sdvl.h File Reference

Self-Describing Variable-Length (SDVL) encoding. More...

#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>

Include dependency graph for sdvl.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Enumerations
enum	rohc_sdvl_max_bits_t { ROHC_SDVL_MAX_BITS_IN_1_BYTE = 7U, ROHC_SDVL_MAX_BITS_IN_2_BYTES = 14U, ROHC_SDVL_MAX_BITS_IN_3_BYTES = 21U, ROHC_SDVL_MAX_BITS_IN_4_BYTES = 29U }
Functions
bool	sdvl_can_value_be_encoded (uint32_t value)
	Can the given value be encoded with SDVL?
size_t	c_bytesSdvl (uint32_t value, size_t length)
	Find out how many bytes are needed to represent the value using Self-Describing Variable-Length (SDVL) encoding.
int	c_encodeSdvl (unsigned char *dest, uint32_t value, size_t length)
	Encode a value using Self-Describing Variable-Length (SDVL) encoding.
int	d_sdvalue_size (const unsigned char *data)
	Find out a size of the Self-Describing Variable-Length (SDVL) value.
int	d_sdvalue_decode (const unsigned char *data)
	Decode a Self-Describing Variable-Length (SDVL) value.

---

Detailed Description

Self-Describing Variable-Length (SDVL) encoding.

Author:

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

The hackers from ROHC for Linux

---

Enumeration Type Documentation

enum rohc_sdvl_max_bits_t

The maximum numbers of bits that can be SDVL-encoded in 1, 2, 3 and 4 bytes

Enumerator:

ROHC_SDVL_MAX_BITS_IN_1_BYTE	Maximum number of bits in 1 SDVL-encoded byte
ROHC_SDVL_MAX_BITS_IN_2_BYTES	Maximum number of bits in 2 SDVL-encoded byte
ROHC_SDVL_MAX_BITS_IN_3_BYTES	Maximum number of bits in 3 SDVL-encoded byte
ROHC_SDVL_MAX_BITS_IN_4_BYTES	Maximum number of bits in 4 SDVL-encoded byte

---

Function Documentation

size_t c_bytesSdvl	(	uint32_t	value,
		size_t	length
	)

Find out how many bytes are needed to represent the value using Self-Describing Variable-Length (SDVL) encoding.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

value	The value to encode
length	The length of the value to encode (0 to let the SDVL encoding find the length itself)

Returns:

The size needed to represent the SDVL-encoded value

References rohc_debugf, ROHC_SDVL_MAX_BITS_IN_1_BYTE, ROHC_SDVL_MAX_BITS_IN_2_BYTES, ROHC_SDVL_MAX_BITS_IN_3_BYTES, ROHC_SDVL_MAX_BITS_IN_4_BYTES, ROHC_SDVL_MAX_VALUE_IN_1_BYTE, ROHC_SDVL_MAX_VALUE_IN_2_BYTES, ROHC_SDVL_MAX_VALUE_IN_3_BYTES, and ROHC_SDVL_MAX_VALUE_IN_4_BYTES.

Referenced by c_encodeSdvl(), code_cid_values(), code_EXT3_packet(), f_append_cid(), rtp_code_dynamic_rtp_part(), and rtp_header_flags_and_fields().

int c_encodeSdvl	(	unsigned char *	dest,
		uint32_t	value,
		size_t	length
	)

Encode a value using Self-Describing Variable-Length (SDVL) encoding.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

dest	The destination to write the SDVL-encoded to
value	The value to encode
length	The length of the value to encode (0 to let the SDVL encoding find the length itself)

Returns:

1 if SDVL encoding is successful, 0 in case of failure (failure may be due to a value greater than 2^29)

References c_bytesSdvl(), and rohc_debugf.

Referenced by code_cid_values(), code_EXT3_packet(), f_append_cid(), rtp_code_dynamic_rtp_part(), and rtp_header_flags_and_fields().

int d_sdvalue_decode

(

const unsigned char *

data

)

Decode a Self-Describing Variable-Length (SDVL) value.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

data	The SDVL data to decode

Returns:

The decoded value

References GET_BIT_0_4, GET_BIT_0_5, GET_BIT_0_6, GET_BIT_0_7, GET_BIT_5_7, GET_BIT_6_7, and GET_BIT_7.

Referenced by c_deliver_feedback(), decode_extension3(), and rtp_decode_dynamic_rtp().

int d_sdvalue_size

(

const unsigned char *

data

)

Find out a size of the Self-Describing Variable-Length (SDVL) value.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

data	The SDVL data to analyze

Returns:

The size of the SDVL value (possible values are 1-4)

References GET_BIT_5_7, GET_BIT_6_7, GET_BIT_7, and rohc_debugf.

Referenced by c_deliver_feedback(), decode_extension3(), rtp_decode_dynamic_rtp(), rtp_detect_ir_dyn_size(), and rtp_detect_ir_size().

bool sdvl_can_value_be_encoded

(

uint32_t

value

)

Can the given value be encoded with SDVL?

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

value

The value to encode

Returns:

Whether the value can be encoded with SDVL or not

References ROHC_SDVL_MAX_VALUE_IN_4_BYTES.

Referenced by c_add_ts().