1 /*
2  * SUN audio output driver
3  *
4  * This file is part of MPlayer.
5  *
6  * MPlayer is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * MPlayer is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <sys/ioctl.h>
29 #include <sys/time.h>
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #include <sys/audioio.h>
33 #ifdef	AUDIO_SWFEATURE_MIXER	/* solaris8 or newer? */
34 # define HAVE_SYS_MIXER_H 1
35 #endif
36 #if	HAVE_SYS_MIXER_H
37 # include <sys/mixer.h>
38 #endif
39 #ifdef	__svr4__
40 #include <stropts.h>
41 #endif
42 
43 #include "config.h"
44 #include "mixer.h"
45 
46 #include "audio_out.h"
47 #include "audio_out_internal.h"
48 #include "libaf/af_format.h"
49 #include "mp_msg.h"
50 #include "help_mp.h"
51 
52 static const ao_info_t info =
53 {
54     "Sun audio output",
55     "sun",
56     "Juergen Keil",
57     ""
58 };
59 
60 LIBAO_EXTERN(sun)
61 
62 
63 /* These defines are missing on NetBSD */
64 #ifndef	AUDIO_PRECISION_8
65 #define AUDIO_PRECISION_8	8
66 #define AUDIO_PRECISION_16	16
67 #endif
68 #ifndef	AUDIO_CHANNELS_MONO
69 #define	AUDIO_CHANNELS_MONO	1
70 #define	AUDIO_CHANNELS_STEREO	2
71 #endif
72 
73 
74 static char *sun_mixer_device = NULL;
75 static char *audio_dev = NULL;
76 static int queued_bursts = 0;
77 static int queued_samples = 0;
78 static int bytes_per_sample = 0;
79 static int byte_per_sec = 0;
80 static int audio_fd = -1;
81 static enum {
82     RTSC_UNKNOWN = 0,
83     RTSC_ENABLED,
84     RTSC_DISABLED
85 } enable_sample_timing;
86 
87 
flush_audio(int fd)88 static void flush_audio(int fd) {
89 #ifdef AUDIO_FLUSH
90   ioctl(fd, AUDIO_FLUSH, 0);
91 #elif defined(__svr4__)
92   ioctl(fd, I_FLUSH, FLUSHW);
93 #endif
94 }
95 
96 // convert an OSS audio format specification into a sun audio encoding
af2sunfmt(int format)97 static int af2sunfmt(int format)
98 {
99     switch (format){
100     case AF_FORMAT_MU_LAW:
101 	return AUDIO_ENCODING_ULAW;
102     case AF_FORMAT_A_LAW:
103 	return AUDIO_ENCODING_ALAW;
104     case AF_FORMAT_S16_NE:
105 	return AUDIO_ENCODING_LINEAR;
106 #ifdef	AUDIO_ENCODING_LINEAR8	// Missing on SunOS 5.5.1...
107     case AF_FORMAT_U8:
108 	return AUDIO_ENCODING_LINEAR8;
109 #endif
110     case AF_FORMAT_S8:
111 	return AUDIO_ENCODING_LINEAR;
112 #ifdef	AUDIO_ENCODING_DVI	// Missing on NetBSD...
113     case AF_FORMAT_IMA_ADPCM:
114 	return AUDIO_ENCODING_DVI;
115 #endif
116     default:
117 	return AUDIO_ENCODING_NONE;
118   }
119 }
120 
121 // try to figure out, if the soundcard driver provides usable (precise)
122 // sample counter information
realtime_samplecounter_available(char * dev)123 static int realtime_samplecounter_available(char *dev)
124 {
125     int fd = -1;
126     audio_info_t info;
127     int rtsc_ok = RTSC_DISABLED;
128     int len;
129     void *silence = NULL;
130     struct timeval start, end;
131     struct timespec delay;
132     int usec_delay;
133     unsigned last_samplecnt;
134     unsigned increment;
135     unsigned min_increment;
136 
137     len = 44100 * 4 / 4;    /* amount of data for 0.25sec of 44.1khz, stereo,
138 			     * 16bit.  44kbyte can be sent to all supported
139 			     * sun audio devices without blocking in the
140 			     * "write" below.
