Quisk version 4.2.51

CHANGELOG.txt

@@ -1,3 +1,7 @@
+Quisk Version 4.2.51  May 2026
+==============================
+This version can use the TCI protocol to connect to WSJT-X. Please see Digital Modes in the documentation.
+
 Quisk Version 4.2.50  December 2025
 ===================================
 This is a quick fix for a bug in 4.2.49 that results in the repeated message

__init__.py

@@ -1,2 +1,2 @@
-#Quisk version 4.2.50
+#Quisk version 4.2.51
 from .quisk import main

base64.c

@@ -0,0 +1,155 @@
+/*
+ * Base64 encoding/decoding (RFC1341)
+ * Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include "base64.h"
+
+static const unsigned char base64_table[65] =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+/**
+ * base64_encode - Base64 encode
+ * @src: Data to be encoded
+ * @len: Length of the data to be encoded
+ * @out_len: Pointer to output length variable, or %NULL if not used
+ * Returns: Allocated buffer of out_len bytes of encoded data,
+ * or %NULL on failure
+ *
+ * Caller is responsible for freeing the returned buffer. Returned buffer is
+ * nul terminated to make it easier to use as a C string. The nul terminator is
+ * not included in out_len.
+ */
+unsigned char * base64_encode(const unsigned char *src, size_t len,
+			      size_t *out_len)
+{
+	unsigned char *out, *pos;
+	const unsigned char *end, *in;
+	size_t olen;
+	int line_len;
+
+	olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
+	olen += olen / 72; /* line feeds */
+	olen++; /* nul termination */
+	if (olen < len)
+		return NULL; /* integer overflow */
+	out = malloc(olen);
+	if (out == NULL)
+		return NULL;
+
+	end = src + len;
+	in = src;
+	pos = out;
+	line_len = 0;
+	while (end - in >= 3) {
+		*pos++ = base64_table[in[0] >> 2];
+		*pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
+		*pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
+		*pos++ = base64_table[in[2] & 0x3f];
+		in += 3;
+		line_len += 4;
+		if (line_len >= 72) {
+			*pos++ = '\n';
+			line_len = 0;
+		}
+	}
+
+	if (end - in) {
+		*pos++ = base64_table[in[0] >> 2];
+		if (end - in == 1) {
+			*pos++ = base64_table[(in[0] & 0x03) << 4];
+			*pos++ = '=';
+		} else {
+			*pos++ = base64_table[((in[0] & 0x03) << 4) |
+					      (in[1] >> 4)];
+			*pos++ = base64_table[(in[1] & 0x0f) << 2];
+		}
+		*pos++ = '=';
+		line_len += 4;
+	}
+
+	if (line_len)
+		*pos++ = '\n';
+
+	*pos = '\0';
+	if (out_len)
+		*out_len = pos - out;
+	return out;
+}
+
+
+/**
+ * base64_decode - Base64 decode
+ * @src: Data to be decoded
+ * @len: Length of the data to be decoded
+ * @out_len: Pointer to output length variable
+ * Returns: Allocated buffer of out_len bytes of decoded data,
+ * or %NULL on failure
+ *
+ * Caller is responsible for freeing the returned buffer.
+ */
+unsigned char * base64_decode(const unsigned char *src, size_t len,
+			      size_t *out_len)
+{
+	unsigned char dtable[256], *out, *pos, block[4], tmp;
+	size_t i, count, olen;
+	int pad = 0;
+
+	memset(dtable, 0x80, 256);
+	for (i = 0; i < sizeof(base64_table) - 1; i++)
+		dtable[base64_table[i]] = (unsigned char) i;
+	dtable['='] = 0;
+
+	count = 0;
+	for (i = 0; i < len; i++) {
+		if (dtable[src[i]] != 0x80)
+			count++;
+	}
+
+	if (count == 0 || count % 4)
+		return NULL;
+
+	olen = count / 4 * 3;
+	pos = out = malloc(olen);
+	if (out == NULL)
+		return NULL;
+
+	count = 0;
+	for (i = 0; i < len; i++) {
+		tmp = dtable[src[i]];
+		if (tmp == 0x80)
+			continue;
+
+		if (src[i] == '=')
+			pad++;
+		block[count] = tmp;
+		count++;
+		if (count == 4) {
+			*pos++ = (block[0] << 2) | (block[1] >> 4);
+			*pos++ = (block[1] << 4) | (block[2] >> 2);
+			*pos++ = (block[2] << 6) | block[3];
+			count = 0;
+			if (pad) {
+				if (pad == 1)
+					pos--;
+				else if (pad == 2)
+					pos -= 2;
+				else {
+					/* Invalid padding */
+					free(out);
+					return NULL;
+				}
+				break;
+			}
+		}
+	}
+
+	*out_len = pos - out;
+	return out;
+}

base64.h

@@ -0,0 +1,19 @@
+/*
+ * Base64 encoding/decoding (RFC1341)
+ * Copyright (c) 2005, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#ifndef BASE64_H
+#define BASE64_H
+
+#include <sys/types.h>
+
+unsigned char * base64_encode(const unsigned char *src, size_t len,
+			      size_t *out_len);
+unsigned char * base64_decode(const unsigned char *src, size_t len,
+			      size_t *out_len);
+
+#endif /* BASE64_H */

configure.py

@@ -4203,6 +4203,9 @@ class RadioRemote(BaseWindow):		# The Remote page in the second-level notebook f
           heading = None
           self.NextRow()
           self.col = 2
+      if not heading:
+        heading = self.AddTextHeading("TCI", text,
+'Rig control commands and digital sample streams are sent to multiple clients using the TCI protocol.')
       if not heading:
         heading = self.AddTextHeading("Hamlib Rig 2", text,
 'Rig control commands using "Hamlib Rig 2" are sent to a Quisk TCP port from multiple clients.')

docs.html

@@ -1434,9 +1434,35 @@ is no longer needed
 <br>
 </p>
 <h2 id="Digital">Digital Modes </h2>
+<br>
+<h3>Digital Modes with the TCI Protocol</h3>
 <p>
+Using the sound devices in a PC to transfer digital sample streams has always caused problems.
+Several new methods are now becoming available. These are the <a href="https://github.com/ExpertSDR3/TCI">TCI protocol</a>
+used by <a href="https://eesdr.com/en/">Expert Electronics</a> for
+their SunSDR hardware
+and <a href="https://www.vita.com/page-1855484">Vita49</a> used by <a href="https://www.flexradio.com">FlexRadio</a>.
+And Hamlib is planning to add digital stream support.
+</p>
+<br>
+<p>
+Quisk can now connect to WSJT-X version 3.0.0 with the TCI protocol.
+On the Quisk Config/radio/Remote screen enter IP address 127.0.0.1 and port 40001.
+Use USB for digital modes. The DGT-* modes are for sound cards.
+In WSJT-X choose the radio "TCI Client RX1", and for audio choose "TCI audio".
+And enter the same IP and port. Everything then just works.
+If your WSJT-X does not have "TCI Client RX1" you need to update to a more recent version.
+This feature is new. To see the TCI conversation, use the "Debug level" on the Config/radio/Options screen.
+</p>
+<br>
+<h3>Digital Modes with Sound Cards</h3>
+<p>
+Digital modes need to receive the audio from the radio to decode it.
+They need to send audio to the radio to transmit.
+These audio streams have traditionally been sent using PC sound cards or
+an artificial sound card known as a Virtual Audio Cable.
 Quisk has a number of modes "DGT-" to receive and transmit digital
-signals. The modes "DGT-U" and "DGT-L" decode the signal as upper
+signals on sound devices. The modes "DGT-U" and "DGT-L" decode the signal as upper
 or lower sideband, and send the stereo audio to the digital sound
 device. The left and right channel are the same.
 The bandwidth is set with the filter buttons as

