Wave recording and playback now uses multi channels

7 files changed, 200 insertions, 66 deletions

diff --git a/src/common/main_common.c b/src/common/main_common.c
index 399a6eb..48e3eb4 100644
--- a/src/common/main_common.c
+++ b/src/common/main_common.c
@@ -60,7 +60,9 @@ const char *write_tx_wave = NULL;
 const char *read_rx_wave = NULL;
 static const char *sdr_args = "";
 double sdr_rx_gain = 0, sdr_tx_gain = 0;
-
+const char *write_iq_rx_wave = NULL;
+const char *write_iq_tx_wave = NULL;
+const char *read_iq_rx_wave = NULL;
 void print_help_common(const char *arg0, const char *ext_usage)
 {
 	printf("Usage: %s -k <kanal/channel> %s[options] [station-id]\n", arg0, ext_usage);
@@ -111,18 +113,25 @@ void print_help_common(const char *arg0, const char *ext_usage)
 	printf(" -r --realtime <prio>\n");
 	printf("        Set prio: 0 to diable, 99 for maximum (default = %d)\n", rt_prio);
 	printf("    --write-rx-wave <file>\n");
-	printf("        Write received audio to given wav audio file.\n");
+	printf("        Write received audio to given wave file.\n");
 	printf("    --write-tx-wave <file>\n");
-	printf("        Write transmitted audio to given wav audio file.\n");
+	printf("        Write transmitted audio to given wave file.\n");
 	printf("    --read-rx-wave <file>\n");
-	printf("        Replace received audio by given wav audio file.\n");
+	printf("        Replace received audio by given wave file.\n");
 #ifdef HAVE_SDR
+	printf("\nSDR options:\n");
 	printf("    --sdr-args <args>\n");
 	printf("        Optional SDR device arguments\n");
 	printf("    --sdr-rx-gain <gain>\n");
 	printf("        SDR device's RX gain in dB (default = %.1f)\n", sdr_rx_gain);
 	printf("    --sdr-tx-gain <gain>\n");
 	printf("        SDR device's TX gain in dB (default = %.1f)\n", sdr_tx_gain);
+	printf("    --write-iq-rx-wave <file>\n");
+	printf("        Write received IQ data to given wave file.\n");
+	printf("    --write-iq-tx-wave <file>\n");
+	printf("        Write transmitted IQ data to given wave file.\n");
+	printf("    --read-iq-rx-wave <file>\n");
+	printf("        Replace received IQ data by given wave file.\n");
 #endif
 }
 
@@ -138,9 +147,13 @@ void print_hotkeys_common(void)
 #define	OPT_WRITE_RX_WAVE	1001
 #define	OPT_WRITE_TX_WAVE	1002
 #define	OPT_READ_RX_WAVE	1003
-#define	OPT_SDR_ARGS		1004
-#define	OPT_SDR_RX_GAIN		1005
-#define	OPT_SDR_TX_GAIN		1006
+
+#define	OPT_SDR_ARGS		1100
+#define	OPT_SDR_RX_GAIN		1101
+#define	OPT_SDR_TX_GAIN		1102
+#define	OPT_WRITE_IQ_RX_WAVE	1103
+#define	OPT_WRITE_IQ_TX_WAVE	1104
+#define	OPT_READ_IQ_RX_WAVE	1105
 
 static struct option long_options_common[] = {
 	{"help", 0, 0, 'h'},
@@ -165,6 +178,9 @@ static struct option long_options_common[] = {
 	{"sdr-args", 1, 0, OPT_SDR_ARGS},
 	{"sdr-rx-gain", 1, 0, OPT_SDR_RX_GAIN},
 	{"sdr-tx-gain", 1, 0, OPT_SDR_TX_GAIN},
+	{"write-iq-rx-wave", 1, 0, OPT_WRITE_IQ_RX_WAVE},
+	{"write-iq-tx-wave", 1, 0, OPT_WRITE_IQ_TX_WAVE},
+	{"read-iq-rx-wave", 1, 0, OPT_READ_IQ_RX_WAVE},
 	{0, 0, 0, 0}
 };
 
