aboutsummaryrefslogtreecommitdiffstats
path: root/src/libsdr/sdr.c
blob: 69e07c14f2a83ed29d211c335a43ffbdf72b62c7 (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
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
/* SDR processing
 *
 * (C) 2017 by Andreas Eversberg <jolly@eversberg.eu>
 * All Rights Reserved
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

enum paging_signal;

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <math.h>
#include <getopt.h>
#define __USE_GNU
#include <pthread.h>
#include <unistd.h>
#include "../common/sample.h"
#include "../libfm/fm.h"
#include "../libtimer/timer.h"
#include "../common/sender.h"
#include "sdr_config.h"
#include "sdr.h"
#ifdef HAVE_UHD
#include "uhd.h"
#endif
#ifdef HAVE_SOAPY
#include "soapy.h"
#endif
#include "../common/debug.h"

/* enable to debug buffer handling */
//#define DEBUG_BUFFER

/* enable to test without oversampling filter */
//#define DISABLE_FILTER

/* usable bandwidth of IQ rate, because no filter is perfect */
#define USABLE_BANDWIDTH	0.75

int sdr_rx_overflow = 0;

typedef struct sdr_thread {
	int use;
	volatile int running, exit;	/* flags to control exit of threads */
	int buffer_size;
	volatile float *buffer;
	float *buffer2;
	volatile int in, out;		/* in and out pointers (atomic, so no locking required) */
	int max_fill;			/* measure maximum buffer fill */
	double max_fill_timer;		/* timer to display/reset maximum fill */
	iir_filter_t lp[2];		/* filter for upsample/downsample IQ data */
} sdr_thread_t;

typedef struct sdr_chan {
	double		tx_frequency;	/* frequency used */
	double		rx_frequency;	/* frequency used */
	fm_mod_t	mod;		/* modulator instance */
	fm_demod_t	demod;		/* demodulator instance */
	dispmeasparam_t	*dmp_rf_level;
	dispmeasparam_t	*dmp_freq_offset;
	dispmeasparam_t	*dmp_deviation;
} sdr_chan_t;

typedef struct sdr {
	int		threads;	/* use threads */
	int		oversample;	/* oversample IQ rate */
	sdr_thread_t	thread_read,
			thread_write;
	sdr_chan_t	*chan;		/* settings for all channels */
	int		paging_channel;	/* if set, points to paging channel */
	sdr_chan_t	paging_chan;	/* settings for extra paging channel */
	int		channels;	/* number of frequencies */
	double		amplitude;	/* amplitude of each carrier */
	int		samplerate;	/* sample rate of audio data */
	int		latspl;		/* latency in audio samples */
	wave_rec_t	wave_rx_rec;
	wave_rec_t	wave_tx_rec;
	wave_play_t	wave_rx_play;
	wave_play_t	wave_tx_play;
	float		*modbuff;	/* buffer for FM transmodulation */
	sample_t	*modbuff_I;
	sample_t	*modbuff_Q;
	sample_t	*wavespl0;	/* sample buffer for wave generation */
	sample_t	*wavespl1;
} sdr_t;

void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_frequency, double *rx_frequency, int channels, double paging_frequency, int samplerate, int latspl, double max_deviation, double max_modulation)
{
	sdr_t *sdr;
	int threads = 1, oversample = 1; /* always use threads */
	double bandwidth;
	double tx_center_frequency = 0.0, rx_center_frequency = 0.0;
	int rc;
	int c;

	PDEBUG(DSDR, DEBUG_DEBUG, "Open SDR device\n");

	if (sdr_config->samplerate != samplerate) {
		if (samplerate > sdr_config->samplerate) {
			PDEBUG(DSDR, DEBUG_ERROR, "SDR sample rate must be greater than audio sample rate!\n");
			PDEBUG(DSDR, DEBUG_ERROR, "You selected an SDR rate of %d and an audio rate of %d.\n", sdr_config->samplerate, samplerate);
			return NULL;
		}
		if ((sdr_config->samplerate % samplerate)) {
			PDEBUG(DSDR, DEBUG_ERROR, "SDR sample rate must be a multiple of audio sample rate!\n");
			PDEBUG(DSDR, DEBUG_ERROR, "You selected an SDR rate of %d and an audio rate of %d.\n", sdr_config->samplerate, samplerate);
			return NULL;
		}
		oversample = sdr_config->samplerate / samplerate;
		threads = 1;
	}

