summaryrefslogtreecommitdiff
path: root/pjmedia/src/pjmedia/wav_player.c
blob: 1e9a92ca5dad34db79d5e3d0e55b088a1f0d3dac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
/* $Id$ */
/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#include <pjmedia/wav_port.h>
#include <pjmedia/alaw_ulaw.h>
#include <pjmedia/errno.h>
#include <pjmedia/wave.h>
#include <pj/assert.h>
#include <pj/file_access.h>
#include <pj/file_io.h>
#include <pj/log.h>
#include <pj/pool.h>
#include <pj/string.h>


#define THIS_FILE   "wav_player.c"


#define SIGNATURE	    PJMEDIA_SIG_PORT_WAV_PLAYER
#define BITS_PER_SAMPLE	    16

#if 1
#   define TRACE_(x)	PJ_LOG(4,x)
#else
#   define TRACE_(x)
#endif

#if defined(PJ_IS_BIG_ENDIAN) && PJ_IS_BIG_ENDIAN!=0
    static void samples_to_host(pj_int16_t *samples, unsigned count)
    {
	unsigned i;
	for (i=0; i<count; ++i) {
	    samples[i] = pj_swap16(samples[i]);
	}
    }
#else
#   define samples_to_host(samples,count)
#endif

struct file_reader_port
{
    pjmedia_port     base;
    unsigned	     options;
    pjmedia_wave_fmt_tag fmt_tag;
    pj_uint16_t	     bytes_per_sample;
    pj_bool_t	     eof;
    pj_uint32_t	     bufsize;
    char	    *buf;
    char	    *readpos;
    char	    *eofpos;

    pj_off_t	     fsize;
    unsigned	     start_data;
    unsigned         data_len;
    unsigned         data_left;
    pj_off_t	     fpos;
    pj_oshandle_t    fd;

    pj_status_t	   (*cb)(pjmedia_port*, void*);
};


static pj_status_t file_get_frame(pjmedia_port *this_port, 
				  pjmedia_frame *frame);
static pj_status_t file_on_destroy(pjmedia_port *this_port);

static struct file_reader_port *create_file_port(pj_pool_t *pool)
{
    const pj_str_t name = pj_str("file");
    struct file_reader_port *port;

    port = PJ_POOL_ZALLOC_T(pool, struct file_reader_port);
    if (!port)
	return NULL;

    /* Put in default values.
     * These will be overriden once the file is read.
     */
    pjmedia_port_info_init(&port->base.info, &name, SIGNATURE, 
			   8000, 1, 16, 80);

    port->base.get_frame = &file_get_frame;
    port->base.on_destroy = &file_on_destroy;


    return port;
}

/*
 * Fill buffer.
 */
static pj_status_t fill_buffer(struct file_reader_port *fport)
{
    pj_uint32_t size_left = fport->bufsize;
    unsigned size_to_read;
    pj_ssize_t size;
    pj_status_t status;

    fport->eofpos = NULL;
    
    while (size_left > 0) {

	/* Calculate how many bytes to read in this run. */
	size = size_to_read = size_left;
	status = pj_file_read(fport->fd, 
			      &fport->buf[fport->bufsize-size_left], 
			      &size);
	if (status != PJ_SUCCESS)
	    return status;
	if (size < 0) {
	    /* Should return more appropriate error code here.. */
	    return PJ_ECANCELLED;
	}

        if (size > (pj_ssize_t)fport->data_left) {
            /* We passed the end of the data chunk,
             * only count the portion read from the data chunk.
             */
            size = (pj_ssize_t)fport->data_left;
        }

	size_left -= (pj_uint32_t)size;
        fport->data_left -= (pj_uint32_t)size;
	fport->fpos += size;

