FreeDATA/modem.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Wed Dec 23 07:04:24 2020

@author: DJ2LS
"""

import ctypes
from ctypes import *
import pathlib
import pyaudio
import audioop
import asyncio
#import sys
import logging
import time
import threading

import helpers
import static
import data_handler

import Hamlib



class RF():
    
    def __init__(self):  
        #-------------------------------------------- LOAD FREEDV
        libname = pathlib.Path().absolute() / "codec2/build_linux/src/libcodec2.so"
        self.c_lib = ctypes.CDLL(libname)
        #--------------------------------------------CREATE PYAUDIO  INSTANCE
        self.p = pyaudio.PyAudio()
        #--------------------------------------------GET SUPPORTED SAMPLE RATES FROM SOUND DEVICE
        #static.AUDIO_SAMPLE_RATE_RX = int(self.p.get_device_info_by_index(static.AUDIO_INPUT_DEVICE)['defaultSampleRate'])
        #static.AUDIO_SAMPLE_RATE_TX = int(self.p.get_device_info_by_index(static.AUDIO_OUTPUT_DEVICE)['defaultSampleRate'])
        static.AUDIO_SAMPLE_RATE_TX = 8000
        static.AUDIO_SAMPLE_RATE_RX = 8000
        #--------------------------------------------OPEN AUDIO CHANNEL RX
        self.stream_rx = self.p.open(format=pyaudio.paInt16, 
                            channels=static.AUDIO_CHANNELS,
                            rate=static.AUDIO_SAMPLE_RATE_RX,
                            frames_per_buffer=static.AUDIO_FRAMES_PER_BUFFER,
                            input=True,
                            input_device_index=static.AUDIO_INPUT_DEVICE,
                            ) 
        #--------------------------------------------OPEN AUDIO CHANNEL TX
        self.stream_tx = self.p.open(format=pyaudio.paInt16,
                            channels=1,
                            rate=static.AUDIO_SAMPLE_RATE_TX,
                            frames_per_buffer=static.AUDIO_FRAMES_PER_BUFFER, #n_nom_modem_samples
                            output=True,
                            output_device_index=static.AUDIO_OUTPUT_DEVICE,  #static.AUDIO_OUTPUT_DEVICE
                            )  
        #--------------------------------------------START DECODER THREAD                
        FREEDV_DECODER_THREAD_10 = threading.Thread(target=self.receive, args=[10], name="FREEDV_DECODER_THREAD")
        FREEDV_DECODER_THREAD_10.start()
        
        FREEDV_DECODER_THREAD_11 = threading.Thread(target=self.receive, args=[11], name="FREEDV_DECODER_THREAD")
        FREEDV_DECODER_THREAD_11.start()
        
        FREEDV_DECODER_THREAD_12 = threading.Thread(target=self.receive, args=[12], name="FREEDV_DECODER_THREAD")
        FREEDV_DECODER_THREAD_12.start()
        
        FREEDV_DECODER_THREAD_14 = threading.Thread(target=self.receive, args=[static.FREEDV_SIGNALLING_MODE], name="FREEDV_DECODER_THREAD")
        FREEDV_DECODER_THREAD_14.start()
       
        
        #--------------------------------------------CONFIGURE HAMLIB
        Hamlib.rig_set_debug(Hamlib.RIG_DEBUG_NONE)

        # Init RIG_MODEL_DUMMY
        self.my_rig = Hamlib.Rig(Hamlib.RIG_MODEL_DUMMY)
        self.my_rig.set_conf("rig_pathname", "/dev/Rig")
        self.my_rig.set_conf("retry", "5")

        self.my_rig.open ()
        
        
        if static.HAMLIB_PTT_TYPE == 'RIG_PTT_RIG':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_RIG
        elif static.HAMLIB_PTT_TYPE == 'RIG_PTT_SERIAL_DTR':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_SERIAL_DTR
        elif static.HAMLIB_PTT_TYPE == 'RIG_PTT_SERIAL_RTS':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_SERIAL_RTS
        elif static.HAMLIB_PTT_TYPE == 'RIG_PTT_PARALLEL':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_PARALLEL
        elif static.HAMLIB_PTT_TYPE == 'RIG_PTT_RIG_MICDATA':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_RIG_MICDATA
        elif static.HAMLIB_PTT_TYPE == 'RIG_PTT_CM108':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_CM108
        else:# static.HAMLIB_PTT_TYPE == 'RIG_PTT_NONE':
            self.hamlib_ptt_type = Hamlib.RIG_PTT_NONE
        
        self.my_rig.set_ptt(self.hamlib_ptt_type,0)  