	bandwidth = 2.0 * (max_deviation + max_modulation);
	PDEBUG(DSDR, DEBUG_INFO, "Require bandwidth of each channel is 2 * (%.1f deviation + %.1f modulation) = %.1f KHz\n", max_deviation / 1e3, max_modulation / 1e3, bandwidth / 1e3);

	if (channels < 1) {
		PDEBUG(DSDR, DEBUG_ERROR, "No channel given, please fix!\n");
		abort();
	}

	sdr = calloc(sizeof(*sdr), 1);
	if (!sdr) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}
	sdr->channels = channels;
	sdr->amplitude = 1.0 / (double)channels;
	sdr->samplerate = samplerate;
	sdr->latspl = latspl;
	sdr->threads = threads; /* always requried, because write may block */
	sdr->oversample = oversample;

	if (threads) {
		memset(&sdr->thread_read, 0, sizeof(sdr->thread_read));
		sdr->thread_read.buffer_size = sdr->latspl * 2 * sdr->oversample + 2;
		sdr->thread_read.buffer = calloc(sdr->thread_read.buffer_size, sizeof(*sdr->thread_read.buffer));
		if (!sdr->thread_read.buffer) {
			PDEBUG(DSDR, DEBUG_ERROR, "No mem!\n");
			goto error;
		}
		sdr->thread_read.buffer2 = calloc(sdr->thread_read.buffer_size, sizeof(*sdr->thread_read.buffer2));
		if (!sdr->thread_read.buffer2) {
			PDEBUG(DSDR, DEBUG_ERROR, "No mem!\n");
			goto error;
		}
		sdr->thread_read.in = sdr->thread_read.out = 0;
		if (oversample > 1) {
			iir_lowpass_init(&sdr->thread_read.lp[0], samplerate / 2.0, sdr_config->samplerate, 2);
			iir_lowpass_init(&sdr->thread_read.lp[1], samplerate / 2.0, sdr_config->samplerate, 2);
		}
		memset(&sdr->thread_write, 0, sizeof(sdr->thread_write));
		sdr->thread_write.buffer_size = sdr->latspl * 2 + 2;
		sdr->thread_write.buffer = calloc(sdr->thread_write.buffer_size, sizeof(*sdr->thread_write.buffer));
		if (!sdr->thread_write.buffer) {
			PDEBUG(DSDR, DEBUG_ERROR, "No mem!\n");
			goto error;
		}
		sdr->thread_write.buffer2 = calloc(sdr->thread_write.buffer_size * sdr->oversample, sizeof(*sdr->thread_write.buffer2));
		if (!sdr->thread_write.buffer2) {
			PDEBUG(DSDR, DEBUG_ERROR, "No mem!\n");
			goto error;
		}
		sdr->thread_write.in = sdr->thread_write.out = 0;
		if (oversample > 1) {
			iir_lowpass_init(&sdr->thread_write.lp[0], samplerate / 2.0, sdr_config->samplerate, 2);
			iir_lowpass_init(&sdr->thread_write.lp[1], samplerate / 2.0, sdr_config->samplerate, 2);
		}
	}

	/* alloc fm modulation buffers */
	sdr->modbuff = calloc(sdr->latspl * 2, sizeof(*sdr->modbuff));
	if (!sdr->modbuff) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}
	sdr->modbuff_I = calloc(sdr->latspl, sizeof(*sdr->modbuff_I));
	if (!sdr->modbuff_I) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}
	sdr->modbuff_Q = calloc(sdr->latspl, sizeof(*sdr->modbuff_Q));
	if (!sdr->modbuff_Q) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}
	sdr->wavespl0 = calloc(sdr->latspl, sizeof(*sdr->wavespl0));
	if (!sdr->wavespl0) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}
	sdr->wavespl1 = calloc(sdr->latspl, sizeof(*sdr->wavespl1));
	if (!sdr->wavespl1) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}

	/* special case where we use a paging frequency */
	if (paging_frequency) {
		/* add extra paging channel */
		sdr->paging_channel = channels;
	}