	/* If size is less than size_to_read, it indicates that we've
	 * encountered EOF. Rewind the file.
	 */
        if (size < (pj_ssize_t)size_to_read) {
            fport->eof = PJ_TRUE;
            fport->eofpos = fport->buf + fport->bufsize - size_left;

            if (fport->options & PJMEDIA_FILE_NO_LOOP) {
                /* Zero remaining buffer */
                if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_PCM) {
                    pj_bzero(fport->eofpos, size_left);
                } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW) {
                    int val = pjmedia_linear2ulaw(0);
                    pj_memset(fport->eofpos, val, size_left);
                } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ALAW) {
                    int val = pjmedia_linear2alaw(0);
                    pj_memset(fport->eofpos, val, size_left);
                }
		size_left = 0;
            }

	    /* Rewind file */
	    fport->fpos = fport->start_data;
	    pj_file_setpos( fport->fd, fport->fpos, PJ_SEEK_SET);
            fport->data_left = fport->data_len;
	}
    }

    /* Convert samples to host rep */
    samples_to_host((pj_int16_t*)fport->buf, 
		    fport->bufsize/fport->bytes_per_sample);

    return PJ_SUCCESS;
}


/*
 * Create WAVE player port.
 */
PJ_DEF(pj_status_t) pjmedia_wav_player_port_create( pj_pool_t *pool,
						     const char *filename,
						     unsigned ptime,
						     unsigned options,
						     pj_ssize_t buff_size,
						     pjmedia_port **p_port )
{
    pjmedia_wave_hdr wave_hdr;
    pj_ssize_t size_to_read, size_read;
    struct file_reader_port *fport;
    pjmedia_audio_format_detail *ad;
    pj_off_t pos;
    pj_str_t name;
    unsigned samples_per_frame;
    pj_status_t status = PJ_SUCCESS;


    /* Check arguments. */
    PJ_ASSERT_RETURN(pool && filename && p_port, PJ_EINVAL);

    /* Check the file really exists. */
    if (!pj_file_exists(filename)) {
	return PJ_ENOTFOUND;
    }

    /* Normalize ptime */
    if (ptime == 0)
	ptime = 20;

    /* Normalize buff_size */
    if (buff_size < 1) buff_size = PJMEDIA_FILE_PORT_BUFSIZE;


    /* Create fport instance. */
    fport = create_file_port(pool);
    if (!fport) {
	return PJ_ENOMEM;
    }


    /* Get the file size. */
    fport->fsize = pj_file_size(filename);

    /* Size must be more than WAVE header size */
    if (fport->fsize <= sizeof(pjmedia_wave_hdr)) {
	return PJMEDIA_ENOTVALIDWAVE;
    }

    /* Open file. */
    status = pj_file_open( pool, filename, PJ_O_RDONLY, &fport->fd);
    if (status != PJ_SUCCESS)
	return status;

    /* Read the file header plus fmt header only. */
    size_read = size_to_read = sizeof(wave_hdr) - 8;
    status = pj_file_read( fport->fd, &wave_hdr, &size_read);
    if (status != PJ_SUCCESS) {
	pj_file_close(fport->fd);
	return status;
    }
    if (size_read != size_to_read) {
	pj_file_close(fport->fd);
	return PJMEDIA_ENOTVALIDWAVE;
    }

    /* Normalize WAVE header fields values from little-endian to host
     * byte order.
     */
    pjmedia_wave_hdr_file_to_host(&wave_hdr);
    
    /* Validate WAVE file. */
    if (wave_hdr.riff_hdr.riff != PJMEDIA_RIFF_TAG ||
	wave_hdr.riff_hdr.wave != PJMEDIA_WAVE_TAG ||
	wave_hdr.fmt_hdr.fmt != PJMEDIA_FMT_TAG)
    {
	pj_file_close(fport->fd);
	TRACE_((THIS_FILE, 
		"actual value|expected riff=%x|%x, wave=%x|%x fmt=%x|%x",
		wave_hdr.riff_hdr.riff, PJMEDIA_RIFF_TAG,
		wave_hdr.riff_hdr.wave, PJMEDIA_WAVE_TAG,
		wave_hdr.fmt_hdr.fmt, PJMEDIA_FMT_TAG));
	return PJMEDIA_ENOTVALIDWAVE;
    }