@@ -316,6 +332,18 @@ void opt_switch_common(int c, char *arg0, int *skip_args)
 		sdr_tx_gain = atof(optarg);
 		*skip_args += 2;
 		break;
+	case OPT_WRITE_IQ_RX_WAVE:
+		write_iq_rx_wave = strdup(optarg);
+		*skip_args += 2;
+		break;
+	case OPT_WRITE_IQ_TX_WAVE:
+		write_iq_tx_wave = strdup(optarg);
+		*skip_args += 2;
+		break;
+	case OPT_READ_IQ_RX_WAVE:
+		read_iq_rx_wave = strdup(optarg);
+		*skip_args += 2;
+		break;
 	default:
 		exit (0);
 	}
diff --git a/src/common/sdr.c b/src/common/sdr.c
index 60ac610..2644968 100644
--- a/src/common/sdr.c
+++ b/src/common/sdr.c
@@ -50,16 +50,20 @@ typedef struct sdr {
 	int channels;		/* number of frequencies */
 	double samplerate;	/* IQ rate */
 	double amplitude;	/* amplitude of each carrier */
+	wave_rec_t wave_rx_rec;
+	wave_rec_t wave_tx_rec;
+	wave_play_t wave_rx_play;
 } sdr_t;
 
 static const char *sdr_device_args;
 static double sdr_rx_gain, sdr_tx_gain;
+const char *sdr_write_iq_rx_wave, *sdr_write_iq_tx_wave, *sdr_read_iq_rx_wave;
 
 #ifdef FAST_SINE
 static float sdr_sine[256];
 #endif
 
-int sdr_init(const char *device_args, double rx_gain, double tx_gain)
+int sdr_init(const char *device_args, double rx_gain, double tx_gain, const char *write_iq_rx_wave, const char *write_iq_tx_wave, const char *read_iq_rx_wave)
 {
 #ifdef FAST_SINE
 	int i;
@@ -72,6 +76,9 @@ int sdr_init(const char *device_args, double rx_gain, double tx_gain)
 	sdr_device_args = strdup(device_args);
 	sdr_rx_gain = rx_gain;
 	sdr_tx_gain = tx_gain;
+	sdr_write_iq_rx_wave = write_iq_rx_wave;
+	sdr_write_iq_tx_wave = write_iq_tx_wave;
+	sdr_read_iq_rx_wave = read_iq_rx_wave;
 
 	return 0;
 }
@@ -181,6 +188,28 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 	}
 	PDEBUG(DSDR, DEBUG_INFO, "Using gain: TX %.1f dB, RX %.1f dB\n", sdr_tx_gain, sdr_rx_gain);
 
+	if (sdr_write_iq_rx_wave) {
+		rc = wave_create_record(&sdr->wave_rx_rec, sdr_write_iq_rx_wave, sdr->samplerate, 2);
+		if (rc < 0) {
+			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
+			goto error;
+		}
+	}
+	if (sdr_write_iq_tx_wave) {
+		rc = wave_create_record(&sdr->wave_tx_rec, sdr_write_iq_tx_wave, sdr->samplerate, 2);
+		if (rc < 0) {
+			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
+			goto error;
+		}
+	}
+	if (sdr_read_iq_rx_wave) {
+		rc = wave_create_playback(&sdr->wave_rx_play, sdr_read_iq_rx_wave, sdr->samplerate, 2);
+		if (rc < 0) {
+			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
+			goto error;
+		}
+	}
+
 #ifdef HAVE_UHD
 	rc = uhd_open(sdr_device_args, tx_center_frequency, rx_center_frequency, sdr->samplerate, sdr_rx_gain, sdr_tx_gain);
 	if (rc)
@@ -203,6 +232,9 @@ void sdr_close(void *inst)
 #endif
 
 	if (sdr) {
+		wave_destroy_record(&sdr->wave_rx_rec);
+		wave_destroy_record(&sdr->wave_tx_rec);
+		wave_destroy_playback(&sdr->wave_rx_play);
 		free(sdr->chan);
 		free(sdr);
 		sdr = NULL;
@@ -258,6 +290,27 @@ int sdr_write(void *inst, int16_t **samples, int num, enum paging_signal __attri
 		sdr->chan[c].tx_phase = phase;
 	}
 