	/* create list of channel states */
	sdr->chan = calloc(sizeof(*sdr->chan), channels + (sdr->paging_channel != 0));
	if (!sdr->chan) {
		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
		goto error;
	}

	if (tx_frequency) {
		/* calculate required bandwidth (IQ rate) */
		for (c = 0; c < channels; c++) {
			PDEBUG(DSDR, DEBUG_INFO, "Frequency #%d: TX = %.6f MHz\n", c, tx_frequency[c] / 1e6);
			sdr->chan[c].tx_frequency = tx_frequency[c];
		}
		if (sdr->paging_channel) {
			PDEBUG(DSDR, DEBUG_INFO, "Paging Frequency: TX = %.6f MHz\n", paging_frequency / 1e6);
			sdr->chan[sdr->paging_channel].tx_frequency = paging_frequency;
		}

		double tx_low_frequency = sdr->chan[0].tx_frequency, tx_high_frequency = sdr->chan[0].tx_frequency;
		for (c = 1; c < channels; c++) {
			if (sdr->chan[c].tx_frequency < tx_low_frequency)
				tx_low_frequency = sdr->chan[c].tx_frequency;
			if (sdr->chan[c].tx_frequency > tx_high_frequency)
				tx_high_frequency = sdr->chan[c].tx_frequency;
		}
		if (sdr->paging_channel) {
			if (sdr->chan[sdr->paging_channel].tx_frequency < tx_low_frequency)
				tx_low_frequency = sdr->chan[sdr->paging_channel].tx_frequency;
			if (sdr->chan[sdr->paging_channel].tx_frequency > tx_high_frequency)
				tx_high_frequency = sdr->chan[sdr->paging_channel].tx_frequency;
		}
		/* range of TX */
		double range = tx_high_frequency - tx_low_frequency + bandwidth;
		PDEBUG(DSDR, DEBUG_INFO, "Total bandwidth for all TX Frequencies: %.0f Hz\n", range);
		if (range > samplerate * USABLE_BANDWIDTH) {
			PDEBUG(DSDR, DEBUG_NOTICE, "*******************************************************************************\n");
			PDEBUG(DSDR, DEBUG_NOTICE, "The required bandwidth of %.0f Hz exceeds %.0f%% of the sample rate.\n", range, USABLE_BANDWIDTH * 100.0);
			PDEBUG(DSDR, DEBUG_NOTICE, "Please increase samplerate!\n");
			PDEBUG(DSDR, DEBUG_NOTICE, "*******************************************************************************\n");
			goto error;
		}
		tx_center_frequency = (tx_high_frequency + tx_low_frequency) / 2.0;
		PDEBUG(DSDR, DEBUG_INFO, "Using center frequency: TX %.6f MHz\n", tx_center_frequency / 1e6);
		/* set offsets to center frequency */
		for (c = 0; c < channels; c++) {
			double tx_offset;
			tx_offset = sdr->chan[c].tx_frequency - tx_center_frequency;
			PDEBUG(DSDR, DEBUG_DEBUG, "Frequency #%d: TX offset: %.6f MHz\n", c, tx_offset / 1e6);
			rc = fm_mod_init(&sdr->chan[c].mod, samplerate, tx_offset, sdr->amplitude);
			if (rc < 0)
				goto error;
		}
		if (sdr->paging_channel) {
			double tx_offset;
			tx_offset = sdr->chan[sdr->paging_channel].tx_frequency - tx_center_frequency;
			PDEBUG(DSDR, DEBUG_DEBUG, "Paging Frequency: TX offset: %.6f MHz\n", tx_offset / 1e6);
			rc = fm_mod_init(&sdr->chan[sdr->paging_channel].mod, samplerate, tx_offset, sdr->amplitude);
			if (rc < 0)
				goto error;
		}
		/* show gain */
		PDEBUG(DSDR, DEBUG_INFO, "Using gain: TX %.1f dB\n", sdr_config->tx_gain);
		/* open wave */
		if (sdr_config->write_iq_tx_wave) {
			rc = wave_create_record(&sdr->wave_tx_rec, sdr_config->write_iq_tx_wave, samplerate, 2, 1.0);
			if (rc < 0) {
				PDEBUG(DSDR, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
				goto error;
			}
		}
		if (sdr_config->read_iq_tx_wave) {
			rc = wave_create_playback(&sdr->wave_tx_play, sdr_config->read_iq_tx_wave, samplerate, 2, 1.0);
			if (rc < 0) {
				PDEBUG(DSDR, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
				goto error;
			}
		}
	}

	if (rx_frequency) {
		for (c = 0; c < channels; c++) {
			PDEBUG(DSDR, DEBUG_INFO, "Frequency #%d: RX = %.6f MHz\n", c, rx_frequency[c] / 1e6);
			sdr->chan[c].rx_frequency = rx_frequency[c];
		}

