FSK demodulator: PCM audio data is written to the decoder and the decoded data is written to the output that was defined with setOutput(). Supported input formats are 8, 16 or 32 bit signed integer samples with any number of channels (only config.channel is evaluated). The decoding is compatible with minimodem –tx. More...

#include <FSKDecoder.h>

Inheritance diagram for tinymodem::FSKDecoder:

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Collaboration diagram for tinymodem::FSKDecoder:

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Public Member Functions
	FSKDecoder ()=default
	FSKDecoder (Print &out)
ModemConfig	defaultConfig ()
	Provides a default configuration for a 1200 baud Bell 202 modem.
void	setAudioInfo (audio_tools::AudioInfo info) override
	Defines the format of the input audio data.
audio_tools::AudioInfo	audioInfo () override
bool	begin (ModemConfig config)
	Starts the processing with the indicated modem configuration.
bool	begin () override
void	end () override
	Processes the remaining samples and reports the end of the carrier.
void	flush () override
	Processes all buffered samples (e.g. at the end of the input).
size_t	write (const uint8_t *data, size_t len) override
	Provide PCM data to the decoder.
bool	isCarrier () override
	true while a carrier is detected
bool	isFinished () override
	true if the decoding was stopped (rx_one)
ModemConfig &	config ()
const ModemConfig &	activeConfig () const
	The active configuration with all derived values (e.g. frequencies).
float	markFrequency ()
	Actual mark frequency (e.g. after the carrier auto detection).
	operator bool () override
Public Member Functions inherited from tinymodem::ModemDecoder
void	setStatusOutput (Print &out)
	Defines the output for the ### CARRIER / ### NOCARRIER messages.
void	setQuiet (bool quiet)
	Suppresses the status messages.
const char *	mime () override

Protected Member Functions
void	setupCodec ()
void	resetState ()
int	buildExpectBits (char *str, bool use_expect_bits, uint64_t expect_bits)
float	noise ()
	uniform random value in the range -0.5 to 0.5
void	addSample (float sample)
void	applyAdvance ()
bool	step (bool eof)
void	reportCarrier ()
void	reportNoCarrier ()
Protected Member Functions inherited from tinymodem::ModemDecoder
void	status (const char *fmt,...)

Protected Attributes
ModemConfig	cfg
ModemConfig	active_cfg
bool	is_active = false
bool	is_finished = false
FSKDemodulator	plan
AsciiCodec	ascii
BaudotCodec	baudot
BinaryCodec	binary
CallerIDCodec	callerid
UICCodec	uic
DataCodec *	p_codec = &ascii
PrintFilter	print_filter
audio_tools::Vector< float >	samplebuf
size_t	samples_nvalid = 0
size_t	process_threshold = 0
size_t	advance = 0
size_t	skip = 0
float	nsamples_per_bit = 0
unsigned	nsamples_overscan = 0
float	frame_n_bits = 0
unsigned	frame_nsamples = 0
char	expect_data_string [MAX_EXPECT]
char	expect_sync_string [MAX_EXPECT]
unsigned	expect_n_bits = 0
unsigned	expect_nsamples = 0
PcmInput	input
uint32_t	noise_seed = 1
bool	carrier = false
int	carrier_band = -1
float	confidence_total = 0
float	amplitude_total = 0
unsigned	nframes_decoded = 0
size_t	carrier_nsamples = 0
unsigned	noconfidence = 0
float	track_amplitude = 0.0f
float	peak_confidence = 0.0f
Protected Attributes inherited from tinymodem::ModemDecoder
Print *	p_status = nullptr
bool	is_quiet = false

Static Protected Attributes
static constexpr int	MAX_EXPECT = 80
static constexpr int	FSK_ANALYZE_NSTEPS = 3
static constexpr int	FSK_ANALYZE_NSTEPS_FINE = 8
static constexpr unsigned	FSK_MAX_NOCONFIDENCE_BITS = 20
static constexpr float	FRAME_OVERSCAN = 0.5f

Detailed Description

FSK demodulator: PCM audio data is written to the decoder and the decoded data is written to the output that was defined with setOutput(). Supported input formats are 8, 16 or 32 bit signed integer samples with any number of channels (only config.channel is evaluated). The decoding is compatible with minimodem –tx.

Status messages (### CARRIER and ### NOCARRIER) are written in the minimodem format to the Print defined with setStatusOutput().

Copyright: GPLv3

Constructor & Destructor Documentation

◆ FSKDecoder() [1/2]

tinymodem::FSKDecoder::FSKDecoder ( )

default

◆ FSKDecoder() [2/2]

tinymodem::FSKDecoder::FSKDecoder ( Print & out )

inline

Member Function Documentation

◆ activeConfig()

const ModemConfig & tinymodem::FSKDecoder::activeConfig ( ) const

inline

The active configuration with all derived values (e.g. frequencies).

