MQC - Implementation of an MQ-Coder

Data Structures
struct	opj_mqc_state
	This struct defines the state of a context. More...
struct	opj_mqc
	MQ coder. More...
Defines
#define	MQC_NUMCTXS 19
Typedefs
typedef struct opj_mqc_state	opj_mqc_state_t
	This struct defines the state of a context.
typedef struct opj_mqc	opj_mqc_t
	MQ coder.
Local static functions

static void	mqc_byteout (opj_mqc_t *mqc)
	Output a byte, doing bit-stuffing if necessary.
static void	mqc_renorme (opj_mqc_t *mqc)
	Renormalize mqc->a and mqc->c while encoding, so that mqc->a stays between 0x8000 and 0x10000.
static void	mqc_codemps (opj_mqc_t *mqc)
	Encode the most probable symbol.
static void	mqc_codelps (opj_mqc_t *mqc)
	Encode the most least symbol.
static void	mqc_setbits (opj_mqc_t *mqc)
	Fill mqc->c with 1's for flushing.
static void	mqc_bytein (opj_mqc_t *mqc)
	FIXME: documentation ???
static void	mqc_renormd (opj_mqc_t *mqc)
	Renormalize mqc->a and mqc->c while decoding.
Exported functions

opj_mqc_t *	mqc_create (void)
	Create a new MQC handle.
void	mqc_destroy (opj_mqc_t *mqc)
	Destroy a previously created MQC handle.
int	mqc_numbytes (opj_mqc_t *mqc)
	Return the number of bytes written/read since initialisation.
void	mqc_resetstates (opj_mqc_t *mqc)
	Reset the states of all the context of the coder/decoder (each context is set to a state where 0 and 1 are more or less equiprobable).
void	mqc_setstate (opj_mqc_t *mqc, int ctxno, int msb, int prob)
	Set the state of a particular context.
void	mqc_init_enc (opj_mqc_t mqc, unsigned char bp)
	Initialize the encoder.
void	mqc_encode (opj_mqc_t *mqc, int d)
	Encode a symbol using the MQ-coder.
void	mqc_flush (opj_mqc_t *mqc)
	Flush the encoder, so that all remaining data is written.
void	mqc_bypass_init_enc (opj_mqc_t *mqc)
	BYPASS mode switch, initialization operation.
void	mqc_bypass_enc (opj_mqc_t *mqc, int d)
	BYPASS mode switch, coding operation.
int	mqc_bypass_flush_enc (opj_mqc_t *mqc)
	BYPASS mode switch, flush operation.
void	mqc_reset_enc (opj_mqc_t *mqc)
	RESET mode switch.
int	mqc_restart_enc (opj_mqc_t *mqc)
	RESTART mode switch (TERMALL).
void	mqc_restart_init_enc (opj_mqc_t *mqc)
	RESTART mode switch (TERMALL) reinitialisation.
void	mqc_erterm_enc (opj_mqc_t *mqc)
	ERTERM mode switch (PTERM).
void	mqc_segmark_enc (opj_mqc_t *mqc)
	SEGMARK mode switch (SEGSYM).
void	mqc_init_dec (opj_mqc_t mqc, unsigned char bp, int len)
	Initialize the decoder.
int	mqc_decode (opj_mqc_t *mqc)
	Decode a symbol.
#define	mqc_setcurctx(mqc, ctxno) (mqc)->curctx = &(mqc)->ctxs[(int)(ctxno)]
	Set the current context used for coding/decoding.

Define Documentation

#define MQC_NUMCTXS 19

Referenced by mqc_resetstates().

#define mqc_setcurctx	(	mqc,
		ctxno		)	(mqc)->curctx = &(mqc)->ctxs[(int)(ctxno)]

Set the current context used for coding/decoding.

Parameters:

mqc

MQC handle

Parameters:

ctxno

Number that identifies the context

Referenced by mqc_init_dec(), mqc_init_enc(), mqc_restart_init_enc(), mqc_segmark_enc(), t1_dec_clnpass(), t1_dec_clnpass_step(), t1_dec_refpass_step(), t1_dec_sigpass_step(), t1_enc_clnpass(), t1_enc_clnpass_step(), t1_enc_refpass_step(), and t1_enc_sigpass_step().

Typedef Documentation

typedef struct opj_mqc_state opj_mqc_state_t

This struct defines the state of a context.

typedef struct opj_mqc opj_mqc_t

MQ coder.