		/* calculate required bandwidth (IQ rate) */
		double rx_low_frequency = sdr->chan[0].rx_frequency, rx_high_frequency = sdr->chan[0].rx_frequency;
		for (c = 1; c < channels; c++) {
			if (sdr->chan[c].rx_frequency < rx_low_frequency)
				rx_low_frequency = sdr->chan[c].rx_frequency;
			if (sdr->chan[c].rx_frequency > rx_high_frequency)
				rx_high_frequency = sdr->chan[c].rx_frequency;
		}
		/* range of RX */
		double range = rx_high_frequency - rx_low_frequency + bandwidth;
		PDEBUG(DSDR, DEBUG_INFO, "Total bandwidth for all RX Frequencies: %.0f Hz\n", range);
		if (range > samplerate * USABLE_BANDWIDTH) {
			PDEBUG(DSDR, DEBUG_NOTICE, "*******************************************************************************\n");
			PDEBUG(DSDR, DEBUG_NOTICE, "The required bandwidth of %.0f Hz exceeds %.0f%% of the sample rate.\n", range, USABLE_BANDWIDTH * 100.0);
			PDEBUG(DSDR, DEBUG_NOTICE, "Please increase samplerate!\n");
			PDEBUG(DSDR, DEBUG_NOTICE, "*******************************************************************************\n");
			goto error;
		}
		rx_center_frequency = (rx_high_frequency + rx_low_frequency) / 2.0;
		PDEBUG(DSDR, DEBUG_INFO, "Using center frequency: RX %.6f MHz\n", rx_center_frequency / 1e6);
		/* set offsets to center frequency */
		for (c = 0; c < channels; c++) {
			double rx_offset;
			rx_offset = sdr->chan[c].rx_frequency - rx_center_frequency;
			PDEBUG(DSDR, DEBUG_DEBUG, "Frequency #%d: RX offset: %.6f MHz\n", c, rx_offset / 1e6);
			rc = fm_demod_init(&sdr->chan[c].demod, samplerate, rx_offset, bandwidth);
			if (rc < 0)
				goto error;
		}
		/* show gain */
		PDEBUG(DSDR, DEBUG_INFO, "Using gain: RX %.1f dB\n", sdr_config->rx_gain);
		/* open wave */
		if (sdr_config->write_iq_rx_wave) {
			rc = wave_create_record(&sdr->wave_rx_rec, sdr_config->write_iq_rx_wave, samplerate, 2, 1.0);
			if (rc < 0) {
				PDEBUG(DSDR, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
				goto error;
			}
		}
		if (sdr_config->read_iq_rx_wave) {
			rc = wave_create_playback(&sdr->wave_rx_play, sdr_config->read_iq_rx_wave, samplerate, 2, 1.0);
			if (rc < 0) {
				PDEBUG(DSDR, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
				goto error;
			}
		}
		/* init measurements display */
		for (c = 0; c < channels; c++) {
			sender_t *sender = get_sender_by_empfangsfrequenz(sdr->chan[c].rx_frequency);
			if (!sender)
				continue;
			sdr->chan[c].dmp_rf_level = display_measurements_add(sender, "RF Level", "%.1f dB", DISPLAY_MEAS_AVG, DISPLAY_MEAS_LEFT, -96.0, 0.0, -INFINITY);
			sdr->chan[c].dmp_freq_offset = display_measurements_add(sender, "Freq. Offset", "%+.2f KHz", DISPLAY_MEAS_AVG, DISPLAY_MEAS_CENTER, -max_deviation / 1000.0 * 2.0, max_deviation / 1000.0 * 2.0, 0.0);
			sdr->chan[c].dmp_deviation = display_measurements_add(sender, "Deviation", "%.2f KHz", DISPLAY_MEAS_PEAK2PEAK, DISPLAY_MEAS_LEFT, 0.0, max_deviation / 1000.0 * 1.5, max_deviation / 1000.0);
		}
	}

	if (sdr_config->swap_links) {
		double temp;
		PDEBUG(DSDR, DEBUG_NOTICE, "Sapping RX and TX frequencies!\n");
		temp = rx_center_frequency;
		rx_center_frequency = tx_center_frequency;
		tx_center_frequency = temp;
	}

	display_iq_init(samplerate);
	display_spectrum_init(samplerate, rx_center_frequency);

#ifdef HAVE_UHD
	if (sdr_config->uhd) {
		rc = uhd_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, tx_center_frequency, rx_center_frequency, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth, sdr_config->uhd_tx_timestamps);
		if (rc)
			goto error;
	}
#endif

