jpc_dec.h

用C语言实现的JPEG编码

	/* The y-coordinate of the bottom-right corner of the precinct
	  (plus one). */
	uint_fast32_t yend;

	/* The number of code blocks spanning this precinct in the horizontal
	  direction. */
	int numhcblks;

	/* The number of code blocks spanning this precinct in the vertical
	  direction. */
	int numvcblks;

	/* The total number of code blocks in this precinct. */
	int numcblks;

	/* The per code block information. */
	jpc_dec_cblk_t *cblks;

	/* The inclusion tag tree. */
	jpc_tagtree_t *incltagtree;

	/* The insignificant MSBs tag tree. */
	jpc_tagtree_t *numimsbstagtree;

} jpc_dec_prc_t;

/* Decoder per-band state information. */

typedef struct {

	/* The per-code-block-group state information. */
	jpc_dec_prc_t *prcs;

	/* The sample data associated with this band. */
	jas_matrix_t *data;

	/* The orientation of this band (i.e., LL, LH, HL, or HH). */
	int orient;

	/* The encoded quantizer step size. */
	int stepsize;

	/* The absolute quantizer step size. */
	jpc_fix_t absstepsize;

	/* The number of bit planes for this band. */
	int numbps;

	/* The analysis gain associated with this band. */
	int analgain;

	/* The ROI shift value for this band. */
	int roishift;

} jpc_dec_band_t;

/* Decoder per-resolution-level state information. */

typedef struct {

	/* The number of bands associated with this resolution level. */
	int numbands;

	/* The per-band information. */
	jpc_dec_band_t *bands;

	/* The x-coordinate of the top-left corner of the tile-component
	  at this resolution. */
	uint_fast32_t xstart;

	/* The y-coordinate of the top-left corner of the tile-component
	  at this resolution. */
	uint_fast32_t ystart;

	/* The x-coordinate of the bottom-right corner of the tile-component
	  at this resolution (plus one). */
	uint_fast32_t xend;

	/* The y-coordinate of the bottom-right corner of the tile-component
	  at this resolution (plus one). */
	uint_fast32_t yend;

	/* The exponent value for the nominal precinct width measured
	  relative to the associated LL band. */
	int prcwidthexpn;

	/* The exponent value for the nominal precinct height measured
	  relative to the associated LL band. */
	int prcheightexpn;

	/* The number of precincts in the horizontal direction. */
	int numhprcs;

	/* The number of precincts in the vertical direction. */
	int numvprcs;

	/* The total number of precincts. */
	int numprcs;

	/* The exponent value for the nominal code block group width.
	  This quantity is associated with the next lower resolution level
	  (assuming that there is one). */
	int cbgwidthexpn;

	/* The exponent value for the nominal code block group height
	  This quantity is associated with the next lower resolution level
	  (assuming that there is one). */
	int cbgheightexpn;

	/* The exponent value for the code block width. */
	uint_fast16_t cblkwidthexpn;

	/* The exponent value for the code block height. */
	uint_fast16_t cblkheightexpn;

} jpc_dec_rlvl_t;

/* Decoder per-tile-component state information. */

typedef struct {

	/* The x-coordinate of the top-left corner of the tile-component
	  in the coordinate system of the tile-component. */
	uint_fast32_t xstart;

	/* The y-coordinate of the top-left corner of the tile-component
	  in the coordinate system of the tile-component. */
	uint_fast32_t ystart;

	/* The x-coordinate of the bottom-right corner of the tile-component
	  in the coordinate system of the tile-component (plus one). */
	uint_fast32_t xend;

	/* The y-coordinate of the bottom-right corner of the tile-component
	  in the coordinate system of the tile-component (plus one). */
	uint_fast32_t yend;

	/* The component data for the current tile. */
	jas_matrix_t *data;

	/* The number of resolution levels. */
	int numrlvls;

	/* The per resolution level information. */
	jpc_dec_rlvl_t *rlvls;

	/* The TSFB. */
	jpc_tsfb_t *tsfb;

} jpc_dec_tcomp_t;

/*
 * Tile states.
 */

#define	JPC_TILE_INIT	0
#define	JPC_TILE_ACTIVE	1
#define	JPC_TILE_ACTIVELAST	2
#define	JPC_TILE_DONE	3

/* Decoder per-tile state information. */

typedef struct {

	/* The processing state for this tile. */
	int state;

	/* The x-coordinate of the top-left corner of the tile on the reference
	  grid. */
	uint_fast32_t xstart;

	/* The y-coordinate of the top-left corner of the tile on the reference
	  grid. */
	uint_fast32_t ystart;

	/* The x-coordinate of the bottom-right corner of the tile on the
	  reference grid (plus one). */
	uint_fast32_t xend;

