mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-12-25 23:39:37 -05:00
540 lines
16 KiB
C++
540 lines
16 KiB
C++
/*
|
|
* Copyright (C) 1996 Thomas Sailer (sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu)
|
|
* Copyright (C) 2012-2014 Elias Oenal (multimon-ng@eliasoenal.com)
|
|
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
|
|
* Copyright (C) 2016 Furrtek
|
|
*
|
|
* This file is part of PortaPack.
|
|
*
|
|
* 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 2, 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; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include "proc_pocsag.hpp"
|
|
|
|
#include "event_m4.hpp"
|
|
|
|
#include <cstdint>
|
|
#include <cstddef>
|
|
#include <algorithm> // std::max
|
|
#include <cmath>
|
|
|
|
|
|
void POCSAGProcessor::execute(const buffer_c8_t& buffer) {
|
|
// This is called at 1500Hz
|
|
|
|
if (!configured) return;
|
|
|
|
// Get 24kHz audio
|
|
const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
|
|
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
|
|
const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
|
|
auto audio = demod.execute(channel_out, audio_buffer);
|
|
smooth.Process(audio.p, audio.count); // Smooth the data to make decoding more accurate
|
|
audio_output.write(audio);
|
|
|
|
processDemodulatedSamples(audio.p, 16);
|
|
extractFrames();
|
|
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int POCSAGProcessor::OnDataWord(uint32_t word, int pos)
|
|
{
|
|
packet.set(pos, word);
|
|
return 0;
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int POCSAGProcessor::OnDataFrame(int len, int baud)
|
|
{
|
|
if (len > 0)
|
|
{
|
|
packet.set_bitrate(baud);
|
|
packet.set_flag(pocsag::PacketFlag::NORMAL);
|
|
packet.set_timestamp(Timestamp::now());
|
|
const POCSAGPacketMessage message(packet);
|
|
shared_memory.application_queue.push(message);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void POCSAGProcessor::on_message(const Message* const message) {
|
|
if (message->id == Message::ID::POCSAGConfigure)
|
|
configure();
|
|
}
|
|
|
|
void POCSAGProcessor::configure() {
|
|
constexpr size_t decim_0_input_fs = baseband_fs;
|
|
constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0.decimation_factor;
|
|
|
|
constexpr size_t decim_1_input_fs = decim_0_output_fs;
|
|
constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1.decimation_factor;
|
|
|
|
constexpr size_t channel_filter_input_fs = decim_1_output_fs;
|
|
const size_t channel_filter_output_fs = channel_filter_input_fs / 2;
|
|
|
|
const size_t demod_input_fs = channel_filter_output_fs;
|
|
|
|
decim_0.configure(taps_11k0_decim_0.taps, 33554432);
|
|
decim_1.configure(taps_11k0_decim_1.taps, 131072);
|
|
channel_filter.configure(taps_11k0_channel.taps, 2);
|
|
demod.configure(demod_input_fs, 4500);
|
|
// Smoothing should be roughly sample rate over max baud
|
|
// 24k / 3.2k is 7.5
|
|
smooth.SetSize(8);
|
|
audio_output.configure(false);
|
|
|
|
// Set up the frame extraction, limits of baud
|
|