Function Documentation

void mqc_bypass_enc	(	opj_mqc_t *	mqc,
		int	d
	)

BYPASS mode switch, coding operation.

JPEG 2000 p 505.

Not fully implemented and tested !!

Parameters:

mqc

MQC handle

Parameters:

d

The symbol to be encoded (0 or 1)

References opj_mqc::bp, opj_mqc::c, and opj_mqc::ct.

Referenced by t1_enc_refpass_step(), and t1_enc_sigpass_step().

int mqc_bypass_flush_enc ( opj_mqc_t * mqc )

BYPASS mode switch, flush operation.

Not fully implemented and tested !!

Parameters:

mqc

MQC handle

Returns:: Returns 1 (always)

References opj_mqc::bp, opj_mqc::c, and opj_mqc::ct.

void mqc_bypass_init_enc ( opj_mqc_t * mqc )

BYPASS mode switch, initialization operation.

JPEG 2000 p 505.

Not fully implemented and tested !!

Parameters:

mqc

MQC handle

References opj_mqc::c, and opj_mqc::ct.

Referenced by t1_encode_cblk().

static void mqc_bytein ( opj_mqc_t * mqc ) [static]

FIXME: documentation ???

Parameters:

mqc

MQC handle

Returns:: FIXME: documentation ???

Parameters:

mqc

MQC handle

Returns:: Input a byte

Parameters:

mqc

MQC handle

References opj_mqc::bp, opj_mqc::c, opj_mqc::ct, and opj_mqc::end.

Referenced by mqc_init_dec(), and mqc_renormd().

static void mqc_byteout ( opj_mqc_t * mqc ) [static]

Output a byte, doing bit-stuffing if necessary.

After a 0xff byte, the next byte must be smaller than 0x90.

Parameters:

mqc

MQC handle

References opj_mqc::bp, opj_mqc::c, and opj_mqc::ct.

Referenced by mqc_erterm_enc(), mqc_flush(), mqc_renorme(), and mqc_restart_enc().

static void mqc_codelps ( opj_mqc_t * mqc ) [static]

Encode the most least symbol.

Parameters:

mqc

MQC handle

References opj_mqc::a, opj_mqc::c, opj_mqc::curctx, and mqc_renorme().

Referenced by mqc_encode().

static void mqc_codemps ( opj_mqc_t * mqc ) [static]

Encode the most probable symbol.

Parameters:

mqc

MQC handle

References opj_mqc::a, opj_mqc::c, opj_mqc::curctx, and mqc_renorme().

Referenced by mqc_encode().

opj_mqc_t* mqc_create ( void )

Create a new MQC handle.

Returns:: Returns a new MQC handle if successful, returns NULL otherwise

References opj_malloc.

Referenced by t1_create().

int mqc_decode ( opj_mqc_t * mqc )

Decode a symbol.

Parameters:

mqc

MQC handle

Returns:: Returns the decoded symbol (0 or 1)

References opj_mqc::a, opj_mqc::c, opj_mqc::curctx, and mqc_renormd().

Referenced by t1_dec_clnpass(), t1_dec_clnpass_step(), t1_dec_refpass_step(), and t1_dec_sigpass_step().

void mqc_destroy ( opj_mqc_t * mqc )

Destroy a previously created MQC handle.

Parameters:

mqc

MQC handle to destroy

References opj_free.

Referenced by t1_destroy().

void mqc_encode	(	opj_mqc_t *	mqc,
		int	d
	)

Encode a symbol using the MQ-coder.

Parameters:

mqc

MQC handle

Parameters:

d

The symbol to be encoded (0 or 1)

References opj_mqc::curctx, mqc_codelps(), and mqc_codemps().

Referenced by mqc_segmark_enc(), t1_enc_clnpass(), t1_enc_clnpass_step(), t1_enc_refpass_step(), and t1_enc_sigpass_step().

void mqc_erterm_enc ( opj_mqc_t * mqc )

ERTERM mode switch (PTERM).

Parameters:

mqc

MQC handle

References opj_mqc::bp, opj_mqc::c, opj_mqc::ct, and mqc_byteout().

Referenced by t1_encode_cblk().

void mqc_flush ( opj_mqc_t * mqc )

Flush the encoder, so that all remaining data is written.

Parameters:

mqc

MQC handle

References opj_mqc::bp, opj_mqc::c, opj_mqc::ct, mqc_byteout(), and mqc_setbits().

Referenced by t1_encode_cblk().

void mqc_init_dec	(	opj_mqc_t *	mqc,
		unsigned char *	bp,
		int	len
	)

Initialize the decoder.