	/* The y-coordinate of the bottom-right corner of the tile on the
	  reference grid (plus one). */
	uint_fast32_t yend;

	/* The packed packet header data for this tile. */
	jpc_ppxstab_t *pptstab;

	/* A stream containing the packed packet header data for this tile. */
	jas_stream_t *pkthdrstream;

	/* The current position within the packed packet header stream. */
	long pkthdrstreampos;

	/* The coding parameters for this tile. */
	jpc_dec_cp_t *cp;

	/* The per tile-component information. */
	jpc_dec_tcomp_t *tcomps;

	/* The next expected tile-part number. */
	int partno;

	/* The number of tile-parts. */
	int numparts;

	/* The coding mode. */
	int realmode;

	/* The packet iterator for this tile. */
	jpc_pi_t *pi;

} jpc_dec_tile_t;

/* Decoder per-component state information. */

typedef struct {

	/* The horizontal sampling period. */
	uint_fast32_t hstep;

	/* The vertical sampling period. */
	uint_fast32_t vstep;

	/* The number of samples in the horizontal direction. */
	uint_fast32_t width;

	/* The number of samples in the vertical direction. */
	uint_fast32_t height;

	/* The precision of the sample data. */
	uint_fast16_t prec;

	/* The signedness of the sample data. */
	bool sgnd;

	/* The sample alignment horizontal offset. */
	uint_fast32_t hsubstep;
	
	/* The sample alignment vertical offset. */
	uint_fast32_t vsubstep;

} jpc_dec_cmpt_t;

/* Decoder state information. */

typedef struct {

	/* The decoded image. */
	jas_image_t *image;

	/* The x-coordinate of the top-left corner of the image area on
	  the reference grid. */
	uint_fast32_t xstart;

	/* The y-coordinate of the top-left corner of the image area on
	  the reference grid. */
	uint_fast32_t ystart;

	/* The x-coordinate of the bottom-right corner of the image area on
	  the reference grid (plus one). */
	uint_fast32_t xend;

	/* The y-coordinate of the bottom-right corner of the image area on
	  the reference grid (plus one). */
	uint_fast32_t yend;

	/* The nominal tile width in units of the image reference grid. */
	uint_fast32_t tilewidth;

	/* The nominal tile height in units of the image reference grid. */
	uint_fast32_t tileheight;

	/* The horizontal offset from the origin of the reference grid to the
	  left side of the first tile. */
	uint_fast32_t tilexoff;

	/* The vertical offset from the origin of the reference grid to the
	  top side of the first tile. */
	uint_fast32_t tileyoff;

	/* The number of tiles spanning the image area in the vertical
	  direction. */
	int numhtiles;

	/* The number of tiles spanning the image area in the horizontal
	  direction. */
	int numvtiles;

	/* The total number of tiles. */
	int numtiles;

	/* The per-tile information. */
	jpc_dec_tile_t *tiles;

	/* The tile currently being processed. */
	jpc_dec_tile_t *curtile;

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

	/* The stream containing the input JPEG-2000 code stream data. */
	jas_stream_t *in;

	/* The default coding parameters for all tiles. */
	jpc_dec_cp_t *cp;

	/* The maximum number of layers that may be decoded. */
	int maxlyrs;

	/* The maximum number of packets that may be decoded. */
	int maxpkts;

	/* The number of packets decoded so far in the processing of the entire
	  code stream. */
	int numpkts;

	/* The next expected PPM marker segment sequence number. */
	int ppmseqno;

	/* The current state for code stream processing. */
	int state;

	/* The per-component information. */
	jpc_dec_cmpt_t *cmpts;

	/* The information from PPM marker segments. */
	jpc_ppxstab_t *ppmstab;

	/* A list of streams containing packet header data from PPM marker
	  segments. */
	jpc_streamlist_t *pkthdrstreams;

	/* The expected ending offset for a tile-part. */
	long curtileendoff;

	/* This is required by the tier-2 decoder. */
	jpc_cstate_t *cstate;

} jpc_dec_t;

/* Decoder options. */

typedef struct {

	/* The debug level for the decoder. */
	int debug;

	/* The maximum number of layers to decode. */
	int maxlyrs;

	/* The maximum number of packets to decode. */
	int maxpkts;

} jpc_dec_importopts_t;

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

/* Create a decoder segment object. */
jpc_dec_seg_t *jpc_seg_alloc(void);

/* Destroy a decoder segment object. */
void jpc_seg_destroy(jpc_dec_seg_t *seg);

/* Remove a segment from a segment list. */
void jpc_seglist_remove(jpc_dec_seglist_t *list, jpc_dec_seg_t *node);

/* Insert a segment into a segment list. */
void jpc_seglist_insert(jpc_dec_seglist_t *list, jpc_dec_seg_t *ins,
  jpc_dec_seg_t *node);

#endif