1 /*
2 SDL_mixer: An audio mixer library based on the SDL library
3 Copyright (C) 1997-2018 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 #include "SDL_endian.h"
32 #include "SDL_mixer.h"
33 #include "load_aiff.h"
34
35 /*********************************************/
36 /* Define values for AIFF (IFF audio) format */
37 /*********************************************/
38 #define FORM 0x4d524f46 /* "FORM" */
39
40 #define AIFF 0x46464941 /* "AIFF" */
41 #define SSND 0x444e5353 /* "SSND" */
42 #define COMM 0x4d4d4f43 /* "COMM" */
43
44 #define _8SVX 0x58565338 /* "8SVX" */
45 #define VHDR 0x52444856 /* "VHDR" */
46 #define BODY 0x59444F42 /* "BODY" */
47
48 /* This function was taken from libsndfile. I don't pretend to fully
49 * understand it.
50 */
51
SANE_to_Uint32(Uint8 * sanebuf)52 static Uint32 SANE_to_Uint32 (Uint8 *sanebuf)
53 {
54 /* Is the frequency outside of what we can represent with Uint32? */
55 if ((sanebuf[0] & 0x80) || (sanebuf[0] <= 0x3F) || (sanebuf[0] > 0x40)
56 || (sanebuf[0] == 0x40 && sanebuf[1] > 0x1C))
57 return 0;
58
59 return ((sanebuf[2] << 23) | (sanebuf[3] << 15) | (sanebuf[4] << 7)
60 | (sanebuf[5] >> 1)) >> (29 - sanebuf[1]);
61 }
62
63 /* This function is based on SDL_LoadWAV_RW(). */
64
Mix_LoadAIFF_RW(SDL_RWops * src,int freesrc,SDL_AudioSpec * spec,Uint8 ** audio_buf,Uint32 * audio_len)65 SDL_AudioSpec *Mix_LoadAIFF_RW (SDL_RWops *src, int freesrc,
66 SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
67 {
68 int was_error;
69 int found_SSND;
70 int found_COMM;
71 int found_VHDR;
72 int found_BODY;
73 Sint64 start = 0;
74
75 Uint32 chunk_type;
76 Uint32 chunk_length;
77 Sint64 next_chunk;
78
79 /* AIFF magic header */
80 Uint32 FORMchunk;
81 Uint32 AIFFmagic;
82
83 /* SSND chunk */
84 Uint32 offset;
85 Uint32 blocksize;
86
87 /* COMM format chunk */
88 Uint16 channels = 0;
89 Uint32 numsamples = 0;
90 Uint16 samplesize = 0;
91 Uint8 sane_freq[10];
92 Uint32 frequency = 0;
93
94 /* Make sure we are passed a valid data source */
95 was_error = 0;
96 if (src == NULL) {
97 was_error = 1;
98 goto done;
99 }
100
101 FORMchunk = SDL_ReadLE32(src);
102 chunk_length = SDL_ReadBE32(src);
103 if (chunk_length == AIFF) { /* The FORMchunk has already been read */
104 AIFFmagic = chunk_length;
105 chunk_length = FORMchunk;
106 FORMchunk = FORM;
107 } else {
108 AIFFmagic = SDL_ReadLE32(src);
109 }
110 if ((FORMchunk != FORM) || ((AIFFmagic != AIFF) && (AIFFmagic != _8SVX))) {
111 SDL_SetError("Unrecognized file type (not AIFF nor 8SVX)");
112 was_error = 1;
113 goto done;
114 }
115
116 /* TODO: Better santity-checking. */
117
118 found_SSND = 0;
119 found_COMM = 0;
120 found_VHDR = 0;
121 found_BODY = 0;
122
123 do {
124 chunk_type = SDL_ReadLE32(src);
125 chunk_length = SDL_ReadBE32(src);
126 next_chunk = SDL_RWtell(src) + chunk_length;
127 /* Paranoia to avoid infinite loops */