#--------------------------------------------------------------------------------------------------------     
    def transmit_signalling(self,ack_buffer):
        #print(ack_buffer)
        #static.ARQ_STATE = 'SENDING_ACK'
        
        state_before_transmit = static.CHANNEL_STATE
        static.CHANNEL_STATE = 'SENDING_SIGNALLING'
        
        static.PTT_STATE = True
        self.my_rig.set_ptt(self.hamlib_ptt_type,1) 
        
                
        self.c_lib.freedv_open.restype = ctypes.POINTER(ctypes.c_ubyte)
        freedv = self.c_lib.freedv_open(static.FREEDV_SIGNALLING_MODE)
        bytes_per_frame = int(self.c_lib.freedv_get_bits_per_modem_frame(freedv)/8)
        payload_per_frame = bytes_per_frame -2
        n_nom_modem_samples = self.c_lib.freedv_get_n_nom_modem_samples(freedv)
        n_tx_modem_samples = self.c_lib.freedv_get_n_tx_modem_samples(freedv) #get n_tx_modem_samples which defines the size of the modulation object
        n_tx_preamble_modem_samples = self.c_lib.freedv_get_n_tx_preamble_modem_samples(freedv)  
        
        mod_out = ctypes.c_short * n_tx_modem_samples
        mod_out = mod_out()
        mod_out_preamble = ctypes.c_short * n_tx_preamble_modem_samples #*2 #1760 for mode 10,11,12 #4000 for mode 9
        mod_out_preamble = mod_out_preamble()

        buffer = bytearray(payload_per_frame) # use this if CRC16 checksum is required ( DATA1-3)
        buffer[:len(ack_buffer)] = ack_buffer # set buffersize to length of data which will be send

        crc = ctypes.c_ushort(self.c_lib.freedv_gen_crc16(bytes(buffer), payload_per_frame))     # generate CRC16
        crc = crc.value.to_bytes(2, byteorder='big') # convert crc to 2 byte hex string
        buffer += crc        # append crc16 to buffer
        data = (ctypes.c_ubyte * bytes_per_frame).from_buffer_copy(buffer)
        
        self.c_lib.freedv_rawdatapreambletx(freedv, mod_out_preamble)   
        self.c_lib.freedv_rawdatatx(freedv,mod_out,data) # modulate DATA and safe it into mod_out pointer     
        txbuffer = bytearray()    
        txbuffer += bytes(mod_out_preamble)
        txbuffer += bytes(mod_out)
     
        # -------------- transmit audio twice
        
        logging.debug("SEND SIGNALLING FRAME " + str(ack_buffer))
        self.stream_tx.write(bytes(txbuffer))
        
        self.my_rig.set_ptt(self.hamlib_ptt_type,0) 
        static.PTT_STATE = False
        
        static.CHANNEL_STATE = state_before_transmit
        #static.CHANNEL_STATE = 'RECEIVING_SIGNALLING'
        #static.ARQ_STATE = 'RECEIVING_DATA'
#--------------------------------------------------------------------------------------------------------     
   # GET ARQ BURST FRAME VOM BUFFER AND MODULATE IT 
    async def transmit_arq_burst(self):
    
        self.my_rig.set_ptt(self.hamlib_ptt_type,1) 
        static.PTT_STATE = True
        state_before_transmit = static.CHANNEL_STATE
        static.CHANNEL_STATE = 'SENDING_DATA'

        self.c_lib.freedv_open.restype = ctypes.POINTER(ctypes.c_ubyte)
        freedv = self.c_lib.freedv_open(static.FREEDV_DATA_MODE)
        static.FREEDV_DATA_BYTES_PER_FRAME = int(self.c_lib.freedv_get_bits_per_modem_frame(freedv)/8)
        static.FREEDV_DATA_PAYLOAD_PER_FRAME = static.FREEDV_DATA_BYTES_PER_FRAME -2
         
        n_nom_modem_samples = self.c_lib.freedv_get_n_nom_modem_samples(freedv)
        n_tx_modem_samples = self.c_lib.freedv_get_n_tx_modem_samples(freedv)#*2 #get n_tx_modem_samples which defines the size of the modulation object
        n_tx_preamble_modem_samples = self.c_lib.freedv_get_n_tx_preamble_modem_samples(freedv)
          
        mod_out = ctypes.c_short * n_tx_modem_samples
        mod_out = mod_out()
        mod_out_preamble = ctypes.c_short * n_tx_preamble_modem_samples #*2 #1760 for mode 10,11,12 #4000 for mode 9
        mod_out_preamble = mod_out_preamble()

        self.c_lib.freedv_rawdatapreambletx(freedv, mod_out_preamble);

        txbuffer = bytearray()
        txbuffer += bytes(mod_out_preamble)

        if static.ARQ_RPT_RECEIVED == False:
            for n in range(0,static.ARQ_TX_N_FRAMES_PER_BURST):

