+/**
+ * Pulse demodulation functions
+ *
+ * Binary demodulators (PWM/PPM/Manchester/...) using a pulse data structure as input
+ *
+ * Copyright (C) 2015 Tommy Vestermark
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef INCLUDE_PULSE_DEMOD_H_
+#define INCLUDE_PULSE_DEMOD_H_
+
+#include <stdint.h>
+#include "pulse_detect.h"
+#include "rtl_433.h"
+
+
+/// Demodulate a Pulse Code Modulation signal
+///
+/// Demodulate a Pulse Code Modulation (PCM) signal where bit width
+/// is fixed and each bit starts with a pulse or not. It may be either
+/// Return-to-Zero (RZ) encoding, where pulses are shorter than bit width
+/// or Non-Return-to-Zero (NRZ) encoding, where pulses are equal to bit width
+/// The presence of a pulse is:
+/// - Presence of a pulse equals 1
+/// - Absence of a pulse equals 0
+/// @param device->short_limit: Nominal width of pulse [us]
+/// @param device->long_limit: Nominal width of bit period [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @return number of events processed
+int pulse_demod_pcm(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// Demodulate a Pulse Position Modulation signal
+///
+/// Demodulate a Pulse Position Modulation (PPM) signal consisting of pulses with variable gap.
+/// Pulse width may be fixed or variable.
+/// Gap between pulses determine the encoding:
+/// - Short gap will add a 0 bit
+/// - Long gap will add a 1 bit
+/// @param device->short_limit: Threshold between short and long gap [us]
+/// @param device->long_limit: Maximum gap size before new row of bits [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @return number of events processed
+int pulse_demod_ppm(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// Demodulate a Pulse Width Modulation signal
+///
+/// Demodulate a Pulse Width Modulation (PWM) signal consisting of short and long high pulses.
+/// Gap between pulses may be of fixed size or variable (e.g. fixed period)
+/// - Short pulse will add a 1 bit
+/// - Long pulse will add a 0 bit
+/// @param device->short_limit: Threshold between short and long pulse [us]
+/// @param device->long_limit: Maximum gap size before new row of bits [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @param device->demod_arg = 0: Do not remove any startbits
+/// @param device->demod_arg = 1: First bit in each message is considered a startbit and not stored in bitbuffer
+/// @return number of events processed
+int pulse_demod_pwm(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// Parameters for pulse_demod_pwm_precise
+typedef struct {
+ int pulse_sync_width; // Width of a sync pulse [samples] (optional, ignored if 0)
+ int pulse_tolerance; // Tolerance of pulse widths [samples]
+} PWM_Precise_Parameters;
+
+
+/// Demodulate a Pulse Width Modulation signal with precise timing
+///
+/// Demodulate a Pulse Width Modulation (PWM) signal consisting of short and long high pulses.
+/// Gap between pulses may be of fixed size or variable (e.g. fixed period)
+/// - Short pulse will add a 1 bit
+/// - Long pulse will add a 0 bit
+/// - Sync pulse will add a new row to bitbuffer
+/// @param device->short_limit: Width in samples of '1' [us]
+/// @param device->long_limit: Width in samples of '0' [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @param device->demod_arg: pointer to PWM_Precise_Parameters
+/// @return number of events processed
+int pulse_demod_pwm_precise(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// Demodulate a Pulse Width Modulation signal with three pulse widths
+///
+/// Demodulate a Pulse Width Modulation (PWM) signal consisting of short, middle and long high pulses.
+/// Gap between pulses may be of fixed size or variable (e.g. fixed period)
+/// The sync bit will add a new row to the bitbuffer
+/// @param device->short_limit: Threshold between short and middle pulse [us]
+/// @param device->long_limit: Threshold between middle and long pulse [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @param device->demod_arg = 0: Short pulse is sync, middle is 0, long is 1
+/// @param device->demod_arg = 1: Short pulse is 0, middle is sync, long is 1
+/// @param device->demod_arg = 2: Short pulse is 0, middle is 1, long is sync
+/// @return number of events processed
+int pulse_demod_pwm_ternary(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// Demodulate a Manchester encoded signal with a hardcoded zerobit in front
+///
+/// Demodulate a Manchester encoded signal where first rising edge is counted as a databit
+/// and therefore always will be zero (Most likely a hardcoded Oregon Scientific peculiarity)
+///
+/// Clock is recovered from the data based on pulse width. When time since last bit is more
+/// than 1.5 times the clock half period (short_width) it is declared a data edge where:
+/// - Rising edge means bit = 0
+/// - Falling edge means bit = 1
+/// @param device->short_limit: Nominal width of clock half period [us]
+/// @param device->long_limit: Not used
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @return number of events processed
+int pulse_demod_manchester_zerobit(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+/// No level shift within the clock cycle translates to a logic 0
+/// One level shift within the clock cycle translates to a logic 1
+/// Each clock cycle begins with a level shift
+///
+/// +---+ +---+ +-------+ + high
+/// | | | | | | |
+/// | | | | | | |
+/// + +---+ +---+ +-------+ low
+///
+/// ^ ^ ^ ^ ^ clock cycle
+/// | 1 | 1 | 0 | 0 | translates as
+///
+/// @param device->short_limit: Width in samples of '1' [us]
+/// @param device->long_limit: Width in samples of '0' [us]
+/// @param device->reset_limit: Maximum gap size before End Of Message [us].
+/// @param device->demod_arg: pointer to PWM_Precise_Parameters (only pulse_tolerance used)
+/// @return number of events processed
+int pulse_demod_clock_bits(const pulse_data_t *pulses, struct protocol_state *device);
+
+
+int pulse_demod_osv1(const pulse_data_t *pulses, struct protocol_state *device);
+
+#endif /* INCLUDE_PULSE_DEMOD_H_ */
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