#ifdef HAVE_SOAPY
	if (sdr_config->soapy) {
		rc = soapy_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, tx_center_frequency, rx_center_frequency, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth);
		if (rc)
			goto error;
	}
#endif

	return sdr;

error:
	sdr_close(sdr);
	return NULL;
}

static void *sdr_write_child(void *arg)
{
	sdr_t *sdr = (sdr_t *)arg;
	int num;
	int fill, out;
	int s, ss, o;

	while (sdr->thread_write.running) {
		/* write to SDR */
		fill = (sdr->thread_write.in - sdr->thread_write.out + sdr->thread_write.buffer_size) % sdr->thread_write.buffer_size;
		num = fill / 2;
		if (num) {
#ifdef DEBUG_BUFFER
			printf("Thread found %d samples in write buffer and forwards them to SDR.\n", num);
#endif
			out = sdr->thread_write.out;
			for (s = 0, ss = 0; s < num; s++) {
				for (o = 0; o < sdr->oversample; o++) {
					sdr->thread_write.buffer2[ss++] = sdr->thread_write.buffer[out];
					sdr->thread_write.buffer2[ss++] = sdr->thread_write.buffer[out + 1];
				}
				out = (out + 2) % sdr->thread_write.buffer_size;
			}
			sdr->thread_write.out = out;
#ifndef DISABLE_FILTER
			/* filter spectrum */
			if (sdr->oversample > 1) {
				iir_process_baseband(&sdr->thread_write.lp[0], sdr->thread_write.buffer2, num * sdr->oversample);
				iir_process_baseband(&sdr->thread_write.lp[1], sdr->thread_write.buffer2 + 1, num * sdr->oversample);
			}
#endif
#ifdef HAVE_UHD
			if (sdr_config->uhd)
				uhd_send(sdr->thread_write.buffer2, num * sdr->oversample);
#endif
#ifdef HAVE_SOAPY
			if (sdr_config->soapy)
				soapy_send(sdr->thread_write.buffer2, num * sdr->oversample);
#endif
		}

		/* delay some time */
		usleep(1000);
	}

	PDEBUG(DSDR, DEBUG_DEBUG, "Thread received exit!\n");
	sdr->thread_write.exit = 1;
	return NULL;
}

static void *sdr_read_child(void *arg)
{
	sdr_t *sdr = (sdr_t *)arg;
	int num, count = 0;
	int space, in;
	int s, ss;

	while (sdr->thread_read.running) {
		/* read from SDR */
		space = (sdr->thread_read.out - sdr->thread_read.in - 2 + sdr->thread_read.buffer_size) % sdr->thread_read.buffer_size;
		num = space / 2;
		if (num) {
#ifdef HAVE_UHD
			if (sdr_config->uhd)
				count = uhd_receive(sdr->thread_read.buffer2, num);
#endif
#ifdef HAVE_SOAPY
			if (sdr_config->soapy)
				count = soapy_receive(sdr->thread_read.buffer2, num);
#endif
			if (count > 0) {
#ifdef DEBUG_BUFFER
				printf("Thread read %d samples from SDR and writes them to read buffer.\n", count);
#endif
#ifndef DISABLE_FILTER
				/* filter spectrum */
				if (sdr->oversample > 1) {
					iir_process_baseband(&sdr->thread_read.lp[0], sdr->thread_read.buffer2, count);
					iir_process_baseband(&sdr->thread_read.lp[1], sdr->thread_read.buffer2 + 1, count);
				}
#endif
				in = sdr->thread_read.in;
				for (s = 0, ss = 0; s < count; s++) {
					sdr->thread_read.buffer[in++] = sdr->thread_read.buffer2[ss++];
					sdr->thread_read.buffer[in++] = sdr->thread_read.buffer2[ss++];
					in %= sdr->thread_read.buffer_size;
				}
				sdr->thread_read.in = in;
			}
		}

		/* delay some time */
		usleep(1000);
	}

	PDEBUG(DSDR, DEBUG_DEBUG, "Thread received exit!\n");
	sdr->thread_read.exit = 1;
	return NULL;
}

/* start streaming */
int sdr_start(void *inst)
{
	sdr_t *sdr = (sdr_t *)inst;
	int rc = -EINVAL;

#ifdef HAVE_UHD
	if (sdr_config->uhd)
		rc = uhd_start();
#endif
#ifdef HAVE_SOAPY
	if (sdr_config->soapy)
		rc = soapy_start();
#endif
	if (rc < 0)
		return rc;

	if (sdr->threads) {
		int rc;
		pthread_t tid;
		char tname[64];