handshake.c

@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2016-2024  Davidson Francis <davidsondfgl@gmail.com>
+ *
+ * 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/>
+ */
+#define _POSIX_C_SOURCE 200809L
+#include "base64.h"
+#include "sha1.h"
+#include "ws.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+/**
+ * @dir src/
+ * @brief Handshake routines directory
+ *
+ * @file handshake.c
+ * @brief Handshake routines.
+ */
+
+/**
+ * @brief Gets the field Sec-WebSocket-Accept on response, by
+ * an previously informed key.
+ *
+ * @param wsKey Sec-WebSocket-Key
+ * @param dest source to be stored the value.
+ *
+ * @return Returns 0 if success and a negative number
+ * otherwise.
+ *
+ * @attention This is part of the internal API and is documented just
+ * for completeness.
+ */
+int get_handshake_accept(char *wsKey, unsigned char **dest)
+{
+	unsigned char hash[SHA1HashSize]; /* SHA-1 Hash.                   */
+	SHA1Context ctx;                  /* SHA-1 Context.                */
+	char *str;                        /* WebSocket key + magic string. */
+
+	/* Invalid key. */
+	if (!wsKey)
+		return (-1);
+
+	str = calloc(1, sizeof(char) * (WS_KEY_LEN + WS_MS_LEN + 1));
+	if (!str)
+		return (-1);
+
+	strncpy(str, wsKey, WS_KEY_LEN);
+	strcat(str, MAGIC_STRING);
+
+	SHA1Reset(&ctx);
+	SHA1Input(&ctx, (const uint8_t *)str, WS_KEYMS_LEN);
+	SHA1Result(&ctx, hash);
+
+	*dest = base64_encode(hash, SHA1HashSize, NULL);
+	*(*dest + strlen((const char *)*dest) - 1) = '\0';
+	free(str);
+	return (0);
+}
+
+/**
+ * @brief Finds the ocorrence of @p needle in @p haystack, case
+ * insensitive.
+ *
+ * @param haystack Target string to be searched.
+ * @param needle   Substring to search for.
+ *
+ * @returns If found, returns a pointer at the beginning of the
+ * found substring. Otherwise, returns NULL.
+ */
+static const char *strstricase(const char *haystack, const char *needle)
+{
+	size_t length;
+	for (length = strlen(needle); *haystack; haystack++)
+		if (!strncasecmp(haystack, needle, length))
+			return haystack;
+	return (NULL);
+}
+
+/**
+ * @brief Gets the complete response to accomplish a succesfully
+ * handshake.
+ *
+ * @param hsrequest  Client request.
+ * @param hsresponse Server response.
+ *
+ * @return Returns 0 if success and a negative number
+ * otherwise.
+ *
+ * @attention This is part of the internal API and is documented just
+ * for completeness.
+ */
+int get_handshake_response(char *hsrequest, char **hsresponse)
+{
+	unsigned char *accept; /* Accept message.     */
+	char *saveptr;         /* strtok_r() pointer. */
+	char *s;               /* Current string.     */
+	int ret;               /* Return value.       */
+
+	saveptr = NULL;
+	for (s = strtok_r(hsrequest, "\r\n", &saveptr); s != NULL;
+		 s = strtok_r(NULL, "\r\n", &saveptr))
+	{
+		if (strstricase(s, WS_HS_REQ) != NULL)
+			break;
+	}
+
+	/* Ensure that we have a valid pointer. */
+	if (s == NULL)
+		return (-1);
+
+	saveptr = NULL;
+	s       = strtok_r(s, " ", &saveptr);
+	s       = strtok_r(NULL, " ", &saveptr);
+
+	ret = get_handshake_accept(s, &accept);
+	if (ret < 0)
+		return (ret);
+
+	*hsresponse = malloc(sizeof(char) * WS_HS_ACCLEN);
+	if (*hsresponse == NULL)
+		return (-1);
+
+	strcpy(*hsresponse, WS_HS_ACCEPT);
+	strcat(*hsresponse, (const char *)accept);
+	strcat(*hsresponse, "\r\n\r\n");
+
+	free(accept);
+	return (0);
+}

microphone.c

@@ -1219,6 +1219,10 @@ int quisk_process_microphone(int mic_sample_rate, complex double * cSamples, int
 			count *= interp;
 			transmit_mic_carrier(cSamples, count, quiskSpotLevel / 1000.0);
 		}
+		else if (tci_tx_audio_client) {
+			count = tx_filter_digital(cSamples, count);	// filter samples, minimal processing
+			process_alc(cSamples, count, &tx_alc, DGT_U);
+		}
 		else switch (rxMode) {
 		case LSB:		// LSB
 		case USB:		// USB

quisk.c

@@ -6188,6 +6188,8 @@ static PyMethodDef QuiskMethods[] = {
 	{"watfall_GetPixels", watfall_GetPixels, METH_VARARGS, "Write the Waterfall image to be displayed."},
 	{"write_fftw_wisdom", write_fftw_wisdom, METH_VARARGS, "Write the current fftw wisdom to the wisdom file."},
 	{"read_fftw_wisdom", read_fftw_wisdom, METH_VARARGS, "Return the current fftw wisdom as a byte array."},
+	{"tci_get_params", (PyCFunction)quisk_tci_get_params, METH_VARARGS, "Return parameters from TCI."},
+	{"tci_set_params", (PyCFunction)quisk_tci_set_params, METH_VARARGS|METH_KEYWORDS, "Set parameters for TCI."},
 // Remote Quisk control head and slave by Ben, AC2YD
 	{"start_control_head_remote_sound", quisk_start_control_head_remote_sound, METH_VARARGS, "Start running UDP remote sound on control_head."},
 	{"stop_control_head_remote_sound", quisk_stop_control_head_remote_sound, METH_VARARGS, "Stop running UDP remote sound on control_head."},

quisk.h

@@ -260,6 +260,13 @@ extern PyObject * quisk_stop_remote_radio_remote_sound(PyObject * self, PyObject
 extern int receive_graph_data(double * fft_avg);
 extern void send_graph_data(double * fft_avg, int fft_size, double zoom, double deltaf, int fft_sample_rate, double scale);
 
+// TCI server
+PyObject * quisk_tci_set_params(PyObject * self, PyObject * args, PyObject * keywds);
+PyObject * quisk_tci_get_params(PyObject * self, PyObject * args);
+void tci_send_audio(complex double * cSamples, int nSamples);
+int tci_get_mic(complex double * cSamples, int mic_count);
+extern uint64_t tci_tx_audio_client;	// This is ws_cli_conn_t defined in ws.h.
+
 void QuiskWavClose(struct QuiskWav *);
 int QuiskWavWriteOpen(struct QuiskWav *, char *, short, short, short, int, double);
 void QuiskWavWriteC(struct QuiskWav *, complex double *, int);
@@ -394,6 +401,7 @@ int quisk_play_sidetone(struct sound_dev *);
 void quisk_set_play_state(void);
 void quisk_poll_hardware_key(void);
 void PreDistort(complex double * amp_in_samples, complex double * amp_out_samples, int nSamples, complex double * tx_samples, int num_tx);
+int CircularBuffer(int channel, complex double * cSamples, int nRead, int nWrite);
 
 // Driver function definitions=================================================
 int  quisk_read_alsa(struct sound_dev *, complex double *);

quisk.py

@@ -3938,6 +3938,7 @@ class App(wx.App):
     self.hot_key_ptt_active = False
     self.serial_ptt_active = False
     self.vox_ptt_active = False
+    self.tci_ptt_active = False
     self.hermes_LNA_dB = 20
     self.hermes_atten_dB = 0
     if hasattr(Hardware, "OnChangeRxTx"):
@@ -4028,6 +4029,8 @@ class App(wx.App):
     self.file_name_play_samples = ''
     self.file_name_play_cq = ''
     self.midiControls = {}		# Control object and associated function for Midi control name
+    self.tci_vfo = 0
+    self.tci_started = False
     # get the screen size - thanks to Lucian Langa
     x, y, self.screen_width, self.screen_height = wx.Display().GetGeometry()	# Using display index 0
     self.Bind(wx.EVT_IDLE, self.OnIdle)
@@ -4353,6 +4356,19 @@ class App(wx.App):
     if hasattr(bw, "sliderLNA"):
       self.midiControls["RfLna"]	= (bw.sliderLNA,	bw.OnLNA)
     self.Bind(wx.EVT_CHAR_HOOK, self.OnKeyHook)
+    # Start the TCI server
+    if conf.tci_ip and conf.tci_port:
+      value = getattr(conf, "pulse_audio_verbose_output")
+      QS.tci_set_params(verbose=value)
+      QS.tci_set_params(start=1);
+      self.tci_started = True
+      QS.tci_set_params(tci_dds=self.VFO)
+      QS.tci_set_params(tci_if=self.txFreq)
+      self.tci_vfo = self.txFreq + self.VFO
+      QS.tci_set_params(tci_vfo=self.tci_vfo)
+      QS.tci_set_params(tci_modulation=self.mode)
+      QS.tci_set_params(tci_trx=0)
+      QS.tci_set_params(tci_split_enable=0)
     return True
   def OnStartWsjtx(self, ctrl):
     method = ctrl.GetValue()
@@ -4762,6 +4778,7 @@ class App(wx.App):
   def ImmediateChange(self, name):
     if name == "pulse_audio_verbose_output":
       value = getattr(conf, name)
+      QS.tci_set_params(verbose=value)
       if value == 0:
         self.std_out_err.Show(False)
       else:
@@ -5765,6 +5782,7 @@ class App(wx.App):
       QS.set_sidetone(self.sidetone_volume, self.sidetone_0to1, self.ritFreq, conf.keyupDelay)
   def OnBtnSplit(self, event):	# Called when the Split check button is pressed
     self.split_rxtx = self.splitButton.GetValue()
+    QS.tci_set_params(tci_split_enable=self.split_rxtx)
     if self.split_rxtx:
       if self.split_offset == 0:
         if self.mode in ("CWL", "CWU"):
@@ -6150,6 +6168,7 @@ class App(wx.App):
       self.ChangeRxTxFrequency(self.rxFreq + delta + self.VFO, self.txFreq + delta + self.VFO)
     Hardware.ChangeMode(mode)
     self.mode = mode
+    QS.tci_set_params(tci_modulation=mode)
     self.MakeFilterButtons(self.Mode2Filters(mode))
     QS.set_rx_mode(Mode2Index.get(mode, 3))
     if mode == 'CWL':
@@ -6677,11 +6696,13 @@ class App(wx.App):
       if not self.tx_indicator:
         self.tx_indicator = True
         self.pttButton.Tx.TurnOn(True)
+        QS.tci_set_params(tci_trx=1)
     else:
       if self.tx_indicator:
         self.tx_indicator = False
         self.pttButton.Tx.TurnOn(False)
-    if True:	# Manage the PTT button using serial port, VOX, hot keys, WAV file play, PTT button, MIDI, CAT
+        QS.tci_set_params(tci_trx=0)
+    if True:	# Manage the PTT button using serial port, VOX, hot keys, WAV file play, PTT button, MIDI, CAT, TCI
       ptt_button_down = self.pttButton.GetValue()
       ptt = None
       if conf.quisk_serial_cts[0:4] == "PTT " or conf.quisk_serial_dsr[0:4] == "PTT ":
@@ -6736,6 +6757,14 @@ class App(wx.App):
         self.hot_key_ptt_pressed = False
       if self.tx_inhibit:
         ptt = False
+      tci = QS.tci_get_params("tci_trx")
+      if tci is not None:
+        if tci:
+          self.tci_ptt_active = True
+          ptt = True
+        elif self.tci_ptt_active:
+          self.tci_ptt_active = False
+          ptt = False
       if ptt is True and not ptt_button_down:
         self.SetPTT(True)
       elif ptt is False and ptt_button_down:
@@ -6803,6 +6832,19 @@ class App(wx.App):
     if self.timer - self.heart_time0 > 0.10:	# call hardware to perform background tasks:
       self.heart_time0 = self.timer
       Hardware.HeartBeat()
+      if self.tci_started:
+        if self.tci_vfo != self.txFreq + self.VFO:	# limit the speed of frequency updates
+          self.tci_vfo = self.txFreq + self.VFO
+          QS.tci_set_params(tci_vfo=self.tci_vfo)
+        freq = QS.tci_get_params("tci_vfo")
+        if freq is not None:	# TCI frequency
+          self.ChangeRxTxFrequency(freq, None)
+        mode = QS.tci_get_params("tci_modulation")
+        if mode is not None:	# TCI mode
+          self.modeButns.SetLabel(mode, True)
+        split = QS.tci_get_params("tci_split_enable")
+        if split is not None:	# TCI split_enable
+          self.splitButton.SetValue(split, True)
       if self.is_HermesLite2:
         self.tx_inhibit = QS.get_params('quisk_tx_inhibit')
       else:

