    /*
     * jpegint.h
     *
     * Copyright (C) 1991-1997, Thomas G. Lane.
     * Modified 1997-2020 by Guido Vollbeding.
     * 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));
    };

    /* Coefficient buffer control */
    struct jpeg_c_coef_controller {
      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 */
    };

    /* Forward DCT (also controls coefficient quantization) */
    typedef JMETHOD(void, forward_DCT_ptr,
    		(j_compress_ptr cinfo, jpeg_component_info * compptr,
    		 JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
    		 JDIMENSION start_col, JDIMENSION num_blocks));

    struct jpeg_forward_dct {
      JMETHOD(void, start_pass, (j_compress_ptr cinfo));
      /* It is useful to allow each component to have a separate FDCT method. */
      forward_DCT_ptr forward_DCT[MAX_COMPONENTS];
    };

    /* Entropy encoding */
    struct jpeg_entropy_encoder {
      JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
      JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKARRAY MCU_data));
      JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
    };

    /* 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));
    };

    /* Coefficient buffer control */
    struct jpeg_d_coef_controller {
      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));
      /* Pointer to array of coefficient virtual arrays, or NULL if none */
      jvirt_barray_ptr *coef_arrays;
    };

    /* 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 */
    };

    /* Entropy decoding */
    struct jpeg_entropy_decoder {
      JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
      JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo, JBLOCKARRAY MCU_data));
      JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
    };

    /* Inverse DCT (also performs dequantization) */
    typedef JMETHOD(void, inverse_DCT_method_ptr,
    		(j_decompress_ptr cinfo, jpeg_component_info * compptr,
    		 JCOEFPTR coef_block,
    		 JSAMPARRAY output_buf, JDIMENSION output_col));

    struct jpeg_inverse_dct {
      JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
      /* It is useful to allow each component to have a separate IDCT method. */
      inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
    };

    /* 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));
    };

    /* Definition of range extension bits for decompression processes.
     * See the comments with prepare_range_limit_table (in jdmaster.c)
     * for more info.
     * The recommended default value for normal applications is 2.
     * Applications with special requirements may use a different value.
     * For example, Ghostscript wants to use 3 for proper handling of
     * wacky images with oversize coefficient values.
     */

    #define RANGE_BITS	2
    #define RANGE_CENTER	(CENTERJSAMPLE << RANGE_BITS)

    /* 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 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	INT32 shift_temp;
    #define RIGHT_SHIFT(x,shft)  \
    	((shift_temp = (x)) < 0 ? \
    	 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
    	 (shift_temp >> (shft)))
    #else
    #define SHIFT_TEMPS
    #define RIGHT_SHIFT(x,shft)	((x) >> (shft))
    #endif

    /* Descale and correctly round an INT32 value that's scaled by N bits.
     * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
     * the fudge factor is correct for either sign of X.
     */

    #define DESCALE(x,n)	RIGHT_SHIFT((x) + ((INT32) 1 << ((n)-1)), n)

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

    #ifdef NEED_SHORT_EXTERNAL_NAMES
    #define jinit_compress_master	jICompress
    #define jinit_c_master_control	jICMaster
    #define jinit_c_main_controller	jICMainC
    #define jinit_c_prep_controller	jICPrepC
    #define jinit_c_coef_controller	jICCoefC
    #define jinit_color_converter	jICColor
    #define jinit_downsampler	jIDownsampler
    #define jinit_forward_dct	jIFDCT
    #define jinit_huff_encoder	jIHEncoder
    #define jinit_arith_encoder	jIAEncoder
    #define jinit_marker_writer	jIMWriter
    #define jinit_master_decompress	jIDMaster
    #define jinit_d_main_controller	jIDMainC
    #define jinit_d_coef_controller	jIDCoefC
    #define jinit_d_post_controller	jIDPostC
    #define jinit_input_controller	jIInCtlr
    #define jinit_marker_reader	jIMReader
    #define jinit_huff_decoder	jIHDecoder
    #define jinit_arith_decoder	jIADecoder
    #define jinit_inverse_dct	jIIDCT
    #define jinit_upsampler		jIUpsampler
    #define jinit_color_deconverter	jIDColor
    #define jinit_1pass_quantizer	jI1Quant
    #define jinit_2pass_quantizer	jI2Quant
    #define jinit_merged_upsampler	jIMUpsampler
    #define jinit_memory_mgr	jIMemMgr
    #define jdiv_round_up		jDivRound
    #define jround_up		jRound
    #define jzero_far		jZeroFar
    #define jcopy_sample_rows	jCopySamples
    #define jcopy_block_row		jCopyBlocks
    #define jpeg_zigzag_order	jZIGTable
    #define jpeg_natural_order	jZAGTable
    #define jpeg_natural_order7	jZAG7Table
    #define jpeg_natural_order6	jZAG6Table
    #define jpeg_natural_order5	jZAG5Table
    #define jpeg_natural_order4	jZAG4Table
    #define jpeg_natural_order3	jZAG3Table
    #define jpeg_natural_order2	jZAG2Table
    #define jpeg_aritab		jAriTab
    #endif /* NEED_SHORT_EXTERNAL_NAMES */

    /* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
     * and coefficient-block arrays.  This won't work on 80x86 because the arrays
     * are FAR and we're assuming a small-pointer memory model.  However, some
     * DOS compilers provide far-pointer versions of memcpy() and memset() even
     * in the small-model libraries.  These will be used if USE_FMEM is defined.
     * Otherwise, the routines in jutils.c do it the hard way.
     */

    #ifndef NEED_FAR_POINTERS	/* normal case, same as regular macro */
    #define FMEMZERO(target,size)	MEMZERO(target,size)
    #else				/* 80x86 case */
    #ifdef USE_FMEM
    #define FMEMZERO(target,size)	_fmemset((void FAR *)(target), 0, (size_t)(size))
    #else
    EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
    #define FMEMZERO(target,size)	jzero_far(target, size)
    #endif
    #endif

    /* Compression module initialization routines */
    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_c_coef_controller JPP((j_compress_ptr cinfo,
    					  boolean need_full_buffer));
    EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
    EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
    EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
    EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
    EXTERN(void) jinit_arith_encoder JPP((j_compress_ptr cinfo));
    EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
    /* Decompression module initialization routines */
    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_d_coef_controller JPP((j_decompress_ptr cinfo,
    					  boolean need_full_buffer));
    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));
    EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
    EXTERN(void) jinit_arith_decoder JPP((j_decompress_ptr cinfo));
    EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
    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,
    				    JSAMPARRAY output_array,
    				    int num_rows, JDIMENSION num_cols));
    EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
    				  JDIMENSION num_blocks));
    /* 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 */
    extern const int jpeg_natural_order7[]; /* zz to natural order for 7x7 block */
    extern const int jpeg_natural_order6[]; /* zz to natural order for 6x6 block */
    extern const int jpeg_natural_order5[]; /* zz to natural order for 5x5 block */
    extern const int jpeg_natural_order4[]; /* zz to natural order for 4x4 block */
    extern const int jpeg_natural_order3[]; /* zz to natural order for 3x3 block */
    extern const int jpeg_natural_order2[]; /* zz to natural order for 2x2 block */

    /* Arithmetic coding probability estimation tables in jaricom.c */
    extern const INT32 jpeg_aritab[];

    /* 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 */