setFrameExtractParams(demod_input_fs, 4000, 300, 32);
|
|
|
|
// Mark the class as ready to accept data
|
|
configured = true;
|
|
}
|
|
|
|
|
|
|
|
// -----------------------------
|
|
// Frame extractraction methods
|
|
// -----------------------------
|
|
#define BAUD_STABLE (104)
|
|
#define MAX_CONSEC_SAME (32)
|
|
#define MAX_WITHOUT_SINGLE (64)
|
|
#define MAX_BAD_TRANS (10)
|
|
|
|
#define M_SYNC (0x7cd215d8)
|
|
#define M_NOTSYNC (0x832dea27)
|
|
|
|
#define M_IDLE (0x7a89c197)
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
inline int bitsDiff(unsigned long left, unsigned long right)
|
|
{
|
|
unsigned long xord = left ^ right;
|
|
int count = 0;
|
|
for (int i = 0; i < 32; i++)
|
|
{
|
|
if ((xord & 0x01) != 0) ++count;
|
|
xord = xord >> 1;
|
|
}
|
|
return(count);
|
|
|
|
}
|
|
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
void POCSAGProcessor::initFrameExtraction()
|
|
{
|
|
m_averageSymbolLen_1024 = m_maxSymSamples_1024;
|
|
m_lastStableSymbolLen_1024 = m_minSymSamples_1024;
|
|
|
|
m_badTransitions = 0;
|
|
m_bitsStart = 0;
|
|
m_bitsEnd = 0;
|
|
m_inverted = false;
|
|
|
|
resetVals();
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
void POCSAGProcessor::resetVals()
|
|
{
|
|
// Reset the parameters
|
|
// --------------------
|
|
m_goodTransitions = 0;
|
|
m_badTransitions = 0;
|
|
m_averageSymbolLen_1024 = m_maxSymSamples_1024;
|
|
m_shortestGoodTrans_1024 = m_maxSymSamples_1024;
|
|
m_valMid = 0;
|
|
|
|
// And reset the counts
|
|
// --------------------
|
|
m_lastTransPos_1024 = 0;
|
|
m_lastBitPos_1024 = 0;
|
|
m_lastSample = 0;
|
|
m_sampleNo = 0;
|
|
m_nextBitPos_1024 = m_maxSymSamples_1024;
|
|
m_nextBitPosInt = (long)m_nextBitPos_1024;
|
|
|
|
// Extraction
|
|
m_fifo.numBits = 0;
|
|
m_gotSync = false;
|
|
m_numCode = 0;
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
void POCSAGProcessor::setFrameExtractParams(long a_samplesPerSec, long a_maxBaud, long a_minBaud, long maxRunOfSameValue)
|
|
{
|
|
m_samplesPerSec = a_samplesPerSec;
|
|
m_minSymSamples_1024 = (uint32_t)(1024.0f * (float)a_samplesPerSec / (float)a_maxBaud);
|
|
m_maxSymSamples_1024 = (uint32_t)(1024.0f*(float)a_samplesPerSec / (float)a_minBaud);
|
|
m_maxRunOfSameValue = maxRunOfSameValue;
|
|
|
|
m_shortestGoodTrans_1024 = m_maxSymSamples_1024;
|
|
m_averageSymbolLen_1024 = m_maxSymSamples_1024;
|
|
m_lastStableSymbolLen_1024 = m_minSymSamples_1024;
|
|
|
|
m_nextBitPos_1024 = m_averageSymbolLen_1024 / 2;
|
|
m_nextBitPosInt = m_nextBitPos_1024 >> 10;
|
|
|
|
initFrameExtraction();
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int POCSAGProcessor::processDemodulatedSamples(float * sampleBuff, int noOfSamples)
|
|
{
|
|
bool transition = false;
|
|
uint32_t samplePos_1024 = 0;
|
|
uint32_t len_1024 = 0;
|
|
|
|
// Loop through the block of data
|
|
// ------------------------------
|
|
for (int pos = 0; pos < noOfSamples; ++pos)
|
|
{
|
|
m_sample = sampleBuff[pos];
|
|
m_valMid += (m_sample - m_valMid) / 1024.0f;
|
|
|
|
++m_sampleNo;
|
|
|
|
// Detect Transition
|
|
