jpc_enc.h

用C语言实现的JPEG编码

	/* The number of passes. */
	int numpasses;

	/* The per-pass information. */
	jpc_enc_pass_t *passes;

	/* The number of passes encoded so far. */
	int numencpasses;

	/* The number of insignificant MSBs. */
	int numimsbs;

	/* The number of bits used to encode pass data lengths. */
	int numlenbits;

	/* The byte stream for this code block. */
	jas_stream_t *stream;

	/* The entropy encoder. */
	jpc_mqenc_t *mqenc;

	/* The data for this code block. */
	jas_matrix_t *data;

	/* The state for this code block. */
	jas_matrix_t *flags;

	/* The number of bit planes required for this code block. */
	int numbps;

	/* The next pass to be encoded. */
	jpc_enc_pass_t *curpass;

	/* The per-code-block-group state information. */
	struct jpc_enc_prc_s *prc;

	/* The saved current pass. */
	/* This is used by the rate control code. */
	jpc_enc_pass_t *savedcurpass;

	/* The saved length indicator size. */
	/* This is used by the rate control code. */
	int savednumlenbits;

	/* The saved number of encoded passes. */
	/* This is used by the rate control code. */
	int savednumencpasses;

} jpc_enc_cblk_t;

/* Encoder per-code-block-group state information. */

typedef struct jpc_enc_prc_s {

	/* The x-coordinate of the top-left corner of the precinct. */
	uint_fast32_t tlx;

	/* The y-coordinate of the top-left corner of the precinct. */
	uint_fast32_t tly;

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

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

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

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

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

	/* The per-code-block information. */
	jpc_enc_cblk_t *cblks;

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

	/* The insignifcant MSBs tag tree. */
	jpc_tagtree_t *nlibtree;

	/* The per-band information. */
	struct jpc_enc_band_s *band;

	/* The saved inclusion tag tree. */
	/* This is used by rate control. */
	jpc_tagtree_t *savincltree;

	/* The saved leading-insignificant-bit-planes tag tree. */
	/* This is used by rate control. */
	jpc_tagtree_t *savnlibtree;

} jpc_enc_prc_t;

/* Encoder per-band state information. */

typedef struct jpc_enc_band_s {

	/* The per precinct information. */
	jpc_enc_prc_t *prcs;

	/* The coefficient data for this band. */
	jas_matrix_t *data;

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

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

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

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

	/* The L2 norm of the synthesis basis functions associated with
	  this band.  (The MCT is not considered in this value.) */
	jpc_fix_t synweight;

	/* The analysis gain for this band. */
	int analgain;

	/* The per-resolution-level information. */
	struct jpc_enc_rlvl_s *rlvl;

} jpc_enc_band_t;

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

typedef struct jpc_enc_rlvl_s {

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

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

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

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

	/* 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 spanning the resolution level in the
	  horizontal direction. */
	int numhprcs;

	/* The number of precincts spanning the resolution level 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;

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

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

	/* The parent tile-component. */
	struct jpc_enc_tcmpt_s *tcmpt;

} jpc_enc_rlvl_t;

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

typedef struct jpc_enc_tcmpt_s {

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

	/* The per-resolution-level information. */
	jpc_enc_rlvl_t *rlvls;

	/* The tile-component data. */
	jas_matrix_t *data;

	/* The QMFB. */
	int qmfbid;

	/* The number of bands. */
	int numbands;

	/* The TSFB. */
	jpc_tsfb_t *tsfb;

	/* The synthesis energy weight (for the MCT). */
	jpc_fix_t synweight;

	/* The precinct width exponents. */
	int prcwidthexpns[JPC_MAXRLVLS];

	/* The precinct height exponents. */
	int prcheightexpns[JPC_MAXRLVLS];

	/* The code block width exponent. */
	int cblkwidthexpn;

	/* The code block height exponent. */
	int cblkheightexpn;

	/* Coding style (i.e., explicit precinct sizes). */
	int csty;

	/* Code block style. */
	int cblksty;

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

	/* The encoded quantizer step sizes. */
	uint_fast16_t stepsizes[JPC_MAXBANDS];

	/* The parent tile. */
	struct jpc_enc_tile_s *tile;

} jpc_enc_tcmpt_t;

/* Encoder per-tile state information. */

typedef struct jpc_enc_tile_s {

	/* The tile number. */
	uint_fast32_t tileno;

	/* The x-coordinate of the top-left corner of the tile measured with
	  respect to the reference grid. */
	uint_fast32_t tlx;

	/* The y-coordinate of the top-left corner of the tile measured with
	  respect to the reference grid. */
	uint_fast32_t tly;

	/* The x-coordinate of the bottom-right corner of the tile measured
	  with respect to the reference grid (plus one). */
	uint_fast32_t brx;

	/* The y-coordinate of the bottom-right corner of the tile measured
	  with respect to the reference grid (plus one). */
	uint_fast32_t bry;

	/* The coding style. */
	uint_fast8_t csty;

	/* The progression order. */
	uint_fast8_t prg;

	/* The number of layers. */
	int numlyrs;

	/* The MCT to employ (if any). */
	uint_fast8_t mctid;

	/* The packet iterator (used to determine the order of packet
	  generation). */
	jpc_pi_t *pi;

	/* The coding mode (i.e., integer or real). */
	bool intmode;

	/* The number of bytes to allocate to the various layers. */
	uint_fast32_t *lyrsizes;

	/* The number of tile-components. */
	int numtcmpts;

	/* The per tile-component information. */
	jpc_enc_tcmpt_t *tcmpts;

	/* The raw (i.e., uncompressed) size of this tile. */
	uint_fast32_t rawsize;

} jpc_enc_tile_t;

/* Encoder class. */

typedef struct jpc_enc_s {

	/* The image being encoded. */
	jas_image_t *image;

	/* The output stream. */
	jas_stream_t *out;

	/* The coding parameters. */
	jpc_enc_cp_t *cp;

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

	/* The code stream state. */
	jpc_cstate_t *cstate;

	/* The number of bytes output so far. */
	uint_fast32_t len;

	/* The number of bytes available for the main body of the code stream. */
	/* This is used for rate allocation purposes. */
	uint_fast32_t mainbodysize;

	/* The marker segment currently being processed. */
	/* This member is a convenience for making cleanup easier. */
	jpc_ms_t *mrk;

	/* The stream used to temporarily hold tile-part data. */
	jas_stream_t *tmpstream;

} jpc_enc_t;

#endif