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record.c revision 1.20
      1 /*	$NetBSD: record.c,v 1.20 2002/01/15 17:17:13 mrg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1999 Matthew R. Green
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*
     32  * SunOS compatible audiorecord(1)
     33  */
     34 
     35 #include <sys/types.h>
     36 #include <sys/audioio.h>
     37 #include <sys/ioctl.h>
     38 #include <sys/time.h>
     39 #include <sys/uio.h>
     40 
     41 #include <err.h>
     42 #include <fcntl.h>
     43 #include <paths.h>
     44 #include <signal.h>
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <string.h>
     48 #include <unistd.h>
     49 
     50 #include "libaudio.h"
     51 #include "auconv.h"
     52 
     53 audio_info_t info, oinfo;
     54 ssize_t	total_size = -1;
     55 char	*device;
     56 char	*ctldev;
     57 int	format = AUDIO_FORMAT_SUN;
     58 char	*header_info;
     59 char	default_info[8] = { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0' };
     60 int	audiofd, ctlfd, outfd;
     61 int	qflag, aflag, fflag;
     62 int	verbose;
     63 int	monitor_gain, omonitor_gain;
     64 int	gain;
     65 int	balance;
     66 int	port;
     67 int	encoding;
     68 char	*encoding_str;
     69 int	precision;
     70 int	sample_rate;
     71 int	channels;
     72 struct timeval record_time;
     73 struct timeval start_time;	/* XXX because that's what gettimeofday returns */
     74 
     75 void (*conv_func) (u_char *, size_t);
     76 
     77 void usage (void);
     78 int main (int, char *[]);
     79 int timeleft (struct timeval *, struct timeval *);
     80 void cleanup (int) __attribute__((__noreturn__));
     81 int write_header_sun (void **, size_t *, int *);
     82 int write_header_wav (void **, size_t *, int *);
     83 void write_header (void);
     84 void rewrite_header (void);
     85 
     86 int
     87 main(argc, argv)
     88 	int argc;
     89 	char *argv[];
     90 {
     91 	char	*buffer;
     92 	size_t	len, bufsize;
     93 	int	ch, no_time_limit = 1;
     94 
     95 	while ((ch = getopt(argc, argv, "ab:C:F:c:d:e:fhi:m:P:p:qt:s:Vv:")) != -1) {
     96 		switch (ch) {
     97 		case 'a':
     98 			aflag++;
     99 			break;
    100 		case 'b':
    101 			decode_int(optarg, &balance);
    102 			if (balance < 0 || balance > 63)
    103 				errx(1, "balance must be between 0 and 63\n");
    104 			break;
    105 		case 'C':
    106 			ctldev = optarg;
    107 			break;
    108 		case 'F':
    109 			format = audio_format_from_str(optarg);
    110 			if (format < 0)
    111 				errx(1, "Unknown audio format; "
    112 				    "supported formats: \"sun\" and \"wav\"");
    113 			break;
    114 		case 'c':
    115 			decode_int(optarg, &channels);
    116 			if (channels < 0 || channels > 16)
    117 				errx(1, "channels must be between 0 and 16\n");
    118 			break;
    119 		case 'd':
    120 			device = optarg;
    121 			break;
    122 		case 'e':
    123 			encoding_str = optarg;
    124 			break;
    125 		case 'f':
    126 			fflag++;
    127 			break;
    128 		case 'i':
    129 			header_info = optarg;
    130 			break;
    131 		case 'm':
    132 			decode_int(optarg, &monitor_gain);
    133 			if (monitor_gain < 0 || monitor_gain > 255)