◆ addSample()

void tinymodem::FSKDecoder::addSample ( float sample )

inlineprotected

◆ applyAdvance()

void tinymodem::FSKDecoder::applyAdvance ( )

inlineprotected

◆ audioInfo()

audio_tools::AudioInfo tinymodem::FSKDecoder::audioInfo ( )

inlineoverride

◆ begin() [1/2]

bool tinymodem::FSKDecoder::begin ( )

inlineoverride

◆ begin() [2/2]

bool tinymodem::FSKDecoder::begin ( ModemConfig config )

inline

Starts the processing with the indicated modem configuration.

◆ buildExpectBits()

int tinymodem::FSKDecoder::buildExpectBits	(	char *	str,
		bool	use_expect_bits,
		uint64_t	expect_bits )

inlineprotected

Builds the expected framing pattern e.g. "10dddddddd1" (prev_stop, start, data bits, stop)

◆ config()

ModemConfig & tinymodem::FSKDecoder::config ( )

inline

The configuration which was provided in begin(): you can change it and call begin() again

◆ defaultConfig()

ModemConfig tinymodem::FSKDecoder::defaultConfig ( )

inline

Provides a default configuration for a 1200 baud Bell 202 modem.

◆ end()

void tinymodem::FSKDecoder::end ( )

inlineoverride

Processes the remaining samples and reports the end of the carrier.

◆ flush()

void tinymodem::FSKDecoder::flush ( )

inlineoverridevirtual

Processes all buffered samples (e.g. at the end of the input).

Implements tinymodem::ModemDecoder.

◆ isCarrier()

bool tinymodem::FSKDecoder::isCarrier ( )

inlineoverridevirtual

true while a carrier is detected

Implements tinymodem::ModemDecoder.

◆ isFinished()

bool tinymodem::FSKDecoder::isFinished ( )

inlineoverridevirtual

true if the decoding was stopped (rx_one)

Implements tinymodem::ModemDecoder.

◆ markFrequency()

float tinymodem::FSKDecoder::markFrequency ( )

inline

Actual mark frequency (e.g. after the carrier auto detection).

◆ noise()

float tinymodem::FSKDecoder::noise ( )

inlineprotected

uniform random value in the range -0.5 to 0.5

◆ operator bool()

tinymodem::FSKDecoder::operator bool ( )

inlineoverride

◆ reportCarrier()

void tinymodem::FSKDecoder::reportCarrier ( )

inlineprotected

◆ reportNoCarrier()

void tinymodem::FSKDecoder::reportNoCarrier ( )

inlineprotected

◆ resetState()

void tinymodem::FSKDecoder::resetState ( )

inlineprotected

◆ setAudioInfo()

void tinymodem::FSKDecoder::setAudioInfo ( audio_tools::AudioInfo info )

inlineoverride

Defines the format of the input audio data.

◆ setupCodec()

void tinymodem::FSKDecoder::setupCodec ( )

inlineprotected

◆ step()

bool tinymodem::FSKDecoder::step ( bool eof )

inlineprotected

One iteration of the minimodem receive loop: returns false if more data is needed or if the processing has ended.

◆ write()

size_t tinymodem::FSKDecoder::write	(	const uint8_t *	data,
		size_t	len )

inlineoverride

Provide PCM data to the decoder.

Member Data Documentation

◆ active_cfg

ModemConfig tinymodem::FSKDecoder::active_cfg

protected

◆ advance

size_t tinymodem::FSKDecoder::advance = 0

protected

◆ amplitude_total

float tinymodem::FSKDecoder::amplitude_total = 0

protected

◆ ascii

AsciiCodec tinymodem::FSKDecoder::ascii

protected

◆ baudot

BaudotCodec tinymodem::FSKDecoder::baudot

protected

◆ binary

BinaryCodec tinymodem::FSKDecoder::binary

protected

◆ callerid

CallerIDCodec tinymodem::FSKDecoder::callerid

protected

◆ carrier

bool tinymodem::FSKDecoder::carrier = false

protected

◆ carrier_band

int tinymodem::FSKDecoder::carrier_band = -1

protected

◆ carrier_nsamples

size_t tinymodem::FSKDecoder::carrier_nsamples = 0

protected

◆ cfg

ModemConfig tinymodem::FSKDecoder::cfg

protected

◆ confidence_total

float tinymodem::FSKDecoder::confidence_total = 0

protected

◆ expect_data_string

char tinymodem::FSKDecoder::expect_data_string[MAX_EXPECT]