    /* Validate format and its attributes (i.e: bits per sample, block align) */
    switch (wave_hdr.fmt_hdr.fmt_tag) {
    case PJMEDIA_WAVE_FMT_TAG_PCM:
	if (wave_hdr.fmt_hdr.bits_per_sample != 16 || 
	    wave_hdr.fmt_hdr.block_align != 2 * wave_hdr.fmt_hdr.nchan)
	    status = PJMEDIA_EWAVEUNSUPP;
	break;

    case PJMEDIA_WAVE_FMT_TAG_ALAW:
    case PJMEDIA_WAVE_FMT_TAG_ULAW:
	if (wave_hdr.fmt_hdr.bits_per_sample != 8 ||
	    wave_hdr.fmt_hdr.block_align != wave_hdr.fmt_hdr.nchan)
	    status = PJMEDIA_ENOTVALIDWAVE;
	break;

    default:
	status = PJMEDIA_EWAVEUNSUPP;
	break;
    }

    if (status != PJ_SUCCESS) {
	pj_file_close(fport->fd);
	return status;
    }

    fport->fmt_tag = (pjmedia_wave_fmt_tag)wave_hdr.fmt_hdr.fmt_tag;
    fport->bytes_per_sample = (pj_uint16_t) 
			      (wave_hdr.fmt_hdr.bits_per_sample / 8);

    /* If length of fmt_header is greater than 16, skip the remaining
     * fmt header data.
     */
    if (wave_hdr.fmt_hdr.len > 16) {
	size_to_read = wave_hdr.fmt_hdr.len - 16;
	status = pj_file_setpos(fport->fd, size_to_read, PJ_SEEK_CUR);
	if (status != PJ_SUCCESS) {
	    pj_file_close(fport->fd);
	    return status;
	}
    }

    /* Repeat reading the WAVE file until we have 'data' chunk */
    for (;;) {
	pjmedia_wave_subchunk subchunk;
	size_read = 8;
	status = pj_file_read(fport->fd, &subchunk, &size_read);
	if (status != PJ_SUCCESS || size_read != 8) {
	    pj_file_close(fport->fd);
	    return PJMEDIA_EWAVETOOSHORT;
	}

	/* Normalize endianness */
	PJMEDIA_WAVE_NORMALIZE_SUBCHUNK(&subchunk);

	/* Break if this is "data" chunk */
	if (subchunk.id == PJMEDIA_DATA_TAG) {
	    wave_hdr.data_hdr.data = PJMEDIA_DATA_TAG;
	    wave_hdr.data_hdr.len = subchunk.len;
	    break;
	}

	/* Otherwise skip the chunk contents */
	size_to_read = subchunk.len;
	status = pj_file_setpos(fport->fd, size_to_read, PJ_SEEK_CUR);
	if (status != PJ_SUCCESS) {
	    pj_file_close(fport->fd);
	    return status;
	}
    }

    /* Current file position now points to start of data */
    status = pj_file_getpos(fport->fd, &pos);
    fport->start_data = (unsigned)pos;
    fport->data_len = wave_hdr.data_hdr.len;
    fport->data_left = wave_hdr.data_hdr.len;

    /* Validate length. */
    if (wave_hdr.data_hdr.len > fport->fsize - fport->start_data) {
	pj_file_close(fport->fd);
	return PJMEDIA_EWAVEUNSUPP;
    }
    if (wave_hdr.data_hdr.len < ptime * wave_hdr.fmt_hdr.sample_rate *
				wave_hdr.fmt_hdr.nchan / 1000)
    {
	pj_file_close(fport->fd);
	return PJMEDIA_EWAVETOOSHORT;
    }

    /* It seems like we have a valid WAVE file. */

    /* Initialize */
    fport->options = options;

