FreeDATA/test/test_multimode_tx.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-


import argparse
import ctypes
import sys
import time

import numpy as np
import pyaudio

sys.path.insert(0, "..")
from tnc import codec2


def test_mm_tx():
    # AUDIO PARAMETERS
    AUDIO_FRAMES_PER_BUFFER = 2400
    MODEM_SAMPLE_RATE = codec2.api.FREEDV_FS_8000
    AUDIO_SAMPLE_RATE_TX = 48000
    assert (AUDIO_SAMPLE_RATE_TX % MODEM_SAMPLE_RATE) == 0

    args = parse_arguments()

    if args.LIST:
        p_audio = pyaudio.PyAudio()
        for dev in range(p_audio.get_device_count()):
            print("audiodev: ", dev, p_audio.get_device_info_by_index(dev)["name"])
        sys.exit()

    N_BURSTS = args.N_BURSTS
    N_FRAMES_PER_BURST = args.N_FRAMES_PER_BURST
    DELAY_BETWEEN_BURSTS = args.DELAY_BETWEEN_BURSTS / 1000
    AUDIO_OUTPUT_DEVICE = args.AUDIO_OUTPUT_DEVICE

    resampler = codec2.resampler()

    # Data binary string
    data_out = b"HELLO WORLD!"

    modes = [
        codec2.api.FREEDV_MODE_DATAC0,
        codec2.api.FREEDV_MODE_DATAC1,
        codec2.api.FREEDV_MODE_DATAC3,
    ]

    if AUDIO_OUTPUT_DEVICE != -1:
        p_audio = pyaudio.PyAudio()
        # Auto search for loopback devices
        if AUDIO_OUTPUT_DEVICE == -2:
            loopback_list = [
                dev
                for dev in range(p_audio.get_device_count())
                if "Loopback: PCM" in p_audio.get_device_info_by_index(dev)["name"]
            ]

            if len(loopback_list) >= 2:
                AUDIO_OUTPUT_DEVICE = loopback_list[1]  # 0  = RX   1 = TX
                print(f"loopback_list tx: {loopback_list}", file=sys.stderr)
            else:
                sys.exit()

        # pyaudio init
        stream_tx = p_audio.open(
            format=pyaudio.paInt16,
            channels=1,
            rate=AUDIO_SAMPLE_RATE_TX,
            frames_per_buffer=AUDIO_FRAMES_PER_BUFFER,  # n_nom_modem_samples
            output=True,
            output_device_index=AUDIO_OUTPUT_DEVICE,
        )

    for mode in modes:
        freedv = ctypes.cast(codec2.api.freedv_open(mode), ctypes.c_void_p)

        n_tx_modem_samples = codec2.api.freedv_get_n_tx_modem_samples(freedv)
        mod_out = ctypes.create_string_buffer(2 * n_tx_modem_samples)

        n_tx_preamble_modem_samples = codec2.api.freedv_get_n_tx_preamble_modem_samples(
            freedv
        )
        mod_out_preamble = ctypes.create_string_buffer(2 * n_tx_preamble_modem_samples)

        n_tx_postamble_modem_samples = (
            codec2.api.freedv_get_n_tx_postamble_modem_samples(freedv)
        )
        mod_out_postamble = ctypes.create_string_buffer(
            2 * n_tx_postamble_modem_samples
        )

        bytes_per_frame = int(codec2.api.freedv_get_bits_per_modem_frame(freedv) / 8)
        payload_per_frame = bytes_per_frame - 2

        buffer = bytearray(payload_per_frame)
        # Set buffer size to length of data which will be sent
        buffer[: len(data_out)] = data_out

        # Generate CRC16
        crc = ctypes.c_ushort(
            codec2.api.freedv_gen_crc16(bytes(buffer), payload_per_frame)
        )
        # Convert CRC to 2 byte hex string
        crc = crc.value.to_bytes(2, byteorder="big")
        buffer += crc  # Append crc16 to buffer
        data = (ctypes.c_ubyte * bytes_per_frame).from_buffer_copy(buffer)

        for brst in range(1, N_BURSTS + 1):
            # Write preamble to txbuffer
            codec2.api.freedv_rawdatapreambletx(freedv, mod_out_preamble)
            txbuffer = bytes(mod_out_preamble)

            # Create modulaton for N = FRAMESPERBURST and append it to txbuffer
            for frm in range(1, N_FRAMES_PER_BURST + 1):
                data = (ctypes.c_ubyte * bytes_per_frame).from_buffer_copy(buffer)
                # Modulate DATA and save it into mod_out pointer
                codec2.api.freedv_rawdatatx(freedv, mod_out, data)

                txbuffer += bytes(mod_out)
                print(
                    f"TX BURST: {brst}/{N_BURSTS} FRAME: {frm}/{N_FRAMES_PER_BURST}",
                    file=sys.stderr,
                )

            # Append postamble to txbuffer
            codec2.api.freedv_rawdatapostambletx(freedv, mod_out_postamble)
            txbuffer += bytes(mod_out_postamble)

            # Append a delay between bursts as audio silence
            samples_delay = int(MODEM_SAMPLE_RATE * DELAY_BETWEEN_BURSTS)
            mod_out_silence = ctypes.create_string_buffer(samples_delay * 2)
            txbuffer += bytes(mod_out_silence)

            # Resample up to 48k (resampler works on np.int16)
            audio_buffer = np.frombuffer(txbuffer, dtype=np.int16)
            txbuffer_48k = resampler.resample8_to_48(audio_buffer)

            # Check if we want to use an audio device or stdout
            if AUDIO_OUTPUT_DEVICE != -1:
                stream_tx.write(txbuffer_48k.tobytes())
            else:
                # This test needs a lot of time, so we are having a look at times...
                starttime = time.time()

                # Print data to terminal for piping the output to other programs
                sys.stdout.buffer.write(txbuffer_48k)
                sys.stdout.flush()

                # and at least print the needed time to see which time we needed
                timeneeded = time.time() - starttime
                # print(f"time: {timeneeded} buffer: {len(txbuffer)}", file=sys.stderr)

    # and at last check if we had an opened pyaudio instance and close it
    if AUDIO_OUTPUT_DEVICE != -1:
        time.sleep(stream_tx.get_output_latency())
        stream_tx.stop_stream()
        stream_tx.close()
        p_audio.terminate()


def parse_arguments():
    # GET PARAMETER INPUTS
    parser = argparse.ArgumentParser(description="FreeDATA TEST")
    parser.add_argument("--bursts", dest="N_BURSTS", default=1, type=int)
    parser.add_argument(
        "--framesperburst", dest="N_FRAMES_PER_BURST", default=1, type=int
    )
    parser.add_argument("--delay", dest="DELAY_BETWEEN_BURSTS", default=500, type=int)
    parser.add_argument(
        "--audiodev",
        dest="AUDIO_OUTPUT_DEVICE",
        default=-1,
        type=int,
        help="audio output device number to use",
    )
    parser.add_argument(
        "--list",
        dest="LIST",
        action="store_true",
        help="list audio devices by number and exit",
    )

    args, _ = parser.parse_known_args()
    return args


if __name__ == "__main__":
    test_mm_tx()