gr::blocks::file_meta_sink Class Reference

Write stream to file with meta-data headers. More...

#include <file_meta_sink.h>

Inheritance diagram for gr::blocks::file_meta_sink:

List of all members.

Public Types
typedef boost::shared_ptr < file_meta_sink >	sptr
Public Member Functions
virtual bool	open (const std::string &filename)=0
virtual void	close ()=0
virtual void	do_update ()=0
virtual void	set_unbuffered (bool unbuffered)=0
Static Public Member Functions
static sptr	make (size_t itemsize, const std::string &filename, double samp_rate=1, double relative_rate=1, gr_file_types type=GR_FILE_FLOAT, bool complex=true, size_t max_segment_size=1000000, const std::string &extra_dict="", bool detached_header=false)
	Create a meta-data file sink.

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Detailed Description

Write stream to file with meta-data headers.

These files represent data as binary information in between meta-data headers. The headers contain information about the type of data and properties of the data in the next segment of samples. The information includes:

rx_rate (double): sample rate of data. rx_time (uint64_t, double): time stamp of first sample in segment. size (uint32_t): item size in bytes. type (gr_file_types as int32_t): data type. cplx (bool): Is data complex? strt (uint64_t): Starting byte of data in this segment. bytes (uint64_t): Size in bytes of data in this segment.

Tags can be sent to the file to update the information, which will create a new header. Headers are found by searching from the first header (at position 0 in the file) and reading where the data segment starts plus the data segment size. Following will either be a new header or EOF.

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Member Typedef Documentation

typedef boost::shared_ptr<file_meta_sink> gr::blocks::file_meta_sink::sptr

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Member Function Documentation

virtual void gr::blocks::file_meta_sink::close

(

)

[pure virtual]

Implemented in gr::blocks::file_meta_sink_impl.

virtual void gr::blocks::file_meta_sink::do_update

(

)

[pure virtual]

Implemented in gr::blocks::file_meta_sink_impl.

static sptr gr::blocks::file_meta_sink::make	(	size_t	itemsize,
		const std::string &	filename,
		double	samp_rate = 1,
		double	relative_rate = 1,
		gr_file_types	type = GR_FILE_FLOAT,
		bool	complex = true,
		size_t	max_segment_size = 1000000,
		const std::string &	extra_dict = "",
		bool	detached_header = false
	)		[static]

Create a meta-data file sink.

Parameters:

itemsize	(size_t): Size of data type.
filename	(string): Name of file to write data to.
samp_rate	(double): Sample rate of data. If sample rate will be set by a tag, such as rx_tag from a UHD source, this is basically ignored.
relative_rate	(double): Rate chance from source of sample rate tag to sink.
type	(gr_file_types): Data type (int, float, etc.)
complex	(bool): If data stream is complex
max_segment_size	(size_t): Length of a single segment before the header is repeated (in items).
extra_dict	(string): a serialized PMT dictionary of extra information. Currently not supported.
detached_header	(bool): Set to true to store the header info in a separate file (named filename.hdr)

virtual bool gr::blocks::file_meta_sink::open

(

const std::string &

filename

)

[pure virtual]

Implemented in gr::blocks::file_meta_sink_impl.

virtual void gr::blocks::file_meta_sink::set_unbuffered

(

bool

unbuffered

)

[pure virtual]

Implemented in gr::blocks::file_meta_sink_impl.

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

• file_meta_sink.h