jpeglib.h File Reference

#include <vector>
#include <stdint.h>
#include <stdio.h>
#include "jmorecfg.h"
#include "jconfig.h"

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Classes
struct	JQUANT_TBL
struct	JHUFF_TBL
struct	jpeg_component_info
struct	jpeg_scan_info
struct	jpeg_marker_struct
struct	jpeg_common_struct
struct	jpeg_compress_struct
struct	jpeg_decompress_struct
struct	jpeg_error_mgr
struct	jpeg_progress_mgr
struct	jpeg_destination_mgr
struct	jpeg_source_mgr
struct	jpeg_memory_mgr

Macros
#define	JPEG_LIB_VERSION   62 /* Version 6b */
#define	DCTSIZE   8 /* The basic DCT block is 8x8 samples */
#define	DCTSIZE2   64 /* DCTSIZE squared; # of elements in a block */
#define	NUM_QUANT_TBLS   4 /* Quantization tables are numbered 0..3 */
#define	NUM_HUFF_TBLS   4 /* Huffman tables are numbered 0..3 */
#define	NUM_ARITH_TBLS   16 /* Arith-coding tables are numbered 0..15 */
#define	MAX_COMPS_IN_SCAN   4 /* JPEG limit on # of components in one scan */
#define	MAX_SAMP_FACTOR   4 /* JPEG limit on sampling factors */
#define	C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */
#define	D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */
#define	JDCT_DEFAULT   JDCT_ISLOW
#define	JDCT_FASTEST   JDCT_IFAST
#define	jpeg_common_fields
#define	JMSG_LENGTH_MAX   200 /* recommended size of format_message buffer */
#define	JMSG_STR_PARM_MAX   80
#define	JPOOL_PERMANENT   0 /* lasts until master record is destroyed */
#define	JPOOL_IMAGE   1 /* lasts until done with image/datastream */
#define	JPOOL_NUMPOOLS   2
#define	JPP(arglist)   arglist
#define	jpeg_create_compress(cinfo)
#define	jpeg_create_decompress(cinfo)
#define	JPEG_SUSPENDED   0 /* Suspended due to lack of input data */
#define	JPEG_HEADER_OK   1 /* Found valid image datastream */
#define	JPEG_HEADER_TABLES_ONLY   2 /* Found valid table-specs-only datastream */
#define	JPEG_REACHED_SOS   1 /* Reached start of new scan */
#define	JPEG_REACHED_EOI   2 /* Reached end of image */
#define	JPEG_ROW_COMPLETED   3 /* Completed one iMCU row */
#define	JPEG_SCAN_COMPLETED   4 /* Completed last iMCU row of a scan */
#define	JPEG_RST0   0xD0 /* RST0 marker code */
#define	JPEG_EOI   0xD9 /* EOI marker code */
#define	JPEG_APP0   0xE0 /* APP0 marker code */
#define	JPEG_COM   0xFE /* COM marker code */

Typedefs
typedef JSAMPLE *	JSAMPROW
typedef JSAMPROW *	JSAMPARRAY
typedef JSAMPARRAY *	JSAMPIMAGE
typedef JCOEF	JBLOCK[64]
typedef JBLOCK *	JBLOCKROW
typedef JBLOCKROW *	JBLOCKARRAY
typedef JBLOCKARRAY *	JBLOCKIMAGE
typedef JCOEF *	JCOEFPTR
typedef struct jpeg_marker_struct *	jpeg_saved_marker_ptr
typedef struct jpeg_common_struct *	j_common_ptr
typedef struct jpeg_compress_struct *	j_compress_ptr
typedef struct jpeg_decompress_struct *	j_decompress_ptr
typedef struct jvirt_sarray_control *	jvirt_sarray_ptr
typedef struct jvirt_barray_control *	jvirt_barray_ptr
typedef boolean(*	jpeg_marker_parser_method) ()

Enumerations
enum	J_COLOR_SPACE {   JCS_UNKNOWN, JCS_GRAYSCALE, JCS_RGB, JCS_YCbCr,   JCS_CMYK, JCS_YCCK }
enum	J_DCT_METHOD { JDCT_ISLOW, JDCT_IFAST, JDCT_FLOAT }
enum	J_DITHER_MODE { JDITHER_NONE, JDITHER_ORDERED, JDITHER_FS }