// -----------------
|
|
transition = ! ((m_lastSample < m_valMid) ^ (m_sample >= m_valMid)); // use XOR for speed
|
|
|
|
// If this is a transition
|
|
// -----------------------
|
|
if (transition)
|
|
{
|
|
// Calculate samples since last trans
|
|
// ----------------------------------
|
|
int32_t fractional_1024 = (int32_t)(((m_sample - m_valMid)*1024) / (m_sample - m_lastSample));
|
|
if (fractional_1024 < 0) { fractional_1024 = -fractional_1024; }
|
|
|
|
samplePos_1024 = (m_sampleNo<<10)-fractional_1024;
|
|
len_1024 = samplePos_1024 - m_lastTransPos_1024;
|
|
m_lastTransPos_1024 = samplePos_1024;
|
|
|
|
// If symbol is large enough to be valid
|
|
// -------------------------------------
|
|
if (len_1024 > m_minSymSamples_1024)
|
|
{
|
|
// Check for shortest good transition
|
|
// ----------------------------------
|
|
if ((len_1024 < m_shortestGoodTrans_1024) &&
|
|
(m_goodTransitions < BAUD_STABLE)) // detect change of symbol size
|
|
{
|
|
int32_t fractionOfShortest_1024 = (len_1024<<10) / m_shortestGoodTrans_1024;
|
|
|
|
// If currently at half the baud rate
|
|
// ----------------------------------
|
|
if ((fractionOfShortest_1024 > 410) && (fractionOfShortest_1024 < 614)) // 0.4 and 0.6
|
|
{
|
|
m_averageSymbolLen_1024 /= 2;
|
|
m_shortestGoodTrans_1024 = len_1024;
|
|
}
|
|
// If currently at the wrong baud rate
|
|
// -----------------------------------
|
|
else if (fractionOfShortest_1024 < 768) // 0.75
|
|
{
|
|
m_averageSymbolLen_1024 = len_1024;
|
|
m_shortestGoodTrans_1024 = len_1024;
|
|
m_goodTransitions = 0;
|
|
m_lastSingleBitPos_1024 = samplePos_1024 - len_1024;
|
|
}
|
|
}
|
|
|
|
// Calc the number of bits since events
|
|
// ------------------------------------
|
|
int32_t halfSymbol_1024 = m_averageSymbolLen_1024 / 2;
|
|
int bitsSinceLastTrans = max((uint32_t)1, (len_1024+halfSymbol_1024) / m_averageSymbolLen_1024 );
|
|
int bitsSinceLastSingle = (((m_sampleNo<<10)-m_lastSingleBitPos_1024) + halfSymbol_1024) / m_averageSymbolLen_1024;
|
|
|
|
// Check for single bit
|
|
// --------------------
|
|
if (bitsSinceLastTrans == 1)
|
|
{
|
|
m_lastSingleBitPos_1024 = samplePos_1024;
|
|
}
|
|
|
|
// If too long since last transition
|
|
// ---------------------------------
|
|
if (bitsSinceLastTrans > MAX_CONSEC_SAME)
|
|
{
|
|
resetVals();
|
|
}
|
|
// If too long sice last single bit
|
|
// --------------------------------
|
|
else if (bitsSinceLastSingle > MAX_WITHOUT_SINGLE)
|
|
{
|
|
resetVals();
|
|
}
|
|
else
|
|
{
|
|
// If this is a good transition
|
|
// ----------------------------
|
|
int32_t offsetFromExtectedTransition_1024 = len_1024 - (bitsSinceLastTrans*m_averageSymbolLen_1024);
|
|
if (offsetFromExtectedTransition_1024 < 0) { offsetFromExtectedTransition_1024 = -offsetFromExtectedTransition_1024; }
|
|
if (offsetFromExtectedTransition_1024 < ((int32_t)m_averageSymbolLen_1024 / 4)) // Has to be within 1/4 of symbol to be good
|
|
{
|
|
++m_goodTransitions;
|
|
uint32_t bitsCount = min((uint32_t)BAUD_STABLE, m_goodTransitions);
|
|
|
|