Parameters:

mqc

MQC handle

Parameters:

bp

Pointer to the start of the buffer from which the bytes will be read

Parameters:

len

Length of the input buffer

References opj_mqc::a, opj_mqc::bp, opj_mqc::c, opj_mqc::ct, opj_mqc::end, mqc_bytein(), mqc_setcurctx, and opj_mqc::start.

Referenced by t1_decode_cblk().

void mqc_init_enc	(	opj_mqc_t *	mqc,
		unsigned char *	bp
	)

Initialize the encoder.

Parameters:

mqc

MQC handle

Parameters:

bp

Pointer to the start of the buffer where the bytes will be written

References opj_mqc::a, opj_mqc::bp, opj_mqc::c, opj_mqc::ct, mqc_setcurctx, and opj_mqc::start.

Referenced by t1_encode_cblk().

int mqc_numbytes ( opj_mqc_t * mqc )

Return the number of bytes written/read since initialisation.

Parameters:

mqc

MQC handle

Returns:: Returns the number of bytes already encoded

References opj_mqc::bp, and opj_mqc::start.

Referenced by t1_encode_cblk().

static void mqc_renormd ( opj_mqc_t * mqc ) [static]

Renormalize mqc->a and mqc->c while decoding.

Parameters:

mqc

MQC handle

References opj_mqc::a, opj_mqc::c, opj_mqc::ct, and mqc_bytein().

Referenced by mqc_decode().

static void mqc_renorme ( opj_mqc_t * mqc ) [static]

Renormalize mqc->a and mqc->c while encoding, so that mqc->a stays between 0x8000 and 0x10000.

Parameters:

mqc

MQC handle

References opj_mqc::a, opj_mqc::c, opj_mqc::ct, and mqc_byteout().

Referenced by mqc_codelps(), and mqc_codemps().

void mqc_reset_enc ( opj_mqc_t * mqc )

RESET mode switch.

Parameters:

mqc

MQC handle

References mqc_resetstates(), mqc_setstate(), T1_CTXNO_AGG, T1_CTXNO_UNI, and T1_CTXNO_ZC.

Referenced by t1_encode_cblk().

void mqc_resetstates ( opj_mqc_t * mqc )

Reset the states of all the context of the coder/decoder (each context is set to a state where 0 and 1 are more or less equiprobable).

Parameters:

mqc

MQC handle

References opj_mqc::ctxs, and MQC_NUMCTXS.

Referenced by mqc_reset_enc(), t1_decode_cblk(), and t1_encode_cblk().

int mqc_restart_enc ( opj_mqc_t * mqc )

RESTART mode switch (TERMALL).

Parameters:

mqc

MQC handle

Returns:: Returns 1 (always)

References opj_mqc::c, opj_mqc::ct, and mqc_byteout().

void mqc_restart_init_enc ( opj_mqc_t * mqc )

RESTART mode switch (TERMALL) reinitialisation.

Parameters:

mqc

MQC handle

References opj_mqc::a, opj_mqc::bp, opj_mqc::c, opj_mqc::ct, and mqc_setcurctx.

Referenced by t1_encode_cblk().

void mqc_segmark_enc ( opj_mqc_t * mqc )

SEGMARK mode switch (SEGSYM).

Parameters:

mqc

MQC handle

References mqc_encode(), and mqc_setcurctx.

Referenced by t1_encode_cblk().

static void mqc_setbits ( opj_mqc_t * mqc ) [static]

Fill mqc->c with 1's for flushing.

Parameters:

mqc

MQC handle

References opj_mqc::a, and opj_mqc::c.

Referenced by mqc_flush().

void mqc_setstate	(	opj_mqc_t *	mqc,
		int	ctxno,
		int	msb,
		int	prob
	)

Set the state of a particular context.

Parameters:

mqc

MQC handle

Parameters:

ctxno

Number that identifies the context

Parameters:

msb

The MSB of the new state of the context

Parameters:

prob

Number that identifies the probability of the symbols for the new state of the context

References opj_mqc::ctxs.

Referenced by mqc_reset_enc(), t1_decode_cblk(), and t1_encode_cblk().

MQC - Implementation of an MQ-Coder

Data Structures

Defines

Typedefs

Local static functions

Exported functions

Define Documentation

Typedef Documentation

Function Documentation

Not fully implemented and tested !!

Not fully implemented and tested !!

Not fully implemented and tested !!