    134 				errx(1, "monitor volume must be between 0 and 255\n");
    135 			break;
    136 		case 'P':
    137 			decode_int(optarg, &precision);
    138 			if (precision != 4 && precision != 8 &&
    139 			    precision != 16 && precision != 24 &&
    140 			    precision != 32)
    141 				errx(1, "precision must be between 4, 8, 16, 24 or 32");
    142 			break;
    143 		case 'p':
    144 			len = strlen(optarg);
    145 
    146 			if (strncmp(optarg, "mic", len) == 0)
    147 				port |= AUDIO_MICROPHONE;
    148 			else if (strncmp(optarg, "cd", len) == 0 ||
    149 			           strncmp(optarg, "internal-cd", len) == 0)
    150 				port |= AUDIO_CD;
    151 			else if (strncmp(optarg, "line", len) == 0)
    152 				port |= AUDIO_LINE_IN;
    153 			else
    154 				errx(1,
    155 			    "port must be `cd', `internal-cd', `mic', or `line'");
    156 			break;
    157 		case 'q':
    158 			qflag++;
    159 			break;
    160 		case 's':
    161 			decode_int(optarg, &sample_rate);
    162 			if (sample_rate < 0 || sample_rate > 48000 * 2)	/* XXX */
    163 				errx(1, "sample rate must be between 0 and 96000\n");
    164 			break;
    165 		case 't':
    166 			no_time_limit = 0;
    167 			decode_time(optarg, &record_time);
    168 			break;
    169 		case 'V':
    170 			verbose++;
    171 			break;
    172 		case 'v':
    173 			decode_int(optarg, &gain);
    174 			if (gain < 0 || gain > 255)
    175 				errx(1, "volume must be between 0 and 255\n");
    176 			break;
    177 		/* case 'h': */
    178 		default:
    179 			usage();
    180 			/* NOTREACHED */
    181 		}
    182 	}
    183 	argc -= optind;
    184 	argv += optind;
    185 
    186 	/*
    187 	 * open the audio device, and control device
    188 	 */
    189 	if (device == NULL && (device = getenv("AUDIODEVICE")) == NULL &&
    190 	    (device = getenv("AUDIODEV")) == NULL) /* Sun compatibility */
    191 		device = _PATH_AUDIO;
    192 	if (ctldev == NULL && (ctldev = getenv("AUDIOCTLDEVICE")) == NULL)
    193 		ctldev = _PATH_AUDIOCTL;
    194 
    195 	audiofd = open(device, O_RDONLY);
    196 	if (audiofd < 0)
    197 		err(1, "failed to open %s", device);
    198 	ctlfd = open(ctldev, O_RDWR);
    199 	if (ctlfd < 0)
    200 		err(1, "failed to open %s", ctldev);
    201 
    202 	/*
    203 	 * work out the buffer size to use, and allocate it.  also work out
    204 	 * what the old monitor gain value is, so that we can reset it later.
    205 	 */
    206 	if (ioctl(ctlfd, AUDIO_GETINFO, &oinfo) < 0)
    207 		err(1, "failed to get audio info");
    208 	bufsize = oinfo.record.buffer_size;
    209 	if (bufsize < 32 * 1024)
    210 		bufsize = 32 * 1024;
    211 	omonitor_gain = oinfo.monitor_gain;
    212 
    213 	buffer = malloc(bufsize);
    214 	if (buffer == NULL)
    215 		err(1, "couldn't malloc buffer of %d size", (int)bufsize);
    216 
    217 	/*
    218 	 * open the output file
    219 	 */
    220 	if (argc != 1)
    221 		usage();
    222 	if (argv[0][0] != '-' && argv[0][1] != '\0') {
    223 		outfd = open(*argv, O_CREAT|(aflag ? O_APPEND : O_TRUNC)|O_WRONLY, 0666);
    224 		if (outfd < 0)
    225 			err(1, "could not open %s", *argv);
    226 	} else
    227 		outfd = STDOUT_FILENO;
    228 
    229 	/*
    230 	 * convert the encoding string into a value.
