jpc_cs.h

用C语言实现的JPEG编码

typedef struct {

	/* The component to which the marker applies. */
	uint_fast16_t compno;

	/* The ROI style. */
	uint_fast8_t roisty;

	/* The ROI shift value. */
	uint_fast8_t roishift;

} jpc_rgn_t;

/**************************************\
* QCD/QCC marker segment parameters.
\**************************************/

/*
 * Quantization style constants.
 */

#define	JPC_QCX_NOQNT	0 /* No quantization. */
#define	JPC_QCX_SIQNT	1 /* Scalar quantization, implicit. */
#define	JPC_QCX_SEQNT	2 /* Scalar quantization, explicit. */

/*
 * Stepsize manipulation macros.
 */

#define	JPC_QCX_GETEXPN(x)	((x) >> 11)
#define	JPC_QCX_GETMANT(x)	((x) & 0x07ff)
#define	JPC_QCX_EXPN(x)		(assert(!((x) & (~0x1f))), (((x) & 0x1f) << 11))
#define	JPC_QCX_MANT(x)		(assert(!((x) & (~0x7ff))), ((x) & 0x7ff))

/* Per component information. */

typedef struct {

	/* The quantization style. */
	uint_fast8_t qntsty;

	/* The number of step sizes. */
	int numstepsizes;

	/* The step sizes. */
	uint_fast16_t *stepsizes;

	/* The number of guard bits. */
	uint_fast8_t numguard;

} jpc_qcxcp_t;

/* QCC marker segment parameters. */

typedef struct {

	/* The component associated with this marker segment. */
	uint_fast16_t compno;

	/* The parameters. */
	jpc_qcxcp_t compparms;

} jpc_qcc_t;

/* QCD marker segment parameters. */

typedef struct {

	/* The parameters. */
	jpc_qcxcp_t compparms;

} jpc_qcd_t;

/**************************************\
* POD marker segment parameters.
\**************************************/

typedef struct {

	/* The progression order. */
	uint_fast8_t prgord;

	/* The lower bound (inclusive) on the resolution level for the
	  progression order volume. */
	uint_fast8_t rlvlnostart;

	/* The upper bound (exclusive) on the resolution level for the
	  progression order volume. */
	uint_fast8_t rlvlnoend;

	/* The lower bound (inclusive) on the component for the progression
	  order volume. */
	uint_fast16_t compnostart;

	/* The upper bound (exclusive) on the component for the progression
	  order volume. */
	uint_fast16_t compnoend;

	/* The upper bound (exclusive) on the layer for the progression
	  order volume. */
	uint_fast16_t lyrnoend;

} jpc_pocpchg_t;

/* An alias for the above type. */
typedef jpc_pocpchg_t jpc_pchg_t;

/* POC marker segment parameters. */

typedef struct {

	/* The number of progression order changes. */
	int numpchgs;

	/* The per-progression-order-change information. */
	jpc_pocpchg_t *pchgs;

} jpc_poc_t;

/**************************************\
* PPM/PPT marker segment parameters.
\**************************************/

/* PPM marker segment parameters. */

typedef struct {

	/* The index. */
	uint_fast8_t ind;

	/* The length. */
	uint_fast16_t len;

	/* The data. */
	uchar *data;

} jpc_ppm_t;

/* PPT marker segment parameters. */

typedef struct {

	/* The index. */
	uint_fast8_t ind;

	/* The length. */
	uint_fast32_t len;

	/* The data. */
	unsigned char *data;

} jpc_ppt_t;

/**************************************\
* COM marker segment parameters.
\**************************************/

/*
 * Registration IDs.
 */

#define	JPC_COM_BIN		0x00
#define	JPC_COM_LATIN	0x01

typedef struct {

	/* The registration ID. */
	uint_fast16_t regid;

	/* The length of the data in bytes. */
	uint_fast16_t len;

	/* The data. */
	uchar *data;

} jpc_com_t;

/**************************************\
* SOP marker segment parameters.
\**************************************/

typedef struct {

	/* The sequence number. */
	uint_fast16_t seqno;

} jpc_sop_t;

/**************************************\
* CRG marker segment parameters.
\**************************************/

/* Per component information. */

typedef struct {

	/* The horizontal offset. */
	uint_fast16_t hoff;

	/* The vertical offset. */
	uint_fast16_t voff;

} jpc_crgcomp_t;

typedef struct {

	/* The number of components. */
	int numcomps;

	/* Per component information. */
	jpc_crgcomp_t *comps;

} jpc_crg_t;

/**************************************\
* Marker segment parameters for unknown marker type.
\**************************************/

typedef struct {

	/* The data. */
	uchar *data;

	/* The length. */
	uint_fast16_t len;

} jpc_unk_t;

/**************************************\
* Generic marker segment parameters.
\**************************************/

typedef union {
	int soc;	/* unused */
	jpc_sot_t sot;
	int sod;	/* unused */
	int eoc;	/* unused */
	jpc_siz_t siz;
	jpc_cod_t cod;
	jpc_coc_t coc;
	jpc_rgn_t rgn;
	jpc_qcd_t qcd;
	jpc_qcc_t qcc;
	jpc_poc_t poc;
	/* jpc_plm_t plm; */
	/* jpc_plt_t plt; */
	jpc_ppm_t ppm;
	jpc_ppt_t ppt;
	jpc_sop_t sop;
	int eph;	/* unused */
	jpc_com_t com;
	jpc_crg_t crg;
	jpc_unk_t unk;
} jpc_msparms_t;

/**************************************\
* Marker segment.
\**************************************/