            #---------------------------BUILD ARQ BURST ---------------------------------------------------------------------
                frame_type = 10 + n + 1 #static.ARQ_TX_N_FRAMES_PER_BURST
                frame_type = bytes([frame_type])

                payload_data = bytes(static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + n])
            
                n_current_arq_frame = static.ARQ_N_SENT_FRAMES + n + 1
                static.ARQ_TX_N_CURRENT_ARQ_FRAME = n_current_arq_frame.to_bytes(2, byteorder='big')
            
                n_total_arq_frame = len(static.TX_BUFFER)
                static.ARQ_TX_N_TOTAL_ARQ_FRAMES = n_total_arq_frame.to_bytes(2, byteorder='big')
             
                arqframe = frame_type + \
                       bytes([static.ARQ_TX_N_FRAMES_PER_BURST]) + \
                       static.ARQ_TX_N_CURRENT_ARQ_FRAME + \
                       static.ARQ_TX_N_TOTAL_ARQ_FRAMES + \
                       static.DXCALLSIGN_CRC8 + \
                       static.MYCALLSIGN_CRC8 + \
                       payload_data                                      
                    
                #print(arqframe)
                    
                buffer = bytearray(static.FREEDV_DATA_PAYLOAD_PER_FRAME) # create TX buffer 
                buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send
                                
                crc = ctypes.c_ushort(self.c_lib.freedv_gen_crc16(bytes(buffer), static.FREEDV_DATA_PAYLOAD_PER_FRAME))     # generate CRC16
                crc = crc.value.to_bytes(2, byteorder='big') # convert crc to 2 byte hex string
                buffer += crc        # append crc16 to buffer

                data = (ctypes.c_ubyte * static.FREEDV_DATA_BYTES_PER_FRAME).from_buffer_copy(buffer)
                self.c_lib.freedv_rawdatatx(freedv,mod_out,data) # modulate DATA and safe it into mod_out pointer 
                txbuffer += bytes(mod_out)
                
        elif static.ARQ_RPT_RECEIVED == True:
            
            for n in range(0,len(static.ARQ_RPT_FRAMES)):

                missing_frame = int.from_bytes(static.ARQ_RPT_FRAMES[n], "big")
                               
            #---------------------------BUILD ARQ BURST ---------------------------------------------------------------------
                frame_type = 10 + missing_frame #static.ARQ_TX_N_FRAMES_PER_BURST
                frame_type = bytes([frame_type])

                payload_data = bytes(static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + missing_frame - 1])
            
                n_current_arq_frame = static.ARQ_N_SENT_FRAMES + missing_frame
                static.ARQ_TX_N_CURRENT_ARQ_FRAME = n_current_arq_frame.to_bytes(2, byteorder='big')
            
                n_total_arq_frame = len(static.TX_BUFFER)
                static.ARQ_TX_N_TOTAL_ARQ_FRAMES = n_total_arq_frame.to_bytes(2, byteorder='big')
             
                arqframe = frame_type + \
                       bytes([static.ARQ_TX_N_FRAMES_PER_BURST]) + \
                       static.ARQ_TX_N_CURRENT_ARQ_FRAME + \
                       static.ARQ_TX_N_TOTAL_ARQ_FRAMES + \
                       static.DXCALLSIGN_CRC8 + \
                       static.MYCALLSIGN_CRC8 + \
                       payload_data                                      

                #print(arqframe)

                buffer = bytearray(static.FREEDV_DATA_PAYLOAD_PER_FRAME) # create TX buffer 
                buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send
                                
                crc = ctypes.c_ushort(self.c_lib.freedv_gen_crc16(bytes(buffer), static.FREEDV_DATA_PAYLOAD_PER_FRAME))     # generate CRC16
                crc = crc.value.to_bytes(2, byteorder='big') # convert crc to 2 byte hex string
                buffer += crc        # append crc16 to buffer
                
                data = (ctypes.c_ubyte * static.FREEDV_DATA_BYTES_PER_FRAME).from_buffer_copy(buffer)
                self.c_lib.freedv_rawdatatx(freedv,mod_out,data) # modulate DATA and safe it into mod_out pointer 
                txbuffer += bytes(mod_out)
 
