From 111f00b2302a54c8cdee1878d865766e559b0ee1 Mon Sep 17 00:00:00 2001 From: f4exb Date: Sat, 26 Dec 2015 00:19:41 +0100 Subject: [PATCH] BFM demod: fixed LSB stereo --- include/dsp/phaselock.h | 8 +++-- plugins/channel/bfm/bfmdemod.cpp | 47 +++++++++++++++++++++++------ plugins/channel/bfm/bfmdemod.h | 14 +++++++-- plugins/channel/bfm/bfmdemodgui.cpp | 1 + 4 files changed, 55 insertions(+), 15 deletions(-) diff --git a/include/dsp/phaselock.h b/include/dsp/phaselock.h index 25fa7858f..66092b153 100644 --- a/include/dsp/phaselock.h +++ b/include/dsp/phaselock.h @@ -128,7 +128,9 @@ protected: samples_out[0] = m_psin; // f Pilot // Generate double-frequency output. // sin(2*x) = 2 * sin(x) * cos(x) - samples_out[1] = 2.0 * m_psin * m_pcos; // 2f Pilot + samples_out[1] = 2.0 * m_psin * m_pcos; // 2f Pilot sin + // cos(2*x) = 2 * cos(x) * cos(x) - 1 + samples_out[2] = (2.0 * m_pcos * m_pcos) - 1.0; // 2f Pilot cos } }; @@ -150,6 +152,8 @@ protected: // Generate double-frequency output. // sin(2*x) = 2 * sin(x) * cos(x) samples_out[1] = 2.0 * m_psin * m_pcos; // Pilot signal (2f) - samples_out[2] = m_phase; // Pilot phase + // cos(2*x) = 2 * cos(x) * cos(x) - 1 + samples_out[2] = (2.0 * m_pcos * m_pcos) - 1.0; // 2f Pilot cos + samples_out[3] = m_phase; // Pilot phase } }; diff --git a/plugins/channel/bfm/bfmdemod.cpp b/plugins/channel/bfm/bfmdemod.cpp index e0ad56b26..0c8d4bd01 100644 --- a/plugins/channel/bfm/bfmdemod.cpp +++ b/plugins/channel/bfm/bfmdemod.cpp @@ -50,7 +50,7 @@ BFMDemod::BFMDemod(SampleSink* sampleSink, RDSParser *rdsParser) : m_config.m_audioSampleRate = DSPEngine::instance()->getAudioSampleRate(); // normally 48 kHz m_deemphasisFilterX.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6); m_deemphasisFilterY.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6); - m_rfFilter = new fftfilt(-50000.0 / 384000.0, 50000.0 / 384000.0, rfFilterFftLength); + m_rfFilter = new fftfilt(-50000.0 / 384000.0, 50000.0 / 384000.0, filtFftLen); m_phaseDiscri.setFMScaling(384000/m_fmExcursion); apply(); @@ -79,6 +79,7 @@ void BFMDemod::configure(MessageQueue* messageQueue, Real volume, Real squelch, bool audioStereo, + bool lsbStereo, bool showPilot, bool rdsActive) { @@ -87,6 +88,7 @@ void BFMDemod::configure(MessageQueue* messageQueue, volume, squelch, audioStereo, + lsbStereo, showPilot, rdsActive); messageQueue->push(cmd); @@ -138,8 +140,8 @@ void BFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto if (m_running.m_rdsActive) { - //Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[2]), 0.0); - Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[2]), 0.0); + //Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[3]), 0.0); + Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[3]), 0.0); if (m_interpolatorRDS.interpolate(&m_interpolatorRDSDistanceRemain, r, &cr)) { @@ -173,12 +175,26 @@ void BFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto m_sampleBuffer.push_back(Sample(m_pilotPLLSamples[1] * (1<<15), 0.0)); // debug 38 kHz pilot } - Complex s(demod * 1.17 * m_pilotPLLSamples[1], 0); - - if (m_interpolatorStereo.interpolate(&m_interpolatorStereoDistanceRemain, s, &cs)) + if (m_running.m_lsbStereo) { - sampleStereo = cs.real(); - m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance; + // 1.17 * 0.7 = 0.819 + Complex s(demod * m_pilotPLLSamples[1], demod * m_pilotPLLSamples[2]); + + if (m_interpolatorStereo.interpolate(&m_interpolatorStereoDistanceRemain, s, &cs)) + { + sampleStereo = cs.real() + cs.imag(); + m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance; + } + } + else + { + Complex s(demod * 1.17 * m_pilotPLLSamples[1], 0); + + if (m_interpolatorStereo.interpolate(&m_interpolatorStereoDistanceRemain, s, &cs)) + { + sampleStereo = cs.real(); + m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance; + } } } @@ -191,8 +207,16 @@ void BFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto Real deemph_l, deemph_r; // Pre-emphasis is applied on each channel before multiplexing