128 if (chunk_length == 0)
129 break;
130
131 switch (chunk_type) {
132 case SSND:
133 found_SSND = 1;
134 offset = SDL_ReadBE32(src);
135 blocksize = SDL_ReadBE32(src);
136 start = SDL_RWtell(src) + offset;
137 break;
138
139 case COMM:
140 found_COMM = 1;
141 channels = SDL_ReadBE16(src);
142 numsamples = SDL_ReadBE32(src);
143 samplesize = SDL_ReadBE16(src);
144 SDL_RWread(src, sane_freq, sizeof(sane_freq), 1);
145 frequency = SANE_to_Uint32(sane_freq);
146 if (frequency == 0) {
147 SDL_SetError("Bad AIFF sample frequency");
148 was_error = 1;
149 goto done;
150 }
151 break;
152
153 case VHDR:
154 found_VHDR = 1;
155 SDL_ReadBE32(src);
156 SDL_ReadBE32(src);
157 SDL_ReadBE32(src);
158 frequency = SDL_ReadBE16(src);
159 channels = 1;
160 samplesize = 8;
161 break;
162
163 case BODY:
164 found_BODY = 1;
165 numsamples = chunk_length;
166 start = SDL_RWtell(src);
167 break;
168
169 default:
170 break;
171 }
172 /* a 0 pad byte can be stored for any odd-length chunk */
173 if (chunk_length&1)
174 next_chunk++;
175 } while ((((AIFFmagic == AIFF) && (!found_SSND || !found_COMM))
176 || ((AIFFmagic == _8SVX) && (!found_VHDR || !found_BODY)))
177 && SDL_RWseek(src, next_chunk, RW_SEEK_SET) != 1);
178
179 if ((AIFFmagic == AIFF) && !found_SSND) {
180 SDL_SetError("Bad AIFF (no SSND chunk)");
181 was_error = 1;
182 goto done;
183 }
184
185 if ((AIFFmagic == AIFF) && !found_COMM) {
186 SDL_SetError("Bad AIFF (no COMM chunk)");
187 was_error = 1;
188 goto done;
189 }
190
191 if ((AIFFmagic == _8SVX) && !found_VHDR) {
192 SDL_SetError("Bad 8SVX (no VHDR chunk)");
193 was_error = 1;
194 goto done;
195 }
196
197 if ((AIFFmagic == _8SVX) && !found_BODY) {
198 SDL_SetError("Bad 8SVX (no BODY chunk)");
199 was_error = 1;
200 goto done;
201 }
202
203 /* Decode the audio data format */
204 SDL_memset(spec, 0, sizeof(*spec));
205 spec->freq = frequency;
206 switch (samplesize) {
207 case 8:
208 spec->format = AUDIO_S8;
209 break;
210 case 16:
211 spec->format = AUDIO_S16MSB;
212 break;
213 default:
214 SDL_SetError("Unsupported AIFF samplesize");
215 was_error = 1;
216 goto done;
217 }
218 spec->channels = (Uint8) channels;
219 spec->samples = 4096; /* Good default buffer size */
220
221 *audio_len = channels * numsamples * (samplesize / 8);
222 *audio_buf = (Uint8 *)SDL_malloc(*audio_len);
223 if (*audio_buf == NULL) {
224 SDL_SetError("Out of memory");
225 return(NULL);
226 }
227 SDL_RWseek(src, start, RW_SEEK_SET);
228 if (SDL_RWread(src, *audio_buf, *audio_len, 1) != 1) {
229 SDL_SetError("Unable to read audio data");
230 return(NULL);
231 }
232
233 /* Don't return a buffer that isn't a multiple of samplesize */
234 *audio_len &= ~((samplesize / 8) - 1);
235
236 done:
237 if (freesrc && src) {
238 SDL_RWclose(src);
239 }
240 if (was_error) {
241 spec = NULL;
242 }
243 return(spec);
244 }
245
246 /* vi: set ts=4 sw=4 expandtab: */
247