M17: Demodulator: reduce indentation levels
Removed some indentation levels in M17Demodulator::update function body, no functional change. Signed-off-by: Silvano Seva <silseva@fastwebnet.it>
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Silvano Seva
parent
1c50bf8bad
commit
7b633c5bee
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@ -235,151 +235,148 @@ bool M17Demodulator::update(const bool invertPhase)
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// Read samples from the ADC
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dataBlock_t baseband = inputStream_getData(basebandId);
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if(baseband.data != NULL)
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if(baseband.data == NULL)
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return false;
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// Process samples
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for(size_t i = 0; i < baseband.len; i++)
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{
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// Process samples
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for(size_t i = 0; i < baseband.len; i++)
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// Apply DC removal filter
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int16_t sample = dsp_dcBlockFilter(&dcBlock, baseband.data[i]);
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// Apply RRC on the baseband sample
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float elem = static_cast< float >(sample);
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if(invertPhase) elem = 0.0f - elem;
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sample = static_cast< int16_t >(M17::rrc_24k(elem));
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// Update correlator and sample filter for correlation thresholds
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correlator.sample(sample);
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corrThreshold = sampleFilter(std::abs(sample));
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switch(demodState)
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{
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// Apply DC removal filter
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int16_t sample = dsp_dcBlockFilter(&dcBlock, baseband.data[i]);
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// Apply RRC on the baseband sample
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float elem = static_cast< float >(sample);
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if(invertPhase) elem = 0.0f - elem;
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sample = static_cast< int16_t >(M17::rrc_24k(elem));
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// Update correlator and sample filter for correlation thresholds
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correlator.sample(sample);
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corrThreshold = sampleFilter(std::abs(sample));
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switch(demodState)
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case DemodState::INIT:
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{
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case DemodState::INIT:
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initCount -= 1;
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if(initCount == 0)
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demodState = DemodState::UNLOCKED;
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}
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break;
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case DemodState::UNLOCKED:
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{
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int32_t syncThresh = static_cast< int32_t >(corrThreshold * 33.0f);
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int8_t syncStatus = streamSync.update(correlator, syncThresh, -syncThresh);
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if(syncStatus != 0)
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demodState = DemodState::SYNCED;
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}
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break;
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case DemodState::SYNCED:
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{
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// Set sampling point and deviation, zero frame symbol count
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samplingPoint = streamSync.samplingIndex();
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outerDeviation = correlator.maxDeviation(samplingPoint);
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frameIndex = 0;
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// Quantize the syncword taking data from the correlator
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// memory.
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for(size_t i = 0; i < SYNCWORD_SAMPLES; i++)
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{
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initCount -= 1;
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if(initCount == 0)
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demodState = DemodState::UNLOCKED;
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size_t pos = (correlator.index() + i) % SYNCWORD_SAMPLES;
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int16_t val = correlator.data()[pos];
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if((pos % SAMPLES_PER_SYMBOL) == samplingPoint)
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updateFrame(val);
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}
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uint8_t hd = hammingDistance((*demodFrame)[0], STREAM_SYNC_WORD[0]);
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hd += hammingDistance((*demodFrame)[1], STREAM_SYNC_WORD[1]);
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if(hd == 0)
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{
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locked = true;
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demodState = DemodState::LOCKED;
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}
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else
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{
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demodState = DemodState::UNLOCKED;
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}
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}
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break;
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case DemodState::LOCKED:
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{
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if(sampleIndex != samplingPoint)
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break;
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case DemodState::UNLOCKED:
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{
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int32_t syncThresh = static_cast< int32_t >(corrThreshold * 33.0f);
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int8_t syncStatus = streamSync.update(correlator, syncThresh, -syncThresh);
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// Quantize and update frame at each sampling point
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updateFrame(sample);
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if(syncStatus != 0)
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demodState = DemodState::SYNCED;
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// When we have reached almost the end of a frame, switch
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// to syncpoint update.
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if(frameIndex == (M17_FRAME_SYMBOLS - M17_SYNCWORD_SYMBOLS/2))
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{
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demodState = DemodState::SYNC_UPDATE;
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syncCount = SYNCWORD_SAMPLES * 2;
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}
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break;
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}
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break;
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case DemodState::SYNCED:
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case DemodState::SYNC_UPDATE:
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{
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// Keep filling the ongoing frame!
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if(sampleIndex == samplingPoint)
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updateFrame(sample);
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// Find the new correlation peak
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int32_t syncThresh = static_cast< int32_t >(corrThreshold * 33.0f);
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int8_t syncStatus = streamSync.update(correlator, syncThresh, -syncThresh);
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// Correlation has to coincide with a syncword!
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if((syncStatus != 0) && (frameIndex == M17_SYNCWORD_SYMBOLS))
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{
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// Set sampling point and deviation, zero frame symbol count
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samplingPoint = streamSync.samplingIndex();
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outerDeviation = correlator.maxDeviation(samplingPoint);
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frameIndex = 0;
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// Quantize the syncword taking data from the correlator
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// memory.
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for(size_t i = 0; i < SYNCWORD_SAMPLES; i++)
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{
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size_t pos = (correlator.index() + i) % SYNCWORD_SAMPLES;
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int16_t val = correlator.data()[pos];
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if((pos % SAMPLES_PER_SYMBOL) == samplingPoint)
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updateFrame(val);
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}
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uint8_t hd = hammingDistance((*demodFrame)[0], STREAM_SYNC_WORD[0]);
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hd += hammingDistance((*demodFrame)[1], STREAM_SYNC_WORD[1]);
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if(hd == 0)
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// Valid sync found: update deviation and sample
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// point, then go back to locked state
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if(hd <= 1)
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{
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locked = true;
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demodState = DemodState::LOCKED;
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outerDeviation = correlator.maxDeviation(samplingPoint);
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samplingPoint = streamSync.samplingIndex();
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missedSyncs = 0;
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demodState = DemodState::LOCKED;
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break;
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}
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}
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// No syncword found within the window, increase the count
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// of missed syncs and choose where to go. The lock is lost
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// after four consecutive sync misses.
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if(syncCount == 0)
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{
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if(missedSyncs >= 4)
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{
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demodState = DemodState::UNLOCKED;
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locked = false;
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}
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else
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{
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demodState = DemodState::UNLOCKED;
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demodState = DemodState::LOCKED;
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}
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missedSyncs += 1;
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}
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break;
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case DemodState::LOCKED:
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{
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// Quantize and update frame at each sampling point
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if(sampleIndex == samplingPoint)
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{
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updateFrame(sample);
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// When we have reached almost the end of a frame, switch
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// to syncpoint update.
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if(frameIndex == (M17_FRAME_SYMBOLS - M17_SYNCWORD_SYMBOLS/2))
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{
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demodState = DemodState::SYNC_UPDATE;
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syncCount = SYNCWORD_SAMPLES * 2;
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}
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}
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}
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break;
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case DemodState::SYNC_UPDATE:
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{
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// Keep filling the ongoing frame!
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if(sampleIndex == samplingPoint)
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updateFrame(sample);
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// Find the new correlation peak
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int32_t syncThresh = static_cast< int32_t >(corrThreshold * 33.0f);
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int8_t syncStatus = streamSync.update(correlator, syncThresh, -syncThresh);
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if(syncStatus != 0)
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{
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// Correlation has to coincide with a syncword!
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if(frameIndex == M17_SYNCWORD_SYMBOLS)
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{
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uint8_t hd = hammingDistance((*demodFrame)[0], STREAM_SYNC_WORD[0]);
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hd += hammingDistance((*demodFrame)[1], STREAM_SYNC_WORD[1]);
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// Valid sync found: update deviation and sample
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// point, then go back to locked state
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if(hd <= 1)
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{
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outerDeviation = correlator.maxDeviation(samplingPoint);
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samplingPoint = streamSync.samplingIndex();
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missedSyncs = 0;
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demodState = DemodState::LOCKED;
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break;
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}
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}
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}
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// No syncword found within the window, increase the count
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// of missed syncs and choose where to go. The lock is lost
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// after four consecutive sync misses.
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if(syncCount == 0)
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{
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if(missedSyncs >= 4)
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{
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demodState = DemodState::UNLOCKED;
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locked = false;
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}
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else
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{
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demodState = DemodState::LOCKED;
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}
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missedSyncs += 1;
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}
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syncCount -= 1;
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}
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break;
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syncCount -= 1;
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}
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sampleCount += 1;
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sampleIndex = (sampleIndex + 1) % SAMPLES_PER_SYMBOL;
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break;
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}
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sampleCount += 1;
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sampleIndex = (sampleIndex + 1) % SAMPLES_PER_SYMBOL;
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}
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return newFrame;
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