quisk_conf_defaults.py

@@ -1423,6 +1423,19 @@ fixed_tune_offset = 0
 
 
 ################ Remote
+## tci_ip		IP address for TCI, text
+# Quisk can connect to WSJT-X and other digital programs using the TCI protocol.
+# Enter the TCI server host name.
+tci_ip = "127.0.0.1"
+
+## tci_port		IP port for TCI, integer
+# Quisk can connect to WSJT-X and other digital programs using the TCI protocol.
+# Enter the TCI port number. If the port number is zero, TCI is turned off.
+# The preferred port is 40001.
+tci_port = 0
+#tci_port = 40001
+#tci_port = 50001
+
 ## hamlib_ip            IP address for Hamlib Rig 2, text
 # You can control Quisk from Hamlib.  Set the Hamlib rig to 2 and the device for rig 2 to
 # localhost:4575.  Or choose a different name and port here.  Set the same name and port

setup.py

@@ -7,7 +7,7 @@ import os
 # You must define the version here.  A title string including
 # the version will be written to __init__.py and read by quisk.py.
 
-Version = '4.2.50'
+Version = '4.2.51'
 
 fp = open("__init__.py", "w")	# write title string
 fp.write("#Quisk version %s\n" % Version)
@@ -16,7 +16,8 @@ fp.close()
 
 sources = ['quisk.c', 'sound.c', 'is_key_down.c', 'microphone.c', 'utility.c',
 	'sound_alsa.c', 'sound_pulseaudio.c', 'sound_portaudio.c', 'sound_directx.c', 'sound_wasapi.c',
-	'filter.c', 'extdemod.c', 'freedv.c', 'quisk_wdsp.c', 'ac2yd/remote.c']
+	'filter.c', 'extdemod.c', 'freedv.c', 'quisk_wdsp.c', 'ac2yd/remote.c',
+	'tci.c', 'base64.c', 'handshake.c', 'sha1.c', 'utf8.c', 'ws.c']
 
 # Afedri hardware support added by Alex, Alex@gmail.com
 mAfedri = Extension ('quisk.afedrinet.afedrinet_io',

sha1.c

@@ -0,0 +1,389 @@
+/*
+ *  sha1.c
+ *
+ *  Description:
+ *      This file implements the Secure Hashing Algorithm 1 as
+ *      defined in FIPS PUB 180-1 published April 17, 1995.
+ *
+ *      The SHA-1, produces a 160-bit message digest for a given
+ *      data stream.  It should take about 2**n steps to find a
+ *      message with the same digest as a given message and
+ *      2**(n/2) to find any two messages with the same digest,
+ *      when n is the digest size in bits.  Therefore, this
+ *      algorithm can serve as a means of providing a
+ *      "fingerprint" for a message.
+ *
+ *  Portability Issues:
+ *      SHA-1 is defined in terms of 32-bit "words".  This code
+ *      uses <stdint.h> (included via "sha1.h" to define 32 and 8
+ *      bit unsigned integer types.  If your C compiler does not
+ *      support 32 bit unsigned integers, this code is not
+ *      appropriate.
+ *
+ *  Caveats:
+ *      SHA-1 is designed to work with messages less than 2^64 bits
+ *      long.  Although SHA-1 allows a message digest to be generated
+ *      for messages of any number of bits less than 2^64, this
+ *      implementation only works with messages with a length that is
+ *      a multiple of the size of an 8-bit character.
+ *
+ */
+
+#include "sha1.h"
+
+/*
+ *  Define the SHA1 circular left shift macro
+ */
+#define SHA1CircularShift(bits,word) \
+                (((word) << (bits)) | ((word) >> (32-(bits))))
+
+/* Local Function Prototyptes */
+void SHA1PadMessage(SHA1Context *);
+void SHA1ProcessMessageBlock(SHA1Context *);
+
+/*
+ *  SHA1Reset
+ *
+ *  Description:
+ *      This function will initialize the SHA1Context in preparation
+ *      for computing a new SHA1 message digest.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to reset.
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Reset(SHA1Context *context)
+{
+    if (!context)
+    {
+        return shaNull;
+    }
+
+    context->Length_Low             = 0;
+    context->Length_High            = 0;
+    context->Message_Block_Index    = 0;
+
+    context->Intermediate_Hash[0]   = 0x67452301;
+    context->Intermediate_Hash[1]   = 0xEFCDAB89;
+    context->Intermediate_Hash[2]   = 0x98BADCFE;
+    context->Intermediate_Hash[3]   = 0x10325476;
+    context->Intermediate_Hash[4]   = 0xC3D2E1F0;
+
+    context->Computed   = 0;
+    context->Corrupted  = 0;
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1Result
+ *
+ *  Description:
+ *      This function will return the 160-bit message digest into the
+ *      Message_Digest array  provided by the caller.
+ *      NOTE: The first octet of hash is stored in the 0th element,
+ *            the last octet of hash in the 19th element.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to use to calculate the SHA-1 hash.
+ *      Message_Digest: [out]
+ *          Where the digest is returned.
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Result( SHA1Context *context,
+                uint8_t Message_Digest[SHA1HashSize])
+{
+    int i;
+
+    if (!context || !Message_Digest)
+    {
+        return shaNull;
+    }
+
+    if (context->Corrupted)
+    {
+        return context->Corrupted;
+    }
+
+    if (!context->Computed)
+    {
+        SHA1PadMessage(context);
+        for(i=0; i<64; ++i)
+        {
+            /* message may be sensitive, clear it out */
+            context->Message_Block[i] = 0;
+        }
+        context->Length_Low = 0;    /* and clear length */
+        context->Length_High = 0;
+        context->Computed = 1;
+
+    }
+
+    for(i = 0; i < SHA1HashSize; ++i)
+    {
+        Message_Digest[i] = context->Intermediate_Hash[i>>2]
+                            >> 8 * ( 3 - ( i & 0x03 ) );
+    }
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1Input
+ *
+ *  Description:
+ *      This function accepts an array of octets as the next portion
+ *      of the message.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The SHA context to update
+ *      message_array: [in]
+ *          An array of characters representing the next portion of
+ *          the message.
+ *      length: [in]
+ *          The length of the message in message_array
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Input(    SHA1Context    *context,
+                  const uint8_t  *message_array,
+                  unsigned       length)
+{
+    if (!length)
+    {
+        return shaSuccess;
+    }
+
+    if (!context || !message_array)
+    {
+        return shaNull;
+    }
+
+    if (context->Computed)
+    {
+        context->Corrupted = shaStateError;
+
+        return shaStateError;
+    }
+
+    if (context->Corrupted)
+    {
+         return context->Corrupted;
+    }
+    while(length-- && !context->Corrupted)
+    {
+    context->Message_Block[context->Message_Block_Index++] =
+                    (*message_array & 0xFF);
+
+    context->Length_Low += 8;
+    if (context->Length_Low == 0)
+    {
+        context->Length_High++;
+        if (context->Length_High == 0)
+        {
+            /* Message is too long */
+            context->Corrupted = 1;
+        }
+    }
+
+    if (context->Message_Block_Index == 64)
+    {
+        SHA1ProcessMessageBlock(context);
+    }
+
+    message_array++;
+    }
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1ProcessMessageBlock
+ *
+ *  Description:
+ *      This function will process the next 512 bits of the message
+ *      stored in the Message_Block array.
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+
+ *      Many of the variable names in this code, especially the
+ *      single character names, were used because those were the
+ *      names used in the publication.
+ *
+ *
+ */
+void SHA1ProcessMessageBlock(SHA1Context *context)
+{
+    const uint32_t K[] =    {       /* Constants defined in SHA-1   */
+                            0x5A827999,
+                            0x6ED9EBA1,
+                            0x8F1BBCDC,
+                            0xCA62C1D6
+                            };
+    int           t;                 /* Loop counter                */
+    uint32_t      temp;              /* Temporary word value        */
+    uint32_t      W[80];             /* Word sequence               */
+    uint32_t      A, B, C, D, E;     /* Word buffers                */
+
+    /*
+     *  Initialize the first 16 words in the array W
+     */
+    for(t = 0; t < 16; t++)
+    {
+        W[t]  = (uint32_t)context->Message_Block[t * 4] << 24;
+        W[t] |= (uint32_t)context->Message_Block[t * 4 + 1] << 16;
+        W[t] |= (uint32_t)context->Message_Block[t * 4 + 2] << 8;
+        W[t] |= (uint32_t)context->Message_Block[t * 4 + 3];
+    }
+
+    for(t = 16; t < 80; t++)
+    {
+       W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+    }
+
+    A = context->Intermediate_Hash[0];
+    B = context->Intermediate_Hash[1];
+    C = context->Intermediate_Hash[2];
+    D = context->Intermediate_Hash[3];
+    E = context->Intermediate_Hash[4];
+
+    for(t = 0; t < 20; t++)
+    {
+        temp =  SHA1CircularShift(5,A) +
+                ((B & C) | ((~B) & D)) + E + W[t] + K[0];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+
+        B = A;
+        A = temp;
+    }
+
+    for(t = 20; t < 40; t++)
+    {
+        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 40; t < 60; t++)
+    {
+        temp = SHA1CircularShift(5,A) +
+               ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 60; t < 80; t++)
+    {
+        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    context->Intermediate_Hash[0] += A;
+    context->Intermediate_Hash[1] += B;
+    context->Intermediate_Hash[2] += C;
+    context->Intermediate_Hash[3] += D;
+    context->Intermediate_Hash[4] += E;
+
+    context->Message_Block_Index = 0;
+}
+
+/*
+ *  SHA1PadMessage
+ *
+
+ *  Description:
+ *      According to the standard, the message must be padded to an even
+ *      512 bits.  The first padding bit must be a '1'.  The last 64
+ *      bits represent the length of the original message.  All bits in
+ *      between should be 0.  This function will pad the message
+ *      according to those rules by filling the Message_Block array
+ *      accordingly.  It will also call the ProcessMessageBlock function
+ *      provided appropriately.  When it returns, it can be assumed that
+ *      the message digest has been computed.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to pad
+ *      ProcessMessageBlock: [in]
+ *          The appropriate SHA*ProcessMessageBlock function
+ *  Returns:
+ *      Nothing.
+ *
+ */
+
+void SHA1PadMessage(SHA1Context *context)
+{
+    /*
+     *  Check to see if the current message block is too small to hold
+     *  the initial padding bits and length.  If so, we will pad the
+     *  block, process it, and then continue padding into a second
+     *  block.
+     */
+    if (context->Message_Block_Index > 55)
+    {
+        context->Message_Block[context->Message_Block_Index++] = 0x80;
+        while(context->Message_Block_Index < 64)
+        {
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+
+        SHA1ProcessMessageBlock(context);
+
+        while(context->Message_Block_Index < 56)
+        {
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+    }
+    else
+    {
+        context->Message_Block[context->Message_Block_Index++] = 0x80;
+        while(context->Message_Block_Index < 56)
+        {
+
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+    }
+
+    /*
+     *  Store the message length as the last 8 octets
+     */
+    context->Message_Block[56] = context->Length_High >> 24;
+    context->Message_Block[57] = context->Length_High >> 16;
+    context->Message_Block[58] = context->Length_High >> 8;
+    context->Message_Block[59] = context->Length_High;
+    context->Message_Block[60] = context->Length_Low >> 24;
+    context->Message_Block[61] = context->Length_Low >> 16;
+    context->Message_Block[62] = context->Length_Low >> 8;
+    context->Message_Block[63] = context->Length_Low;
+
+    SHA1ProcessMessageBlock(context);
+}