uint32_t propFromPrevious = m_averageSymbolLen_1024*bitsCount;
|
|
uint32_t propFromCurrent = (len_1024 / bitsSinceLastTrans);
|
|
m_averageSymbolLen_1024 = (propFromPrevious + propFromCurrent) / (bitsCount + 1);
|
|
m_badTransitions = 0;
|
|
//if ( len < m_shortestGoodTrans ){m_shortestGoodTrans = len;}
|
|
// Store the old symbol size
|
|
if (m_goodTransitions >= BAUD_STABLE)
|
|
{
|
|
m_lastStableSymbolLen_1024 = m_averageSymbolLen_1024;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Set the point of the last bit if not yet stable
|
|
// -----------------------------------------------
|
|
if ((m_goodTransitions < BAUD_STABLE) || (m_badTransitions > 0))
|
|
{
|
|
m_lastBitPos_1024 = samplePos_1024 - (m_averageSymbolLen_1024 / 2);
|
|
}
|
|
|
|
// Calculate the exact positiom of the next bit
|
|
// --------------------------------------------
|
|
int32_t thisPlusHalfsymbol_1024 = samplePos_1024 + (m_averageSymbolLen_1024/2);
|
|
int32_t lastPlusSymbol = m_lastBitPos_1024 + m_averageSymbolLen_1024;
|
|
m_nextBitPos_1024 = lastPlusSymbol + ((thisPlusHalfsymbol_1024 - lastPlusSymbol) / 16);
|
|
|
|
// Check for bad pos error
|
|
// -----------------------
|
|
if (m_nextBitPos_1024 < samplePos_1024) m_nextBitPos_1024 += m_averageSymbolLen_1024;
|
|
|
|
// Calculate integer sample after next bit
|
|
// ---------------------------------------
|
|
m_nextBitPosInt = (m_nextBitPos_1024>>10) + 1;
|
|
|
|
} // symbol is large enough to be valid
|
|
else
|
|
{
|
|
// Bad transition, so reset the counts
|
|
// -----------------------------------
|
|
++m_badTransitions;
|
|
if (m_badTransitions > MAX_BAD_TRANS)
|
|
{
|
|
resetVals();
|
|
}
|
|
}
|
|
} // end of if transition
|
|
|
|
// Reached the point of the next bit
|
|
// ---------------------------------
|
|
if (m_sampleNo >= m_nextBitPosInt)
|
|
{
|
|
// Everything is good so extract a bit
|
|
// -----------------------------------
|
|
if (m_goodTransitions > 20)
|
|
{
|
|
// Store value at the center of bit
|
|
// --------------------------------
|
|
storeBit();
|
|
}
|
|
// Check for long 1 or zero
|
|
// ------------------------
|
|
uint32_t bitsSinceLastTrans = ((m_sampleNo<<10) - m_lastTransPos_1024) / m_averageSymbolLen_1024;
|
|
if (bitsSinceLastTrans > m_maxRunOfSameValue)
|
|
{
|
|
resetVals();
|
|
}
|
|
|
|
// Store the point of the last bit
|
|
// -------------------------------
|
|
m_lastBitPos_1024 = m_nextBitPos_1024;
|
|
|
|
// Calculate the exact point of the next bit
|
|
// -----------------------------------------
|
|
m_nextBitPos_1024 += m_averageSymbolLen_1024;
|
|
|
|
// Look for the bit after the next bit pos
|
|
// ---------------------------------------
|
|
m_nextBitPosInt = (m_nextBitPos_1024>>10) + 1;
|
|
|
|
} // Reached the point of the next bit
|
|
|
|
m_lastSample = m_sample;
|
|
|
|
} // Loop through the block of data
|
|
|
|
return getNoOfBits();
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
void POCSAGProcessor::storeBit()
|
|
{
|
|
if (++m_bitsStart >= BIT_BUF_SIZE) { m_bitsStart = 0; }
|
|
|
|
// Calculate the bit value
