1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 1989-2002 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Miscellaneous audio-related operations.
29 */
30
31 #include <stdio.h>
32 #include <string.h>
33 #include <math.h>
34
35 #include <libaudio_impl.h>
36 #include <audio_errno.h>
37 #include <audio_hdr.h>
38
39 /*
40 * Convert a byte count into a floating-point time value, in seconds,
41 * using the encoding specified in the given audio header structure.
42 * Note that the byte count is not the same as the offset in an audio file,
43 * since the size of the audio file header is not taken into account.
44 */
45 double
audio_bytes_to_secs(Audio_hdr * hp,unsigned int cnt)46 audio_bytes_to_secs(Audio_hdr *hp, unsigned int cnt)
47 {
48 return ((double)cnt /
49 ((double)(hp->channels * hp->bytes_per_unit * hp->sample_rate) /
50 (double)hp->samples_per_unit));
51 }
52
53 /*
54 * Convert a floating-point time value, in seconds, to a byte count for
55 * the audio encoding in the given audio header. Note that the byte count
56 * is not the same as the offset in an audio file, since the size of the
57 * audio file header is not taken into account.
58 */
59 unsigned
audio_secs_to_bytes(Audio_hdr * hp,double sec)60 audio_secs_to_bytes(Audio_hdr *hp, double sec)
61 {
62 unsigned offset;
63
64 offset = (unsigned)(0.5 + (sec *
65 ((double)(hp->channels * hp->bytes_per_unit * hp->sample_rate) /
66 (double)hp->samples_per_unit)));
67
68 /* Round down to the start of the nearest sample frame */
69 offset -= (offset % (hp->bytes_per_unit * hp->channels));
70 return (offset);
71 }
72
73 /*
74 * Convert an ASCII time value (hh:mm:ss.dd) into floating-point seconds.
75 * Returns value if successfully converted. Otherwise, returns HUGE_VAL.
76 *
77 * XXX - currently allows the ridiculous construct: 5.3E3:-47.3E-1:17.3
78 */
79 double
audio_str_to_secs(char * str)80 audio_str_to_secs(char *str)
81 {
82 double val;
83 char *str2;
84
85 val = strtod(str, &str2); /* get first numeric field */
86 if (str2 == str)
87 return (HUGE_VAL);
88
89 if (*str2 == ':') { /* that was hours (or minutes) */
90 val *= 60.;
91 str = str2 + 1;
92 val += strtod(str, &str2); /* another field is required */
93 if (str2 == str)
94 return (HUGE_VAL);
95 }
96
97 if (*str2 == ':') { /* converted hours and minutes */
98 val *= 60.;
99 str = str2 + 1;
100 val += strtod(str, &str2); /* another field is required */
101 if (str2 == str)
102 return (HUGE_VAL);
103 }
104
105 if (*str2 != '\0')
106 return (HUGE_VAL);
107 return (val);
108 }
109
110 /*
111 * Convert floating-point seconds into an ASCII time value (hh:mm:ss.dd).
112 *
113 * HUGE_VAL is converted to 0:00. 'Precision' specifies the maximum
114 * number of digits after the decimal point (-1 allows the max).
115 *
116 * Store the resulting string in the specified buffer (must be at least
117 * AUDIO_MAX_TIMEVAL bytes long). The string address is returned.
118 */
119 char *
audio_secs_to_str(double sec,char * str,int precision)120 audio_secs_to_str(double sec, char *str, int precision)
121 {
122 char *p;
123 unsigned ovflow;
124 int hours;
125 double x;
126 char buf[64];
127
128 if (sec == HUGE_VAL) {
129 (void) strcpy(str, "0:00");
130 return (str);
131 }
132
133 /* Limit precision arg to reasonable value */
134 if ((precision > 10) || (precision < 0))
135 precision = 10;
136
137 /* If negative, write a minus sign and get on with it. */
138 p = str;
139 if (sec < 0.) {
140 sec = -sec;
141
142 /* Round off within precision to avoid -.01 printing as -0:00 */
143 (void) sprintf(buf, "%.*f", precision, sec);
144 (void) sscanf(buf, "%lf", &sec);
145 if (sec > 0.)