protected

◆ expect_n_bits

unsigned tinymodem::FSKDecoder::expect_n_bits = 0

protected

◆ expect_nsamples

unsigned tinymodem::FSKDecoder::expect_nsamples = 0

protected

◆ expect_sync_string

char tinymodem::FSKDecoder::expect_sync_string[MAX_EXPECT]

protected

◆ frame_n_bits

float tinymodem::FSKDecoder::frame_n_bits = 0

protected

◆ frame_nsamples

unsigned tinymodem::FSKDecoder::frame_nsamples = 0

protected

◆ FRAME_OVERSCAN

float tinymodem::FSKDecoder::FRAME_OVERSCAN = 0.5f

staticconstexprprotected

◆ FSK_ANALYZE_NSTEPS

int tinymodem::FSKDecoder::FSK_ANALYZE_NSTEPS = 3

staticconstexprprotected

◆ FSK_ANALYZE_NSTEPS_FINE

int tinymodem::FSKDecoder::FSK_ANALYZE_NSTEPS_FINE = 8

staticconstexprprotected

◆ FSK_MAX_NOCONFIDENCE_BITS

unsigned tinymodem::FSKDecoder::FSK_MAX_NOCONFIDENCE_BITS = 20

staticconstexprprotected

◆ input

PcmInput tinymodem::FSKDecoder::input

protected

◆ is_active

bool tinymodem::FSKDecoder::is_active = false

protected

◆ is_finished

bool tinymodem::FSKDecoder::is_finished = false

protected

◆ MAX_EXPECT

int tinymodem::FSKDecoder::MAX_EXPECT = 80

staticconstexprprotected

◆ nframes_decoded

unsigned tinymodem::FSKDecoder::nframes_decoded = 0

protected

◆ noconfidence

unsigned tinymodem::FSKDecoder::noconfidence = 0

protected

◆ noise_seed

uint32_t tinymodem::FSKDecoder::noise_seed = 1

protected

◆ nsamples_overscan

unsigned tinymodem::FSKDecoder::nsamples_overscan = 0

protected

◆ nsamples_per_bit

float tinymodem::FSKDecoder::nsamples_per_bit = 0

protected

◆ p_codec

DataCodec* tinymodem::FSKDecoder::p_codec = &ascii

protected

◆ peak_confidence

float tinymodem::FSKDecoder::peak_confidence = 0.0f

protected

◆ plan

FSKDemodulator tinymodem::FSKDecoder::plan

protected

◆ print_filter

PrintFilter tinymodem::FSKDecoder::print_filter

protected

◆ process_threshold

size_t tinymodem::FSKDecoder::process_threshold = 0

protected

◆ samplebuf

audio_tools::Vector<float> tinymodem::FSKDecoder::samplebuf

protected

◆ samples_nvalid

size_t tinymodem::FSKDecoder::samples_nvalid = 0

protected

◆ skip

size_t tinymodem::FSKDecoder::skip = 0

protected

◆ track_amplitude

float tinymodem::FSKDecoder::track_amplitude = 0.0f

protected

◆ uic

UICCodec tinymodem::FSKDecoder::uic

protected

The documentation for this class was generated from the following file:

src/modem/FSKDecoder.h

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ FSKDecoder() [1/2]

◆ FSKDecoder() [2/2]

Member Function Documentation

◆ activeConfig()

◆ addSample()

◆ applyAdvance()

◆ audioInfo()

◆ begin() [1/2]

◆ begin() [2/2]

◆ buildExpectBits()

◆ config()

◆ defaultConfig()

◆ end()

◆ flush()

◆ isCarrier()

◆ isFinished()

◆ markFrequency()

◆ noise()

◆ operator bool()

◆ reportCarrier()

◆ reportNoCarrier()

◆ resetState()

◆ setAudioInfo()

◆ setupCodec()

◆ step()

◆ write()

Member Data Documentation

◆ active_cfg

◆ advance

◆ amplitude_total

◆ ascii

◆ baudot

◆ binary

◆ callerid

◆ carrier

◆ carrier_band

◆ carrier_nsamples

◆ cfg

◆ confidence_total

◆ expect_data_string

◆ expect_n_bits

◆ expect_nsamples

◆ expect_sync_string

◆ frame_n_bits

◆ frame_nsamples

◆ FRAME_OVERSCAN

◆ FSK_ANALYZE_NSTEPS

◆ FSK_ANALYZE_NSTEPS_FINE

◆ FSK_MAX_NOCONFIDENCE_BITS

◆ input

◆ is_active

◆ is_finished

◆ MAX_EXPECT

◆ nframes_decoded

◆ noconfidence

◆ noise_seed

◆ nsamples_overscan

◆ nsamples_per_bit

◆ p_codec

◆ peak_confidence

◆ plan

◆ print_filter

◆ process_threshold

◆ samplebuf

◆ samples_nvalid

◆ skip

◆ track_amplitude

◆ uic