jpegint8.h

/*
 * jpegint.h
 *
 * Copyright (C) 1991-1998, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file provides common declarations for the various JPEG modules.
 * These declarations are considered internal to the JPEG library; most
 * applications using the library shouldn't need to include this file.
 */


/* Declarations for both compression & decompression */

typedef enum {			/* Operating modes for buffer controllers */
	JBUF_PASS_THRU,		/* Plain stripwise operation */
	/* Remaining modes require a full-image buffer to have been created */
	JBUF_SAVE_SOURCE,	/* Run source subobject only, save output */
	JBUF_CRANK_DEST,	/* Run dest subobject only, using saved data */
	JBUF_SAVE_AND_PASS	/* Run both subobjects, save output */
} J_BUF_MODE;

/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
#define CSTATE_START	100	/* after create_compress */
#define CSTATE_SCANNING	101	/* start_compress done, write_scanlines OK */
#define CSTATE_RAW_OK	102	/* start_compress done, write_raw_data OK */
#define CSTATE_WRCOEFS	103	/* jpeg_write_coefficients done */
#define DSTATE_START	200	/* after create_decompress */
#define DSTATE_INHEADER	201	/* reading header markers, no SOS yet */
#define DSTATE_READY	202	/* found SOS, ready for start_decompress */
#define DSTATE_PRELOAD	203	/* reading multiscan file in start_decompress*/
#define DSTATE_PRESCAN	204	/* performing dummy pass for 2-pass quant */
#define DSTATE_SCANNING	205	/* start_decompress done, read_scanlines OK */
#define DSTATE_RAW_OK	206	/* start_decompress done, read_raw_data OK */
#define DSTATE_BUFIMAGE	207	/* expecting jpeg_start_output */
#define DSTATE_BUFPOST	208	/* looking for SOS/EOI in jpeg_finish_output */
#define DSTATE_RDCOEFS	209	/* reading file in jpeg_read_coefficients */
#define DSTATE_STOPPING	210	/* looking for EOI in jpeg_finish_decompress */


/* Declarations for compression modules */

/* Master control module */
struct jpeg_comp_master {
  JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
  JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));

  /* State variables made visible to other modules */
  boolean call_pass_startup;	/* True if pass_startup must be called */
  boolean is_last_pass;		/* True during last pass */
};

/* Main buffer control (downsampled-data buffer) */
struct jpeg_c_main_controller {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  JMETHOD(void, process_data, (j_compress_ptr cinfo,
			       JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
			       JDIMENSION in_rows_avail));
};

/* Compression preprocessing (downsampling input buffer control) */
struct jpeg_c_prep_controller {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
				   JSAMPARRAY input_buf,
				   JDIMENSION *in_row_ctr,
				   JDIMENSION in_rows_avail,
				   JSAMPIMAGE output_buf,
				   JDIMENSION *out_row_group_ctr,
				   JDIMENSION out_row_groups_avail));
};

/* Compression codec (compressor proper) */
struct jpeg_c_codec {
  JMETHOD(void, entropy_start_pass, (j_compress_ptr cinfo,
				     boolean gather_statistics));
  JMETHOD(void, entropy_finish_pass, (j_compress_ptr cinfo));
  JMETHOD(boolean, need_optimization_pass, (j_compress_ptr cinfo));
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
  JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
				   JSAMPIMAGE input_buf));
};

/* Colorspace conversion */
struct jpeg_color_converter {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
  JMETHOD(void, color_convert, (j_compress_ptr cinfo,
				JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
				JDIMENSION output_row, int num_rows));
};

/* Downsampling */
struct jpeg_downsampler {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
  JMETHOD(void, downsample, (j_compress_ptr cinfo,
			     JSAMPIMAGE input_buf, JDIMENSION in_row_index,
			     JSAMPIMAGE output_buf,
			     JDIMENSION out_row_group_index));

  boolean need_context_rows;	/* TRUE if need rows above & below */
};

/* Marker writing */
struct jpeg_marker_writer {
  JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
  JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
  JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
  JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
  JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
  /* These routines are exported to allow insertion of extra markers */
  /* Probably only COM and APPn markers should be written this way */
  JMETHOD(void, write_marker_header, (j_compress_ptr cinfo, int marker,
				      unsigned int datalen));
  JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
};


/* Declarations for decompression modules */

/* Master control module */
struct jpeg_decomp_master {
  JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
  JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));

  /* State variables made visible to other modules */
  boolean is_dummy_pass;	/* True during 1st pass for 2-pass quant */
};