		PDEBUG(DSDR, DEBUG_DEBUG, "Create threads!\n");
		sdr->thread_write.running = 1;
		sdr->thread_write.exit = 0;
		rc = pthread_create(&tid, NULL, sdr_write_child, inst);
		if (rc < 0) {
			sdr->thread_write.running = 0;
			PDEBUG(DSDR, DEBUG_ERROR, "Failed to create thread!\n");
			return rc;
		}
		pthread_getname_np(tid, tname, sizeof(tname));
		strncat(tname, "-sdr_tx", sizeof(tname));
		tname[sizeof(tname) - 1] = '\0';
		pthread_setname_np(tid, tname);
		sdr->thread_read.running = 1;
		sdr->thread_read.exit = 0;
		rc = pthread_create(&tid, NULL, sdr_read_child, inst);
		if (rc < 0) {
			sdr->thread_read.running = 0;
			PDEBUG(DSDR, DEBUG_ERROR, "Failed to create thread!\n");
			return rc;
		}
		pthread_getname_np(tid, tname, sizeof(tname));
		strncat(tname, "-sdr_rx", sizeof(tname));
		tname[sizeof(tname) - 1] = '\0';
		pthread_setname_np(tid, tname);
	}

	return 0;
}

void sdr_close(void *inst)
{
	sdr_t *sdr = (sdr_t *)inst;

	PDEBUG(DSDR, DEBUG_DEBUG, "Close SDR device\n");

	if (sdr->threads) {
		if (sdr->thread_write.running) {
			PDEBUG(DSDR, DEBUG_DEBUG, "Thread sending exit!\n");
			sdr->thread_write.running = 0;
			while (sdr->thread_write.exit == 0)
				usleep(1000);
		}
		if (sdr->thread_read.running) {
			PDEBUG(DSDR, DEBUG_DEBUG, "Thread sending exit!\n");
			sdr->thread_read.running = 0;
			while (sdr->thread_read.exit == 0)
				usleep(1000);
		}
	}

	if (sdr->thread_read.buffer)
		free((void *)sdr->thread_read.buffer);
	if (sdr->thread_read.buffer2)
		free((void *)sdr->thread_read.buffer2);
	if (sdr->thread_write.buffer)
		free((void *)sdr->thread_write.buffer);
	if (sdr->thread_write.buffer2)
		free((void *)sdr->thread_write.buffer2);

#ifdef HAVE_UHD
	if (sdr_config->uhd)
		uhd_close();
#endif

#ifdef HAVE_SOAPY
	if (sdr_config->soapy)
		soapy_close();
#endif

	if (sdr) {
		free(sdr->modbuff);
		free(sdr->modbuff_I);
		free(sdr->modbuff_Q);
		free(sdr->wavespl0);
		free(sdr->wavespl1);
		wave_destroy_record(&sdr->wave_rx_rec);
		wave_destroy_record(&sdr->wave_tx_rec);
		wave_destroy_playback(&sdr->wave_rx_play);
		wave_destroy_playback(&sdr->wave_tx_play);
		if (sdr->chan) {
			int c;

			for (c = 0; c < sdr->channels; c++) {
				fm_mod_exit(&sdr->chan[c].mod);
				fm_demod_exit(&sdr->chan[c].demod);
			}
			if (sdr->paging_channel)
				fm_mod_exit(&sdr->chan[sdr->paging_channel].mod);
			free(sdr->chan);
		}
		free(sdr);
		sdr = NULL;
	}
}

int sdr_write(void *inst, sample_t **samples, uint8_t **power, int num, enum paging_signal __attribute__((unused)) *paging_signal, int *on, int channels)
{
	sdr_t *sdr = (sdr_t *)inst;
	float *buff = NULL;
	int c, s, ss;
	int sent = 0;

	if (num > sdr->latspl) {
		fprintf(stderr, "exceeding maximum size given by sdr_latspl, please fix!\n");
		abort();
	}
	if (channels != sdr->channels && channels != 0) {
		PDEBUG(DSDR, DEBUG_ERROR, "Invalid number of channels, please fix!\n");
		abort();
	}