141 			     */
142     silence = calloc(1, len);
143     if (silence == NULL)
144 	goto error;
145 
146     if ((fd = open(dev, O_WRONLY)) < 0)
147 	goto error;
148 
149     AUDIO_INITINFO(&info);
150     info.play.sample_rate = 44100;
151     info.play.channels = AUDIO_CHANNELS_STEREO;
152     info.play.precision = AUDIO_PRECISION_16;
153     info.play.encoding = AUDIO_ENCODING_LINEAR;
154     info.play.samples = 0;
155     if (ioctl(fd, AUDIO_SETINFO, &info)) {
156         mp_msg(MSGT_AO, MSGL_ERR, MSGTR_AO_SUN_RtscSetinfoFailed);
157 	goto error;
158     }
159 
160     if (write(fd, silence, len) != len) {
161         mp_msg(MSGT_AO, MSGL_ERR, MSGTR_AO_SUN_RtscWriteFailed);
162 	goto error;
163     }
164 
165     if (ioctl(fd, AUDIO_GETINFO, &info)) {
166         perror("rtsc: GETINFO1");
167 	goto error;
168     }
169 
170     last_samplecnt = info.play.samples;
171     min_increment = ~0;
172 
173     gettimeofday(&start, NULL);
174     for (;;) {
175 	delay.tv_sec = 0;
176 	delay.tv_nsec = 10000000;
177 	nanosleep(&delay, NULL);
178 	gettimeofday(&end, NULL);
179 	usec_delay = (end.tv_sec - start.tv_sec) * 1000000
180 	    + end.tv_usec - start.tv_usec;
181 
182 	// stop monitoring sample counter after 0.2 seconds
183 	if (usec_delay > 200000)
184 	    break;
185 
186 	if (ioctl(fd, AUDIO_GETINFO, &info)) {
187             perror("rtsc: GETINFO2 failed");
188 	    goto error;
189 	}
190 	if (info.play.samples < last_samplecnt) {
191             mp_msg(MSGT_AO, MSGL_ERR, "rtsc: %d > %d?\n", last_samplecnt, info.play.samples);
192 	    goto error;
193 	}
194 
195 	if ((increment = info.play.samples - last_samplecnt) > 0) {
196 	    if ( mp_msg_test(MSGT_AO,MSGL_V) )
197 	        mp_msg(MSGT_AO,MSGL_V,"ao_sun: sample counter increment: %d\n", increment);
198 	    if (increment < min_increment) {
199 		min_increment = increment;
200 		if (min_increment < 2000)
201 		    break;	// looks good
202 	    }
203 	}
204 	last_samplecnt = info.play.samples;
205     }
206 
207     /*
208      * For 44.1kkz, stereo, 16-bit format we would send sound data in 16kbytes
209      * chunks (== 4096 samples) to the audio device.  If we see a minimum
210      * sample counter increment from the soundcard driver of less than
211      * 2000 samples,  we assume that the driver provides a useable realtime
212      * sample counter in the AUDIO_INFO play.samples field.  Timing based
213      * on sample counts should be much more accurate than counting whole
214      * 16kbyte chunks.
215      */
216     if (min_increment < 2000)
217 	rtsc_ok = RTSC_ENABLED;
218 
219     if ( mp_msg_test(MSGT_AO,MSGL_V) )
220 	mp_msg(MSGT_AO,MSGL_V,"ao_sun: minimum sample counter increment per 10msec interval: %d\n"
221 	       "\t%susing sample counter based timing code\n",
222 	       min_increment, rtsc_ok == RTSC_ENABLED ? "" : "not ");
223 
224 
225 error:
226     free(silence);
227     if (fd >= 0) {
228 	// remove the 0 bytes from the above measurement from the
229 	// audio driver's STREAMS queue
230         flush_audio(fd);
231 	close(fd);
232     }
233 
234     return rtsc_ok;
235 }
236 
237 
238 // match the requested sample rate |sample_rate| against the
239 // sample rates supported by the audio device |dev|.  Return
240 // a supported sample rate,  if that sample rate is close to
241 // (< 1% difference) the requested rate; return 0 otherwise.
