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 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 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 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 * 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 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 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