ts_sc_comp.h File Reference

Scaled RTP Timestamp encoding. More...

#include "wlsb.h"
#include "dllexport.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
int ROHC_EXPORT	c_create_sc (struct ts_sc_comp *const ts_sc, const size_t wlsb_window_width)
	Create the ts_sc_comp object.
void ROHC_EXPORT	c_destroy_sc (struct ts_sc_comp *const ts_sc)
	Destroy the ts_sc_comp object.
void ROHC_EXPORT	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.
bool ROHC_EXPORT	nb_bits_scaled (const struct ts_sc_comp ts_sc, size_t *const bits_nr)
	Return the number of bits needed to encode TS_SCALED.
void ROHC_EXPORT	add_scaled (const struct ts_sc_comp *const ts_sc, uint16_t sn)
	Add a new TS_SCALED value to the ts_sc_comp object.
uint32_t ROHC_EXPORT	get_ts_stride (const struct ts_sc_comp ts_sc)
	Return the TS_STRIDE value.
uint32_t ROHC_EXPORT	get_ts_scaled (const struct ts_sc_comp ts_sc)
	Return the TS_SCALED value.

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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 ROHC_EXPORT add_scaled	(	const struct ts_sc_comp *const	ts_sc,
		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

References c_add_wlsb(), ts_sc_comp::scaled_window, and ts_sc_comp::ts_scaled.

void ROHC_EXPORT 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

References INIT_STRIDE, INIT_TS, ts_sc_comp::is_deductible, ts_sc_comp::nr_init_stride_packets, ts_sc_comp::old_sn, ts_sc_comp::old_ts, rohc_debugf, sdvl_can_value_be_encoded(), SEND_SCALED, sn, ts_sc_comp::sn, ts_sc_comp::state, ts_sc_decomp::ts, ts_sc_comp::ts, ts_sc_comp::ts_delta, ts_sc_comp::ts_offset, ts_sc_comp::ts_scaled, and ts_sc_comp::ts_stride.

int ROHC_EXPORT c_create_sc	(	struct ts_sc_comp *const	ts_sc,
		const size_t	wlsb_window_width
	)

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)

Returns:

1 if creation is successful, 0 otherwise

References c_create_wlsb(), INIT_TS, ts_sc_comp::is_deductible, ts_sc_comp::nr_init_stride_packets, ts_sc_comp::old_sn, ts_sc_comp::old_ts, rohc_debugf, ROHC_LSB_SHIFT_RTP_TS, ts_sc_comp::scaled_window, ts_sc_comp::sn, ts_sc_comp::state, ts_sc_comp::ts, ts_sc_comp::ts_delta, ts_sc_comp::ts_offset, ts_sc_comp::ts_scaled, and ts_sc_comp::ts_stride.

Referenced by c_rtp_create().

void ROHC_EXPORT 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

References c_destroy_wlsb(), and ts_sc_comp::scaled_window.

Referenced by c_rtp_destroy().

uint32_t ROHC_EXPORT get_ts_scaled

(

const struct ts_sc_comp

ts_sc

)

Return the TS_SCALED value.

Parameters:

ts_sc

The ts_sc_comp object

Returns:

The TS_SCALED value

References ts_sc_comp::ts_scaled.

uint32_t ROHC_EXPORT get_ts_stride

(

const struct ts_sc_comp

ts_sc

)

Return the TS_STRIDE value.

Parameters:

ts_sc

The ts_sc_comp object

Returns:

TS_STRIDE value

References ts_sc_comp::ts_stride.

Referenced by rtp_code_dynamic_rtp_part(), and rtp_header_flags_and_fields().

bool ROHC_EXPORT nb_bits_scaled	(	const struct ts_sc_comp	ts_sc,
		size_t *const	bits_nr
	)

Return the number of bits needed to encode TS_SCALED.

Parameters:

ts_sc	The ts_sc_comp object
bits_nr	OUT: The number of bits needed

Returns:

true in case of success, false if the minimal number of bits can not be found

References ts_sc_comp::is_deductible, ts_sc_comp::scaled_window, ts_sc_comp::ts_scaled, and wlsb_get_k_32bits().