    231 	 */
    232 	if (encoding_str) {
    233 		encoding = audio_enc_to_val(encoding_str);
    234 		if (encoding == -1)
    235 			errx(1, "unknown encoding, bailing...");
    236 	}
    237 	else
    238 		encoding = AUDIO_ENCODING_ULAW;
    239 
    240 	/*
    241 	 * set up audio device for recording with the speified parameters
    242 	 */
    243 	AUDIO_INITINFO(&info);
    244 
    245 	/*
    246 	 * for these, get the current values for stuffing into the header
    247 	 */
    248 #define SETINFO(x)	if (x) info.record.x = x; else x = oinfo.record.x
    249 	SETINFO (sample_rate);
    250 	SETINFO (channels);
    251 	SETINFO (precision);
    252 	SETINFO (encoding);
    253 	SETINFO (gain);
    254 	SETINFO (port);
    255 	SETINFO (balance);
    256 #undef SETINFO
    257 
    258 	if (monitor_gain)
    259 		info.monitor_gain = monitor_gain;
    260 	else
    261 		monitor_gain = oinfo.monitor_gain;
    262 
    263 	info.mode = AUMODE_RECORD;
    264 	if (ioctl(ctlfd, AUDIO_SETINFO, &info) < 0)
    265 		err(1, "failed to reset audio info");
    266 
    267 	signal(SIGINT, cleanup);
    268 	write_header();
    269 	total_size = 0;
    270 
    271 	(void)gettimeofday(&start_time, NULL);
    272 	while (no_time_limit || timeleft(&start_time, &record_time)) {
    273 		if (read(audiofd, buffer, bufsize) != bufsize)
    274 			err(1, "read failed");
    275 		if (conv_func)
    276 			(*conv_func)(buffer, bufsize);
    277 		if (write(outfd, buffer, bufsize) != bufsize)
    278 			err(1, "write failed");
    279 		total_size += bufsize;
    280 	}
    281 	cleanup(0);
    282 }
    283 
    284 int
    285 timeleft(start_tvp, record_tvp)
    286 	struct timeval *start_tvp;
    287 	struct timeval *record_tvp;
    288 {
    289 	struct timeval now, diff;
    290 
    291 	(void)gettimeofday(&now, NULL);
    292 	timersub(&now, start_tvp, &diff);
    293 	timersub(record_tvp, &diff, &now);
    294 
    295 	return (now.tv_sec > 0 || (now.tv_sec == 0 && now.tv_usec > 0));
    296 }
    297 
    298 void
    299 cleanup(signo)
    300 	int signo;
    301 {
    302 
    303 	close(audiofd);
    304 	rewrite_header();
    305 	close(outfd);
    306 	if (omonitor_gain) {
    307 		AUDIO_INITINFO(&info);
    308 		info.monitor_gain = omonitor_gain;
    309 		if (ioctl(ctlfd, AUDIO_SETINFO, &info) < 0)
    310 			err(1, "failed to reset audio info");
    311 	}
    312 	close(ctlfd);
    313 	exit(0);
    314 }
    315 
    316 int
    317 write_header_sun(hdrp, lenp, leftp)
    318 	void **hdrp;
    319 	size_t *lenp;
    320 	int *leftp;
    321 {
    322 	static int warned = 0;
    323 	static sun_audioheader auh;
    324 	int sunenc, oencoding = encoding;
    325 
    326 	if (encoding == AUDIO_ENCODING_ULINEAR_LE) {
    327 		if (precision == 16)
    328 			conv_func = swap_bytes;
    329 		else if (precision == 32)
    330 			conv_func = swap_bytes32;
    331 		encoding = AUDIO_ENCODING_SLINEAR_BE;
    332 	} else if (encoding == AUDIO_ENCODING_ULINEAR_BE) {
    333 		if (precision == 16)
    334 			conv_func = change_sign16_be;
    335 		else if (precision == 32)
    336 			conv_func = change_sign32_be;
    337 		encoding = AUDIO_ENCODING_SLINEAR_BE;
    338 	} else if (encoding == AUDIO_ENCODING_SLINEAR_LE) {
    339 		if (precision == 16)
    340 			conv_func = change_sign16_swap_bytes_le;
    341 		else if (precision == 32)
    342 			conv_func = change_sign32_swap_bytes_le;
    343 		encoding = AUDIO_ENCODING_SLINEAR_BE;
    344 	}
    345 
    346 	/* if we can't express this as a Sun header, don't write any */
    347 	if (audio_encoding_to_sun(encoding, precision, &sunenc) != 0) {
    348 		if (!qflag && !warned)