sha1.h

@@ -0,0 +1,73 @@
+/*
+ *  sha1.h
+ *
+ *  Description:
+ *      This is the header file for code which implements the Secure
+ *      Hashing Algorithm 1 as defined in FIPS PUB 180-1 published
+ *      April 17, 1995.
+ *
+ *      Many of the variable names in this code, especially the
+ *      single character names, were used because those were the names
+ *      used in the publication.
+ *
+ *      Please read the file sha1.c for more information.
+ *
+ */
+
+#ifndef _SHA1_H_
+#define _SHA1_H_
+
+#include <stdint.h>
+/*
+ * If you do not have the ISO standard stdint.h header file, then you
+ * must typdef the following:
+ *    name              meaning
+ *  uint32_t         unsigned 32 bit integer
+ *  uint8_t          unsigned 8 bit integer (i.e., unsigned char)
+ *  int_least16_t    integer of >= 16 bits
+ *
+ */
+
+#ifndef _SHA_enum_
+#define _SHA_enum_
+enum
+{
+    shaSuccess = 0,
+    shaNull,            /* Null pointer parameter */
+    shaInputTooLong,    /* input data too long */
+    shaStateError       /* called Input after Result */
+};
+#endif
+#define SHA1HashSize 20
+
+/*
+ *  This structure will hold context information for the SHA-1
+ *  hashing operation
+ */
+typedef struct SHA1Context
+{
+    uint32_t Intermediate_Hash[SHA1HashSize/4]; /* Message Digest  */
+
+    uint32_t Length_Low;            /* Message length in bits      */
+    uint32_t Length_High;           /* Message length in bits      */
+
+                               /* Index into message block array   */
+    int_least16_t Message_Block_Index;
+    uint8_t Message_Block[64];      /* 512-bit message blocks      */
+
+    int Computed;               /* Is the digest computed?         */
+    int Corrupted;             /* Is the message digest corrupted? */
+} SHA1Context;
+
+/*
+ *  Function Prototypes
+ */
+
+int SHA1Reset(  SHA1Context *);
+int SHA1Input(  SHA1Context *,
+                const uint8_t *,
+                unsigned int);
+int SHA1Result( SHA1Context *,
+                uint8_t Message_Digest[SHA1HashSize]);
+
+#endif

sound.c

@@ -113,7 +113,7 @@ void quisk_sample_level(const char * msg, complex double * cSamples, int nSample
 			level = d;
 	}
 	if (QuiskTimeSec() - time0 > 0.1) {
-		printf ("sample_level %s: %10.6lf count %8d\n", msg, level / scale, count);
+		printf ("peak sample level %s: %14.6lf count %8d\n", msg, level / scale, count);
 		level = 0;
 		count = 0;
 		time0 = QuiskTimeSec();
@@ -1019,7 +1019,9 @@ int quisk_read_sound(void)	// Called from sound thread
    
 	// Play digital if required
 	//if (is_DGT)
-		play_sound_interface(&DigitalOutput, nSamples, cSamples, 1, digital_output_level);
+	play_sound_interface(&DigitalOutput, nSamples, cSamples, 1, digital_output_level);
+	// Send radio sound to TCI
+	tci_send_audio(cSamples, nSamples);
    
 	// Perhaps record the speaker audio to a file
 	if ( ! key_state && file_rec_audio.fp)
@@ -1065,7 +1067,10 @@ int quisk_read_sound(void)	// Called from sound thread
 		for (i = 0; i < mic_count; i++)
 			cSamples[i] = 0;
 	}
-	//quisk_sample_level("read mic or DGT", cSamples, mic_count, CLIP16);
+	// Receive microphone sound from TCI
+	//quisk_sample_level("read mic or DGT", cSamples, mic_count, CLIP32);
+	mic_count = tci_get_mic(cSamples, mic_count);
+	//quisk_sample_level("quisk_tci", cSamples, mic_count, CLIP32);
 	// Perhaps record the microphone audio to the speaker audio file
 	if (key_state && file_rec_audio.fp)
 		quisk_record_audio(&file_rec_audio, cSamples, mic_count);