|
|
float sample = (m_sample + m_lastSample) / 2;
|
|
//int32_t sample_1024 = m_sample_1024;
|
|
bool bit = sample > m_valMid;
|
|
|
|
// If buffer not full
|
|
if (m_bitsStart != m_bitsEnd)
|
|
{
|
|
// Decide on output val
|
|
if (bit)
|
|
{
|
|
m_bits[m_bitsStart] = 0;
|
|
}
|
|
else
|
|
{
|
|
m_bits[m_bitsStart] = 1;
|
|
}
|
|
}
|
|
// Throw away bits if the buffer is full
|
|
else
|
|
{
|
|
if (--m_bitsStart <= -1)
|
|
{
|
|
m_bitsStart = BIT_BUF_SIZE - 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int POCSAGProcessor::extractFrames()
|
|
{
|
|
int msgCnt = 0;
|
|
// While there is unread data in the bits buffer
|
|
//----------------------------------------------
|
|
while (getNoOfBits() > 0)
|
|
{
|
|
m_fifo.codeword = (m_fifo.codeword << 1) + getBit();
|
|
m_fifo.numBits++;
|
|
|
|
// If number of bits in fifo equals 32
|
|
//------------------------------------
|
|
if (m_fifo.numBits >= 32)
|
|
{
|
|
// Not got sync
|
|
// ------------
|
|
if (!m_gotSync)
|
|
{
|
|
if (bitsDiff(m_fifo.codeword, M_SYNC) <= 2)
|
|
{
|
|
m_inverted = false;
|
|
m_gotSync = true;
|
|
m_numCode = -1;
|
|
m_fifo.numBits = 0;
|
|
}
|
|
else if (bitsDiff(m_fifo.codeword, M_NOTSYNC) <= 2)
|
|
{
|
|
m_inverted = true;
|
|
m_gotSync = true;
|
|
m_numCode = -1;
|
|
m_fifo.numBits = 0;
|
|
}
|
|
else
|
|
{
|
|
// Cause it to load one more bit
|
|
m_fifo.numBits = 31;
|
|
}
|
|
} // Not got sync
|
|
else
|
|
{
|
|
// Increment the word count
|
|
// ------------------------
|
|
++m_numCode; // It got set to -1 when a sync was found, now count the 16 words
|
|
uint32_t val = m_inverted ? ~m_fifo.codeword : m_fifo.codeword;
|
|
OnDataWord(val, m_numCode);
|
|
|
|
// If at the end of a 16 word block
|
|
// --------------------------------
|
|
if (m_numCode >= 15)
|
|
{
|
|
msgCnt += OnDataFrame(m_numCode+1, (m_samplesPerSec<<10) / m_lastStableSymbolLen_1024);
|
|
m_gotSync = false;
|
|
m_numCode = -1;
|
|
}
|
|
m_fifo.numBits = 0;
|
|
}
|
|
} // If number of bits in fifo equals 32
|
|
} // While there is unread data in the bits buffer
|
|
return msgCnt;
|
|
} // extractFrames
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
short POCSAGProcessor::getBit()
|
|
{
|
|
if (m_bitsEnd != m_bitsStart)
|
|
{
|
|
if (++m_bitsEnd >= BIT_BUF_SIZE)
|
|
{
|
|
m_bitsEnd = 0;
|
|
}
|
|
return m_bits[m_bitsEnd];
|
|
}
|
|
else
|
|
{
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int POCSAGProcessor::getNoOfBits()
|
|
{
|
|
int bits = m_bitsEnd - m_bitsStart;
|
|
if (bits < 0) { bits += BIT_BUF_SIZE; }
|
|
return bits;
|
|
}
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
uint32_t POCSAGProcessor::getRate()
|
|
{
|
|
return ((m_samplesPerSec<<10)+512) / m_lastStableSymbolLen_1024;
|
|
}
|
|
|
|
|
|
// ====================================================================
|
|
//
|
|
// ====================================================================
|
|
int main() {
|
|
EventDispatcher event_dispatcher { std::make_unique<POCSAGProcessor>() };
|
|
event_dispatcher.run();
|
|
return 0;
|
|
}
|