    /* Update port info. */
    ad = pjmedia_format_get_audio_format_detail(&fport->base.info.fmt, 1);
    pj_strdup2(pool, &name, filename);
    samples_per_frame = ptime * wave_hdr.fmt_hdr.sample_rate *
		        wave_hdr.fmt_hdr.nchan / 1000;
    pjmedia_port_info_init(&fport->base.info, &name, SIGNATURE,
			   wave_hdr.fmt_hdr.sample_rate,
			   wave_hdr.fmt_hdr.nchan,
			   BITS_PER_SAMPLE,
			   samples_per_frame);

    /* If file is shorter than buffer size, adjust buffer size to file
     * size. Otherwise EOF callback will be called multiple times when
     * fill_buffer() is called.
     */
    if (wave_hdr.data_hdr.len < (unsigned)buff_size)
	buff_size = wave_hdr.data_hdr.len;

    /* Create file buffer.
     */
    fport->bufsize = (pj_uint32_t)buff_size;


    /* samples_per_frame must be smaller than bufsize (because get_frame()
     * doesn't handle this case).
     */
    if (samples_per_frame * fport->bytes_per_sample >= fport->bufsize) {
	pj_file_close(fport->fd);
	return PJ_EINVAL;
    }

    /* Create buffer. */
    fport->buf = (char*) pj_pool_alloc(pool, fport->bufsize);
    if (!fport->buf) {
	pj_file_close(fport->fd);
	return PJ_ENOMEM;
    }
 
    fport->readpos = fport->buf;

    /* Set initial position of the file. */
    fport->fpos = fport->start_data;

    /* Fill up the buffer. */
    status = fill_buffer(fport);
    if (status != PJ_SUCCESS) {
	pj_file_close(fport->fd);
	return status;
    }

    /* Done. */

    *p_port = &fport->base;


    PJ_LOG(4,(THIS_FILE, 
	      "File player '%.*s' created: samp.rate=%d, ch=%d, bufsize=%uKB, "
	      "filesize=%luKB",
	      (int)fport->base.info.name.slen,
	      fport->base.info.name.ptr,
	      ad->clock_rate,
	      ad->channel_count,
	      fport->bufsize / 1000,
	      (unsigned long)(fport->fsize / 1000)));

    return PJ_SUCCESS;
}


/*
 * Get additional info about the file player.
 */
PJ_DEF(pj_status_t) pjmedia_wav_player_get_info(
					pjmedia_port *port,
					pjmedia_wav_player_info *info)
{
    struct file_reader_port *fport;
    PJ_ASSERT_RETURN(port && info, PJ_EINVAL);

    pj_bzero(info, sizeof(*info));

    /* Check that this is really a player port */
    PJ_ASSERT_RETURN(port->info.signature == SIGNATURE, PJ_EINVALIDOP);

    fport = (struct file_reader_port*) port;

    if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_PCM) {
	info->fmt_id = PJMEDIA_FORMAT_PCM;
	info->payload_bits_per_sample = 16;
    } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW) {
	info->fmt_id = PJMEDIA_FORMAT_ULAW;
	info->payload_bits_per_sample = 8;
    } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ALAW) {
	info->fmt_id = PJMEDIA_FORMAT_ALAW;
	info->payload_bits_per_sample = 8;
    } else {
	pj_assert(!"Unsupported format");
	return PJ_ENOTSUP;
    }

    info->size_bytes = pjmedia_wav_player_get_len(port);
    info->size_samples = info->size_bytes /
			 (info->payload_bits_per_sample / 8);

    return PJ_SUCCESS;
}

/*
 * Get the data length, in bytes.
 */
PJ_DEF(pj_ssize_t) pjmedia_wav_player_get_len(pjmedia_port *port)
{
    struct file_reader_port *fport;
    pj_ssize_t size;

    /* Sanity check */
    PJ_ASSERT_RETURN(port, -PJ_EINVAL);

    /* Check that this is really a player port */
    PJ_ASSERT_RETURN(port->info.signature == SIGNATURE, -PJ_EINVALIDOP);

    fport = (struct file_reader_port*) port;

    size = (pj_ssize_t) fport->fsize;
    return size - fport->start_data;
}


/*
 * Set position.
 */
PJ_DEF(pj_status_t) pjmedia_wav_player_port_set_pos(pjmedia_port *port,
						    pj_uint32_t bytes )
{
    struct file_reader_port *fport;
    pj_status_t status;