    349 			warnx("failed to convert to sun encoding from %d:%d; "
    350 			      "Sun audio header not written",
    351 			      oencoding, precision);
    352 		conv_func = 0;
    353 		warned = 1;
    354 		return -1;
    355 	}
    356 
    357 	auh.magic = htonl(AUDIO_FILE_MAGIC);
    358 	if (outfd == STDOUT_FILENO)
    359 		auh.data_size = htonl(AUDIO_UNKNOWN_SIZE);
    360 	else
    361 		auh.data_size = htonl(total_size);
    362 	auh.encoding = htonl(sunenc);
    363 	auh.sample_rate = htonl(sample_rate);
    364 	auh.channels = htonl(channels);
    365 	if (header_info) {
    366 		int 	len, infolen;
    367 
    368 		infolen = ((len = strlen(header_info)) + 7) & 0xfffffff8;
    369 		*leftp = infolen - len;
    370 		auh.hdr_size = htonl(sizeof(auh) + infolen);
    371 	} else {
    372 		*leftp = sizeof(default_info);
    373 		auh.hdr_size = htonl(sizeof(auh) + *leftp);
    374 	}
    375 	*(sun_audioheader **)hdrp = &auh;
    376 	*lenp = sizeof auh;
    377 	return 0;
    378 }
    379 
    380 int
    381 write_header_wav(hdrp, lenp, leftp)
    382 	void **hdrp;
    383 	size_t *lenp;
    384 	int *leftp;
    385 {
    386 	/*
    387 	 * WAV header we write looks like this:
    388 	 *
    389 	 *      bytes   purpose
    390 	 *      0-3     "RIFF"
    391 	 *      4-7     file length (minus 8)
    392 	 *      8-15    "WAVEfmt "
    393 	 *      16-19   format size
    394 	 *      20-21   format tag
    395 	 *      22-23   number of channels
    396 	 *      24-27   sample rate
    397 	 *      28-31   average bytes per second
    398 	 *      32-33   block alignment
    399 	 *      34-35   bits per sample
    400 	 *
    401 	 * then for ULAW and ALAW outputs, we have an extended chunk size
    402 	 * and a WAV "fact" to add:
    403 	 *
    404 	 *      36-37   length of extension (== 0)
    405 	 *      38-41   "fact"
    406 	 *      42-45   fact size
    407 	 *      46-49   number of samples written
    408 	 *      50-53   "data"
    409 	 *      54-57   data length
    410 	 *      58-     raw audio data
    411 	 *
    412 	 * for PCM outputs we have just the data remaining:
    413 	 *
    414 	 *      36-39   "data"
    415 	 *      40-43   data length
    416 	 *      44-     raw audio data
    417 	 *
    418 	 *	RIFF\^@^C^@WAVEfmt ^P^@^@^@^A^@^B^@D<AC>^@^@^P<B1>^B^@^D^@^P^@data^@^@^C^@^@^@^@^@^@^@^@^@^@
    419 	 */
    420 	char	wavheaderbuf[64], *p = wavheaderbuf;
    421 	char	*riff = "RIFF", *wavefmt = "WAVEfmt ", *fact = "fact", *data = "data";
    422 	u_int32_t filelen, fmtsz, sps, abps, factsz = 4, nsample, datalen;
    423 	u_int16_t fmttag, nchan, align, bps, extln = 0;
    424 
    425 	if (header_info)
    426 		warnx("header information not supported for WAV");
    427 	*leftp = NULL;
    428 
    429 	switch (precision) {
    430 	case 8:
    431 		bps = 8;
    432 		break;
    433 	case 16:
    434 		bps = 16;
    435 		break;
    436 	case 32:
    437 		bps = 32;
    438 		break;
    439 	default:
    440 		{
    441 			static int warned = 0;
    442 
    443 			if (warned == 0) {
    444 				warnx("can not support precision of %d\n", precision);
    445 				warned = 1;
    446 			}
    447 		}
    448 		return (-1);
    449 	}
    450 
    451 	switch (encoding) {
    452 	case AUDIO_ENCODING_ULAW:
    453 		fmttag = WAVE_FORMAT_MULAW;
    454 		fmtsz = 18;
    455 		align = channels;
    456 		break;
    457 	case AUDIO_ENCODING_ALAW:
    458 		fmttag = WAVE_FORMAT_ALAW;
    459 		fmtsz = 18;
    460 		align = channels;
    461 		break;
    462 	/*
    463 	 * we could try to support RIFX but it seems to be more portable
    464 	 * to output little-endian data for WAV files.