tci.c

@@ -0,0 +1,651 @@
+#include <Python.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "ws.h"
+#include <pthread.h>
+#include <complex.h>
+#include <time.h>
+#include "quisk.h"
+
+#define TCI_RX_BUF_SIZE	1024
+#define TCI_TX_BUFFER_MSEC	30	// Buffer delay in milliseconds
+#define TCI_COMMAND_SIZE	32
+
+static int verbose;	// non-zero for verbose log messages
+static int tci_port;
+
+// Implement the ExpertSDR2 Version 1.4 protocol:
+// The only sample rate is 48000. The Tx audio parameters are copied from the Rx audio stream.
+// The only sample type is FLOAT32, type 4. The FLOAT32 type is 3 in ExpertSDR3. We will always use 3.
+// WSJT-X RX_AUDIO_STREAM must be two channels and Stream.length is the number of floats (not samples).
+// WSJT-X TX_AUDIO_STREAM always returns two channels but the data is one channel in half the data length.
+// It is unclear whether stream.length is the number of floats, or half that for two channels. And version 1.4 lacks stream.channels.
+// The protocol name for TCI version 1.4 is "protocol:ESDR,1.4;" and the port is 40001.
+// The protocol name for TCI version 2.0 is "protocol:ExpertSDR3,2.0;" and the port is 50001.
+// The TCI modulations are: AM, SAM, DSB, LSB, USB, CW, NFM, WFM, SPEC, DIGL, DIGU, DRM.
+
+// These are TCI parameters:
+//static int quisk_dds;
+//static int quisk_if;
+static int quisk_vfo;
+static int client_vfo=-1;
+static int quisk_trx;
+static int client_trx=-1;
+static int quisk_split_enable;
+static int client_split_enable=-1;
+static char   quisk_modulation[TCI_COMMAND_SIZE];
+static char   client_modulation[TCI_COMMAND_SIZE]={0};
+
+static ws_cli_conn_t tci_clients_list[MAX_CLIENTS];	// list of TCI clients
+static int           tci_clients_count;
+ws_cli_conn_t tci_tx_audio_client;			// single client providing Tx audio
+static int tci_started;		// Did we start the TCI server?
+
+static pthread_mutex_t clients_list_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t tx_buffer_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+enum StreamType		// ExpertSDR3
+{
+IQ_STREAM = 0,		// Receiver IQ signal stream
+RX_AUDIO_STREAM = 1,	// Receiver audio stream
+TX_AUDIO_STREAM = 2,	// Audio stream for transmitter
+TX_CHRONO = 3,		// Time marker flow for audio signal transmission
+LINEOUT_STREAM = 4	// Linear audio output audio stream
+} ;
+
+enum SampleType		// ExpertSDR3
+{
+TCI_INT16 = 0,	// 16-bit integral character type
+TCI_INT24 = 1,	// 24-bit integral character type
+TCI_INT32 = 2,	// 32-bit integral character type
+TCI_FLOAT32 = 3,	// 32-bit type with a floating point (was 4 in SDR2)
+} ;
+
+struct ClientData {	// data for each client
+	char msg_buf[TCI_RX_BUF_SIZE];
+	int msg_length;
+	int send_Rx_audio_stream;
+	int audio_stream_samplerate;
+	int audio_stream_sample_type;
+	int audio_stream_channels;
+	int audio_stream_samples;
+	int audio_stream_bytes_per_sample;
+} ;
+
+struct _Stream {
+	uint32_t receiver;	// receiver number
+	uint32_t sample_rate;	// sampling rate
+	uint32_t format;	// sample type determined in SampleType
+	uint32_t codec;		// compression algorithm (not implemented), always 0
+	uint32_t crc;		// checksum (not implemented), always 0
+	int32_t  length;	// number of samples
+	uint32_t type;		// stream type determined in StreamType
+	uint32_t channels;	// number of channels for ExpertSDR3
+	uint32_t reserv[8];	// reserved
+	uint8_t  data[16384];	// samples
+} ;
+
+struct _TxChrono {
+	uint32_t receiver;	// receiver number
+	uint32_t sample_rate;	// sampling rate
+	uint32_t format;	// sample type determined in SampleType
+	uint32_t codec;		// compression algorithm (not implemented), always 0
+	uint32_t crc;		// checksum (not implemented), always 0
+	int32_t  length;	// number of samples
+	uint32_t type;		// stream type determined in StreamType
+	uint32_t channels;	// number of channels for ExpertSDR3
+	uint32_t reserv[8];	// reserved
+} ;
+
+static struct _TxChrono TxChrono = {
+	.receiver = 0,
+	.sample_rate = 48000,
+	.format = TCI_FLOAT32,
+	.codec = 0,
+	.crc = 0,
+	.length = 0,
+	.type = TX_CHRONO,
+	.channels = 1,
+	.reserv = {0, 0, 0, 0, 0, 0, 0, 0}
+} ;
+
+struct _StreamTypes {
+	char * name;
+	time_t when;
+} ;
+
+#define NUM_STREAM_TYPES	5
+struct _StreamTypes StreamTypes[NUM_STREAM_TYPES] = {
+	{"iq       ", 0},
+	{"rx_audio ", 0},
+	{"tx_audio ", 0},
+	{"tx_chrono", 0},
+	{"lineout  ", 0}
+} ;
+
+static void PrintStream(const char * msg, size_t size)
+{
+	struct _Stream * pt = (struct _Stream *)msg;
+
+	if (time(NULL) - StreamTypes[pt->type].when > 5) {
+		StreamTypes[pt->type].when = time(NULL);
+		if (pt->type == TX_AUDIO_STREAM)
+			QuiskPrintf("TCI     Receiving %slength %5d:", StreamTypes[pt->type].name, (int)size);
+		else
+			QuiskPrintf("TCI Sending %s      length %5d:", StreamTypes[pt->type].name, (int)size);
+		QuiskPrintf("%d %5d %d %d %d %5d %d %d\n", (int)(pt->receiver), (int)(pt->sample_rate), (int)(pt->format), (int)(pt->codec),
+			(int)(pt->crc), (int)(pt->length), (int)(pt->type), (int)(pt->channels));
+	}
+}
+
+static int sendframe_txt(ws_cli_conn_t client, const char * msg)
+{
+	if (verbose)
+		QuiskPrintf("TCI Send text              %s\n", msg);
+	return ws_sendframe_txt(client, msg);
+}
+
+static int sendframe_txt_bcast(uint16_t port, const char * msg)
+{
+	if (verbose)
+		QuiskPrintf("TCI Broadcast text         %s\n", msg);
+	return ws_sendframe_txt_bcast(port, msg);
+}
+
+static size_t sendframe_bin(ws_cli_conn_t client, const char * msg, size_t size)
+{
+	if (verbose)
+		PrintStream(msg, size);
+	return ws_sendframe_bin(client, msg, size);
+}
+
+static int text_message(ws_cli_conn_t client, struct ClientData * ctx)
+{  // This function alters the message ctx->msg_buf.
+	int i;
+	char char_buf[TCI_COMMAND_SIZE];
+	char * saveptr, * command;
+	char * arg1, * arg2, * arg3;
+
+	if (verbose)
+		QuiskPrintf("TCI     Received text      %s\n", ctx->msg_buf);
+	for (i = 0; ctx->msg_buf[i]; i++)
+		ctx->msg_buf[i] = tolower(ctx->msg_buf[i]);
+	command = strtok_r(ctx->msg_buf, ":", &saveptr);
+	if (command == NULL)
+		return 0;
+	arg1 = strtok_r(NULL, ",;", &saveptr);
+	arg2 = strtok_r(NULL, ",;", &saveptr);
+	arg3 = strtok_r(NULL, ",;", &saveptr);
+	// The command will be broadcast to all clients unless the return value is zero.
+	switch (command[0]) {
+	case 'a':
+		if (strcmp(command, "audio_start") == 0) {
+			pthread_mutex_lock(&clients_list_mutex);
+			for (i = 0; i < tci_clients_count; i++) {
+				if (tci_clients_list[i] == client) {
+					ctx->send_Rx_audio_stream = 1;
+					break;
+				}
+			}
+			pthread_mutex_unlock(&clients_list_mutex);
+		}
+		else if (strcmp(command, "audio_stop") == 0) {
+			pthread_mutex_lock(&clients_list_mutex);
+			for (i = 0; i < tci_clients_count; i++) {
+				if (tci_clients_list[i] == client) {
+					ctx->send_Rx_audio_stream = 0;
+					break;
+				}
+			}
+			pthread_mutex_unlock(&clients_list_mutex);
+		}
+		else if (strcmp(command, "audio_stream_sample_type") == 0) {
+			if (strcmp(arg1, "float32") == 0) {
+				ctx->audio_stream_sample_type = TCI_FLOAT32;
+				ctx->audio_stream_bytes_per_sample = 4;
+			}
+			else {
+				return 0;
+			}
+		}
+		else if (strcmp(command, "audio_samplerate") == 0) {
+			if (atoi(arg1) != 48000)
+				return 0;
+		}
+		else if (strcmp(command, "audio_stream_channels") == 0) {
+			if (strcmp(arg1, "1") == 0)
+				ctx->audio_stream_channels = 1;
+			else if (strcmp(arg1, "2") == 0)
+				ctx->audio_stream_channels = 2;
+			else
+				return 0;
+		}
+		else if (strcmp(command, "audio_stream_samples") == 0) {
+			return 0;	// do not send
+		}
+		break;
+	case 'i':
+		if (strcmp(command, "iq_start") == 0)
+			return 0;	// do not send
+		else if (strcmp(command, "iq_stop") == 0)
+			return 0;	// do not send
+		else if (strcmp(command, "iq_samplerate") == 0)
+			return 0;	// do not send
+		break;
+	case 'm':
+		if (strcmp(command, "modulation") == 0) {
+			if (arg2) {
+				for (i = 0; arg2[i]; i++)
+					arg2[i] = toupper(arg2[i]);
+				strncpy(client_modulation, arg2, TCI_COMMAND_SIZE - 1);
+			}
+			else {
+				snprintf(char_buf, TCI_COMMAND_SIZE, "modulation:0,%.9s;", quisk_modulation);
+				sendframe_txt(client, char_buf);
+			}
+			return 0;
+		}
+		break;
+	case 's':
+		if (strcmp(command, "split_enable") == 0) {
+			if (arg2) {
+				if (strcmp(arg2, "true") == 0)
+					client_split_enable = 1;
+				else
+					client_split_enable = 0;
+			}
+			else {
+				if (quisk_split_enable)
+					sendframe_txt(client, "split_enable:0,true;");
+				else
+					sendframe_txt(client, "split_enable:0,false;");
+			}
+			return 0;
+		}
+		break;
+	case 't':
+		if (strcmp(command, "trx") == 0) {
+			if (arg2) {
+				if (strcmp(arg2, "true") == 0) {
+					if (quisk_trx == 0) {
+						client_trx = 1;
+						CircularBuffer(0, NULL, TCI_TX_BUFFER_MSEC * ctx->audio_stream_samplerate / 1000, 0);
+						tci_tx_audio_client = client;
+					}
+				}
+				else if (client == tci_tx_audio_client) {
+					client_trx = 0;
+					tci_tx_audio_client = 0;
+				}
+			}
+			else {
+				if (quisk_trx)
+					sendframe_txt(client, "trx:0,true;");
+				else
+					sendframe_txt(client, "trx:0,false;");
+			}
+			return 0;
+		}
+		else if (strcmp(command, "tx_stream_audio_buffering") == 0) {
+			return 0;	// do not send
+		}
+		break;
+	case 'v':
+		if (strcmp(command, "vfo") == 0) {
+			if (arg3) {
+				client_vfo = atoi(arg3);
+			}
+			else {
+				snprintf(char_buf, TCI_COMMAND_SIZE, "vfo:0,0,%d;", quisk_vfo);
+				sendframe_txt(client, char_buf);
+			}
+			return 0;
+		}
+		break;
+	}
+	return 1;	// send to all clients
+}
+
+static void onopen(ws_cli_conn_t client)
+{
+	char *cli;
+	char command[TCI_COMMAND_SIZE];
+	struct ClientData * ctx;
+
+	// Make parameters for each client:
+	ctx = malloc(sizeof(struct ClientData));
+	ctx->msg_length = 0;
+	ctx->send_Rx_audio_stream = 0;
+	ctx->audio_stream_samplerate = 48000;
+	ctx->audio_stream_sample_type = TCI_FLOAT32;
+	ctx->audio_stream_channels = 2;
+	ctx->audio_stream_samples = 0;
+	ctx->audio_stream_bytes_per_sample = 4;
+	ws_set_connection_context(client, ctx);
+
+	pthread_mutex_lock(&clients_list_mutex);
+	tci_clients_list[tci_clients_count++] = client;
+	pthread_mutex_unlock(&clients_list_mutex);
+
+	if (verbose) {
+		cli = ws_getaddress(client);
+		QuiskPrintf("TCI *Connection opened, addr: %s\n", cli);
+	}
+