       
        # -------------- transmit audio
        self.stream_tx.write(bytes(txbuffer)) 
        #static.ARQ_STATE = 'IDLE'
        #static.CHANNEL_STATE = state_before_transmit
        static.CHANNEL_STATE = 'RECEIVING_SIGNALLING'
        static.PTT_STATE = False
        self.my_rig.set_ptt(self.hamlib_ptt_type,0) 
#--------------------------------------------------------------------------------------------------------         

    def receive(self,mode):
        force = True
        
        self.c_lib.freedv_open.restype = ctypes.POINTER(ctypes.c_ubyte)      
        freedv = self.c_lib.freedv_open(mode)
 
        bytes_per_frame = int(self.c_lib.freedv_get_bits_per_modem_frame(freedv)/8)
 
        if mode == static.FREEDV_SIGNALLING_MODE:
            static.FREEDV_SIGNALLING_BYTES_PER_FRAME = bytes_per_frame
            static.FREEDV_SIGNALLING_PAYLOAD_PER_FRAME = bytes_per_frame - 2
            
            self.c_lib.freedv_set_frames_per_burst(freedv, 1);
        
        elif mode == static.ARQ_DATA_CHANNEL_MODE:
            static.FREEDV_DATA_BYTES_PER_FRAME = bytes_per_frame
            static.FREEDV_DATA_PAYLOAD_PER_FRAME = bytes_per_frame - 2
            
            self.c_lib.freedv_set_frames_per_burst(freedv, 0);
        else:
            pass
            
      
      
        bytes_out = (ctypes.c_ubyte * bytes_per_frame)
        bytes_out = bytes_out() #get pointer to bytes_out    

        while static.FREEDV_RECEIVE == True:
            time.sleep(0.05)
            
            # stuck in sync counter
            stuck_in_sync_counter = 0
            stuck_in_sync_10_counter = 0
            #
            
            # here we do a buffer cleanup before returning to demod loop
            dummy_mod = bytes(self.c_lib.freedv_nin(freedv))
            self.c_lib.freedv_rawdatarx(freedv, bytes_out, dummy_mod)
            
            #demod loop
            while (static.CHANNEL_STATE == 'RECEIVING_DATA' and static.ARQ_DATA_CHANNEL_MODE == mode) or (static.CHANNEL_STATE == 'RECEIVING_SIGNALLING' and static.FREEDV_SIGNALLING_MODE == mode):
                time.sleep(0.01)
                # refresh vars, so the correct parameters of the used mode are set
                static.FREEDV_DATA_BYTES_PER_FRAME = bytes_per_frame
                static.FREEDV_DATA_PAYLOAD_PER_FRAME = bytes_per_frame - 2
                
                nin = self.c_lib.freedv_nin(freedv)
                #nin = int(nin*(static.AUDIO_SAMPLE_RATE_RX/static.MODEM_SAMPLE_RATE))
                data_in = self.stream_rx.read(nin,  exception_on_overflow = False)  
                #print(audioop.rms(data_in, 2))
                #self.c_lib.freedv_rawdatarx.argtype = [ctypes.POINTER(ctypes.c_ubyte), data_bytes_out, data_in] # check if really neccessary 
                nbytes = self.c_lib.freedv_rawdatarx(freedv, bytes_out, data_in) # demodulate audio
                #logging.debug(self.c_lib.freedv_get_rx_status(freedv))
                #print("listening-" + str(mode) + "-" + str(self.c_lib.freedv_get_rx_status(freedv)))
                
                #-------------STUCK IN SYNC DETECTOR            
                stuck_in_sync_counter += 1
                if self.c_lib.freedv_get_rx_status(freedv) == 10:
                    stuck_in_sync_10_counter += 1
                    
                    
                if stuck_in_sync_counter == 33 and self.c_lib.freedv_get_rx_status(freedv) == 10:
                    logging.critical("stuck in sync #1")
                    self.c_lib.freedv_set_sync(freedv, 0) #FORCE UNSYNC
                    stuck_in_sync_counter = 0
                    stuck_in_sync_10_counter = 0
                    
                if stuck_in_sync_counter >= 66 and stuck_in_sync_10_counter >= 2:
                    logging.critical("stuck in sync #2")
                    self.c_lib.freedv_set_sync(freedv, 0) #FORCE UNSYNC
                    stuck_in_sync_counter = 0    
                    stuck_in_sync_10_counter = 0
                #-----------------------------------
                
                
                if nbytes == bytes_per_frame:##########################################################FREEDV_DATA_BYTES_PER_FRAME
                    self.calculate_ber(freedv)

                    # counter reset for stuck in sync counter
                    stuck_in_sync_counter = 0
                    stuck_in_sync_10_counter = 0
                    #
                                          
