skulltag / jpeg-6b / jpegint.h

 * jpegint.h
 * Copyright (C) 1991-1997, 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 */

/* 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 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));

/* 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:
  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
 * 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.

#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)))
#define RIGHT_SHIFT(x,shft)	((x) >> (shft))

/* 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 */
static INLINE long jdiv_round_up (long a, long b)
/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
/* Assumes a >= 0, b > 0 */
	return (a + b - 1L) / b;

static INLINE long jround_up (long a, long b)
/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
/* Assumes a >= 0, b > 0 */
	a += b - 1L;
	return a - (a % 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));

/* 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 */
extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */