mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-09-20 16:15:51 +00:00
Rebake of AM, NFM demodulators -- more flexible filtering/configuration.
Also make SpectrumCollector dynamically configurable. Add deemphasis filter to NFM.
This commit is contained in:
Jared Boone
parent
df593c2f0f
commit
bbfcca8ec0
@ -34,6 +34,12 @@ constexpr iir_biquad_config_t audio_hpf_config {
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constexpr iir_biquad_config_t non_audio_hpf_config {
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{ 0.51891061f, -0.95714180f, 0.51891061f },
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{ 1.0f , -0.79878302f, 0.43960231f }
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// scipy.signal.butter(1, 300 / 24000.0, 'lowpass', analog=False)
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// NOTE: Technically, order-1 filter, b[2] = a[2] = 0.
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constexpr iir_biquad_config_t audio_deemph_300_6_config {
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{ 0.01925927f, 0.01925927f, 0.00000000f, },
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{ 1.00000000f, -0.96148145f, 0.00000000f, },
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};
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#endif/*__DSP_IIR_CONFIG_H__*/
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@ -21,39 +21,77 @@
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#include "proc_am_audio.hpp"
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#include <cstdint>
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// DSB AM 6K00A3E emission type ///////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=3000, stop=339000, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_6k0_decim_0 { {
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39, 104, 224, 412, 674, 1008, 1400, 1821,
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2234, 2594, 2863, 3006, 3006, 2863, 2594, 2234,
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1821, 1400, 1008, 674, 412, 224, 104, 39,
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} };
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// IFIR prototype filter: fs=384000, pass=3000, stop=45000, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_6k0_decim_1 { {
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-26, -63, -123, -195, -263, -295, -253, -99,
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199, 651, 1242, 1927, 2633, 3273, 3760, 4023,
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4023, 3760, 3273, 2633, 1927, 1242, 651, 199,
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-99, -253, -295, -263, -195, -123, -63, -26,
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} };
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// Channel filter: fs=48000, pass=3000, stop=6700, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_6k0_channel { {
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95, 178, 247, 208, -21, -474, -1080, -1640,
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-1857, -1411, -83, 2134, 4978, 7946, 10413, 11815,
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11815, 10413, 7946, 4978, 2134, -83, -1411, -1857,
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-1640, -1080, -474, -21, 208, 247, 178, 95,
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} };
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NarrowbandAMAudio::NarrowbandAMAudio() {
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constexpr size_t baseband_fs = 3072000;
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constexpr size_t decim_0_input_fs = baseband_fs;
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constexpr size_t decim_0_decimation_factor = 8;
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constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0_decimation_factor;
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constexpr size_t decim_1_input_fs = decim_0_output_fs;
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constexpr size_t decim_1_decimation_factor = 8;
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constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1_decimation_factor;
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constexpr size_t channel_filter_input_fs = decim_1_output_fs;
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constexpr size_t channel_filter_decimation_factor = 1;
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constexpr size_t channel_filter_output_fs = channel_filter_input_fs / channel_filter_decimation_factor;
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decim_0.configure(taps_6k0_decim_0, 33554432);
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decim_1.configure(taps_6k0_decim_1, 131072);
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channel_filter.configure(taps_6k0_channel, 1);
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channel_filter_pass_f = 3000;
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channel_filter_stop_f = 6700;
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channel_spectrum.set_decimation_factor(std::floor((channel_filter_output_fs / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2)));
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}
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void NarrowbandAMAudio::execute(const buffer_c8_t& buffer) {
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auto decimator_out = decimator.execute(buffer);
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const buffer_c16_t work_baseband_buffer {
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(complex16_t*)decimator_out.p,
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sizeof(*decimator_out.p) * decimator_out.count
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const buffer_c16_t dst_buffer {
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dst.data(),
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dst.size()
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};
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/* 96kHz complex<int16_t>[64]
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* -> FIR filter, <?kHz (0.???fs) pass, gain 1.0
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* -> 48kHz int16_t[32] */
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auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
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const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
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const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
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const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
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// TODO: Feed channel_stats post-decimation data?
