|
0
|
1 /*
|
|
|
2 SDL - Simple DirectMedia Layer
|
|
|
3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
|
|
|
4
|
|
|
5 This library is free software; you can redistribute it and/or
|
|
|
6 modify it under the terms of the GNU Library General Public
|
|
|
7 License as published by the Free Software Foundation; either
|
|
|
8 version 2 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 Library General Public License for more details.
|
|
|
14
|
|
|
15 You should have received a copy of the GNU Library General Public
|
|
|
16 License along with this library; if not, write to the Free
|
|
|
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
18
|
|
|
19 Sam Lantinga
|
|
|
20 slouken@devolution.com
|
|
|
21 */
|
|
|
22
|
|
|
23 #ifdef SAVE_RCSID
|
|
|
24 static char rcsid =
|
|
|
25 "@(#) $Id$";
|
|
|
26 #endif
|
|
|
27
|
|
|
28 /* This provides the default mixing callback for the SDL audio routines */
|
|
|
29
|
|
|
30 #include <stdio.h>
|
|
|
31 #include <stdlib.h>
|
|
|
32 #include <string.h>
|
|
|
33
|
|
|
34 #include "SDL_audio.h"
|
|
|
35 #include "SDL_mutex.h"
|
|
|
36 #include "SDL_timer.h"
|
|
|
37 #include "SDL_sysaudio.h"
|
|
|
38
|
|
|
39
|
|
|
40 /* This table is used to add two sound values together and pin
|
|
|
41 * the value to avoid overflow. (used with permission from ARDI)
|
|
|
42 * Changed to use 0xFE instead of 0xFF for better sound quality.
|
|
|
43 */
|
|
|
44 static const Uint8 mix8[] =
|
|
|
45 {
|
|
|
46 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
47 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
48 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
49 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
50 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
51 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
52 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
53 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
54 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
55 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
56 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
|
57 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03,
|
|
|
58 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
|
|
|
59 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
|
|
|
60 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
|
|
|
61 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
|
|
|
62 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
|
|
|
63 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
|
|
|
64 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
|
|
|
65 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
|
|
|
66 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
|
|
|
67 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71,
|
|
|
68 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
|
|
|
69 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
|
|
|
70 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
|
|
|
71 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D,
|
|
|
72 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
|
|
|
73 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
|
|
|
74 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE,
|
|
|
75 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9,
|
|
|
76 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4,
|
|
|
77 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
|
|
|
78 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
|
|
|
79 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5,
|
|
|
80 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFE, 0xFE,
|
|
|
81 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
82 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
83 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
84 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
85 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