                    # CHECK IF FRAMETYPE IS BETWEEN 10 and 50 ------------------------
                    frametype = int.from_bytes(bytes(bytes_out[:1]), "big")
                    frame = frametype - 10
                    n_frames_per_burst = int.from_bytes(bytes(bytes_out[1:2]), "big")
                        
                    #self.c_lib.freedv_set_frames_per_burst(freedv_data, n_frames_per_burst);
                    
                    if 50 >= frametype >= 10:                     
                        if frame != 3 or force == True:

                            data_handler.arq_data_received(bytes(bytes_out[:-2])) #send payload data to arq checker without CRC16 
                                            
                            #print("static.ARQ_RX_BURST_BUFFER.count(None) " + str(static.ARQ_RX_BURST_BUFFER.count(None)))
                            if static.ARQ_RX_BURST_BUFFER.count(None) <= 1:
                                logging.debug("FULL BURST BUFFER ---> UNSYNC")
                                self.c_lib.freedv_set_sync(freedv, 0)
                        
                        else:
                            logging.critical("---------------------------SIMULATED MISSING FRAME")
                            force = True

                    # BURST ACK
                    elif frametype == 60:
                       logging.debug("ACK RECEIVED....")
                       data_handler.burst_ack_received()
                       
                    # FRAME ACK
                    elif frametype == 61:
                       logging.debug("FRAME ACK RECEIVED....")
                       data_handler.frame_ack_received()
                       
                    # FRAME RPT
                    elif frametype == 62:
                       logging.debug("REPEAT REQUEST RECEIVED....")
                       data_handler.burst_rpt_received(bytes_out[:-2])

                    # CQ FRAME
                    elif frametype == 200:
                       logging.info("CQ RECEIVED....")
                       
                    # PING FRAME
                    elif frametype == 210:
                       logging.debug("PING RECEIVED....")
                       data_handler.received_ping(bytes_out[:-2])

                    # PING ACK
                    elif frametype == 211:
                       logging.debug("PING ACK RECEIVED....")
                       data_handler.received_ping_ack(bytes_out[:-2])

                    # ARQ CONNECT
                    elif frametype == 220:
                       logging.debug("ARQ CONNECT RECEIVED....")
                       data_handler.arq_received_connect(bytes_out[:-2])

                    # ARQ CONNECT ACK / KEEP ALIVE
                    elif frametype == 221:
                       logging.debug("ARQ CONNECT ACK RECEIVED / KEEP ALIVE....")
                       data_handler.arq_received_connect_keep_alive(bytes_out[:-2])

                    # ARQ CONNECT ACK / KEEP ALIVE
                    elif frametype == 222:
                       logging.debug("ARQ DISCONNECT RECEIVED")
                       data_handler.arq_disconnect_received(bytes_out[:-2])

                   # ARQ FILE TRANSFER RECEIVED!
                    elif frametype == 225:
                       logging.debug("ARQ arq_received_data_channel_opener RECEIVED")
                       data_handler.arq_received_data_channel_opener(bytes_out[:-2])
                    
                    # ARQ CHANNEL IS OPENED
                    elif frametype == 226:
                       logging.debug("ARQ arq_received_channel_is_open RECEIVED")
                       data_handler.arq_received_channel_is_open(bytes_out[:-2])
  
                    # ARQ CONNECT ACK / KEEP ALIVE
                    elif frametype == 230:
                       logging.debug("BEACON RECEIVED")
                       
                    else:
                        logging.info("OTHER FRAME: " + str(bytes_out[:-2]))
                        print(frametype)
                    
                    # DO UNSYNC AFTER LAST BURST by checking the frame nums agains the total frames per burst
                    if frame == n_frames_per_burst: 
                        logging.debug("LAST FRAME ---> UNSYNC")
                        self.c_lib.freedv_set_sync(freedv, 0) #FORCE UNSYNC
                
                rxstatus = self.c_lib.freedv_get_rx_status(freedv)     
                #logging.info("DATA-" + str(mode) + " " +str(rxstatus))
                if rxstatus == 10:
                    self.c_lib.freedv_set_sync(freedv, 0) #FORCE UNSYNC
                    logging.warning("MODEM | SYNC 10 TRIGGER | M:" + str(mode))
                    self.calculate_ber(freedv)
 
  
    def calculate_ber(self,freedv):
        Tbits = self.c_lib.freedv_get_total_bits(freedv)
        Terrs = self.c_lib.freedv_get_total_bit_errors(freedv)
        if Tbits != 0:
            ber = (Terrs/Tbits)*100 
            static.BER = int(ber)
            
        self.c_lib.freedv_set_total_bit_errors(freedv,0)
        self.c_lib.freedv_set_total_bits(freedv,0)