/* Input control module */
struct jpeg_input_controller {
  JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
  JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
  JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));

  /* State variables made visible to other modules */
  boolean has_multiple_scans;	/* True if file has multiple scans */
  boolean eoi_reached;		/* True when EOI has been consumed */
};

/* Main buffer control (downsampled-data buffer) */
struct jpeg_d_main_controller {
  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
  JMETHOD(void, process_data, (j_decompress_ptr cinfo,
			       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
			       JDIMENSION out_rows_avail));
};

/* Decompression codec (decompressor proper) */
struct jpeg_d_codec {
  JMETHOD(void, calc_output_dimensions, (j_decompress_ptr cinfo));
  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
  JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
  JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
  JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
				 JSAMPIMAGE output_buf));
};

/* Decompression postprocessing (color quantization buffer control) */
struct jpeg_d_post_controller {
  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
  JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
				    JSAMPIMAGE input_buf,
				    JDIMENSION *in_row_group_ctr,
				    JDIMENSION in_row_groups_avail,
				    JSAMPARRAY output_buf,
				    JDIMENSION *out_row_ctr,
				    JDIMENSION out_rows_avail));
};

/* Marker reading & parsing */
struct jpeg_marker_reader {
  JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
  /* Read markers until SOS or EOI.
   * Returns same codes as are defined for jpeg_consume_input:
   * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
   */
  JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
  /* Read a restart marker --- exported for use by entropy decoder only */
  jpeg_marker_parser_method read_restart_marker;

  /* State of marker reader --- nominally internal, but applications
   * supplying COM or APPn handlers might like to know the state.
   */
  boolean saw_SOI;		/* found SOI? */
  boolean saw_SOF;		/* found SOF? */
  int next_restart_num;		/* next restart number expected (0-7) */
  unsigned int discarded_bytes;	/* # of bytes skipped looking for a marker */
};

/* Upsampling (note that upsampler must also call color converter) */
struct jpeg_upsampler {
  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
  JMETHOD(void, upsample, (j_decompress_ptr cinfo,
			   JSAMPIMAGE input_buf,
			   JDIMENSION *in_row_group_ctr,
			   JDIMENSION in_row_groups_avail,
			   JSAMPARRAY output_buf,
			   JDIMENSION *out_row_ctr,
			   JDIMENSION out_rows_avail));

  boolean need_context_rows;	/* TRUE if need rows above & below */
};

/* Colorspace conversion */
struct jpeg_color_deconverter {
  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
  JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
				JSAMPIMAGE input_buf, JDIMENSION input_row,
				JSAMPARRAY output_buf, int num_rows));
};

/* Color quantization or color precision reduction */
struct jpeg_color_quantizer {
  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
  JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
				 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
				 int num_rows));
  JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
  JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
};


/* Miscellaneous useful macros */

#undef MAX
#define MAX(a,b)	((a) > (b) ? (a) : (b))
#undef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))


/* We assume that right shift corresponds to signed division by 2 with
 * rounding towards minus infinity.  This is correct for typical "arithmetic
 * shift" instructions that shift in copies of the sign bit.  But some
 * C compilers implement >> with an unsigned shift.  For these machines you
 * must define RIGHT_SHIFT_IS_UNSIGNED.
 * RIGHT_SHIFT provides a proper signed right shift of an IJG_INT32 quantity.
 * It is only applied with constant shift counts.  SHIFT_TEMPS must be
 * included in the variables of any routine using RIGHT_SHIFT.
 */

#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define SHIFT_TEMPS	IJG_INT32 shift_temp;
#define RIGHT_SHIFT(x,shft)  \
	((shift_temp = (x)) < 0 ? \
	 (shift_temp >> (shft)) | ((~((IJG_INT32) 0)) << (32-(shft))) : \
	 (shift_temp >> (shft)))
#else
#define SHIFT_TEMPS
#define RIGHT_SHIFT(x,shft)	((x) >> (shft))
#endif