242 
243 #define	MAX_RATE_ERR	1
244 
245 static unsigned
find_close_samplerate_match(int dev,unsigned sample_rate)246 find_close_samplerate_match(int dev, unsigned sample_rate)
247 {
248 #if	HAVE_SYS_MIXER_H
249     am_sample_rates_t *sr;
250     unsigned i, num, err, best_err, best_rate;
251 
252     for (num = 16; num < 1024; num *= 2) {
253 	sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
254 	if (!sr)
255 	    return 0;
256 	sr->type = AUDIO_PLAY;
257 	sr->flags = 0;
258 	sr->num_samp_rates = num;
259 	if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
260 	    free(sr);
261 	    return 0;
262 	}
263 	if (sr->num_samp_rates <= num)
264 	    break;
265 	free(sr);
266     }
267 
268     if (sr->flags & MIXER_SR_LIMITS) {
269 	/*
270 	 * HW can playback any rate between
271 	 * sr->samp_rates[0] .. sr->samp_rates[1]
272 	 */
273 	free(sr);
274 	return 0;
275     } else {
276 	/* HW supports fixed sample rates only */
277 
278 	best_err = 65535;
279 	best_rate = 0;
280 
281 	for (i = 0; i < sr->num_samp_rates; i++) {
282 	    err = abs(sr->samp_rates[i] - sample_rate);
283 	    if (err == 0) {
284 		/*
285 		 * exact supported sample rate match, no need to
286 		 * retry something else
287 		 */
288 		best_rate = 0;
289 		break;
290 	    }
291 	    if (err < best_err) {
292 		best_err = err;
293 		best_rate = sr->samp_rates[i];
294 	    }
295 	}
296 
297 	free(sr);
298 
299 	if (best_rate > 0 && (100/MAX_RATE_ERR)*best_err < sample_rate) {
300 	    /* found a supported sample rate with <1% error? */
301 	    return best_rate;
302 	}
303 	return 0;
304     }
305 #else	/* old audioio driver, cannot return list of supported rates */
306     /* XXX: hardcoded sample rates */
307     unsigned i, err;
308     unsigned audiocs_rates[] = {
309 	5510, 6620, 8000, 9600, 11025, 16000, 18900, 22050,
310 	27420, 32000, 33075, 37800, 44100, 48000, 0
311     };
312 
313     for (i = 0; audiocs_rates[i]; i++) {
314 	err = abs(audiocs_rates[i] - sample_rate);
315 	if (err == 0) {
316 	    /*
317 	     * exact supported sample rate match, no need to
318 	     * retry something elise
319 	     */
320 	    return 0;
321 	}
322 	if ((100/MAX_RATE_ERR)*err < audiocs_rates[i]) {
323 	    /* <1% error? */
324 	    return audiocs_rates[i];
325 	}
326     }
327 
328     return 0;
329 #endif
330 }
331 
332 
333 // return the highest sample rate supported by audio device |dev|.
