comp_scaled_rtp_ts.h File Reference

Scaled RTP Timestamp encoding. More...

#include "comp_wlsb.h"
#include "rohc_traces.h"
#include <stdbool.h>

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Data Structures
struct	ts_sc_comp
	Scaled RTP Timestamp encoding object. More...
Enumerations
enum	ts_sc_state { INIT_TS = 1, INIT_STRIDE = 2, SEND_SCALED = 3 }
	State of scaled RTP Timestamp encoding. More...
Functions
bool	c_create_sc (struct ts_sc_comp *const ts_sc, const size_t wlsb_window_width, rohc_trace_callback2_t trace_cb, void *const trace_cb_priv)
	Create the ts_sc_comp object.
void	c_destroy_sc (struct ts_sc_comp *const ts_sc)
	Destroy the ts_sc_comp object.
void	c_add_ts (struct ts_sc_comp *const ts_sc, const uint32_t ts, const uint16_t sn)
	Store the new TS, calculate new values and update the state.
void	nb_bits_unscaled (const struct ts_sc_comp *const ts_sc, size_t *const bits_nr_less_equal_than_2, size_t *const bits_nr_more_than_2)
	Return the number of bits needed to encode unscaled TS.
void	add_unscaled (const struct ts_sc_comp *const ts_sc, const uint16_t sn)
	Add a new unscaled TS value to the ts_sc_comp object.
void	nb_bits_scaled (const struct ts_sc_comp *const ts_sc, size_t *const bits_nr_less_equal_than_2, size_t *const bits_nr_more_than_2)
	Return the number of bits needed to encode TS_SCALED.
void	add_scaled (const struct ts_sc_comp *const ts_sc, const uint16_t sn)
	Add a new TS_SCALED value to the ts_sc_comp object.
uint32_t	get_ts_stride (const struct ts_sc_comp *const ts_sc)
	Return the TS_STRIDE value.
uint32_t	get_ts_scaled (const struct ts_sc_comp *const ts_sc)
	Return the TS_SCALED value.
uint32_t	get_ts_unscaled (const struct ts_sc_comp *const ts_sc)
	Return the unscaled TS value.
bool	rohc_ts_sc_is_deducible (const struct ts_sc_comp *const ts_sc)
	Whether TimeStamp (TS) is deducible from the Sequence Number (SN) or not.

---

Detailed Description

Scaled RTP Timestamp encoding.

Author:

David Moreau from TAS

Didier Barvaux <didier.barvaux@toulouse.viveris.com>

Didier Barvaux <didier@barvaux.org>

See section 4.5.3 of RFC 3095 for details about Scaled RTP Timestamp encoding.

---

Enumeration Type Documentation

enum ts_sc_state

State of scaled RTP Timestamp encoding.

See section 4.5.3 of RFC 3095 for details about Scaled RTP Timestamp encoding.

Enumerator:

INIT_TS	Initialization state (TS_STRIDE value not yet computed).
INIT_STRIDE	Initialization state (TS_STRIDE value computed and sent).
SEND_SCALED	Compression state (TS_SCALED value computed and sent).

---

Function Documentation

void add_scaled	(	const struct ts_sc_comp *const	ts_sc,
		const uint16_t	sn
	)

Add a new TS_SCALED value to the ts_sc_comp object.

Parameters:

	ts_sc	The ts_sc_comp object
	sn	The Sequence Number

void add_unscaled	(	const struct ts_sc_comp *const	ts_sc,
		const uint16_t	sn
	)

Add a new unscaled TS value to the ts_sc_comp object.

Parameters:

	ts_sc	The ts_sc_comp object
	sn	The Sequence Number

void c_add_ts	(	struct ts_sc_comp *const	ts_sc,
		const uint32_t	ts,
		const uint16_t	sn
	)

Store the new TS, calculate new values and update the state.

Parameters:

	ts_sc	The ts_sc_comp object
	ts	The timestamp to add
	sn	The sequence number of the RTP packet

bool c_create_sc	(	struct ts_sc_comp *const	ts_sc,
		const size_t	wlsb_window_width,
		rohc_trace_callback2_t	trace_cb,
		void *const	trace_cb_priv
	)

Create the ts_sc_comp object.

Parameters:

	ts_sc	The ts_sc_comp object to create
	wlsb_window_width	The width of the W-LSB sliding window to use for TS_STRIDE (must be > 0)
	trace_cb	The trace callback
	trace_cb_priv	An optional private context for the trace callback, may be NULL

Returns:

true if creation is successful, false otherwise

void c_destroy_sc

(

struct ts_sc_comp *const

ts_sc

)

Destroy the ts_sc_comp object.

Parameters:

ts_sc

The ts_sc_comp object to destroy

uint32_t get_ts_scaled

(

const struct ts_sc_comp *const

ts_sc

)

Return the TS_SCALED value.

Parameters:

ts_sc

The ts_sc_comp object

Returns:

The TS_SCALED value

uint32_t get_ts_stride

(

const struct ts_sc_comp *const

ts_sc

)

Return the TS_STRIDE value.

Parameters:

ts_sc

The ts_sc_comp object

Returns:

TS_STRIDE value

uint32_t get_ts_unscaled

(

const struct ts_sc_comp *const

ts_sc

)

Return the unscaled TS value.

Parameters:

ts_sc

The ts_sc_comp object

Returns:

The unscaled TS value

void nb_bits_scaled	(	const struct ts_sc_comp *const	ts_sc,
		size_t *const	bits_nr_less_equal_than_2,
		size_t *const	bits_nr_more_than_2
	)

Return the number of bits needed to encode TS_SCALED.

Parameters:

	ts_sc	The ts_sc_comp object
[out]	bits_nr_less_equal_than_2	The number of bits needed to encode TS_SCALED in a field that is smaller than or equal to 2 bits
[out]	bits_nr_more_than_2	The number of bits needed to encode TS_SCALED in a field that is strictly larger than to 2 bits

void nb_bits_unscaled	(	const struct ts_sc_comp *const	ts_sc,
		size_t *const	bits_nr_less_equal_than_2,
		size_t *const	bits_nr_more_than_2
	)

Return the number of bits needed to encode unscaled TS.

Parameters:

	ts_sc	The ts_sc_comp object
[out]	bits_nr_less_equal_than_2	The number of bits needed to encode TS_SCALED in a field that is smaller than or equal to 2 bits
[out]	bits_nr_more_than_2	The number of bits needed to encode TS_SCALED in a field that is strictly larger than to 2 bits

bool rohc_ts_sc_is_deducible

(

const struct ts_sc_comp *const

ts_sc

)

Whether TimeStamp (TS) is deducible from the Sequence Number (SN) or not.

Parameters:

ts_sc

The TS SCALED compression context

Returns:

true if TS is deducible from SN, false otherwise