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 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 /*
30 * Miscellaneous audio-related operations.
31 */
32
33 #include <stdio.h>
34 #include <string.h>
35 #include <math.h>
36
37 #include <libaudio_impl.h>
38 #include <audio_errno.h>
39 #include <audio_hdr.h>
40
41 /*
42 * Convert a byte count into a floating-point time value, in seconds,
43 * using the encoding specified in the given audio header structure.
44 * Note that the byte count is not the same as the offset in an audio file,
45 * since the size of the audio file header is not taken into account.
46 */
47 double
audio_bytes_to_secs(Audio_hdr * hp,unsigned int cnt)48 audio_bytes_to_secs(Audio_hdr *hp, unsigned int cnt)
49 {
50 return ((double)cnt /
51 ((double)(hp->channels * hp->bytes_per_unit * hp->sample_rate) /
52 (double)hp->samples_per_unit));
53 }
54
55 /*
56 * Convert a floating-point time value, in seconds, to a byte count for
57 * the audio encoding in the given audio header. Note that the byte count
58 * is not the same as the offset in an audio file, since the size of the
59 * audio file header is not taken into account.
60 */
61 unsigned
audio_secs_to_bytes(Audio_hdr * hp,double sec)62 audio_secs_to_bytes(Audio_hdr *hp, double sec)
63 {
64 unsigned offset;
65
66 offset = (unsigned)(0.5 + (sec *
67 ((double)(hp->channels * hp->bytes_per_unit * hp->sample_rate) /
68 (double)hp->samples_per_unit)));
69
70 /* Round down to the start of the nearest sample frame */
71 offset -= (offset % (hp->bytes_per_unit * hp->channels));
72 return (offset);
73 }
74
75 /*
76 * Convert an ASCII time value (hh:mm:ss.dd) into floating-point seconds.
77 * Returns value if successfully converted. Otherwise, returns HUGE_VAL.
78 *
79 * XXX - currently allows the ridiculous construct: 5.3E3:-47.3E-1:17.3
80 */
81 double
audio_str_to_secs(char * str)82 audio_str_to_secs(char *str)
83 {
84 double val;
85 char *str2;
86
87 val = strtod(str, &str2); /* get first numeric field */
88 if (str2 == str)
89 return (HUGE_VAL);
90
91 if (*str2 == ':') { /* that was hours (or minutes) */
92 val *= 60.;
93 str = str2 + 1;
94 val += strtod(str, &str2); /* another field is required */
95 if (str2 == str)
96 return (HUGE_VAL);
97 }
98
99 if (*str2 == ':') { /* converted hours and minutes */
100 val *= 60.;
101 str = str2 + 1;
102 val += strtod(str, &str2); /* another field is required */
103 if (str2 == str)
104 return (HUGE_VAL);
105 }
106
107 if (*str2 != '\0')
108 return (HUGE_VAL);
109 return (val);
110 }
111
112 /*
113 * Convert floating-point seconds into an ASCII time value (hh:mm:ss.dd).
114 *
115 * HUGE_VAL is converted to 0:00. 'Precision' specifies the maximum
116 * number of digits after the decimal point (-1 allows the max).
117 *
118 * Store the resulting string in the specified buffer (must be at least
119 * AUDIO_MAX_TIMEVAL bytes long). The string address is returned.
120 */
121 char *
audio_secs_to_str(double sec,char * str,int precision)122 audio_secs_to_str(double sec, char *str, int precision)
123 {
124 char *p;
125 unsigned ovflow;
126 int hours;
127 double x;
128 char buf[64];
129
130 if (sec == HUGE_VAL) {
131 (void) strcpy(str, "0:00");
132 return (str);
133 }
134
135 /* Limit precision arg to reasonable value */
136 if ((precision > 10) || (precision < 0))
137 precision = 10;
138
139 /* If negative, write a minus sign and get on with it. */
140 p = str;
141 if (sec < 0.) {
142 sec = -sec;
143
144 /* Round off within precision to avoid -.01 printing as -0:00 */
145 (void) sprintf(buf, "%.*f", precision, sec);
146 (void) sscanf(buf, "%lf", &sec);
147 if (sec > 0.)