334 static unsigned
find_highest_samplerate(int dev)335 find_highest_samplerate(int dev)
336 {
337 #if	HAVE_SYS_MIXER_H
338     am_sample_rates_t *sr;
339     unsigned i, num, max_rate;
340 
341     for (num = 16; num < 1024; num *= 2) {
342 	sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
343 	if (!sr)
344 	    return 0;
345 	sr->type = AUDIO_PLAY;
346 	sr->flags = 0;
347 	sr->num_samp_rates = num;
348 	if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
349 	    free(sr);
350 	    return 0;
351 	}
352 	if (sr->num_samp_rates <= num)
353 	    break;
354 	free(sr);
355     }
356 
357     if (sr->flags & MIXER_SR_LIMITS) {
358 	/*
359 	 * HW can playback any rate between
360 	 * sr->samp_rates[0] .. sr->samp_rates[1]
361 	 */
362 	max_rate = sr->samp_rates[1];
363     } else {
364 	/* HW supports fixed sample rates only */
365 	max_rate = 0;
366 	for (i = 0; i < sr->num_samp_rates; i++) {
367 	    if (sr->samp_rates[i] > max_rate)
368 		max_rate = sr->samp_rates[i];
369 	}
370     }
371     free(sr);
372     return max_rate;
373 
374 #else	/* old audioio driver, cannot return list of supported rates */
375     return 44100;	/* should be supported even on old ISA SB cards */
376 #endif
377 }
378 
379 
setup_device_paths(void)380 static void setup_device_paths(void)
381 {
382     if (audio_dev == NULL) {
383 	if ((audio_dev = getenv("AUDIODEV")) == NULL)
384 	    audio_dev = "/dev/audio";
385     }
386 
387     if (sun_mixer_device == NULL) {
388 	if ((sun_mixer_device = mixer_device) == NULL || !sun_mixer_device[0]) {
389 	    sun_mixer_device = malloc(strlen(audio_dev) + 4);
390 	    strcpy(sun_mixer_device, audio_dev);
391 	    strcat(sun_mixer_device, "ctl");
392 	}
393     }
394 
395     if (ao_subdevice) audio_dev = ao_subdevice;
396 }
397 
398 // to set/get/query special features/parameters
control(int cmd,void * arg)399 static int control(int cmd,void *arg){
400     switch(cmd){
401     case AOCONTROL_SET_DEVICE:
402 	audio_dev=(char*)arg;
403 	return CONTROL_OK;
404     case AOCONTROL_QUERY_FORMAT:
405 	return CONTROL_TRUE;
406     case AOCONTROL_GET_VOLUME:
407     {
408         int fd;
409 
410 	if ( !sun_mixer_device )    /* control function is used before init? */
411 	    setup_device_paths();
412 
413 	fd=open( sun_mixer_device,O_RDONLY );
414 	if ( fd != -1 )
415 	{
416 	    ao_control_vol_t *vol = (ao_control_vol_t *)arg;
417 	    float volume;
418 	    struct audio_info info;
419 	    ioctl( fd,AUDIO_GETINFO,&info);
420 	    volume = info.play.gain * 100. / AUDIO_MAX_GAIN;
421 	    if ( info.play.balance == AUDIO_MID_BALANCE ) {
422 		vol->right = vol->left = volume;
423 	    } else if ( info.play.balance < AUDIO_MID_BALANCE ) {
424 		vol->left  = volume;
425 		vol->right = volume * info.play.balance / AUDIO_MID_BALANCE;
426 	    } else {
427 		vol->left  = volume * (AUDIO_RIGHT_BALANCE-info.play.balance)
428 							/ AUDIO_MID_BALANCE;
429 		vol->right = volume;
430 	    }
431 	    close( fd );
432 	    return CONTROL_OK;
433 	}
434 	return CONTROL_ERROR;
435     }
436     case AOCONTROL_SET_VOLUME:
437     {
438 	ao_control_vol_t *vol = (ao_control_vol_t *)arg;
439         int fd;
440 
441 	if ( !sun_mixer_device )    /* control function is used before init? */
442 	    setup_device_paths();
443 
444 	fd=open( sun_mixer_device,O_RDONLY );
445 	if ( fd != -1 )
446 	{
447 	    struct audio_info info;
448 	    float volume;
449 	    AUDIO_INITINFO(&info);
450 	    volume = vol->right > vol->left ? vol->right : vol->left;
451 	    if ( volume != 0 ) {