    465 	 */
    466 	case AUDIO_ENCODING_ULINEAR_BE:
    467 		if (bps == 16)
    468 			conv_func = change_sign16_swap_bytes_be;
    469 		else if (bps == 32)
    470 			conv_func = change_sign32_swap_bytes_be;
    471 		goto fmt_pcm;
    472 	case AUDIO_ENCODING_SLINEAR_BE:
    473 		if (bps == 16)
    474 			conv_func = swap_bytes;
    475 		else if (bps == 32)
    476 			conv_func = swap_bytes32;
    477 		goto fmt_pcm;
    478 	case AUDIO_ENCODING_ULINEAR_LE:
    479 		if (bps == 16)
    480 			conv_func = change_sign16_le;
    481 		else if (bps == 32)
    482 			conv_func = change_sign32_le;
    483 		/* FALLTHROUGH */
    484 	case AUDIO_ENCODING_SLINEAR_LE:
    485 	case AUDIO_ENCODING_PCM16:
    486 fmt_pcm:
    487 		fmttag = WAVE_FORMAT_PCM;
    488 		fmtsz = 16;
    489 		align = channels * (bps / 8);
    490 		break;
    491 	default:
    492 		{
    493 			static int warned = 0;
    494 
    495 			if (warned == 0) {
    496 				warnx("can not support encoding of %s\n", wav_enc_from_val(encoding));
    497 				warned = 1;
    498 			}
    499 		}
    500 		return (-1);
    501 	}
    502 
    503 	nchan = channels;
    504 	sps = sample_rate;
    505 
    506 	/* data length */
    507 	if (outfd == STDOUT_FILENO)
    508 		datalen = 0;
    509 	else
    510 		datalen = total_size;
    511 
    512 	/* file length */
    513 	filelen = 4 + (8 + fmtsz) + (8 + datalen);
    514 	if (fmttag != WAVE_FORMAT_PCM)
    515 		filelen += 8 + factsz;
    516 
    517 	abps = (double)align*sample_rate / (double)1 + 0.5;
    518 
    519 	nsample = (datalen / bps) / sample_rate;
    520 
    521 	/*
    522 	 * now we've calculated the info, write it out!