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feed_channel_stats(channel);
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channel_spectrum.feed(
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channel,
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decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
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decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
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);
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feed_channel_stats(channel_out);
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channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f);
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const buffer_s16_t work_audio_buffer {
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(int16_t*)decimator_out.p,
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sizeof(*decimator_out.p) * decimator_out.count
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(int16_t*)dst.data(),
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sizeof(*dst.data()) * dst.size()
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};
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/* 48kHz complex<int16_t>[32]
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* -> AM demodulation
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* -> 48kHz int16_t[32] */
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auto audio = demod.execute(channel, work_audio_buffer);
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auto audio = demod.execute(channel_out, work_audio_buffer);
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audio_hpf.execute_in_place(audio);
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fill_audio_buffer(audio);
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}
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@ -33,22 +33,27 @@
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#include "spectrum_collector.hpp"
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#include <cstdint>
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#include <array>
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class NarrowbandAMAudio : public BasebandProcessor {
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public:
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NarrowbandAMAudio() {
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decimator.set_decimation_factor(ChannelDecimator::DecimationFactor::By32);
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channel_filter.configure(channel_filter_taps.taps, 2);
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}
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NarrowbandAMAudio();
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void execute(const buffer_c8_t& buffer) override;
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void on_update_spectrum() override { channel_spectrum.update(); }
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private:
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ChannelDecimator decimator;
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const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter;
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std::array<complex16_t, 512> dst;
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dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0;
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dsp::decimate::FIRC16xR16x32Decim8 decim_1;
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dsp::decimate::FIRAndDecimateComplex channel_filter;
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uint32_t channel_filter_pass_f;
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uint32_t channel_filter_stop_f;
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dsp::demodulate::AM demod;
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IIRBiquadFilter audio_hpf { audio_hpf_config };
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SpectrumCollector channel_spectrum;
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@ -24,44 +24,163 @@
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#include <cstdint>
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#include <cstddef>
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// NBFM 16K0F3E emission type /////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=8000, stop=344000, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_16k0_decim_0 { {
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1, 67, 165, 340, 599, 944, 1361, 1820,
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2278, 2684, 2988, 3152, 3152, 2988, 2684, 2278,
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1820, 1361, 944, 599, 340, 165, 67, 1,
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} };
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// IFIR prototype filter: fs=384000, pass=8000, stop=40000, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_16k0_decim_1 { {
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-26, -125, -180, -275, -342, -359, -286, -90,
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250, 733, 1337, 2011, 2688, 3289, 3740, 3982,
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3982, 3740, 3289, 2688, 2011, 1337, 733, 250,
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-90, -286, -359, -342, -275, -180, -125, -26,
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} };
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// Channel filter: fs=48000, pass=8000, stop=12400, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_16k0_channel { {
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-73, -285, -376, -8, 609, 538, -584, -1387,
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-148, 2173, 1959, -2146, -5267, -297, 12915, 24737,
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24737, 12915, -297, -5267, -2146, 1959, 2173, -148,
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-1387, -584, 538, 609, -8, -376, -285, -73,
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} };
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// NBFM 11K0F3E emission type /////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=5500, stop=341500, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_11k0_decim_0 { {
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38, 102, 220, 406, 668, 1004, 1397, 1822,
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2238, 2603, 2875, 3020, 3020, 2875, 2603, 2238,
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1822, 1397, 1004, 668, 406, 220, 102, 38,
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} };
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// IFIR prototype filter: fs=384000, pass=5500, stop=42500, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_11k0_decim_1 { {
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-42, -87, -157, -234, -298, -318, -255, -75,
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246, 713, 1306, 1976, 2656, 3265, 3724, 3971,
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3971, 3724, 3265, 2656, 1976, 1306, 713, 246,
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-75, -255, -318, -298, -234, -157, -87, -42,
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} };
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// Channel filter: fs=48000, pass=5500, stop=8900, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_11k0_channel { {
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-68, -345, -675, -867, -582, 247, 1222, 1562,
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634, -1379, -3219, -3068, 310, 6510, 13331, 17795,
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17795, 13331, 6510, 310, -3068, -3219, -1379, 634,
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1562, 1222, 247, -582, -867, -675, -345, -68,
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} };
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/// NBFM 8K50F3E emission type ////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=4250, stop=340250, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_4k25_decim_0 { {
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38, 103, 222, 409, 671, 1006, 1399, 1821,
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2236, 2599, 2868, 3012, 3012, 2868, 2599, 2236,
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1821, 1399, 1006, 671, 409, 222, 103, 38,
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} };
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// IFIR prototype filter: fs=384000, pass=4250, stop=43750, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_4k25_decim_1 { {
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-33, -74, -139, -214, -280, -306, -254, -87,
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222, 682, 1274, 1951, 2644, 3268, 3741, 3996,
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3996, 3741, 3268, 2644, 1951, 1274, 682, 222,
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-87, -254, -306, -280, -214, -139, -74, -33,
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} };
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// Channel filter: fs=48000, pass=4250, stop=7900, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_4k25_channel { {
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-58, -14, 153, 484, 871, 1063, 770, -141,
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-1440, -2488, -2435, -614, 3035, 7771, 12226, 14927,
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14927, 12226, 7771, 3035, -614, -2435, -2488, -1440,
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-141, 770, 1063, 871, 484, 153, -14, -58,
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} };
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NarrowbandFMAudio::NarrowbandFMAudio() {
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set_mode(Mode::Deviation2K5Narrow);
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}
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void NarrowbandFMAudio::set_mode(const Mode mode) {
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constexpr size_t baseband_fs = 3072000;
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constexpr size_t decim_0_input_fs = baseband_fs;
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constexpr size_t decim_0_decimation_factor = 8;
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constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0_decimation_factor;
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constexpr size_t decim_1_input_fs = decim_0_output_fs;
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constexpr size_t decim_1_decimation_factor = 8;
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constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1_decimation_factor;
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constexpr size_t channel_filter_input_fs = decim_1_output_fs;
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constexpr size_t channel_filter_decimation_factor = 1;
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constexpr size_t channel_filter_output_fs = channel_filter_input_fs / channel_filter_decimation_factor;
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constexpr size_t demod_input_fs = channel_filter_output_fs;
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switch(mode) {
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default:
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case Mode::Deviation5K:
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decim_0.configure(taps_16k0_decim_0, 33554432);
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decim_1.configure(taps_16k0_decim_1, 131072);
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channel_filter.configure(taps_16k0_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 5000);
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channel_filter_pass_f = 8000;
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channel_filter_stop_f = 12400;
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break;
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case Mode::Deviation2K5Wide:
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decim_0.configure(taps_11k0_decim_0, 33554432);
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decim_1.configure(taps_11k0_decim_1, 131072);
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channel_filter.configure(taps_11k0_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 2500);
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channel_filter_pass_f = 5500;
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channel_filter_stop_f = 8900;
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break;
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case Mode::Deviation2K5Narrow:
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decim_0.configure(taps_4k25_decim_0, 33554432);
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decim_1.configure(taps_4k25_decim_1, 131072);
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channel_filter.configure(taps_4k25_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 2500);
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channel_filter_pass_f = 4250;
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channel_filter_stop_f = 7900;
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break;
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}
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channel_spectrum.set_decimation_factor(std::floor((channel_filter_output_fs / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2)));
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}
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void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
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/* Called every 2048/3072000 second -- 1500Hz. */
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auto decimator_out = decimator.execute(buffer);
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const buffer_c16_t work_baseband_buffer {
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(complex16_t*)decimator_out.p,
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sizeof(*decimator_out.p) * decimator_out.count
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const buffer_c16_t dst_buffer {
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dst.data(),
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dst.size()
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};
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/* 96kHz complex<int16_t>[64]
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* -> FIR filter, <6kHz (0.063fs) pass, gain 1.0
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* -> 48kHz int16_t[32] */
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auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
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const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
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const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
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const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
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// TODO: Feed channel_stats post-decimation data?
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feed_channel_stats(channel);
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channel_spectrum.feed(
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channel,
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decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
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decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
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);
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feed_channel_stats(channel_out);
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channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f);
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const buffer_s16_t work_audio_buffer {
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(int16_t*)decimator_out.p,
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sizeof(*decimator_out.p) * decimator_out.count
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(int16_t*)dst.data(),
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sizeof(*dst.data()) * dst.size()
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};
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/* 48kHz complex<int16_t>[32]
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* -> FM demodulation
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* -> 48kHz int16_t[32] */
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auto audio = demod.execute(channel, work_audio_buffer);
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auto audio = demod.execute(channel_out, work_audio_buffer);
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static uint64_t audio_present_history = 0;
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const auto audio_present_now = squelch.execute(audio);
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audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
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const bool audio_present = (audio_present_history != 0);
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audio_hpf.execute_in_place(audio);
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audio_deemph.execute_in_place(audio);
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if( !audio_present ) {
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// Zero audio buffer.
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for(size_t i=0; i<audio.count; i++) {
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@ -69,6 +188,5 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
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}
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}
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audio_hpf.execute_in_place(audio);
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fill_audio_buffer(audio);
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}
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@ -36,22 +36,33 @@
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class NarrowbandFMAudio : public BasebandProcessor {
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public:
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NarrowbandFMAudio() {
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decimator.set_decimation_factor(ChannelDecimator::DecimationFactor::By32);
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channel_filter.configure(channel_filter_taps.taps, 2);
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}
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enum class Mode {
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Deviation5K = 0,
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Deviation2K5Wide = 1,
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Deviation2K5Narrow = 2,
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};
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NarrowbandFMAudio();
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void set_mode(const Mode mode);
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void execute(const buffer_c8_t& buffer) override;
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void on_update_spectrum() override { channel_spectrum.update(); }
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private:
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ChannelDecimator decimator;
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const fir_taps_real<64>& channel_filter_taps = taps_64_lp_042_078_tfilter;
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std::array<complex16_t, 512> dst;
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dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0;
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dsp::decimate::FIRC16xR16x32Decim8 decim_1;
|
||||
|
||||
dsp::decimate::FIRAndDecimateComplex channel_filter;
|
||||
dsp::demodulate::FM demod { 48000, 7500 };
|
||||
uint32_t channel_filter_pass_f = 0;
|
||||
uint32_t channel_filter_stop_f = 0;
|
||||
|
||||
dsp::demodulate::FM demod;
|
||||
|
||||
IIRBiquadFilter audio_hpf { audio_hpf_config };
|
||||
IIRBiquadFilter audio_deemph { audio_deemph_300_6_config };
|
||||
FMSquelch squelch;
|
||||
|
||||
SpectrumCollector channel_spectrum;
|
||||
|
||||
@ -38,7 +38,7 @@ public:
|
||||
private:
|
||||
size_t sample_count = 0;
|
||||
|
||||
SpectrumCollector channel_spectrum { 1 };
|
||||
SpectrumCollector channel_spectrum;
|
||||
|
||||
std::array<complex16_t, 256> spectrum;
|
||||
};
|
||||
|
||||
@ -29,6 +29,12 @@
|
||||
|
||||
#include <algorithm>
|
||||
|
||||
void SpectrumCollector::set_decimation_factor(
|
||||
const size_t decimation_factor
|
||||
) {
|
||||
channel_spectrum_decimator.set_factor(decimation_factor);
|
||||
}
|
||||
|
||||
/* TODO: Refactor to register task with idle thread?
|
||||
* It's sad that the idle thread has to call all the way back here just to
|
||||
* perform the deferred task on the buffer of data we prepared.
|
||||
|
||||
@ -33,11 +33,12 @@
|
||||
class SpectrumCollector {
|
||||
public:
|
||||
constexpr SpectrumCollector(
|
||||
const size_t decimation_factor = 4
|
||||
) : channel_spectrum_decimator { decimation_factor }
|
||||
) : channel_spectrum_decimator { 1 }
|
||||
{
|
||||
}
|
||||
|
||||
void set_decimation_factor(const size_t decimation_factor);
|
||||
|
||||
void feed(
|
||||
const buffer_c16_t& channel,
|
||||
const uint32_t filter_pass_frequency,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user