/* Short forms of external names for systems with brain-damaged linkers. */

#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jinit_c_codec		jinit8_c_codec
#define jinit_c_diff_controller		jinit8_c_diff_controller
#define jinit_lossy_c_codec		jinit8_lossy_c_codec
#define jinit_lossless_c_codec		jinit8_lossless_c_codec
#define jinit_compress_master		jinit8_compress_master
#define jinit_c_master_control		jinit8_c_master_control
#define jinit_c_main_controller		jinit8_c_main_controller
#define jinit_c_prep_controller		jinit8_c_prep_controller
#define jinit_c_coef_controller		jinit8_c_coef_controller
#define jinit_color_converter		jinit8_color_converter
#define jinit_downsampler		jinit8_downsampler
#define jinit_forward_dct		jinit8_forward_dct
#define jinit_shuff_encoder		jinit8_shuff_encoder
#define jinit_phuff_encoder		jinit8_phuff_encoder
#ifdef WITH_ARITHMETIC_PATCH
#define jinit_arith_encoder		jinit8_arith_encoder
#endif
#define jinit_marker_writer		jinit8_marker_writer
#define jinit_d_codec		jinit8_d_codec
#define jinit_lossy_d_codec		jinit8_lossy_d_codec
#define jinit_lossless_d_codec		jinit8_lossless_d_codec
#define jinit_master_decompress		jinit8_master_decompress
#define jinit_d_main_controller		jinit8_d_main_controller
#define jinit_d_coef_controller		jinit8_d_coef_controller
#define jinit_d_diff_controller		jinit8_d_diff_controller
#define jinit_d_post_controller		jinit8_d_post_controller
#define jinit_input_controller		jinit8_input_controller
#define jinit_marker_reader		jinit8_marker_reader
#define jinit_shuff_decoder		jinit8_shuff_decoder
#define jinit_phuff_decoder		jinit8_phuff_decoder
#ifdef WITH_ARITHMETIC_PATCH
#define jinit_arith_decoder		jinit8_arith_decoder
#endif
#define jinit_lhuff_decoder		jinit8_lhuff_decoder
#define jinit_undifferencer		jinit8_undifferencer
#define jinit_d_scaler		jinit8_d_scaler
#define jinit_inverse_dct		jinit8_inverse_dct
#define jinit_upsampler		jinit8_upsampler
#define jinit_color_deconverter		jinit8_color_deconverter
#define jinit_1pass_quantizer		jinit8_1pass_quantizer
#define jinit_2pass_quantizer		jinit8_2pass_quantizer
#define jinit_merged_upsampler		jinit8_merged_upsampler
#define jinit_memory_mgr		jinit8_memory_mgr
#define jdiv_round_up		jdiv8_round_up
#define jround_up		jround8_up
#define jcopy_sample_rows		jcopy8_sample_rows
#define jcopy_block_row		jcopy8_block_row
#define jzero_far		jzero8_far
#define jpeg_zigzag_order		jpeg8_zigzag_order
#define jpeg_natural_order		jpeg8_natural_order
#endif /* NEED_SHORT_EXTERNAL_NAMES */


/* Compression module initialization routines */
EXTERN(void) jinit_c_codec JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_c_diff_controller JPP((j_compress_ptr cinfo, boolean need_full_buffer));
EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
					 boolean transcode_only));
EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
					  boolean need_full_buffer));
EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
					  boolean need_full_buffer));
EXTERN(void) jinit_compressor JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
#ifdef WITH_ARITHMETIC_PATCH
EXTERN(void) jinit_arith_encoder JPP((j_compress_ptr cinfo));
#endif
/* Decompression module initialization routines */
EXTERN(void) jinit_d_codec JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_d_diff_controller JPP((j_decompress_ptr cinfo, boolean need_full_buffer));
EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
					  boolean need_full_buffer));
EXTERN(void) jinit_decompressor JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
					  boolean need_full_buffer));
EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
#ifdef WITH_ARITHMETIC_PATCH
EXTERN(void) jinit_arith_decoder JPP((j_decompress_ptr cinfo));
#endif
EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
/* Memory manager initialization */
EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));

/* Utility routines in jutils.c */
EXTERN(long) jdiv_round_up JPP((long a, long b));
EXTERN(long) jround_up JPP((long a, long b));
EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
				    JSAMPARRAY output_array, int dest_row,
				    int num_rows, JDIMENSION num_cols));
EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
				  JDIMENSION num_blocks));
EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
/* Constant tables in jutils.c */
#if 0				/* This table is not actually needed in v6a */
extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
#endif
extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */

/* Suppress undefined-structure complaints if necessary. */

#ifdef INCOMPLETE_TYPES_BROKEN
#ifndef AM_MEMORY_MANAGER	/* only jmemmgr.c defines these */
struct jvirt_sarray_control { long dummy; };
struct jvirt_barray_control { long dummy; };
#endif
#endif /* INCOMPLETE_TYPES_BROKEN */