jpegint.h

一个国人自己实现图像库的程序（有参考价值）

  /* 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 */