/* Marker segment IDs. */

/* The smallest valid marker value. */
#define	JPC_MS_MIN	0xff00

/* The largest valid marker value. */
#define	JPC_MS_MAX	0xffff

/* The minimum marker value that cannot occur within packet data. */
#define	JPC_MS_INMIN	0xff80
/* The maximum marker value that cannot occur within packet data. */
#define	JPC_MS_INMAX	0xffff

/* Delimiting marker segments. */
#define	JPC_MS_SOC	0xff4f /* Start of code stream (SOC). */
#define	JPC_MS_SOT	0xff90 /* Start of tile-part (SOT). */
#define	JPC_MS_SOD	0xff93 /* Start of data (SOD). */
#define	JPC_MS_EOC	0xffd9 /* End of code stream (EOC). */

/* Fixed information marker segments. */
#define	JPC_MS_SIZ	0xff51 /* Image and tile size (SIZ). */

/* Functional marker segments. */
#define	JPC_MS_COD	0xff52 /* Coding style default (COD). */
#define JPC_MS_COC	0xff53 /* Coding style component (COC). */
#define	JPC_MS_RGN	0xff5e /* Region of interest (RGN). */
#define JPC_MS_QCD	0xff5c /* Quantization default (QCD). */
#define JPC_MS_QCC	0xff5d /* Quantization component (QCC). */
#define JPC_MS_POC	0xff5f /* Progression order default (POC). */

/* Pointer marker segments. */
#define	JPC_MS_TLM	0xff55 /* Tile-part lengths, main header (TLM). */
#define	JPC_MS_PLM	0xff57 /* Packet length, main header (PLM). */
#define	JPC_MS_PLT	0xff58 /* Packet length, tile-part header (PLT). */
#define	JPC_MS_PPM	0xff60 /* Packed packet headers, main header (PPM). */
#define	JPC_MS_PPT	0xff61 /* Packet packet headers, tile-part header (PPT). */

/* In bit stream marker segments. */
#define	JPC_MS_SOP	0xff91	/* Start of packet (SOP). */
#define	JPC_MS_EPH	0xff92	/* End of packet header (EPH). */

/* Informational marker segments. */
#define	JPC_MS_CRG	0xff63 /* Component registration (CRG). */
#define JPC_MS_COM	0xff64 /* Comment (COM). */

/* Forward declaration. */
struct jpc_msops_s;

/* Generic marker segment class. */

typedef struct {

	/* The type of marker segment. */
	uint_fast16_t id;

	/* The length of the marker segment. */
	uint_fast16_t len;

	/* The starting offset within the stream. */
	uint_fast32_t off;

	/* The parameters of the marker segment. */
	jpc_msparms_t parms;

	/* The marker segment operations. */
	struct jpc_msops_s *ops;

} jpc_ms_t;

/* Marker segment operations (which depend on the marker segment type). */

typedef struct jpc_msops_s {

	/* Destroy the marker segment parameters. */
	void (*destroyparms)(jpc_ms_t *ms);

	/* Get the marker segment parameters from a stream. */
	int (*getparms)(jpc_ms_t *ms, jpc_cstate_t *cstate, jas_stream_t *in);

	/* Put the marker segment parameters to a stream. */
	int (*putparms)(jpc_ms_t *ms, jpc_cstate_t *cstate, jas_stream_t *out);

	/* Dump the marker segment parameters (for debugging). */
	int (*dumpparms)(jpc_ms_t *ms, FILE *out);

} jpc_msops_t;

/******************************************************************************\
* Macros/Functions.
\******************************************************************************/

/* Create a code-stream state object. */
jpc_cstate_t *jpc_cstate_create(void);

/* Destroy a code-stream state object. */
void jpc_cstate_destroy(jpc_cstate_t *cstate);

/* Create a marker segment. */
jpc_ms_t *jpc_ms_create(int type);

/* Destroy a marker segment. */
void jpc_ms_destroy(jpc_ms_t *ms);

/* Does a marker segment have parameters? */
#define	JPC_MS_HASPARMS(x) \
	(!((x) == JPC_MS_SOC || (x) == JPC_MS_SOD || (x) == JPC_MS_EOC || \
	  (x) == JPC_MS_EPH || ((x) >= 0xff30 && (x) <= 0xff3f)))

/* Get the marker segment type. */
#define	jpc_ms_gettype(ms) \
	((ms)->id)

/* Read a marker segment from a stream. */
jpc_ms_t *jpc_getms(jas_stream_t *in, jpc_cstate_t *cstate);

/* Write a marker segment to a stream. */
int jpc_putms(jas_stream_t *out, jpc_cstate_t *cstate, jpc_ms_t *ms);

/* Copy code stream data from one stream to another. */
int jpc_getdata(jas_stream_t *in, jas_stream_t *out, long n);

/* Copy code stream data from one stream to another. */
int jpc_putdata(jas_stream_t *out, jas_stream_t *in, long n);

/* Dump a marker segment (for debugging). */
void jpc_ms_dump(jpc_ms_t *ms, FILE *out);

/* Read a 8-bit unsigned integer from a stream. */
int jpc_getuint8(jas_stream_t *in, uint_fast8_t *val);

/* Read a 16-bit unsigned integer from a stream. */
int jpc_getuint16(jas_stream_t *in, uint_fast16_t *val);

/* Read a 32-bit unsigned integer from a stream. */
int jpc_getuint32(jas_stream_t *in, uint_fast32_t *val);

/* Write a 8-bit unsigned integer to a stream. */
int jpc_putuint8(jas_stream_t *out, uint_fast8_t val);

/* Write a 16-bit unsigned integer to a stream. */
int jpc_putuint16(jas_stream_t *out, uint_fast16_t val);

/* Write a 32-bit unsigned integer to a stream. */
int jpc_putuint32(jas_stream_t *out, uint_fast32_t val);

#endif