text: /* +------------------------------------------------------------------------+
     |                     Mobile Robot Programming Toolkit (MRPT)            |
     |                          http://www.mrpt.org/                          |
     |                                                                        |
     | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
     | See: http://www.mrpt.org/Authors - All rights reserved.                |
     | Released under BSD License. See details in http://www.mrpt.org/License |
     +------------------------------------------------------------------------+ */
  
  /* 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) */
  struct jpeg_forward_dct
  {
  	JMETHOD(void, start_pass, (j_compress_ptr cinfo));
  	/* perhaps this should be an array??? */
  	JMETHOD(
  		void, forward_DCT,
  		(j_compress_ptr cinfo, jpeg_component_info* compptr,
  		 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, JDIMENSION start_row,
  		 JDIMENSION start_col, JDIMENSION num_blocks));
  };
  
  /* 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, JBLOCKROW* 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 nullptr 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, JBLOCKROW* MCU_data));
  
  	/* This is here to share code between baseline and progressive decoders; */
  	/* other modules probably should not use it */
  	boolean insufficient_data; /* set TRUE after emitting warning */
  };
  
  /* 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));
  };
  
  /* 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
  
  /* 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_phuff_encoder jIPHEncoder
  #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_phuff_decoder jIPHDecoder
  #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 jcopy_sample_rows jCopySamples
  #define jcopy_block_row jCopyBlocks
  #define jzero_far jZeroFar
  #define jpeg_zigzag_order jZIGTable
  #define jpeg_natural_order jZAGTable
  #endif /* NEED_SHORT_EXTERNAL_NAMES */
  
  /* 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_phuff_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_phuff_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, 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 */
  