452 		info.play.gain = volume * AUDIO_MAX_GAIN / 100;
453 		if ( vol->right == vol->left )
454 		    info.play.balance = AUDIO_MID_BALANCE;
455 		else
456 		    info.play.balance = (vol->right - vol->left + volume) * AUDIO_RIGHT_BALANCE / (2*volume);
457 	    }
458 #if !defined (__OpenBSD__) && !defined (__NetBSD__)
459 	    info.output_muted = (volume == 0);
460 #endif
461 	    ioctl( fd,AUDIO_SETINFO,&info );
462 	    close( fd );
463 	    return CONTROL_OK;
464 	}
465 	return CONTROL_ERROR;
466     }
467     }
468     return CONTROL_UNKNOWN;
469 }
470 
471 // open & setup audio device
472 // return: 1=success 0=fail
init(int rate,int channels,int format,int flags)473 static int init(int rate,int channels,int format,int flags){
474 
475     audio_info_t info;
476     int pass;
477     int ok;
478     int convert_u8_s8;
479 
480     setup_device_paths();
481 
482     if (enable_sample_timing == RTSC_UNKNOWN
483 	&& !getenv("AO_SUN_DISABLE_SAMPLE_TIMING")) {
484 	enable_sample_timing = realtime_samplecounter_available(audio_dev);
485     }
486 
487     mp_msg(MSGT_AO,MSGL_STATUS,"ao2: %d Hz  %d chans  %s [0x%X]\n",
488 	   rate,channels,af_fmt2str_short(format),format);
489 
490     audio_fd=open(audio_dev, O_WRONLY);
491     if(audio_fd<0){
492 	mp_msg(MSGT_AO, MSGL_ERR, MSGTR_AO_SUN_CantOpenAudioDev, audio_dev, strerror(errno));
493 	return 0;
494     }
495 
496     if (af2sunfmt(format) == AUDIO_ENCODING_NONE)
497       format = AF_FORMAT_S16_NE;
498 
499     for (ok = pass = 0; pass <= 5; pass++) { /* pass 6&7 not useful */
500 
501 	AUDIO_INITINFO(&info);
502 	info.play.encoding = af2sunfmt(ao_data.format = format);
503 	info.play.precision =
504 	    (format==AF_FORMAT_S16_NE
505 	     ? AUDIO_PRECISION_16
506 	     : AUDIO_PRECISION_8);
507 	info.play.channels = ao_data.channels = channels;
508 	info.play.sample_rate = ao_data.samplerate = rate;
509 
510 	convert_u8_s8 = 0;
511 
512 	if (pass & 1) {
513 	    /*
514 	     * on some sun audio drivers, 8-bit unsigned LINEAR8 encoding is
515 	     * not supported, but 8-bit signed encoding is.
516 	     *
517 	     * Try S8, and if it works, use our own U8->S8 conversion before
518 	     * sending the samples to the sound driver.
519 	     */
520 #ifdef AUDIO_ENCODING_LINEAR8
521 	    if (info.play.encoding != AUDIO_ENCODING_LINEAR8)
522 #endif
523 		continue;
524 	    info.play.encoding = AUDIO_ENCODING_LINEAR;
525 	    convert_u8_s8 = 1;
526 	}
527 
528 	if (pass & 2) {
529 	    /*
530 	     * on some sun audio drivers, only certain fixed sample rates are
531 	     * supported.
532 	     *
533 	     * In case the requested sample rate is very close to one of the
534 	     * supported rates,  use the fixed supported rate instead.
535 	     */
536 	    if (!(info.play.sample_rate =
537 		  find_close_samplerate_match(audio_fd, rate)))
538 	      continue;
539 
540 	    /*
541 	     * I'm not returning the correct sample rate in
542 	     * |ao_data.samplerate|, to avoid software resampling.
543 	     *
544 	     * ao_data.samplerate = info.play.sample_rate;
545 	     */
546 	}
547 
548 	if (pass & 4) {
549 	    /* like "pass & 2", but use the highest supported sample rate */
550 	    if (!(info.play.sample_rate
551 		  = ao_data.samplerate
552 		  = find_highest_samplerate(audio_fd)))
553 		continue;
554 	}
555 
556 	ok = ioctl(audio_fd, AUDIO_SETINFO, &info) >= 0;
557 	if (ok) {
558 	    /* audio format accepted by audio driver */
559 	    break;
560 	}
561 
562 	/*
563 	 * format not supported?