86 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
87 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
88 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
89 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
90 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
91 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
|
|
|
92 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE
|
|
|
93 };
|
|
|
94
|
|
|
95 /* The volume ranges from 0 - 128 */
|
|
|
96 #define ADJUST_VOLUME(s, v) (s = (s*v)/SDL_MIX_MAXVOLUME)
|
|
|
97 #define ADJUST_VOLUME_U8(s, v) (s = (((s-128)*v)/SDL_MIX_MAXVOLUME)+128)
|
|
|
98
|
|
|
99 void SDL_MixAudio (Uint8 *dst, Uint8 *src, Uint32 len, int volume)
|
|
|
100 {
|
|
|
101 Uint16 format;
|
|
|
102
|
|
|
103 if ( volume == 0 ) {
|
|
|
104 return;
|
|
|
105 }
|
|
|
106 /* Mix the user-level audio format */
|
|
|
107 if ( current_audio ) {
|
|
|
108 if ( current_audio->convert.needed ) {
|
|
|
109 format = current_audio->convert.src_format;
|
|
|
110 } else {
|
|
|
111 format = current_audio->spec.format;
|
|
|
112 }
|
|
|
113 } else {
|
|
|
114 /* HACK HACK HACK */
|
|
|
115 format = AUDIO_S16;
|
|
|
116 }
|
|
|
117 switch (format) {
|
|
|
118
|
|
|
119 case AUDIO_U8: {
|
|
|
120 Uint8 src_sample;
|
|
|
121
|
|
|
122 while ( len-- ) {
|
|
|
123 src_sample = *src;
|
|
|
124 ADJUST_VOLUME_U8(src_sample, volume);
|
|
|
125 *dst = mix8[*dst+src_sample];
|
|
|
126 ++dst;
|
|
|
127 ++src;
|
|
|
128 }
|
|
|
129 }
|
|
|
130 break;
|
|
|
131
|
|
|
132 case AUDIO_S8: {
|
|
|
133 Sint8 *dst8, *src8;
|
|
|
134 Sint8 src_sample;
|
|
|
135 int dst_sample;
|
|
|
136 const int max_audioval = ((1<<(8-1))-1);
|
|
|
137 const int min_audioval = -(1<<(8-1));
|
|
|
138
|
|
|
139 src8 = (Sint8 *)src;
|
|
|
140 dst8 = (Sint8 *)dst;
|
|
|
141 while ( len-- ) {
|
|
|
142 src_sample = *src8;
|
|
|
143 ADJUST_VOLUME(src_sample, volume);
|
|
|
144 dst_sample = *dst8 + src_sample;
|
|
|
145 if ( dst_sample > max_audioval ) {
|
|
|
146 *dst8 = max_audioval;
|
|
|
147 } else
|
|
|
148 if ( dst_sample < min_audioval ) {
|
|
|
149 *dst8 = min_audioval;
|
|
|
150 } else {
|
|
|
151 *dst8 = dst_sample;
|
|
|
152 }
|
|
|
153 ++dst8;
|
|
|
154 ++src8;
|
|
|
155 }
|
|
|
156 }
|
|
|
157 break;
|
|
|
158
|
|
|
159 case AUDIO_S16LSB: {
|
|
|
160 Sint16 src1, src2;
|
|
|
161 int dst_sample;
|
|
|
162 const int max_audioval = ((1<<(16-1))-1);
|
|
|
163 const int min_audioval = -(1<<(16-1));
|
|
|
164
|
|
|
165 len /= 2;
|
|
|
166 while ( len-- ) {
|
|
|
167 src1 = ((src[1])<<8|src[0]);
|
|
|
168 ADJUST_VOLUME(src1, volume);
|
|
|
169 src2 = ((dst[1])<<8|dst[0]);
|
|
|
170 src += 2;
|
|
|
171 dst_sample = src1+src2;
|
|
|
172 if ( dst_sample > max_audioval ) {
|
|
|
173 dst_sample = max_audioval;
|
|
|
174 } else
|
|
|
175 if ( dst_sample < min_audioval ) {
|
|
|
176 dst_sample = min_audioval;
|
|
|
177 }
|
|
|
178 dst[0] = dst_sample&0xFF;
|
|
|
179 dst_sample >>= 8;
|
|
|
180 dst[1] = dst_sample&0xFF;
|
|
|
181 dst += 2;
|
|
|
182 }
|
|
|
183 }
|
|
|
184 break;
|
|
|
185
|
|
|
186 case AUDIO_S16MSB: {
|
|
|
187 Sint16 src1, src2;
|
|
|
188 int dst_sample;
|
|
|
189 const int max_audioval = ((1<<(16-1))-1);
|
|
|
190 const int min_audioval = -(1<<(16-1));
|
|
|
191
|
|
|
192 len /= 2;
|
|
|
193 while ( len-- ) {
|
|
|
194 src1 = ((src[0])<<8|src[1]);
|
|
|
195 ADJUST_VOLUME(src1, volume);
|
|
|
196 src2 = ((dst[0])<<8|dst[1]);
|
|
|
197 src += 2;
|
|
|
198 dst_sample = src1+src2;
|
|
|
199 if ( dst_sample > max_audioval ) {
|
|
|
200 dst_sample = max_audioval;
|
|
|
201 } else
|
|
|
202 if ( dst_sample < min_audioval ) {
|
|
|
203 dst_sample = min_audioval;
|
|
|
204 }
|
|
|
205 dst[1] = dst_sample&0xFF;
|
|
|
206 dst_sample >>= 8;
|
|
|
207 dst[0] = dst_sample&0xFF;
|
|
|
208 dst += 2;
|
|
|
209 }
|
|
|
210 }
|
|
|
211 break;
|
|
|
212
|
|
|
213 default: /* If this happens... FIXME! */
|
|
|
214 SDL_SetError("SDL_MixAudio(): unknown audio format");
|
|
|
215 return;
|
|
|
216 }
|
|
|
217 }
|