    523 	 */
    524 #define put32(x) do { \
    525 	u_int32_t _f; \
    526 	putle32(_f, (x)); \
    527 	memcpy(p, &_f, 4); \
    528 } while (0)
    529 #define put16(x) do { \
    530 	u_int16_t _f; \
    531 	putle16(_f, (x)); \
    532 	memcpy(p, &_f, 2); \
    533 } while (0)
    534 	memcpy(p, riff, 4);
    535 	p += 4;				/* 4 */
    536 	put32(filelen);
    537 	p += 4;				/* 8 */
    538 	memcpy(p, wavefmt, 8);
    539 	p += 8;				/* 16 */
    540 	put32(fmtsz);
    541 	p += 4;				/* 20 */
    542 	put16(fmttag);
    543 	p += 2;				/* 22 */
    544 	put16(nchan);
    545 	p += 2;				/* 24 */
    546 	put32(sps);
    547 	p += 4;				/* 28 */
    548 	put32(abps);
    549 	p += 4;				/* 32 */
    550 	put16(align);
    551 	p += 2;				/* 34 */
    552 	put16(bps);
    553 	p += 2;				/* 36 */
    554 	/* NON PCM formats have an extended chunk; write it */
    555 	if (fmttag != WAVE_FORMAT_PCM) {
    556 		put16(extln);
    557 		p += 2;			/* 38 */
    558 		memcpy(p, fact, 4);
    559 		p += 4;			/* 42 */
    560 		put32(factsz);
    561 		p += 4;			/* 46 */
    562 		put32(nsample);
    563 		p += 4;			/* 50 */
    564 	}
    565 	memcpy(p, data, 4);
    566 	p += 4;				/* 40/54 */
    567 	put32(datalen);
    568 	p += 4;				/* 44/58 */
    569 #undef put32
    570 #undef put16
    571 
    572 	*hdrp = wavheaderbuf;
    573 	*lenp = (p - wavheaderbuf);
    574 
    575 	return 0;
    576 }
    577 
    578 void
    579 write_header()
    580 {
    581 	struct iovec iv[3];
    582 	int veclen, left, tlen;
    583 	void *hdr;
    584 	size_t hdrlen;
    585 
    586 	switch (format) {
    587 	case AUDIO_FORMAT_SUN:
    588 		if (write_header_sun(&hdr, &hdrlen, &left) != 0)
    589 			return;
    590 		break;
    591 	case AUDIO_FORMAT_WAV:
    592 		if (write_header_wav(&hdr, &hdrlen, &left) != 0)
    593 			return;
    594 		break;
    595 	case AUDIO_FORMAT_NONE:
    596 		return;
    597 	default:
    598 		errx(1, "unknown audio format");
    599 	}
    600 
    601 	veclen = 0;
    602 	tlen = 0;
    603 
    604 	if (hdrlen != 0) {
    605 		iv[veclen].iov_base = hdr;
    606 		iv[veclen].iov_len = hdrlen;
    607 		tlen += iv[veclen++].iov_len;
    608 	}
    609 	if (header_info) {
    610 		iv[veclen].iov_base = header_info;
    611 		iv[veclen].iov_len = (int)strlen(header_info) + 1;
    612 		tlen += iv[veclen++].iov_len;
    613 	}
    614 	if (left) {
    615 		iv[veclen].iov_base = default_info;
    616 		iv[veclen].iov_len = left;
    617 		tlen += iv[veclen++].iov_len;
    618 	}
    619 
    620 	if (tlen == 0)
    621 		return;
    622 
    623 	if (writev(outfd, iv, veclen) != tlen)
    624 		err(1, "could not write audio header");
    625 }
    626 
    627 void
    628 rewrite_header()
    629 {
    630 
    631 	/* can't do this here! */
    632 	if (outfd == STDOUT_FILENO)
    633 		return;
    634 
    635 	if (lseek(outfd, SEEK_SET, 0) < 0)
    636 		err(1, "could not seek to start of file for header rewrite");
    637 	write_header();
    638 }
    639 
    640 void
    641 usage()
    642 {
    643 
    644 	fprintf(stderr, "Usage: %s [-afhqV] [options] {files ...|-}\n",
    645 	    getprogname());
    646 	fprintf(stderr, "Options:\n\t"
    647 	    "-C audio control device\n\t"
    648 	    "-F format\n\t"
    649 	    "-b balance (0-63)\n\t"
    650 	    "-c channels\n\t"
    651 	    "-d audio device\n\t"
    652 	    "-e encoding\n\t"
    653 	    "-i header information\n\t"
    654 	    "-m monitor volume\n\t"
    655 	    "-P precision bits (4, 8, 16, 24 or 32)\n\t"
    656 	    "-p input port\n\t"
    657 	    "-s sample rate\n\t"
    658 	    "-t recording time\n\t"
    659 	    "-v volume\n");
    660 	exit(EXIT_FAILURE);
    661 }
    662