Files
SDRPlusPlus/decoder_modules/ryfi_decoder/src/ryfi/transmitter.cpp
2024-07-24 16:31:29 +02:00

177 lines
5.5 KiB
C++

#include "transmitter.h"
namespace ryfi {
Transmitter::Transmitter(double baudrate, double samplerate) {
// Initialize the DSP
rs.setInput(&in);
conv.setInput(&rs.out);
framer.setInput(&conv.out);
resamp.init(&framer.out, baudrate, samplerate);
rrcTaps = dsp::taps::rootRaisedCosine<float>(511, 0.6, baudrate, samplerate);
// Normalize the taps
float tot = 0.0f;
for (int i = 0; i < rrcTaps.size; i++) {
tot += rrcTaps.taps[i];
}
for (int i = 0; i < rrcTaps.size; i++) {
rrcTaps.taps[i] /= tot;
}
rrc.init(&resamp.out, rrcTaps);
out = &rrc.out;
}
Transmitter::~Transmitter() {
// Stop everything
stop();
}
void Transmitter::start() {
// Do nothing if already running
if (running) { return; }
// Start the worker thread
workerThread = std::thread(&Transmitter::worker, this);
// Start the DSP
rs.start();
conv.start();
framer.start();
resamp.start();
rrc.start();
// Update the running state
running = true;
}
void Transmitter::stop() {
// Do nothing if not running
if (!running) { return; }
// Stop the worker thread
in.stopWriter();
if (workerThread.joinable()) { workerThread.join(); }
in.clearWriteStop();
// Stop the DSP
rs.stop();
conv.stop();
framer.stop();
resamp.stop();
rrc.stop();
// Update the running state
running = false;
}
bool Transmitter::send(const Packet& pkt) {
// Acquire the packet queue
std::lock_guard<std::mutex> lck(packetsMtx);
// If there are too many packets queued up, drop the packet
if (packets.size() >= MAX_QUEUE_SIZE) { return false; }
// Push the packet onto the queue
packets.push(pkt);
}
bool Transmitter::txFrame(const Frame& frame) {
// Serialize the frame
int count = frame.serialize(in.writeBuf);
// Send it off
return in.swap(count);
}
Packet Transmitter::popPacket() {
// Acquire the packet queue
std::unique_lock<std::mutex> lck(packetsMtx);
// If no packets are available, return empty packet
if (!packets.size()) { return Packet(); }
// Pop the front packet and return it
Packet pkt = packets.front();
packets.pop();
return pkt;
}
void Transmitter::worker() {
Frame frame;
Packet pkt;
uint16_t counter = 0;
int pktToWrite = 0;
int pktWritten = 0;
uint8_t* pktBuffer = new uint8_t[Packet::MAX_SERIALIZED_SIZE];
while (true) {
// Initialize the frame
frame.counter = counter++;
frame.firstPacket = PKT_OFFS_NONE;
frame.lastPacket = PKT_OFFS_NONE;
int frameOffset = 0;
// Fill the frame with as much packet data as possible
while (frameOffset < sizeof(Frame::content)) {
// If there is no packet in the process of being sent
if (!pktWritten) {
// If there is not enough space for the size of the packet
if ((sizeof(Frame::content) - frameOffset) < 2) {
// Fill the rest of the frame with noise and send it
for (int i = frameOffset; i < sizeof(Frame::content); i++) { frame.content[i] = rand(); }
break;
}
// Get the next packet
pkt = popPacket();
// If there was an available packet
if (pkt) {
// Serialize the packet
pktToWrite = pkt.serializedSize();
pkt.serialize(pktBuffer);
}
}
// If none was available
if (!pkt) {
// Fill the rest of the frame with noise and send it
for (int i = frameOffset; i < sizeof(Frame::content); i++) { frame.content[i] = rand(); }
break;
}
// If this is the beginning of the packet
if (!pktWritten) {
//flog::debug("Starting to write a {} byte packet at offset {}", pktToWrite-2, frameOffset);
// If this is the first packet of the frame, update its offset
if (frame.firstPacket == PKT_OFFS_NONE) { frame.firstPacket = frameOffset; }
// Update the last packet pointer
frame.lastPacket = frameOffset;
}
// Compute the amount of data writeable to the frame
int writeable = std::min<int>(pktToWrite - pktWritten, sizeof(Frame::content) - frameOffset);
// Copy the data to the frame
memcpy(&frame.content[frameOffset], &pktBuffer[pktWritten], writeable);
pktWritten += writeable;
frameOffset += writeable;
// If the packet is done being sent
if (pktWritten >= pktToWrite) {
// Prepare for a new packet
pktToWrite = 0;
pktWritten = 0;
}
}
// Send the frame
if (!txFrame(frame)) { break; }
}
delete[] pktBuffer;
}
}