	/* process all channels */
	if (channels) {
		buff = sdr->modbuff;
		memset(buff, 0, sizeof(*buff) * num * 2);
		for (c = 0; c < channels; c++) {
			/* switch to paging channel, if requested */
			if (on[c] && sdr->paging_channel)
				fm_modulate_complex(&sdr->chan[sdr->paging_channel].mod, samples[c], power[c], num, buff);
			else
				fm_modulate_complex(&sdr->chan[c].mod, samples[c], power[c], num, buff);
		}
	} else {
		buff = (float *)samples;
	}

	if (sdr->wave_tx_rec.fp) {
		sample_t *spl_list[2] = { sdr->wavespl0, sdr->wavespl1 };
		for (s = 0, ss = 0; s < num; s++) {
			spl_list[0][s] = buff[ss++];
			spl_list[1][s] = buff[ss++];
		}
		wave_write(&sdr->wave_tx_rec, spl_list, num);
	}
	if (sdr->wave_tx_play.fp) {
		sample_t *spl_list[2] = { sdr->wavespl0, sdr->wavespl1 };
		wave_read(&sdr->wave_tx_play, spl_list, num);
		for (s = 0, ss = 0; s < num; s++) {
			buff[ss++] = spl_list[0][s];
			buff[ss++] = spl_list[1][s];
		}
	}

	if (sdr->threads) {
		/* store data towards SDR in ring buffer */
		int fill, space, in;

		fill = (sdr->thread_write.in - sdr->thread_write.out + sdr->thread_write.buffer_size) % sdr->thread_write.buffer_size;
		space = (sdr->thread_write.out - sdr->thread_write.in - 2 + sdr->thread_write.buffer_size) % sdr->thread_write.buffer_size;

		/* debug fill level */
		if (fill > sdr->thread_write.max_fill)
			sdr->thread_write.max_fill = fill;
		if (sdr->thread_write.max_fill_timer == 0.0)
			sdr->thread_write.max_fill_timer = get_time();
		if (get_time() - sdr->thread_write.max_fill_timer > 1.0) {
			double delay;
			delay = (double)sdr->thread_write.max_fill / 2.0 / (double)sdr->samplerate;
			sdr->thread_write.max_fill = 0;
			sdr->thread_write.max_fill_timer += 1.0;
			PDEBUG(DSDR, DEBUG_DEBUG, "write delay = %.3f ms\n", delay * 1000.0);
		}

		if (space < num * 2) {
			PDEBUG(DSDR, DEBUG_ERROR, "Write SDR buffer overflow!\n");
			num = space / 2;
		}
#ifdef DEBUG_BUFFER
		printf("Writing %d samples to write buffer.\n", num);
#endif
		in = sdr->thread_write.in;
		for (s = 0, ss = 0; s < num; s++) {
			sdr->thread_write.buffer[in++] = buff[ss++];
			sdr->thread_write.buffer[in++] = buff[ss++];
			in %= sdr->thread_write.buffer_size;
		}
		sdr->thread_write.in = in;
		sent = num;
	} else {
#ifdef HAVE_UHD
		if (sdr_config->uhd)
			sent = uhd_send(buff, num);
#endif
#ifdef HAVE_SOAPY
		if (sdr_config->soapy)
			sent = soapy_send(buff, num);
#endif
		if (sent < 0)
			return sent;
	}
	
	return sent;
}

int sdr_read(void *inst, sample_t **samples, int num, int channels, double *rf_level_db)
{
	sdr_t *sdr = (sdr_t *)inst;
	float *buff = NULL;
	int count = 0;
	int c, s, ss;

	if (num > sdr->latspl) {
		fprintf(stderr, "exceeding maximum size given by sdr_latspl, please fix!\n");
		abort();
	}

	if (channels) {
		buff = sdr->modbuff;
	} else {
		buff = (float *)samples;
	}

	if (sdr->threads) {
		/* load data from SDR out of ring buffer */
		int fill, out;

		fill = (sdr->thread_read.in - sdr->thread_read.out + sdr->thread_read.buffer_size) % sdr->thread_read.buffer_size;