m_deemphasisFilterX.process(ci.real() + sampleStereo, deemph_l); m_deemphasisFilterY.process(ci.real() - sampleStereo, deemph_r); - m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_running.m_volume); - m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_running.m_volume); + if (m_running.m_lsbStereo) + { + m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_running.m_volume); + m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_running.m_volume); + } + else + { + m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_running.m_volume); + m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_running.m_volume); + } } else { @@ -280,6 +304,7 @@ bool BFMDemod::handleMessage(const Message& cmd) m_config.m_volume = cfg.getVolume(); m_config.m_squelch = cfg.getSquelch(); m_config.m_audioStereo = cfg.getAudioStereo(); + m_config.m_lsbStereo = cfg.getLsbStereo(); m_config.m_showPilot = cfg.getShowPilot(); m_config.m_rdsActive = cfg.getRDSActive(); @@ -290,6 +315,7 @@ bool BFMDemod::handleMessage(const Message& cmd) << " m_volume: " << m_config.m_volume << " m_squelch: " << m_config.m_squelch << " m_audioStereo: " << m_config.m_audioStereo + << " m_lsbStereo: " << m_config.m_lsbStereo << " m_showPilot: " << m_config.m_showPilot << " m_rdsActive: " << m_config.m_rdsActive; @@ -392,6 +418,7 @@ void BFMDemod::apply() m_running.m_volume = m_config.m_volume; m_running.m_audioSampleRate = m_config.m_audioSampleRate; m_running.m_audioStereo = m_config.m_audioStereo; + m_running.m_lsbStereo = m_config.m_lsbStereo; m_running.m_showPilot = m_config.m_showPilot; m_running.m_rdsActive = m_config.m_rdsActive; } diff --git a/plugins/channel/bfm/bfmdemod.h b/plugins/channel/bfm/bfmdemod.h index 348585bbe..ed94e25b9 100644 --- a/plugins/channel/bfm/bfmdemod.h +++ b/plugins/channel/bfm/bfmdemod.h @@ -34,8 +34,6 @@ #include "rdsdemod.h" #include "rdsdecoder.h" -#define rfFilterFftLength 1024 - class RDSParser; class BFMDemod : public SampleSink { @@ -49,6 +47,7 @@ public: Real volume, Real squelch, bool audioStereo, + bool lsbStereo, bool showPilot, bool rdsActive); @@ -79,6 +78,7 @@ private: Real getVolume() const { return m_volume; } Real getSquelch() const { return m_squelch; } bool getAudioStereo() const { return m_audioStereo; } + bool getLsbStereo() const { return m_lsbStereo; } bool getShowPilot() const { return m_showPilot; } bool getRDSActive() const { return m_rdsActive; } @@ -87,6 +87,7 @@ private: Real volume, Real squelch, bool audioStereo, + bool lsbStereo, bool showPilot, bool rdsActive) { @@ -95,6 +96,7 @@ private: volume, squelch, audioStereo, + lsbStereo, showPilot, rdsActive); } @@ -105,6 +107,7 @@ private: Real m_volume; Real m_squelch; bool m_audioStereo; + bool m_lsbStereo; bool m_showPilot; bool m_rdsActive; @@ -113,6 +116,7 @@ private: Real volume, Real squelch, bool audioStereo, + bool lsbStereo, bool showPilot, bool rdsActive) : Message(), @@ -121,6 +125,7 @@ private: m_volume(volume), m_squelch(squelch), m_audioStereo(audioStereo), + m_lsbStereo(lsbStereo), m_showPilot(showPilot), m_rdsActive(rdsActive) { } @@ -146,6 +151,7 @@ private: Real m_volume; quint32 m_audioSampleRate; bool m_audioStereo; + bool m_lsbStereo; bool m_showPilot; bool m_rdsActive; @@ -158,6 +164,7 @@ private: m_volume(0), m_audioSampleRate(0), m_audioStereo(false), + m_lsbStereo(false), m_showPilot(false), m_rdsActive(false) { } @@ -181,6 +188,7 @@ private: Lowpass m_lowpass; fftfilt* m_rfFilter; + static const int filtFftLen = 1024; Real m_squelchLevel; int m_squelchState; @@ -198,7 +206,7 @@ private: QMutex m_settingsMutex; RDSPhaseLock m_pilotPLL; - Real m_pilotPLLSamples[3]; + Real m_pilotPLLSamples[4]; RDSDemod m_rdsDemod; RDSDecoder m_rdsDecoder; diff --git a/plugins/channel/bfm/bfmdemodgui.cpp b/plugins/channel/bfm/bfmdemodgui.cpp index 5c169fcf1..d28082bac 100644 --- a/plugins/channel/bfm/bfmdemodgui.cpp +++ b/plugins/channel/bfm/bfmdemodgui.cpp @@ -445,6 +445,7 @@ void BFMDemodGUI::applySettings() ui->volume->value() / 10.0, ui->squelch->value(), ui->audioStereo->isChecked(), + ui->lsbStereo->isChecked(), ui->showPilot->isChecked(), ui->rds->isChecked()); }