+	if (sdr->wave_tx_rec.fp) {
+		int16_t spl[2][num], *spl_list[2] = { spl[0], spl[1] };
+		for (s = 0, ss = 0; s < num; s++) {
+			if (buff[ss] >= 1.0)
+				spl[0][s] = 32767;
+			else if (buff[ss] <= -1.0)
+				spl[0][s] = -32767;
+			else
+				spl[0][s] = 32767.0 * buff[ss];
+			ss++;
+			if (buff[ss] >= 1.0)
+				spl[1][s] = 32767;
+			else if (buff[ss] <= -1.0)
+				spl[1][s] = -32767;
+			else
+				spl[1][s] = 32767.0 * buff[ss];
+			ss++;
+		}
+		wave_write(&sdr->wave_tx_rec, spl_list, num);
+	}
+
 #ifdef HAVE_UHD
 	sent = uhd_send(buff, num);
 #endif
@@ -284,6 +337,34 @@ int sdr_read(void *inst, int16_t **samples, int num, int channels)
 	if (count <= 0)
 		return count;
 
+	if (sdr->wave_rx_rec.fp) {
+		int16_t spl[2][count], *spl_list[2] = { spl[0], spl[1] };
+		for (s = 0, ss = 0; s < count; s++) {
+			if (buff[ss] >= 1.0)
+				spl[0][s] = 32767;
+			else if (buff[ss] <= -1.0)
+				spl[0][s] = -32767;
+			else
+				spl[0][s] = 32767.0 * buff[ss];
+			ss++;
+			if (buff[ss] >= 1.0)
+				spl[1][s] = 32767;
+			else if (buff[ss] <= -1.0)
+				spl[1][s] = -32767;
+			else
+				spl[1][s] = 32767.0 * buff[ss];
+			ss++;
+		}
+		wave_write(&sdr->wave_rx_rec, spl_list, count);
+	}
+	if (sdr->wave_rx_play.fp) {
+		int16_t spl[2][count], *spl_list[2] = { spl[0], spl[1] };
+		wave_read(&sdr->wave_rx_play, spl_list, count);
+		for (s = 0, ss = 0; s < count; s++) {
+			buff[ss++] = (double)spl[0][s] / 32767.0;
+			buff[ss++] = (double)spl[1][s] / 32767.0;
+		}
+	}
 	display_iq(buff, count);
 
 	for (c = 0; c < channels; c++) {
diff --git a/src/common/sdr.h b/src/common/sdr.h
index ecbcbe4..8ccd56a 100644
--- a/src/common/sdr.h
+++ b/src/common/sdr.h
@@ -1,5 +1,5 @@
 
-int sdr_init(const char *device_args, double rx_gain, double tx_gain);
+int sdr_init(const char *device_args, double rx_gain, double tx_gain, const char *write_iq_rx_wave, const char *write_iq_tx_wave, const char *read_iq_rx_wave);
 void *sdr_open(const char *audiodev, double *tx_frequency, double *rx_frequency, int channels, double paging_frequency, int samplerate, double bandwidth, double sample_deviation);
 void sdr_close(void *inst);
 int sdr_write(void *inst, int16_t **samples, int num, enum paging_signal *paging_signal, int *on, int channels);
diff --git a/src/common/sender.c b/src/common/sender.c
index f610dbc..d636974 100644
--- a/src/common/sender.c
+++ b/src/common/sender.c
@@ -50,6 +50,9 @@ int sender_create(sender_t *sender, int kanal, double sendefrequenz, double empf
 	sender->loopback = loopback;
 	sender->loss_volume = loss_volume;
 	sender->paging_signal = paging_signal;
+	sender->write_rx_wave = write_rx_wave;
+	sender->write_tx_wave = write_tx_wave;
+	sender->read_rx_wave = read_rx_wave;
 
 	PDEBUG_CHAN(DSENDER, DEBUG_DEBUG, "Creating 'Sender' instance\n");
 
@@ -118,28 +121,6 @@ int sender_create(sender_t *sender, int kanal, double sendefrequenz, double empf
 		goto error;
 	}
 
