gdf::Reader Class Reference

Class for reading GDF files to disc. More...

#include <Reader.h>

Inheritance diagram for gdf::Reader:

Collaboration diagram for gdf::Reader:

Public Member Functions
	Reader ()
	Constructor.
virtual	~Reader ()
	Destructor.
void	open (const std::string filename)
	Opens file for reading.
void	close ()
	Close file.
void	enableCache (bool b)
	Enable or disable cache.
virtual void	initCache ()
	Set cache to the correct size.
virtual void	resetCache ()
	Reset cache to empty state.
size_t	findRecord (uint16 channel_idx, size_t sample_idx)
	Find Record index to which a sample belongs.
void	getSignals (std::vector< std::vector< double > > &buffer, double start_time=0, double end_time=-1, std::vector< uint16 > signal_indices=std::vector< uint16 >())
	Read Signals from file into buffer (physical units)
void	getSignal (uint16 channel_idx, double *buffer, size_t start=0, size_t end=0)
	Read a single channel from file into buffer.
double	getSample (uint16 channel_idx, size_t sample_idx)
	Read a single Sample (physical units)
Record *	getRecordPtr (size_t index)
	Returns a reference to Record.
void	readRecord (size_t index, Record *rec)
	Read directly into Record rec.
void	precacheRecords (size_t start, size_t end)
	Precache a range of Records.
EventHeader *	getEventHeader ()
	get reference to event header
const GDFHeaderAccess &	getHeaderAccess_readonly () const
	get Constant reference to header access
const MainHeader &	getMainHeader_readonly () const
	get Constant reference to main header
const SignalHeader &	getSignalHeader_readonly (size_t idx) const
	get constant reference to a signal's header
Protected Member Functions
void	readEvents ()
Protected Attributes
std::string	m_filename
GDFHeaderAccess	m_header
EventHeader *	m_events
std::vector< Record * >	m_record_cache
Record *	m_record_nocache
std::list< size_t >	m_cache_entries
std::ifstream	m_file
bool	m_cache_enabled
size_t	m_record_length
size_t	m_record_offset
	Record length in bytes.
size_t	m_event_offset
	Where data records start in the file.

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Detailed Description

Class for reading GDF files to disc.

Data Records are only read on demand and stay in memory until another file is opened or the Reader object is destroyed. This cache can be disabled. Then each data record is loaded from disk everytime it is accessed. This saves memory, but may severly decrease performance.

Definition at line 38 of file Reader.h.

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Member Function Documentation

double gdf::Reader::getSample	(	uint16	channel_idx,
		size_t	sample_idx
	)

Read a single Sample (physical units)

Parameters:

[in]	channel_idx	channel index
[in]	sample_idx	sample index

Reimplemented in gdf::Modifier.

Definition at line 223 of file Reader.cpp.

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void gdf::Reader::getSignal	(	uint16	channel_idx,
		double *	buffer,
		size_t	start = 0,
		size_t	end = 0
	)

Read a single channel from file into buffer.

The buffer must be allocated by the user, who is also responsible that enough memory is allocated.

Parameters:

[in]	channel_idx	index of channel to read
[out]	buffer	pointer to double array
[in]	start_time	samples with n >= start are loaded.
[in]	end_time	samples with n < end are loaded. end <= start loads the complete signal.

Definition at line 192 of file Reader.cpp.

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void gdf::Reader::getSignals	(	std::vector< std::vector< double > > &	buffer,
		double	start_time = 0,
		double	end_time = -1,
		std::vector< uint16 >	signal_indices = std::vector<uint16>()
	)

Read Signals from file into buffer (physical units)

Sample values are converted to physical units.

Parameters:

[out]	buffer	vector; each element is a channel.
[in]	start_time	samples with n >= start_time*fs are loaded.
[in]	end_time	samples with n < end_time*fs are loaded. end_time = -1 loads the complete signal.
[in]	signal_indices	vector with signal indices that should be loaded. If empty, all signals are loaded.

Definition at line 136 of file Reader.cpp.

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

• Reader.h
• Reader.cpp