564 	 * retry with different encoding and/or sample rate
565 	 */
566     }
567 
568     if (!ok) {
569 	char buf[128];
570 	mp_msg(MSGT_AO, MSGL_ERR, MSGTR_AO_SUN_UnsupSampleRate,
571 	       channels, af_fmt2str(format, buf, 128), rate);
572 	return 0;
573     }
574 
575     if (convert_u8_s8)
576       ao_data.format = AF_FORMAT_S8;
577 
578     bytes_per_sample = channels * info.play.precision / 8;
579     ao_data.bps = byte_per_sec = bytes_per_sample * ao_data.samplerate;
580     ao_data.outburst = byte_per_sec > 100000 ? 16384 : 8192;
581 
582     reset();
583 
584     return 1;
585 }
586 
587 // close audio device
uninit(int immed)588 static void uninit(int immed){
589     // throw away buffered data in the audio driver's STREAMS queue
590     if (immed)
591 	flush_audio(audio_fd);
592     else
593 	ioctl(audio_fd, AUDIO_DRAIN, 0);
594     close(audio_fd);
595 }
596 
597 // stop playing and empty buffers (for seeking/pause)
reset(void)598 static void reset(void){
599     audio_info_t info;
600     flush_audio(audio_fd);
601 
602     AUDIO_INITINFO(&info);
603     info.play.samples = 0;
604     info.play.eof = 0;
605     info.play.error = 0;
606     ioctl(audio_fd, AUDIO_SETINFO, &info);
607 
608     queued_bursts = 0;
609     queued_samples = 0;
610 }
611 
612 // stop playing, keep buffers (for pause)
audio_pause(void)613 static void audio_pause(void)
614 {
615     struct audio_info info;
616     AUDIO_INITINFO(&info);
617     info.play.pause = 1;
618     ioctl(audio_fd, AUDIO_SETINFO, &info);
619 }
620 
621 // resume playing, after audio_pause()
audio_resume(void)622 static void audio_resume(void)
623 {
624     struct audio_info info;
625     AUDIO_INITINFO(&info);
626     info.play.pause = 0;
627     ioctl(audio_fd, AUDIO_SETINFO, &info);
628 }
629 
630 
631 // return: how many bytes can be played without blocking
get_space(void)632 static int get_space(void){
633     audio_info_t info;
634 
635     // check buffer
636 #ifdef HAVE_AUDIO_SELECT
637     {
638 	fd_set rfds;
639 	struct timeval tv;
640 	FD_ZERO(&rfds);
641 	FD_SET(audio_fd, &rfds);
642 	tv.tv_sec = 0;
643 	tv.tv_usec = 0;
644 	if(!select(audio_fd+1, NULL, &rfds, NULL, &tv)) return 0; // not block!
645     }
646 #endif
647 
648     ioctl(audio_fd, AUDIO_GETINFO, &info);
649 #if !defined (__OpenBSD__) && !defined(__NetBSD__)
650     if (queued_bursts - info.play.eof > 2)
651 	return 0;
652     return ao_data.outburst;
653 #else
654     return info.hiwat * info.blocksize - info.play.seek;
655 #endif
656 
657 }
658 
659 // plays 'len' bytes of 'data'
660 // it should round it down to outburst*n
661 // return: number of bytes played
play(void * data,int len,int flags)662 static int play(void* data,int len,int flags){
663     if (!(flags & AOPLAY_FINAL_CHUNK)) {
664 	len /= ao_data.outburst;
665 	len *= ao_data.outburst;
666     }
667     if (len <= 0) return 0;
668 
669     len = write(audio_fd, data, len);
670     if(len > 0) {
671 	queued_samples += len / bytes_per_sample;
672 	if (write(audio_fd,data,0) < 0)
673 	    perror("ao_sun: send EOF audio record");
674 	else
675 	    queued_bursts ++;
676     }
677     return len;
678 }
679 
680 
681 // return: delay in seconds between first and last sample in buffer
get_delay(void)682 static float get_delay(void){
683     audio_info_t info;
684     ioctl(audio_fd, AUDIO_GETINFO, &info);
685 #if defined (__OpenBSD__) || defined(__NetBSD__)
686     return (float) info.play.seek/ (float)byte_per_sec ;
687 #else
688     if (info.play.samples && enable_sample_timing == RTSC_ENABLED)
689 	return (float)(queued_samples - info.play.samples) / (float)ao_data.samplerate;
690     else
691 	return (float)((queued_bursts - info.play.eof) * ao_data.outburst) / (float)byte_per_sec;
692 #endif
693 }
694