+	sendframe_txt(client, "protocol:ESDR,1.4;");
+	sendframe_txt(client, "vfo_limits:30000,30000000;");
+	sendframe_txt(client, "if_limits:-48000,48000;");
+	sendframe_txt(client, "trx_count:1;");
+	sendframe_txt(client, "channel_count:1;");
+	sendframe_txt(client, "device:QuiskSDR;");
+	sendframe_txt(client, "receive_only:false;");
+	sendframe_txt(client, "modulations_list:USB,LSB,CW,AM,FM,DIGL,DIGU;");
+	sendframe_txt(client, "ready;");
+
+	sendframe_txt(client, "start;");
+	sendframe_txt(client, "tx_enable:0,true;");
+	//snprintf(command, TCI_COMMAND_SIZE, "dds:0,%d;", quisk_dds);
+	//sendframe_txt(client, command);
+	//snprintf(command, TCI_COMMAND_SIZE, "if:0,0,%d;", quisk_if);
+	//sendframe_txt(client, command);
+	snprintf(command, TCI_COMMAND_SIZE, "modulation:0,%.9s;", quisk_modulation);
+	sendframe_txt(client, command);
+	snprintf(command, TCI_COMMAND_SIZE, "vfo:0,0,%d;", quisk_vfo);
+	sendframe_txt(client, command);
+	if (quisk_trx)
+		sendframe_txt(client, "trx:0,true;");
+	else
+		sendframe_txt(client, "trx:0,false;");
+	if (quisk_split_enable)
+		sendframe_txt(client, "split_enable:0,true;");
+	else
+		sendframe_txt(client, "split_enable:0,false;");
+}
+
+static void onclose(ws_cli_conn_t client)
+{
+	int i, count;
+
+	pthread_mutex_lock(&clients_list_mutex);
+	count = tci_clients_count;
+	tci_clients_count = 0;
+	for (i = 0; i < count; i++)
+		if (tci_clients_list[i] != client)
+			tci_clients_list[tci_clients_count++] = tci_clients_list[i];
+	pthread_mutex_unlock(&clients_list_mutex);
+
+	free(ws_get_connection_context(client));
+	if (verbose) {
+		char * cli = ws_getaddress(client);
+		QuiskPrintf("TCI *Connection closed, addr: %s\n", cli);
+	}
+}
+
+static void onmessage(ws_cli_conn_t client, const unsigned char *msg, uint64_t size, int type)
+{
+	char echo_copy[TCI_RX_BUF_SIZE];
+	complex double sample;
+
+	if (type == WS_FR_OP_TXT) {
+		if (size > TCI_RX_BUF_SIZE / 2)
+			return;		// prevent overflow
+		struct ClientData * ctx = ws_get_connection_context(client);
+		if (ctx->msg_length + size >= TCI_RX_BUF_SIZE - 2)
+			ctx->msg_length = 0;	// prevent overflow
+		memcpy(ctx->msg_buf + ctx->msg_length, msg, size);	// append msg to buffer
+		ctx->msg_length += size;
+		ctx->msg_buf[ctx->msg_length] = '\0';
+		char * semicolon;
+		char save;
+		while ((semicolon = strchr(ctx->msg_buf, ';')) != NULL) {
+			save = *(semicolon + 1);
+			*(semicolon + 1) = '\0';
+			strncpy(echo_copy, ctx->msg_buf, TCI_RX_BUF_SIZE);
+			if (text_message(client, ctx))		// should we send to all clients?
+				sendframe_txt_bcast(tci_port, echo_copy);
+			*(semicolon + 1) = save;
+			size_t processed_len = (semicolon - ctx->msg_buf) + 1;
+			size_t remaining_len = ctx->msg_length - processed_len;
+			memmove(ctx->msg_buf, ctx->msg_buf + processed_len, remaining_len);
+			ctx->msg_length = remaining_len;
+			ctx->msg_buf[ctx->msg_length] = '\0';
+		}
+	}
+	else if (type == WS_FR_OP_BIN) {
+		struct _Stream * pt = (struct _Stream *)msg;
+		int count = 0;
+		float re, im;
+		int channels = TxChrono.channels;
+		int two_channels = channels == 2;
+		int header = 16 * sizeof(uint32_t);
+		const void * vpt = msg + header;
+		const void * vpt_end = vpt + (size - header);
+
+		if (pt->type == TX_AUDIO_STREAM) {
+			if (pt->length > 0 && client == tci_tx_audio_client) {
+				pthread_mutex_lock(&tx_buffer_mutex);
+				switch (TxChrono.format) {
+				case TCI_INT16:
+					break;
+				case TCI_FLOAT32:	// FLOAT32 in version 2.0
+				case 4:			// FLOAT32 in version 1.4
+					// Version 1.4 does not return the number of channels. We assume one channel.
+					while (vpt < vpt_end && count < pt->length) {
+						re = *(float *)vpt;
+						vpt += sizeof(float);
+						if (two_channels) {
+							im = *(float *)vpt;
+							vpt += sizeof(float);
+						}
+						else {
+							im = re;
+						}
+						sample = (re + I * im) * (CLIP32 / 2);
+						count += CircularBuffer(0, &sample, 0, 1);
+					}
+					if (verbose && count != pt->length)
+						QuiskPrintf("TCI TX count %d %d\n", count, pt->length);
+					break;
+				}
+				pthread_mutex_unlock(&tx_buffer_mutex);
+			}
+		}
+		if (verbose)
+			PrintStream((const char *)msg, size);
+
+	}
+
+}
+
+static void tci_startup(void)
+{
+	struct ws_server tci = {
+		.host = NULL,
+		.port = 0,
+		.thread_loop = 1,
+		.timeout_ms = 1000,
+		.evs.onopen = &onopen,
+		.evs.onclose = &onclose,
+		.evs.onmessage = &onmessage
+	};
+	char host32[32];
+
+	tci_clients_count = 0;
+	tci_port = QuiskGetConfigInt("tci_port", 40001);
+	strncpy(host32, QuiskGetConfigString("tci_ip", "127.0.0.1"), 31);
+	tci.host = host32;
+	tci.port = tci_port;
+	ws_socket(&tci);
+	if (verbose)
+		QuiskPrintf("TCI Start server on host %s port %d\n", tci.host, tci.port);
+	return;
+}
+
+void tci_send_audio(complex double * cSamples, int nSamples)	// called from the sound thread
+{
+	int i, n;
+	struct _Stream stream;
+	struct ClientData * ctx;
+
+	if (tci_clients_count <= 0)
+		return;
+
+	if (nSamples <= 0)
+		return;
+
+	pthread_mutex_lock(&clients_list_mutex);
+	for (n = 0; n < tci_clients_count; n++) {
+		ctx = ws_get_connection_context(tci_clients_list[n]);
+		if (ctx->send_Rx_audio_stream == 0)
+			continue;
+		memset(&stream, 0, 16 * sizeof(uint32_t));
+		stream.sample_rate = ctx->audio_stream_samplerate;
+		stream.format = ctx->audio_stream_sample_type;
+		stream.type = RX_AUDIO_STREAM;
+		stream.channels = ctx->audio_stream_channels;
+		int two_channels = stream.channels == 2;
+		int bytes_per_sample = ctx->audio_stream_bytes_per_sample;
+		void * vpt = &stream.data;
+		void * vpt_end = vpt + 16384;
+		switch (ctx->audio_stream_sample_type) {
+		case TCI_FLOAT32:
+			stream.length = 0;	// make a frame
+			for (i = 0; i < nSamples; i++) {
+				*(float *)vpt = (float)(creal(cSamples[i]) / 2147483648);
+				vpt += bytes_per_sample;
+				stream.length++;
+				if (two_channels) {
+					*(float *)vpt = (float)(cimag(cSamples[i]) / 2147483648);
+					vpt += bytes_per_sample;
+					stream.length++;
+				}
+				if (vpt >= vpt_end || i == nSamples - 1) {
+					sendframe_bin(tci_clients_list[n], (const char *)&stream,
+						(16 * sizeof(uint32_t) + stream.length * bytes_per_sample));
+					stream.length = 0;
+				}
+			}
+			break;
+		}
+	}
+	pthread_mutex_unlock(&clients_list_mutex);
+}
+
+int tci_get_mic(complex double * cSamples, int mic_count)	// called from the sound thread
+{
+	if (tci_tx_audio_client) {
+		TxChrono.length = mic_count;
+		sendframe_bin(tci_tx_audio_client, (const char *)&TxChrono, 16 * sizeof(uint32_t));
+		pthread_mutex_lock(&tx_buffer_mutex);
+		mic_count = CircularBuffer(0, cSamples, mic_count, 0);
+		pthread_mutex_unlock(&tx_buffer_mutex);
+	}
+	return mic_count;
+}
+
+PyObject * quisk_tci_set_params(PyObject * self, PyObject * args, PyObject * keywds)	// called from the GUI thread
+{  /* Call with keyword arguments ONLY.
+      Sent from Quisk when parameters change. Broadcast the change to clients.*/
+	static char * kwlist[] = {"start", "verbose", "tci_dds", "tci_if", "tci_vfo", "tci_trx", "tci_split_enable",
+		"tci_modulation", NULL} ;
+	int start=-1, new_dds=-1, new_if=-1, new_vfo=-1, new_trx=-1, new_split_enable=-1;
+	char * mode=NULL;
+	char char_buf[TCI_COMMAND_SIZE];
+
+	if (!PyArg_ParseTupleAndKeywords (args, keywds, "|iiiiiiis", kwlist,
+			&start, &verbose, &new_dds, &new_if, &new_vfo, &new_trx, &new_split_enable,
+			&mode))
+		return NULL;
+	if (start == 1) {
+		tci_started = 1;
+		tci_startup();	// start the TCP server for TCI
+	}
+	if (tci_started == 0) {
+		Py_INCREF (Py_None);
+		return Py_None;
+	}
+	if (new_vfo != -1) {
+		quisk_vfo = new_vfo;
+		snprintf(char_buf, TCI_COMMAND_SIZE, "vfo:0,0,%d;", quisk_vfo);
+		sendframe_txt_bcast(tci_port, char_buf);
+	}
+	if (new_split_enable != -1) {
+		quisk_split_enable = new_split_enable;
+		if (quisk_split_enable)
+			sendframe_txt_bcast(tci_port, "split_enable:0,true;");
+		else
+			sendframe_txt_bcast(tci_port, "split_enable:0,false;");
+	}
+	if (new_trx != -1) {
+		quisk_trx = new_trx;
+		if (quisk_trx) {
+			sendframe_txt_bcast(tci_port, "trx:0,true;");
+		}
+		else {
+			tci_tx_audio_client = 0;
+			sendframe_txt_bcast(tci_port, "trx:0,false;");
+		}
+	}
+	if (mode) {
+		if (strcmp(mode, "DGT-U") == 0)
+			strcpy(quisk_modulation, "DIGU");
+		else if (strcmp(mode, "DGT-L") == 0)
+			strcpy(quisk_modulation, "DIGL");
+		else if (strcmp(mode, "CWL") == 0 || strcmp(mode, "CWU") == 0)
+			strcpy(quisk_modulation, "CW");
+		else if (strcmp(mode, "LSB") == 0 || strcmp(mode, "USB") == 0 ||
+				strcmp(mode, "AM") == 0 || strcmp(mode, "FM") == 0)
+			strncpy(quisk_modulation, mode, TCI_COMMAND_SIZE - 1);
+		else
+			strcpy(quisk_modulation, "USB");
+		snprintf(char_buf, TCI_COMMAND_SIZE, "modulation:0,%.9s;", quisk_modulation);
+		sendframe_txt_bcast(tci_port, char_buf);
+	}
+	Py_INCREF (Py_None);
+	return Py_None;
+}
+
+PyObject * quisk_tci_get_params(PyObject * self, PyObject * args)	// called from the GUI thread
+{  /* Return client request for a parameter change */
+	const char * name;
+	int i;
+	char char_buf[TCI_COMMAND_SIZE];
+
+	if (!PyArg_ParseTuple (args, "s", &name))
+		return NULL;
+	if (tci_started == 0) {
+	}
+	else if (strcmp(name, "tci_vfo") == 0 && client_vfo >= 0) {
+		i = client_vfo;
+		client_vfo = -1;
+		return PyLong_FromLong(i);
+	}
+	else if (strcmp(name, "tci_split_enable") == 0 && client_split_enable >= 0) {
+		i = client_split_enable;
+		client_split_enable = -1;
+		return PyLong_FromLong(i);
+	}
+	else if (strcmp(name, "tci_trx") == 0 && client_trx >= 0) {
+		i = client_trx;
+		client_trx = -1;
+		return PyLong_FromLong(i);
+	}
+	else if (strcmp(name, "tci_modulation") == 0 && client_modulation[0] != 0) {
+		char_buf[0] = 0;
+		if (strcmp(client_modulation, "DIGU") == 0)
+			strcpy(char_buf, "DGT-U");
+		else if (strcmp(client_modulation, "DIGL") == 0)
+			strcpy(char_buf, "DGT-L");
+		else if (strcmp(client_modulation, "CW") == 0)
+			strcpy(char_buf, "CWU");
+		else if (strcmp(client_modulation, "LSB") == 0 || strcmp(client_modulation, "USB") == 0 ||
+				strcmp(client_modulation, "AM") == 0 || strcmp(client_modulation, "FM") == 0)
+			strncpy(char_buf, client_modulation, TCI_COMMAND_SIZE);
+		client_modulation[0] = 0;
+		if (char_buf[0])
+			return PyString_FromString(char_buf);
+	}
+	Py_INCREF (Py_None);
+	return Py_None;
+}