    /* Sanity check */
    PJ_ASSERT_RETURN(port, PJ_EINVAL);

    /* Check that this is really a player port */
    PJ_ASSERT_RETURN(port->info.signature == SIGNATURE, PJ_EINVALIDOP);


    fport = (struct file_reader_port*) port;

    /* Check that this offset does not pass the audio-data (in case of
     * extra chunk after audio data chunk
     */
    PJ_ASSERT_RETURN(bytes < fport->data_len, PJ_EINVAL);

    fport->fpos = fport->start_data + bytes;
    fport->data_left = fport->data_len - bytes;
    pj_file_setpos( fport->fd, fport->fpos, PJ_SEEK_SET);

    fport->eof = PJ_FALSE;
    status = fill_buffer(fport);
    if (status != PJ_SUCCESS)
	return status;

    fport->readpos = fport->buf;

    return PJ_SUCCESS;
}


/*
 * Get the file play position of WAV player (in bytes).
 */
PJ_DEF(pj_ssize_t) pjmedia_wav_player_port_get_pos( pjmedia_port *port )
{
    struct file_reader_port *fport;
    pj_size_t payload_pos;

    /* Sanity check */
    PJ_ASSERT_RETURN(port, -PJ_EINVAL);

    /* Check that this is really a player port */
    PJ_ASSERT_RETURN(port->info.signature == SIGNATURE, -PJ_EINVALIDOP);

    fport = (struct file_reader_port*) port;

    payload_pos = (pj_size_t)(fport->fpos - fport->start_data);
    if (payload_pos >= fport->bufsize)
	return payload_pos - fport->bufsize + (fport->readpos - fport->buf);
    else
	return (fport->readpos - fport->buf) % payload_pos;
}



/*
 * Register a callback to be called when the file reading has reached the
 * end of file.
 */
PJ_DEF(pj_status_t) pjmedia_wav_player_set_eof_cb( pjmedia_port *port,
			       void *user_data,
			       pj_status_t (*cb)(pjmedia_port *port,
						 void *usr_data))
{
    struct file_reader_port *fport;

    /* Sanity check */
    PJ_ASSERT_RETURN(port, -PJ_EINVAL);

    /* Check that this is really a player port */
    PJ_ASSERT_RETURN(port->info.signature == SIGNATURE, -PJ_EINVALIDOP);

    fport = (struct file_reader_port*) port;

    fport->base.port_data.pdata = user_data;
    fport->cb = cb;

    return PJ_SUCCESS;
}


/*
 * Get frame from file.
 */
static pj_status_t file_get_frame(pjmedia_port *this_port, 
				  pjmedia_frame *frame)
{
    struct file_reader_port *fport = (struct file_reader_port*)this_port;
    pj_size_t frame_size;
    pj_status_t status;

    pj_assert(fport->base.info.signature == SIGNATURE);
    pj_assert(frame->size <= fport->bufsize);

    /* EOF is set and readpos already passed the eofpos */
    if (fport->eof && fport->readpos >= fport->eofpos) {
	pj_status_t status = PJ_SUCCESS;

	PJ_LOG(5,(THIS_FILE, "File port %.*s EOF",
		  (int)fport->base.info.name.slen,
		  fport->base.info.name.ptr));

	/* Call callback, if any */
	if (fport->cb)
	    status = (*fport->cb)(this_port, fport->base.port_data.pdata);

	/* If callback returns non PJ_SUCCESS or 'no loop' is specified,
	 * return immediately (and don't try to access player port since
	 * it might have been destroyed by the callback).
	 */
	if ((status != PJ_SUCCESS) || (fport->options & PJMEDIA_FILE_NO_LOOP)) {
	    frame->type = PJMEDIA_FRAME_TYPE_NONE;
	    frame->size = 0;
	    return PJ_EEOF;
	}
    	