148 *p++ = '-';
149 }
150
151 /* Round off within precision to avoid 1:59.999 printing as 1:60.00 */
152 x = fmod(sec, 60.);
153 sec -= x;
154 (void) sprintf(buf, "%.*f", precision, x);
155 (void) sscanf(buf, "%lf", &x);
156 sec += x;
157
158 if (sec >= 60.) {
159 /* Extract minutes */
160 ovflow = ((unsigned)sec) / 60;
161 sec -= (double)(ovflow * 60);
162 hours = (ovflow >= 60);
163 if (hours) {
164 /* convert hours */
165 (void) sprintf(p, "%d:", ovflow / 60);
166 p = &p[strlen(p)];
167 ovflow %= 60;
168 }
169 /* convert minutes (use two digits if hours printed) */
170 (void) sprintf(p, "%0*d:", (hours ? 2 : 1), ovflow);
171 p = &p[strlen(p)];
172 } else {
173 *p++ = '0';
174 *p++ = ':';
175 }
176
177 if (sec < 10.)
178 *p++ = '0';
179 (void) sprintf(p, "%.*f", precision, sec);
180 return (str);
181 }
182
183 /*
184 * Compare the encoding fields of two audio headers.
185 * Return 0 if they are the same, 1 if they are the same except for
186 * sample rate, else -1.
187 */
188 int
audio_cmp_hdr(Audio_hdr * h1,Audio_hdr * h2)189 audio_cmp_hdr(Audio_hdr *h1, Audio_hdr *h2)
190 {
191 if ((h1->encoding != h2->encoding) ||
192 (h1->bytes_per_unit != h2->bytes_per_unit) ||
193 (h1->channels != h2->channels) ||
194 (h1->samples_per_unit != h2->samples_per_unit))
195 return (-1);
196
197 if (h1->sample_rate != h2->sample_rate)
198 return (1);
199
200 return (0);
201 }
202
203 /*
204 * Interpret the encoding information in the specified header
205 * and return an appropriate string in the supplied buffer.
206 * The buffer should contain at least AUDIO_MAX_ENCODE_INFO bytes.
207 * The returned string is something like:
208 * "stereo 16-bit linear PCM @ 44.1kHz"
209 *
210 * Returns AUDIO_ERR_BADHDR if the header cannot be interpreted.
211 */
212 int
audio_enc_to_str(Audio_hdr * hdrp,char * str)213 audio_enc_to_str(Audio_hdr *hdrp, char *str)
214 {
215 char *chan;
216 char *prec;
217 char *enc;
218 char cbuf[AUDIO_MAX_ENCODE_INFO];
219 char pbuf[AUDIO_MAX_ENCODE_INFO];
220 char sbuf[AUDIO_MAX_ENCODE_INFO];
221 int err;
222
223 err = AUDIO_SUCCESS;
224
225 switch (hdrp->channels) {
226 case 0:
227 chan = "(zero channels?)";
228 err = AUDIO_ERR_BADHDR;
229 break;
230 case 1:
231 chan = "mono"; break;
232 case 2:
233 chan = "stereo"; break;
234 case 4:
235 chan = "quad"; break;
236 default:
237 chan = pbuf;
238 (void) sprintf(cbuf, "%u-channel", hdrp->channels); break;
239 }
240
241 switch (hdrp->encoding) {
242 case AUDIO_ENCODING_ULAW:
243 enc = "u-law";
244 goto pcm;
245 case AUDIO_ENCODING_ALAW:
246 enc = "A-law";
247 goto pcm;
248 case AUDIO_ENCODING_LINEAR:
249 enc = "linear PCM";
250 goto pcm;
251 case AUDIO_ENCODING_FLOAT:
252 enc = "floating-point";
253 pcm:
254 if (hdrp->samples_per_unit != 1)
255 goto unknown;
256 prec = pbuf;
257 (void) sprintf(pbuf, "%u-bit", hdrp->bytes_per_unit * 8);
258 break;
259
260 default:
261 unknown:
262 err = AUDIO_ERR_ENCODING;
263 enc = "(unknown encoding?)";
264 if (hdrp->samples_per_unit != 0) {
265 prec = pbuf;
266 (void) sprintf(pbuf, "%f-bit",
267 (double)(hdrp->bytes_per_unit * 8) /
268 (double)hdrp->samples_per_unit);
269 } else {
270 prec = "(unknown precision?)";
271 err = AUDIO_ERR_BADHDR;
272 }
273 }
274
275 (void) sprintf(sbuf, "%.3fkHz", ((double)hdrp->sample_rate / 1000.));
276 (void) sprintf(str, "%s %s %s @ %s", chan, prec, enc, sbuf);
277 return (err);
278 }
279