 || ( (AIFFmagic == _8SVX ) && ( !found_VHDR || !found_BODY ) ) )
182 && SDL_RWseek(src, next_chunk, RW_SEEK_SET) != 1 );
183
184 if ( (AIFFmagic == AIFF) && !found_SSND ) {
185 SDL_SetError("Bad AIFF (no SSND chunk)");
186 was_error = 1;
187 goto done;
188 }
189
190 if ( (AIFFmagic == AIFF) && !found_COMM ) {
191 SDL_SetError("Bad AIFF (no COMM chunk)");
192 was_error = 1;
193 goto done;
194 }
195
196 if ( (AIFFmagic == _8SVX) && !found_VHDR ) {
197 SDL_SetError("Bad 8SVX (no VHDR chunk)");
198 was_error = 1;
199 goto done;
200 }
201
202 if ( (AIFFmagic == _8SVX) && !found_BODY ) {
203 SDL_SetError("Bad 8SVX (no BODY chunk)");
204 was_error = 1;
205 goto done;
206 }
207
208 /* Decode the audio data format */
209 memset(spec, 0, sizeof(*spec));
210 spec->freq = frequency;
211 switch (samplesize) {
212 case 8:
213 spec->format = AUDIO_S8;
214 break;
215 case 16:
216 spec->format = AUDIO_S16MSB;
217 break;
218 default:
219 SDL_SetError("Unsupported AIFF samplesize");
220 was_error = 1;
221 goto done;
222 }
223 spec->channels = (Uint8) channels;
224 spec->samples = 4096; /* Good default buffer size */
225
226 *audio_len = channels * numsamples * (samplesize / 8);
227 *audio_buf = (Uint8 *)SDL_malloc(*audio_len);
228 if ( *audio_buf == NULL ) {
229 SDL_SetError("Out of memory");
230 return(NULL);
231 }
232 SDL_RWseek(src, start, RW_SEEK_SET);
233 if ( SDL_RWread(src, *audio_buf, *audio_len, 1) != 1 ) {
234 SDL_SetError("Unable to read audio data");
235 return(NULL);
236 }
237
238 /* Don't return a buffer that isn't a multiple of samplesize */
239 *audio_len &= ~((samplesize / 8) - 1);
240
241 done:
242 if ( freesrc && src ) {
243 SDL_RWclose(src);
244 }
245 if ( was_error ) {
246 spec = NULL;
247 }
248 return(spec);
249 }
250
251