utf8.c

@@ -0,0 +1,89 @@
+/**
+ * Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * Amazing utf8 decoder & validator grabbed from:
+ *   http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
+ *
+ * All rights goes to the original author.
+ */
+
+#include "utf8.h"
+
+static const uint8_t utf8d[] = {
+	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 00..1f
+	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 20..3f
+	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 40..5f
+	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 60..7f
+	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, // 80..9f
+	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, // a0..bf
+	8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // c0..df
+	0xa,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x4,0x3,0x3, // e0..ef
+	0xb,0x6,0x6,0x6,0x5,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8, // f0..ff
+	0x0,0x1,0x2,0x3,0x5,0x8,0x7,0x1,0x1,0x1,0x4,0x6,0x1,0x1,0x1,0x1, // s0..s0
+	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,1,1,1, // s1..s2
+	1,2,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1, // s3..s4
+	1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,1,1,1, // s5..s6
+	1,3,1,1,1,1,1,3,1,3,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // s7..s8
+};
+
+static
+uint32_t decode(uint32_t* state, uint32_t* codep, uint32_t byte) {
+	uint32_t type = utf8d[byte];
+
+	*codep = (*state != UTF8_ACCEPT) ?
+		(byte & 0x3fu) | (*codep << 6) :
+		(0xff >> type) & (byte);
+
+	*state = utf8d[256 + *state*16 + type];
+	return *state;
+}
+
+int is_utf8(uint8_t *s) {
+	uint32_t codepoint, state = 0;
+
+	while (*s)
+		decode(&state, &codepoint, *s++);
+
+	return state == UTF8_ACCEPT;
+}
+
+int is_utf8_len(uint8_t *s, size_t len) {
+	uint32_t codepoint, state = 0;
+	size_t i;
+
+	for (i = 0; i < len; i++)
+		decode(&state, &codepoint, *s++);
+
+	return state == UTF8_ACCEPT;
+}
+
+uint32_t is_utf8_len_state(uint8_t *s, size_t len, uint32_t state) {
+	uint32_t codepoint;
+	size_t i;
+
+	codepoint = 0;
+	for (i = 0; i < len; i++)
+		decode(&state, &codepoint, *s++);
+
+	return state;
+}

utf8.h

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef UTF8_DECODE_H
+#define UTF8_DECODE_H
+
+	#include <inttypes.h>
+	#include <stddef.h>
+
+	/* UTF8 return state. */
+	#define UTF8_ACCEPT 0
+	#define UTF8_REJECT 1
+
+	extern int is_utf8(uint8_t* s);
+	extern int is_utf8_len(uint8_t *s, size_t len);
+	extern uint32_t is_utf8_len_state(uint8_t *s, size_t len, uint32_t state);
+
+#endif

utility.c

@@ -321,3 +321,65 @@ PyObject * QuiskPrintf(char * format, ...)
         return NULL;
 }
 #endif
+
+#define MAX_CHANNELS	8
+int CircularBuffer(int channel, complex double * cSamples, int nRead, int nWrite)
+{
+// Initialize with cSamples NULL and nRead equal to the buffer delay in samples.
+// Read with nRead, write with nWrite. Only one can be non-zero.
+// Return the number of samples read or written.
+	static struct _channel {
+		complex double * cBuf;	// circular sample buffer; save samples until the buffer fills to nDelay
+		int sizeBuf;		// current size of cBuf in complex samples
+		int nDelay;		// number of samples needed to start reading the buffer
+		int nBuf;		// current number of complex samples in cBuf
+		int filling;		// if true, we are filling the buffer and not returning samples
+		int Windex;		// index of write
+		int Rindex;		// index of read
+	} Channels[MAX_CHANNELS] = {0};
+	struct _channel * ptChannel = Channels + channel;
+	int i, num;
+
+	if ( ! cSamples) {	// initialize
+		ptChannel->nDelay = nRead;
+		ptChannel->sizeBuf = nRead * 8;
+		ptChannel->cBuf = (complex double *)realloc(ptChannel->cBuf, ptChannel->sizeBuf * sizeof(complex double));
+		ptChannel->filling = 1;
+		ptChannel->Windex = 0;
+		ptChannel->Rindex = 0;
+		ptChannel->nBuf = 0;
+		return 0;
+	}
+	if ( ! ptChannel->cBuf)
+		return 0;
+	num = 0;	// number of samples read or written
+	if (nWrite > 0) {		// Copy samples from cSamples to cBuf
+		for (i = 0; i < nWrite && ptChannel->nBuf < ptChannel->sizeBuf; i++) {
+			ptChannel->cBuf[ptChannel->Windex++] = cSamples[i];
+			if (ptChannel->Windex >= ptChannel->sizeBuf)
+				ptChannel->Windex = 0;
+			ptChannel->nBuf++;
+			num++;
+		}
+		if (ptChannel->nBuf >= ptChannel->nDelay)
+			ptChannel->filling = 0;
+	}
+	else if (nRead > 0) {
+		if (ptChannel->filling) {	// return zero-valued samples
+			for (num = 0; num < nRead; num++)
+				cSamples[num] = 0;
+		}
+		else {		// Copy samples from cBuf to cSamples
+			for (i = 0; i < nRead && ptChannel->nBuf > 0; i++) {
+				cSamples[i] = ptChannel->cBuf[ptChannel->Rindex++];
+				if (ptChannel->Rindex >= ptChannel->sizeBuf)
+					ptChannel->Rindex = 0;
+				ptChannel->nBuf--;
+				num++;
+			}
+			if (ptChannel->nBuf <= 0)
+				ptChannel->filling = 1;
+		}
+	}
+	return num;
+}