-	if (write_rx_wave) {
-		rc = wave_create_record(&sender->wave_rx_rec, write_rx_wave, samplerate);
-		if (rc < 0) {
-			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
-			goto error;
-		}
-	}
-	if (write_tx_wave) {
-		rc = wave_create_record(&sender->wave_tx_rec, write_tx_wave, samplerate);
-		if (rc < 0) {
-			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
-			goto error;
-		}
-	}
-	if (read_rx_wave) {
-		rc = wave_create_playback(&sender->wave_rx_play, read_rx_wave, samplerate);
-		if (rc < 0) {
-			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
-			goto error;
-		}
-	}
-
 	rc = init_emphasis(&sender->estate, samplerate, CUT_OFF_EMPHASIS_DEFAULT);
 	if (rc < 0)
 		goto error;
@@ -162,6 +143,7 @@ int sender_open_audio(void)
 	int channels;
 	double paging_frequency = 0.0;
 	int i;
+	int rc;
 
 	for (master = sender_head; master; master = master->next) {
 		/* skip audio slaves */
@@ -184,6 +166,28 @@ int sender_open_audio(void)
 				paging_frequency = inst->ruffrequenz;
 		}
 
+		if (master->write_rx_wave) {
+			rc = wave_create_record(&master->wave_rx_rec, master->write_rx_wave, master->samplerate, channels);
+			if (rc < 0) {
+				PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
+				return rc;
+			}
+		}
+		if (master->write_tx_wave) {
+			rc = wave_create_record(&master->wave_tx_rec, master->write_tx_wave, master->samplerate, channels);
+			if (rc < 0) {
+				PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
+				return rc;
+			}
+		}
+		if (master->read_rx_wave) {
+			rc = wave_create_playback(&master->wave_rx_play, master->read_rx_wave, master->samplerate, channels);
+			if (rc < 0) {
+				PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
+				return rc;
+			}
+		}
+
 		/* open device */
 		master->audio = master->audio_open(master->audiodev, tx_f, rx_f, channels, paging_frequency, master->samplerate, master->bandwidth, master->sample_deviation);
 		if (!master->audio) {
@@ -278,12 +282,8 @@ cant_recover:
 				jitter_load(&inst->dejitter, samples[i], count);
 			else
 				sender_send(inst, samples[i], count);
-			if (inst->wave_tx_rec.fp)
-				wave_write(&inst->wave_tx_rec, samples[i], count);
 			/* internal loopback: loop back TX audio to RX */
 			if (inst->loopback == 1) {
-				if (inst->wave_rx_rec.fp)
-					wave_write(&inst->wave_rx_rec, samples[i], count);
 				display_wave(inst, samples[i], count);
 				sender_receive(inst, samples[i], count);
 			}
@@ -295,6 +295,9 @@ cant_recover:
 			on[i] = sender->paging_on;
 		}
 
+		if (sender->wave_tx_rec.fp)
+			wave_write(&sender->wave_tx_rec, samples, count);
+
 		rc = sender->audio_write(sender->audio, samples, count, paging_signal, on, num_chan);
 		if (rc < 0) {
 			PDEBUG(DSENDER, DEBUG_ERROR, "Failed to write TX data to audio device (rc = %d)\n", rc);
@@ -324,6 +327,11 @@ transmit_later:
 		return;
 	}
 	if (count) {
+		if (sender->wave_rx_rec.fp)
+			wave_write(&sender->wave_rx_rec, samples, count);
+		if (sender->wave_rx_play.fp)
+			wave_read(&sender->wave_rx_play, samples, count);
+
 		/* loop through all channels */
 		for (i = 0, inst = sender; inst; i++, inst = inst->slave) {
 			/* rx gain */
@@ -332,11 +340,7 @@ transmit_later:
 			/* do de emphasis from radio (then write_wave/wave_read), receive audio, process echo test */
 			if (inst->de_emphasis)
 				de_emphasis(&inst->estate, samples[i], count);
-			if (inst->wave_rx_play.fp)
-				wave_read(&inst->wave_rx_play, samples[i], count);
 			if (inst->loopback != 1) {
-				if (inst->wave_rx_rec.fp)
-					wave_write(&inst->wave_rx_rec, samples[i], count);
 				display_wave(inst, samples[i], count);
 				sender_receive(inst, samples[i], count);
 			}
diff --git a/src/common/sender.h b/src/common/sender.h
index 61302f1..12f30ab 100644
--- a/src/common/sender.h
+++ b/src/common/sender.h
@@ -53,6 +53,9 @@ typedef struct sender {
 	int			loopback;		/* 0 = off, 1 = internal, 2 = external */
 