		/* debug fill level */
		if (fill > sdr->thread_read.max_fill)
			sdr->thread_read.max_fill = fill;
		if (sdr->thread_read.max_fill_timer == 0.0)
			sdr->thread_read.max_fill_timer = get_time();
		if (get_time() - sdr->thread_read.max_fill_timer > 1.0) {
			double delay;
			delay = (double)sdr->thread_read.max_fill / 2.0 / (double)sdr_config->samplerate;
			sdr->thread_read.max_fill = 0;
			sdr->thread_read.max_fill_timer += 1.0;
			PDEBUG(DSDR, DEBUG_DEBUG, "read delay = %.3f ms\n", delay * 1000.0);
		}

		if (fill / 2 / sdr->oversample < num)
			num = fill / 2 / sdr->oversample;
#ifdef DEBUG_BUFFER
		printf("Reading %d samples from read buffer.\n", num);
#endif
		out = sdr->thread_read.out;
		for (s = 0, ss = 0; s < num; s++) {
			buff[ss++] = sdr->thread_read.buffer[out];
			buff[ss++] = sdr->thread_read.buffer[out + 1];
			out = (out + 2 * sdr->oversample) % sdr->thread_read.buffer_size;
		}
		sdr->thread_read.out = out;
		count = num;
	} else {
#ifdef HAVE_UHD
		if (sdr_config->uhd)
			count = uhd_receive(buff, num);
#endif
#ifdef HAVE_SOAPY
		if (sdr_config->soapy)
			count = soapy_receive(buff, num);
#endif
		if (count <= 0)
			return count;
	}

	if (sdr_rx_overflow) {
		PDEBUG(DSDR, DEBUG_ERROR, "SDR RX overflow!\n");
		sdr_rx_overflow = 0;
	}

	if (sdr->wave_rx_rec.fp) {
		sample_t *spl_list[2] = { sdr->wavespl0, sdr->wavespl1 };
		for (s = 0, ss = 0; s < count; s++) {
			spl_list[0][s] = buff[ss++];
			spl_list[1][s] = buff[ss++];
		}
		wave_write(&sdr->wave_rx_rec, spl_list, count);
	}
	if (sdr->wave_rx_play.fp) {
		sample_t *spl_list[2] = { sdr->wavespl0, sdr->wavespl1 };
		wave_read(&sdr->wave_rx_play, spl_list, count);
		for (s = 0, ss = 0; s < count; s++) {
			buff[ss++] = spl_list[0][s];
			buff[ss++] = spl_list[1][s];
		}
	}
	display_iq(buff, count);
	display_spectrum(buff, count);

	if (channels) {
		for (c = 0; c < channels; c++) {
			fm_demodulate_complex(&sdr->chan[c].demod, samples[c], count, buff, sdr->modbuff_I, sdr->modbuff_Q);
			sender_t *sender = get_sender_by_empfangsfrequenz(sdr->chan[c].rx_frequency);
			if (!sender || !count)
				continue;
			double min, max, avg;
			avg = 0.0;
			for (s = 0; s < count; s++) {
				/* average the square length of vector */
				avg += sdr->modbuff_I[s] * sdr->modbuff_I[s] + sdr->modbuff_Q[s] * sdr->modbuff_Q[s];
			}
			avg = sqrt(avg /(double)count); /* RMS */
			avg = log10(avg) * 20;
			display_measurements_update(sdr->chan[c].dmp_rf_level, avg, 0.0);
			rf_level_db[c] = avg;
			min = 0.0;
			max = 0.0;
			avg = 0.0;
			for (s = 0; s < count; s++) {
				avg += samples[c][s];
				if (s == 0 || samples[c][s] > max)
					max = samples[c][s];
				if (s == 0 || samples[c][s] < min)
					min = samples[c][s];
			}
			avg /= (double)count;
			display_measurements_update(sdr->chan[c].dmp_freq_offset, avg / 1000.0, 0.0);
			/* use half min and max, because we want the deviation above/below (+-) center frequency. */
			display_measurements_update(sdr->chan[c].dmp_deviation, min / 2.0 / 1000.0, max / 2.0 / 1000.0);
		}
	}

	return count;
}

/* how much do we need to send (in audio sample duration) to get the target delay (latspl) */
int sdr_get_tosend(void *inst, int latspl)
{
	sdr_t *sdr = (sdr_t *)inst;
	int count = 0;

#ifdef HAVE_UHD
	if (sdr_config->uhd)
		count = uhd_get_tosend(latspl * sdr->oversample);
#endif
#ifdef HAVE_SOAPY
	if (sdr_config->soapy)
		count = soapy_get_tosend(latspl * sdr->oversample);
#endif
	if (count < 0)
		return count;
	count /= sdr->oversample;

	if (sdr->threads) {
		/* substract what we have in write buffer, because this is not jent sent to the SDR */
		int fill;

		fill = (sdr->thread_write.in - sdr->thread_write.out + sdr->thread_write.buffer_size) % sdr->thread_write.buffer_size;
		count -= fill / 2;
		if (count < 0)
			count = 0;
	}

	return count;
}