ws.h

@@ -0,0 +1,337 @@
+/*
+ * Copyright (C) 2016-2022  Davidson Francis <davidsondfgl@gmail.com>
+ *
+ * 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/>
+ */
+
+/**
+ * @dir include/
+ * @brief wsServer include directory
+ *
+ * @file ws.h
+ * @brief wsServer constants and functions.
+ */
+#ifndef WS_H
+#define WS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+	#include <stdbool.h>
+	#include <stdint.h>
+	#include <inttypes.h>
+
+	/**
+	 * @name Global configurations
+	 */
+	/**@{*/
+	/**
+	 * @brief Max clients connected simultaneously.
+	 */
+#ifndef MAX_CLIENTS
+	#define MAX_CLIENTS    8
+#endif
+
+	/**
+	 * @name Key and message configurations.
+	 */
+	/**@{*/
+	/**
+	 * @brief Message buffer length.
+	 */
+	#define MESSAGE_LENGTH 2048
+	/**
+	 * @brief Maximum frame/message length.
+	 */
+	#define MAX_FRAME_LENGTH (16*1024*1024)
+	/**
+	 * @brief WebSocket key length.
+	 */
+	#define WS_KEY_LEN     24
+	/**
+	 * @brief Magic string length.
+	 */
+	#define WS_MS_LEN      36
+	/**
+	 * @brief Accept message response length.
+	 */
+	#define WS_KEYMS_LEN   (WS_KEY_LEN + WS_MS_LEN)
+	/**
+	 * @brief Magic string.
+	 */
+	#define MAGIC_STRING   "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+	/**@}*/
+
+	/**
+	 * @name Handshake constants.
+	 */
+	/**@{*/
+	/**
+	 * @brief Alias for 'Sec-WebSocket-Key'.
+	 */
+	#define WS_HS_REQ      "Sec-WebSocket-Key"
+
+	/**
+	 * @brief Handshake accept message length.
+	 */
+	#define WS_HS_ACCLEN   130
+
+	/**
+	 * @brief Handshake accept message.
+	 */
+	#define WS_HS_ACCEPT                       \
+		"HTTP/1.1 101 Switching Protocols\r\n" \
+		"Upgrade: websocket\r\n"               \
+		"Connection: Upgrade\r\n"              \
+		"Sec-WebSocket-Accept: "
+	/**@}*/
+
+	/**
+	 * @name Frame types.
+	 */
+	/**@{*/
+	/**
+	 * @brief Frame FIN.
+	 */
+	#define WS_FIN      128
+
+	/**
+	 * @brief Frame FIN shift
+	 */
+	#define WS_FIN_SHIFT  7
+
+	/**
+	 * @brief Continuation frame.
+	 */
+	#define WS_FR_OP_CONT 0
+
+	/**
+	 * @brief Text frame.
+	 */
+	#define WS_FR_OP_TXT  1
+
+	/**
+	 * @brief Binary frame.
+	 */
+	#define WS_FR_OP_BIN  2
+
+	/**
+	 * @brief Close frame.
+	 */
+	#define WS_FR_OP_CLSE 8
+
+	/**
+	 * @brief Ping frame.
+	 */
+	#define WS_FR_OP_PING 0x9
+
+	/**
+	 * @brief Pong frame.
+	 */
+	#define WS_FR_OP_PONG 0xA
+
+	/**
+	 * @brief Unsupported frame.
+	 */
+	#define WS_FR_OP_UNSUPPORTED 0xF
+	/**@}*/
+
+	/**
+	 * @name Close codes
+	 */
+	/**@{*/
+	/**
+	 * @brief Normal close
+	 */
+	#define WS_CLSE_NORMAL  1000
+	/**
+	 * @brief Protocol error
+	 */
+	#define WS_CLSE_PROTERR 1002
+	/**@}*/
+	/**
+	 * @brief Inconsistent message (invalid utf-8)
+	 */
+	#define WS_CLSE_INVUTF8 1007
+
+	/**
+	 * @name Connection states
+	 */
+	/**@{*/
+	/**
+	 * @brief Connection not established yet.
+	 */
+	#define WS_STATE_CONNECTING 0
+	/**
+	 * @brief Communicating.
+	 */
+	#define WS_STATE_OPEN       1
+	/**
+	 * @brief Closing state.
+	 */
+	#define WS_STATE_CLOSING    2
+	/**
+	 * @brief Closed.
+	 */
+	#define WS_STATE_CLOSED     3
+	/**@}*/
+
+	/**
+	 * @name Timeout util
+	 */
+	/**@{*/
+	/**
+	 * @brief Nanoseconds macro converter
+	 */
+	#define MS_TO_NS(x) ((x)*1000000)
+	/**
+	 * @brief Timeout in milliseconds.
+	 */
+	#define TIMEOUT_MS (500)
+	/**@}*/
+
+	/**
+	 * @name Handshake constants.
+	 */
+	/**@{*/
+	/**
+	 * @brief Debug
+	 */
+	#ifdef VERBOSE_MODE
+	#define DEBUG(...) fprintf(stderr, __VA_ARGS__)
+	#else
+	#define DEBUG(...)
+	#endif
+	/**@}*/
+
+	#ifndef AFL_FUZZ
+	#define SEND(client,buf,len) send_all((client), (buf), (len), MSG_NOSIGNAL)
+	#define RECV(fd,buf,len) recv((fd)->client_sock, (buf), (len), 0)
+	#else
+	#define SEND(client,buf,len) write(fileno(stdout), (buf), (len))
+	#define RECV(fd,buf,len) read((fd)->client_sock, (buf), (len))
+	#endif
+
+	/* Opaque client connection type. */
+	typedef uint64_t ws_cli_conn_t;
+
+	/* Opaque server instance type. */
+	typedef struct ws_server ws_server_t;
+
+	/**
+	 * @brief Get server context.
+	 * Set when initializing `.context` in `struct ws_server`.
+	 */
+	void *ws_get_server_context(ws_cli_conn_t client);
+
+	/**
+	 * @brief Set connection context.
+	 */
+	void ws_set_connection_context(ws_cli_conn_t client, void *ptr);
+
+	/**
+	 * @brief Get connection context.
+	 */
+	void *ws_get_connection_context(ws_cli_conn_t client);
+
+	/**
+	 * @brief events Web Socket events types.
+	 */
+	struct ws_events
+	{
+		/**
+		 * @brief On open event, called when a new client connects.
+		 */
+		void (*onopen)(ws_cli_conn_t client);
+		/**
+		 * @brief On close event, called when a client disconnects.
+		 */
+		void (*onclose)(ws_cli_conn_t client);
+		/**
+		 * @brief On message event, called when a client sends a text
+		 * or binary message.
+		 */
+		void (*onmessage)(ws_cli_conn_t client,
+			const unsigned char *msg, uint64_t msg_size, int type);
+	};
+
+	/**
+	 * @brief server Web Socket server parameters
+	 */
+	struct ws_server
+	{
+		/**
+		 * @brief Required hostname that the wsServer will bind to
+		 */
+		const char *host;
+		/**
+		 * @brief Listening port
+		 */
+		uint16_t port;
+		/**
+		 * @brief Whether if the ws_socket() should create a new thread
+		 * and be non-blocking (1) or not (0).
+		 */
+		int thread_loop;
+		/**
+		 * @brief Ping timeout in milliseconds
+		 */
+		uint32_t timeout_ms;
+		/**
+		 * @brief Server events.
+		 */
+		struct ws_events evs;
+		/**
+		 * @brief Server context.
+		 * Provided by the user, can be accessed via `ws_get_server_context` from `onopen`.
+		 */
+		void* context;
+	};
+
+	/* Forward declarations. */
+
+	/* Internal usage. */
+	extern int get_handshake_accept(char *wsKey, unsigned char **dest);
+	extern int get_handshake_response(char *hsrequest, char **hsresponse);
+
+	/* External usage. */
+	extern char *ws_getaddress(ws_cli_conn_t client);
+	extern char *ws_getport(ws_cli_conn_t client);
+	extern int ws_sendframe(
+		ws_cli_conn_t client, const char *msg, uint64_t size, int type);
+	extern int ws_sendframe_bcast(
+		uint16_t port, const char *msg, uint64_t size, int type);
+	extern int ws_sendframe_txt(ws_cli_conn_t client, const char *msg);
+	extern int ws_sendframe_txt_bcast(uint16_t port, const char *msg);
+	extern int ws_sendframe_bin(ws_cli_conn_t client, const char *msg,
+		uint64_t size);
+	extern int ws_sendframe_bin_bcast(uint16_t port, const char *msg,
+		uint64_t size);
+	extern int ws_get_state(ws_cli_conn_t client);
+	extern int ws_close_client(ws_cli_conn_t client);
+	extern int ws_socket(struct ws_server *ws_srv);
+
+	/* Ping routines. */
+	extern void ws_ping(ws_cli_conn_t cid, int threshold);
+
+#ifdef AFL_FUZZ
+	extern int ws_file(struct ws_events *evs, const char *file);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* WS_H */