146 *p++ = '-';
147 }
148
149 /* Round off within precision to avoid 1:59.999 printing as 1:60.00 */
150 x = fmod(sec, 60.);
151 sec -= x;
152 (void) sprintf(buf, "%.*f", precision, x);
153 (void) sscanf(buf, "%lf", &x);
154 sec += x;
155
156 if (sec >= 60.) {
157 /* Extract minutes */
158 ovflow = ((unsigned)sec) / 60;
159 sec -= (double)(ovflow * 60);
160 hours = (ovflow >= 60);
161 if (hours) {
162 /* convert hours */
163 (void) sprintf(p, "%d:", ovflow / 60);
164 p = &p[strlen(p)];
165 ovflow %= 60;
166 }
167 /* convert minutes (use two digits if hours printed) */
168 (void) sprintf(p, "%0*d:", (hours ? 2 : 1), ovflow);
169 p = &p[strlen(p)];
170 } else {
171 *p++ = '0';
172 *p++ = ':';
173 }
174
175 if (sec < 10.)
176 *p++ = '0';
177 (void) sprintf(p, "%.*f", precision, sec);
178 return (str);
179 }
180
181 /*
182 * Compare the encoding fields of two audio headers.
183 * Return 0 if they are the same, 1 if they are the same except for
184 * sample rate, else -1.
185 */
186 int
audio_cmp_hdr(Audio_hdr * h1,Audio_hdr * h2)187 audio_cmp_hdr(Audio_hdr *h1, Audio_hdr *h2)
188 {
189 if ((h1->encoding != h2->encoding) ||
190 (h1->bytes_per_unit != h2->bytes_per_unit) ||
191 (h1->channels != h2->channels) ||
192 (h1->samples_per_unit != h2->samples_per_unit))
193 return (-1);
194
195 if (h1->sample_rate != h2->sample_rate)
196 return (1);
197
198 return (0);
199 }
200
201 /*
202 * Interpret the encoding information in the specified header
203 * and return an appropriate string in the supplied buffer.
204 * The buffer should contain at least AUDIO_MAX_ENCODE_INFO bytes.
205 * The returned string is something like:
206 * "stereo 16-bit linear PCM @ 44.1kHz"
207 *
208 * Returns AUDIO_ERR_BADHDR if the header cannot be interpreted.
209 */
210 int
audio_enc_to_str(Audio_hdr * hdrp,char * str)211 audio_enc_to_str(Audio_hdr *hdrp, char *str)
212 {
213 char *chan;
214 char *prec;
215 char *enc;
216 char cbuf[AUDIO_MAX_ENCODE_INFO];
217 char pbuf[AUDIO_MAX_ENCODE_INFO];
218 char sbuf[AUDIO_MAX_ENCODE_INFO];
219 int err;
220
221 err = AUDIO_SUCCESS;
222
223 switch (hdrp->channels) {
224 case 0:
225 chan = "(zero channels?)";
226 err = AUDIO_ERR_BADHDR;
227 break;
228 case 1:
229 chan = "mono"; break;
230 case 2:
231 chan = "stereo"; break;
232 case 4:
233 chan = "quad"; break;
234 default:
235 chan = pbuf;
236 (void) sprintf(cbuf, "%u-channel", hdrp->channels); break;
237 }
238
239 switch (hdrp->encoding) {
240 case AUDIO_ENCODING_ULAW:
241 enc = "u-law";
242 goto pcm;
243 case AUDIO_ENCODING_ALAW:
244 enc = "A-law";
245 goto pcm;
246 case AUDIO_ENCODING_LINEAR:
247 enc = "linear PCM";
248 goto pcm;
249 case AUDIO_ENCODING_FLOAT:
250 enc = "floating-point";
251 pcm:
252 if (hdrp->samples_per_unit != 1)
253 goto unknown;
254 prec = pbuf;
255 (void) sprintf(pbuf, "%u-bit", hdrp->bytes_per_unit * 8);
256 break;
257
258 default:
259 unknown:
260 err = AUDIO_ERR_ENCODING;
261 enc = "(unknown encoding?)";
262 if (hdrp->samples_per_unit != 0) {
263 prec = pbuf;
264 (void) sprintf(pbuf, "%f-bit",
265 (double)(hdrp->bytes_per_unit * 8) /
266 (double)hdrp->samples_per_unit);
267 } else {
268 prec = "(unknown precision?)";
269 err = AUDIO_ERR_BADHDR;
270 }
271 }
272
273 (void) sprintf(sbuf, "%.3fkHz", ((double)hdrp->sample_rate / 1000.));
274 (void) sprintf(str, "%s %s %s @ %s", chan, prec, enc, sbuf);
275 return (err);
276 }
277