uhd::rx_metadata_t Struct Reference

#include <uhd/types/metadata.hpp>

Public Types
enum	error_code_t {   ERROR_CODE_NONE = 0x0, ERROR_CODE_TIMEOUT = 0x1, ERROR_CODE_LATE_COMMAND = 0x2, ERROR_CODE_BROKEN_CHAIN = 0x4,   ERROR_CODE_OVERFLOW = 0x8, ERROR_CODE_ALIGNMENT = 0xc, ERROR_CODE_BAD_PACKET = 0xf }

Public Member Functions
	rx_metadata_t ()
	Default constructor. More...
void	reset ()
	Reset values. More...
std::string	to_pp_string (bool compact=true) const
std::string	strerror (void) const

Public Attributes
bool	has_time_spec
	Has time specification? More...
time_spec_t	time_spec
	Time of the first sample. More...
bool	more_fragments
size_t	fragment_offset
bool	start_of_burst
	Start of burst will be true for the first packet in the chain. More...
bool	end_of_burst
	End of burst will be true for the last packet in the chain. More...
enum uhd::rx_metadata_t::error_code_t	error_code
bool	out_of_sequence
	Out of sequence. The transport has either dropped a packet or received data out of order. More...

Detailed Description

RX metadata structure for describing sent IF data. Includes time specification, fragmentation flags, burst flags, and error codes. The receive routines will convert IF data headers into metadata.

Member Enumeration Documentation

error_code_t

enum uhd::rx_metadata_t::error_code_t

The error condition on a receive call.

Note: When an overrun occurs in continuous streaming mode, the device will continue to send samples to the host. For other streaming modes, streaming will discontinue until the user issues a new stream command.

The metadata fields have meaning for the following error codes:

• none
• late command
• broken chain
• overflow

Enumerator
ERROR_CODE_NONE	No error associated with this metadata.
ERROR_CODE_TIMEOUT	No packet received, implementation timed-out.
ERROR_CODE_LATE_COMMAND	A stream command was issued in the past.
ERROR_CODE_BROKEN_CHAIN	Expected another stream command.
ERROR_CODE_OVERFLOW	An internal receive buffer has filled or a sequence error has been detected. So, why is this overloaded? Simple: legacy support. It would have been much cleaner to create a separate error code for a sequence error, but that would have broken legacy applications. So, the out_of_sequence flag was added to differentiate between the two error cases. In either case, data is missing between this time_spec and the and the time_spec of the next successful receive.
ERROR_CODE_ALIGNMENT	Multi-channel alignment failed.
ERROR_CODE_BAD_PACKET	The packet could not be parsed.

Constructor & Destructor Documentation

rx_metadata_t()

uhd::rx_metadata_t::rx_metadata_t ( )

inline

Default constructor.

Member Function Documentation

reset()

void uhd::rx_metadata_t::reset ( )

inline

Reset values.

strerror()

std::string uhd::rx_metadata_t::strerror

(

void

)

const

Similar to C's strerror() function, creates a std::string describing the error code.

Returns

a printable string representing the error.

to_pp_string()

std::string uhd::rx_metadata_t::to_pp_string

(

bool

compact = true

)

const

Convert a rx_metadata_t into a pretty print string.

Parameters

compact

Set to false for a more verbose output.

Returns

a printable string representing the metadata.

Member Data Documentation

end_of_burst

bool uhd::rx_metadata_t::end_of_burst

End of burst will be true for the last packet in the chain.

error_code

enum uhd::rx_metadata_t::error_code_t uhd::rx_metadata_t::error_code

fragment_offset

size_t uhd::rx_metadata_t::fragment_offset

Fragmentation offset: The fragment offset is the sample number at the start of the receive buffer. For non-fragmented receives, the fragment offset should always be zero.

has_time_spec

bool uhd::rx_metadata_t::has_time_spec

Has time specification?

more_fragments

bool uhd::rx_metadata_t::more_fragments

Fragmentation flag: Similar to IPv4 fragmentation: http://en.wikipedia.org/wiki/IPv4#Fragmentation_and_reassembly More fragments is true when the input buffer has insufficient size to fit an entire received packet. More fragments will be false for the last fragment.

out_of_sequence

bool uhd::rx_metadata_t::out_of_sequence

Out of sequence. The transport has either dropped a packet or received data out of order.

start_of_burst

bool uhd::rx_metadata_t::start_of_burst

Start of burst will be true for the first packet in the chain.

time_spec

time_spec_t uhd::rx_metadata_t::time_spec

Time of the first sample.

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

• include/uhd/types/metadata.hpp