#include "DemodulatorThread.h" #include "CubicSDRDefs.h" #include DemodulatorThread::DemodulatorThread(DemodulatorThreadQueue* pQueue, int id) : wxThread(wxTHREAD_DETACHED), m_pQueue(pQueue), m_ID(id) { bandwidth = 200000; resample_ratio = (float) (bandwidth) / (float) SRATE; wbfm_frequency = 100000; wbfm_resample_ratio = (float) (wbfm_frequency) / (float) bandwidth; audio_frequency = AUDIO_FREQUENCY; audio_resample_ratio = (float) (audio_frequency) / (float) wbfm_frequency; float fc = 0.5f * ((float) bandwidth / (float) SRATE) * 0.75; // filter cutoff frequency float ft = 0.05f; // filter transition float As = 60.0f; // stop-band attenuation [dB] float mu = 0.0f; // fractional timing offset // estimate required filter length and generate filter unsigned int h_len = estimate_req_filter_len(ft, As); float h[h_len]; liquid_firdes_kaiser(h_len, fc, As, mu, h); fir_filter = firfilt_crcf_create(h, h_len); h_len = estimate_req_filter_len(ft, As); liquid_firdes_kaiser(h_len, 32000.0 / (float) wbfm_frequency, As, mu, h); fir_audio_filter = firfilt_crcf_create(h, h_len); // create multi-stage arbitrary resampler object resampler = msresamp_crcf_create(resample_ratio, As); msresamp_crcf_print(resampler); wbfm_resampler = msresamp_crcf_create(wbfm_resample_ratio, As); msresamp_crcf_print(wbfm_resampler); audio_resampler = msresamp_crcf_create(audio_resample_ratio, As); msresamp_crcf_print(audio_resampler); float kf = 0.75; // modulation factor fdem = freqdem_create(kf); freqdem_print(fdem); } DemodulatorThread::~DemodulatorThread() { } wxThread::ExitCode DemodulatorThread::Entry() { while (!TestDestroy()) { if (m_pQueue->stackSize()) { while (m_pQueue->stackSize()) { DemodulatorThreadTask task = m_pQueue->pop(); // pop a task from the queue. this will block the worker thread if queue is empty switch (task.m_cmd) { case DemodulatorThreadTask::DEMOD_THREAD_DATA: std::vector *data = &task.data->data; if (data->size()) { liquid_float_complex filtered_input[BUF_SIZE / 2]; for (int i = 0; i < BUF_SIZE / 2; i++) { liquid_float_complex x; liquid_float_complex y; x.real = (float) (*data)[i * 2] / 127.0f; x.imag = (float) (*data)[i * 2 + 1] / 127.0f; firfilt_crcf_push(fir_filter, x); // push input sample firfilt_crcf_execute(fir_filter, &y); // compute output filtered_input[i] = y; } int out_size = ceil((float) (BUF_SIZE / 2) * resample_ratio); liquid_float_complex resampled_output[out_size]; unsigned int num_written; // number of values written to buffer msresamp_crcf_execute(resampler, filtered_input, (BUF_SIZE / 2), resampled_output, &num_written); float waveform_ceil = 0, waveform_floor = 0; float pcm = 0; for (int i = 0; i < num_written; i++) { freqdem_demodulate(fdem, resampled_output[i], &pcm); resampled_output[i].real = (float) pcm; resampled_output[i].imag = 0; if (waveform_ceil < resampled_output[i].real) { waveform_ceil = resampled_output[i].real; } if (waveform_floor > resampled_output[i].real) { waveform_floor = resampled_output[i].real; } } int wbfm_out_size = ceil((float) (num_written) * wbfm_resample_ratio); liquid_float_complex resampled_wbfm_output[wbfm_out_size]; unsigned int num_wbfm_written; msresamp_crcf_execute(wbfm_resampler, resampled_output, num_written, resampled_wbfm_output, &num_wbfm_written); for (int i = 0; i < num_wbfm_written; i++) { firfilt_crcf_push(fir_audio_filter, resampled_wbfm_output[i]); firfilt_crcf_execute(fir_audio_filter, &resampled_wbfm_output[i]); } int audio_out_size = ceil((float) (num_wbfm_written) * audio_resample_ratio); liquid_float_complex resampled_audio_output[audio_out_size]; unsigned int num_audio_written; msresamp_crcf_execute(audio_resampler, resampled_wbfm_output, num_wbfm_written, resampled_audio_output, &num_audio_written); std::vector newBuffer; newBuffer.resize(num_audio_written * 2); for (int i = 0; i < num_audio_written; i++) { liquid_float_complex y = resampled_audio_output[i]; newBuffer[i * 2] = y.real; newBuffer[i * 2 + 1] = y.real; } if (!TestDestroy()) { DemodulatorThreadAudioData *audioOut = new DemodulatorThreadAudioData(task.data->frequency,audio_frequency,newBuffer); m_pQueue->sendAudioData(DemodulatorThreadTask::DEMOD_THREAD_AUDIO_DATA,audioOut); } delete task.data; } break; } } } else { this->Yield(); this->Sleep(1); } } std::cout << std::endl << "Demodulator Thread Done." << std::endl << std::endl; return (wxThread::ExitCode) 0; }