Functions
struct jpeg_error_mgr *	jpeg_std_error (struct jpeg_error_mgr *err)
void	jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
void	jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, size_t structsize)
void	jpeg_destroy_compress (j_compress_ptr cinfo)
void	jpeg_destroy_decompress (j_decompress_ptr cinfo)
void	jpeg_stdio_dest (j_compress_ptr cinfo, FILE *outfile)
void	jpeg_stdio_src (j_decompress_ptr cinfo, FILE *infile)
void	jpeg_set_defaults (j_compress_ptr cinfo)
void	jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
void	jpeg_default_colorspace (j_compress_ptr cinfo)
void	jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
void	jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, boolean force_baseline)
void	jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, const unsigned int *basic_table, int scale_factor, boolean force_baseline)
int	jpeg_quality_scaling (int quality)
void	jpeg_simple_progression (j_compress_ptr cinfo)
void	jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
JQUANT_TBL *	jpeg_alloc_quant_table (j_common_ptr cinfo)
JHUFF_TBL *	jpeg_alloc_huff_table (j_common_ptr cinfo)
void	jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
JDIMENSION	jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION num_lines)
void	jpeg_finish_compress (j_compress_ptr cinfo)
JDIMENSION	jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, JDIMENSION num_lines)
void	jpeg_write_marker (j_compress_ptr cinfo, int marker, const JOCTET *dataptr, unsigned int datalen)
void	jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
void	jpeg_write_m_byte (j_compress_ptr cinfo, int val)
void	jpeg_write_tables (j_compress_ptr cinfo)
int	jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)
boolean	jpeg_start_decompress (j_decompress_ptr cinfo)
JDIMENSION	jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION max_lines)
boolean	jpeg_finish_decompress (j_decompress_ptr cinfo)
JDIMENSION	jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, JDIMENSION max_lines)
boolean	jpeg_has_multiple_scans (j_decompress_ptr cinfo)
boolean	jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
boolean	jpeg_finish_output (j_decompress_ptr cinfo)
boolean	jpeg_input_complete (j_decompress_ptr cinfo)
void	jpeg_new_colormap (j_decompress_ptr cinfo)
int	jpeg_consume_input (j_decompress_ptr cinfo)
void	jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
void	jpeg_save_markers (j_decompress_ptr cinfo, int marker_code, unsigned int length_limit)
void	jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code, jpeg_marker_parser_method routine)
jvirt_barray_ptr *	jpeg_read_coefficients (j_decompress_ptr cinfo)
void	jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr *coef_arrays)
void	jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, j_compress_ptr dstinfo)
void	jpeg_abort_compress (j_compress_ptr cinfo)
void	jpeg_abort_decompress (j_decompress_ptr cinfo)
void	jpeg_abort (j_common_ptr cinfo)
void	jpeg_destroy (j_common_ptr cinfo)
boolean	jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
int	read_JPEG_file (const char *filename, vector< vector< uint8_t > > &image_buffer)
int	read_JPEG_file (const char *filename, JSAMPLE *image_buffer)
void	write_JPEG_file (const char *filename, int quality, J_COLOR_SPACE in_color_space, int image_width, int image_height, JSAMPLE *image_buffer)

Macro Definition Documentation

#define JPEG_LIB_VERSION   62 /* Version 6b */

#define DCTSIZE   8 /* The basic DCT block is 8x8 samples */

#define DCTSIZE2   64 /* DCTSIZE squared; # of elements in a block */

#define NUM_QUANT_TBLS   4 /* Quantization tables are numbered 0..3 */

#define NUM_HUFF_TBLS   4 /* Huffman tables are numbered 0..3 */

#define NUM_ARITH_TBLS   16 /* Arith-coding tables are numbered 0..15 */

#define MAX_COMPS_IN_SCAN   4 /* JPEG limit on # of components in one scan */

#define MAX_SAMP_FACTOR   4 /* JPEG limit on sampling factors */

#define C_MAX_BLOCKS_IN_MCU   10 /* compressor's limit on blocks per MCU */

#define D_MAX_BLOCKS_IN_MCU   10 /* decompressor's limit on blocks per MCU */

#define JDCT_DEFAULT   JDCT_ISLOW

#define JDCT_FASTEST   JDCT_IFAST

#define jpeg_common_fields

Value:

struct jpeg_error_mgr * err;    /* Error handler module */\
  struct jpeg_memory_mgr * mem; /* Memory manager module */\
  struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
  void * client_data;       /* Available for use by application */\
  boolean is_decompressor;  /* So common code can tell which is which */\
  int global_state      /* For checking call sequence validity */

#define JMSG_LENGTH_MAX   200 /* recommended size of format_message buffer */

#define JMSG_STR_PARM_MAX   80

#define JPOOL_PERMANENT   0 /* lasts until master record is destroyed */

#define JPOOL_IMAGE   1 /* lasts until done with image/datastream */

#define JPOOL_NUMPOOLS   2

#define JPP

(

arglist

)

arglist

#define jpeg_create_compress

(

cinfo

)

Value:

jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
            (size_t) sizeof(struct jpeg_compress_struct))

#define jpeg_create_decompress

(

cinfo

)

Value:

jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
              (size_t) sizeof(struct jpeg_decompress_struct))

#define JPEG_SUSPENDED   0 /* Suspended due to lack of input data */

#define JPEG_HEADER_OK   1 /* Found valid image datastream */

#define JPEG_HEADER_TABLES_ONLY   2 /* Found valid table-specs-only datastream */