 	/* record and playback */
+	const char		*write_rx_wave;		/* file name pointers */
+	const char		*write_tx_wave;
+	const char		*read_rx_wave;
 	wave_rec_t		wave_rx_rec;		/* wave recording (from rx) */
 	wave_rec_t		wave_tx_rec;		/* wave recording (from tx) */
 	wave_play_t		wave_rx_play;		/* wave playback (as rx) */
diff --git a/src/common/wave.c b/src/common/wave.c
index 2365078..e18dfb4 100644
--- a/src/common/wave.c
+++ b/src/common/wave.c
@@ -33,7 +33,7 @@ struct fmt {
 	uint16_t	bits_sample; /* bits per sample (one channel) */
 };
 
-int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate)
+int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels)
 {
 	/* RIFFxxxxWAVEfmt xxxx(fmt size)dataxxxx... */
 	char dummyheader[4 + 4 + 4 + 4 + 4 + sizeof(struct fmt) + 4 + 4];
@@ -41,6 +41,7 @@ int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate)
 
 	memset(rec, 0, sizeof(*rec));
 	rec->samplerate = samplerate;
+	rec->channels = channels;
 
 	rec->fp = fopen(filename, "w");
 	if (!rec->fp) {
@@ -56,7 +57,7 @@ int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate)
 	return 0;
 }
 
-int wave_create_playback(wave_play_t *play, const char *filename, int samplerate)
+int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels)
 {
 	uint8_t buffer[256];
 	struct fmt fmt;
@@ -65,6 +66,7 @@ int wave_create_playback(wave_play_t *play, const char *filename, int samplerate
 	int rc = -EINVAL;
 
 	memset(play, 0, sizeof(*play));
+	play->channels = channels;
 
 	play->fp = fopen(filename, "r");
 	if (!play->fp) {
@@ -153,8 +155,8 @@ int wave_create_playback(wave_play_t *play, const char *filename, int samplerate
 		rc = -EINVAL;
 		goto error;
 	}
-	if (fmt.channels != 1) {
-		fprintf(stderr, "WAVE error: We support only mono files!\n");
+	if (fmt.channels !=channels) {
+		fprintf(stderr, "WAVE error: We expect %d cannel(s), but wave file only has %d channel(s)\n", channels, fmt.channels);
 		rc = -EINVAL;
 		goto error;
 	}
@@ -163,13 +165,23 @@ int wave_create_playback(wave_play_t *play, const char *filename, int samplerate
 		rc = -EINVAL;
 		goto error;
 	}
+	if ((int)fmt.data_rate != 2 * channels * samplerate) {
+		fprintf(stderr, "WAVE error: The WAVE file's data rate is only %d bytes per second, but we expect %d bytes per second (2 bytes per sample * channels * samplerate)!\n", fmt.data_rate, 2 * channels * samplerate);
+		rc = -EINVAL;
+		goto error;
+	}
+	if (fmt.bytes_sample != 2 * channels) {
+		fprintf(stderr, "WAVE error: The WAVE file's bytes per sample is only %d, but we expect %d bytes sample (2 bytes per sample * channels)!\n", fmt.bytes_sample, 2 * channels);
+		rc = -EINVAL;
+		goto error;
+	}
 	if (fmt.bits_sample != 16) {
 		fprintf(stderr, "WAVE error: We support only 16 bit files!\n");
 		rc = -EINVAL;
 		goto error;
 	}
 
-	play->left = chunk >> 1;
+	play->left = chunk / 2 / channels;
 
 	printf("*** Replacing received audio by %s.\n", filename);
 
@@ -181,14 +193,15 @@ error:
 	return rc;
 }
 
-int wave_read(wave_play_t *play, int16_t *samples, int length)
+int wave_read(wave_play_t *play, int16_t **samples, int length)
 {
-	uint8_t *buffer = (uint8_t *)samples;
+	uint8_t buff[2 * length * play->channels];
 	int __attribute__((__unused__)) len;
-	int i;
+	int i, j, c;
 
 	if (length > (int)play->left) {
-		memset(samples, 0, length << 1);
+		for (c = 0; c < play->channels; c++)
+			memset(samples[c], 0, 2 * length);
 		length = play->left;
 	}
 	if (!length)
@@ -199,28 +212,31 @@ int wave_read(wave_play_t *play, int16_t *samples, int length)
 		printf("*** Finished reading WAVE file.\n");
 
 	/* read and correct endiness */
-	len = fread(samples, 1, length << 1, play->fp);
-	for (i = 0; i < length; i++) {
-		*samples++ = buffer[0] + (buffer[1] << 8);
-		buffer += 2;
+	len = fread(buff, 1, 2 * length * play->channels, play->fp);
+	for (i = 0, j = 0; i < length; i++) {
+		for (c = 0; c < play->channels; c++) {
+			samples[c][i] = buff[j] + (buff[j + 1] << 8);
+			j += 2;
+		}
 	}
 
 	return length;
 }
 
-int wave_write(wave_rec_t *rec, int16_t *samples, int length)
+int wave_write(wave_rec_t *rec, int16_t **samples, int length)
 {
-	uint8_t buffer[length << 1];
+	uint8_t buff[2 * length * rec->channels];
 	int __attribute__((__unused__)) len;
-	int i, j;
+	int i, j, c;
 
 	/* write and correct endiness */
 	for (i = 0, j = 0; i < length; i++) {
-		buffer[j++] = *samples;
-		buffer[j++] = (*samples) >> 8;
-		samples++;
+		for (c = 0; c < rec->channels; c++) {
+			buff[j++] = samples[c][i];
+			buff[j++] = samples[c][i] >> 8;
+		}
 	}
-	len = fwrite(buffer, 1, length << 1, rec->fp);
+	len = fwrite(buff, 1, 2 * length * rec->channels, rec->fp);
 	rec->written += length;
 
 	return length;
@@ -257,10 +273,10 @@ void wave_destroy_record(wave_rec_t *rec)
 	/* fmt */
 	fprintf(rec->fp, "fmt %c%c%c%c", (uint8_t)sizeof(fmt), 0, 0, 0);
 	fmt.format = 1;
-	fmt.channels = 1;
+	fmt.channels = rec->channels;
 	fmt.sample_rate = rec->samplerate; /* samples/sec */
-	fmt.data_rate = rec->samplerate * 2; /* full data rate */
-	fmt.bytes_sample = 2; /* all channels */
+	fmt.data_rate = rec->samplerate * 2 * rec->channels; /* full data rate */
+	fmt.bytes_sample = 2 * rec->channels; /* all channels */
 	fmt.bits_sample = 16; /* one channel */
 	buffer[0] = fmt.format;
 	buffer[1] = fmt.format >> 8;
diff --git a/src/common/wave.h b/src/common/wave.h
index b9575d6..3c7aa48 100644
--- a/src/common/wave.h
+++ b/src/common/wave.h
@@ -1,19 +1,21 @@
 
 typedef struct wave_rec {
 	FILE		*fp;
+	int		channels;
 	int		samplerate;
 	uint32_t	written;	/* how much samples written */
 } wave_rec_t;
 
 typedef struct wave_play {
 	FILE		*fp;
+	int		channels;
 	uint32_t	left;		/* how much samples left */
 } wave_play_t;
 
-int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate);
-int wave_create_playback(wave_play_t *play, const char *filename, int samplerate);
-int wave_read(wave_play_t *play, int16_t *samples, int length);
-int wave_write(wave_rec_t *rec, int16_t *samples, int length);
+int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels);
+int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels);
+int wave_read(wave_play_t *play, int16_t **samples, int length);
+int wave_write(wave_rec_t *rec, int16_t **samples, int length);
 void wave_destroy_record(wave_rec_t *rec);
 void wave_destroy_playback(wave_play_t *play);