	PJ_LOG(5,(THIS_FILE, "File port %.*s rewinding..",
		  (int)fport->base.info.name.slen,
		  fport->base.info.name.ptr));
	
	fport->eof = PJ_FALSE;
    }

    //pj_assert(frame->size == fport->base.info.bytes_per_frame);
    if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_PCM) {
	frame_size = frame->size;
	//frame->size = frame_size;
    } else {
	/* Must be ULAW or ALAW */
	pj_assert(fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW || 
		  fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ALAW);

	frame_size = frame->size >> 1;
	frame->size = frame_size << 1;
    }

    /* Copy frame from buffer. */
    frame->type = PJMEDIA_FRAME_TYPE_AUDIO;
    frame->timestamp.u64 = 0;

    if ((fport->readpos + frame_size) <= (fport->buf + fport->bufsize))
    {
	/* Read contiguous buffer. */
	pj_memcpy(frame->buf, fport->readpos, frame_size);

	/* Fill up the buffer if all has been read. */
	fport->readpos += frame_size;
	if (fport->readpos == fport->buf + fport->bufsize) {
	    fport->readpos = fport->buf;

	    status = fill_buffer(fport);
	    if (status != PJ_SUCCESS) {
		frame->type = PJMEDIA_FRAME_TYPE_NONE;
		frame->size = 0;
		fport->readpos = fport->buf + fport->bufsize;
		return status;
	    }
	}
    } else {
	unsigned endread;

	/* Split read.
	 * First stage: read until end of buffer. 
	 */
	endread = (unsigned)((fport->buf+fport->bufsize) - fport->readpos);
	pj_memcpy(frame->buf, fport->readpos, endread);

	/* End Of Buffer and EOF and NO LOOP */
	if (fport->eof && (fport->options & PJMEDIA_FILE_NO_LOOP)) {
	    fport->readpos += endread;

            if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_PCM) {
                pj_bzero((char*)frame->buf + endread, frame_size - endread);
            } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW) {
                int val = pjmedia_linear2ulaw(0);
                pj_memset((char*)frame->buf + endread, val,
                          frame_size - endread);
            } else if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ALAW) {
                int val = pjmedia_linear2alaw(0);
                pj_memset((char*)frame->buf + endread, val,
                          frame_size - endread);
            }

	    return PJ_SUCCESS;
	}

	/* Second stage: fill up buffer, and read from the start of buffer. */
	status = fill_buffer(fport);
	if (status != PJ_SUCCESS) {
	    frame->type = PJMEDIA_FRAME_TYPE_NONE;
	    frame->size = 0;
	    fport->readpos = fport->buf + fport->bufsize;
	    return status;
	}

	pj_memcpy(((char*)frame->buf)+endread, fport->buf, frame_size-endread);
	fport->readpos = fport->buf + (frame_size - endread);
    }

    if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW ||
	fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ALAW)
    {
	unsigned i;
	pj_uint16_t *dst;
	pj_uint8_t *src;

	dst = (pj_uint16_t*)frame->buf + frame_size - 1;
	src = (pj_uint8_t*)frame->buf + frame_size - 1;

	if (fport->fmt_tag == PJMEDIA_WAVE_FMT_TAG_ULAW) {
	    for (i = 0; i < frame_size; ++i) {
		*dst-- = (pj_uint16_t) pjmedia_ulaw2linear(*src--);
	    }
	} else {
	    for (i = 0; i < frame_size; ++i) {
		*dst-- = (pj_uint16_t) pjmedia_alaw2linear(*src--);
	    }
	}
    }

    return PJ_SUCCESS;
}

/*
 * Destroy port.
 */
static pj_status_t file_on_destroy(pjmedia_port *this_port)
{
    struct file_reader_port *fport = (struct file_reader_port*) this_port;

    pj_assert(this_port->info.signature == SIGNATURE);

    pj_file_close(fport->fd);
    return PJ_SUCCESS;
}