#define JPEG_REACHED_SOS   1 /* Reached start of new scan */

#define JPEG_REACHED_EOI   2 /* Reached end of image */

#define JPEG_ROW_COMPLETED   3 /* Completed one iMCU row */

#define JPEG_SCAN_COMPLETED   4 /* Completed last iMCU row of a scan */

#define JPEG_RST0   0xD0 /* RST0 marker code */

#define JPEG_EOI   0xD9 /* EOI marker code */

#define JPEG_APP0   0xE0 /* APP0 marker code */

#define JPEG_COM   0xFE /* COM marker code */

Typedef Documentation

typedef JSAMPLE* JSAMPROW

typedef JSAMPROW* JSAMPARRAY

typedef JSAMPARRAY* JSAMPIMAGE

typedef JCOEF JBLOCK[64]

typedef JBLOCK* JBLOCKROW

typedef JBLOCKROW* JBLOCKARRAY

typedef JBLOCKARRAY* JBLOCKIMAGE

typedef JCOEF* JCOEFPTR

typedef struct jpeg_marker_struct* jpeg_saved_marker_ptr

typedef struct jpeg_common_struct* j_common_ptr

typedef struct jpeg_compress_struct* j_compress_ptr

typedef struct jpeg_decompress_struct* j_decompress_ptr

typedef struct jvirt_sarray_control* jvirt_sarray_ptr

typedef struct jvirt_barray_control* jvirt_barray_ptr

typedef boolean(* jpeg_marker_parser_method) ()

Enumeration Type Documentation

enum J_COLOR_SPACE

Enumerator
JCS_UNKNOWN
JCS_GRAYSCALE
JCS_RGB
JCS_YCbCr
JCS_CMYK
JCS_YCCK

             {
    JCS_UNKNOWN,        /* error/unspecified */
    JCS_GRAYSCALE,      /* monochrome */
    JCS_RGB,        /* red/green/blue */
    JCS_YCbCr,      /* Y/Cb/Cr (also known as YUV) */
    JCS_CMYK,       /* C/M/Y/K */
    JCS_YCCK        /* Y/Cb/Cr/K */
} J_COLOR_SPACE;

enum J_DCT_METHOD

Enumerator
JDCT_ISLOW
JDCT_IFAST
JDCT_FLOAT

             {
    JDCT_ISLOW,     /* slow but accurate integer algorithm */
    JDCT_IFAST,     /* faster, less accurate integer method */
    JDCT_FLOAT      /* floating-point: accurate, fast on fast HW */
} J_DCT_METHOD;

enum J_DITHER_MODE

Enumerator
JDITHER_NONE
JDITHER_ORDERED
JDITHER_FS

             {
    JDITHER_NONE,       /* no dithering */
    JDITHER_ORDERED,    /* simple ordered dither */
    JDITHER_FS      /* Floyd-Steinberg error diffusion dither */
} J_DITHER_MODE;

Function Documentation

struct jpeg_error_mgr* jpeg_std_error

(

struct jpeg_error_mgr *

err

)

{
  err->error_exit = error_exit;
  err->emit_message = emit_message;
  err->output_message = output_message;
  err->format_message = format_message;
  err->reset_error_mgr = reset_error_mgr;

  err->trace_level = 0;     /* default = no tracing */
  err->num_warnings = 0;    /* no warnings emitted yet */
  err->msg_code = 0;        /* may be useful as a flag for "no error" */

  /* Initialize message table pointers */
  err->jpeg_message_table = jpeg_std_message_table;
  err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;

  err->addon_message_table = NULL;
  err->first_addon_message = 0; /* for safety */
  err->last_addon_message = 0;

  return err;
}

void jpeg_CreateCompress	(	j_compress_ptr	cinfo,
		int	version,
		size_t	structsize
	)

{
  int i;

  /* Guard against version mismatches between library and caller. */
  cinfo->mem = NULL;        /* so jpeg_destroy knows mem mgr not called */
  if (version != JPEG_LIB_VERSION)
    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
  if (structsize != SIZEOF(struct jpeg_compress_struct))
    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, 
         (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);

  /* For debugging purposes, we zero the whole master structure.
   * But the application has already set the err pointer, and may have set
   * client_data, so we have to save and restore those fields.
   * Note: if application hasn't set client_data, tools like Purify may
   * complain here.
   */
  {
    struct jpeg_error_mgr * err = cinfo->err;
    void * client_data = cinfo->client_data; /* ignore Purify complaint here */
    MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
    cinfo->err = err;
    cinfo->client_data = client_data;
  }
  cinfo->is_decompressor = FALSE;

  /* Initialize a memory manager instance for this object */
  jinit_memory_mgr((j_common_ptr) cinfo);

  /* Zero out pointers to permanent structures. */
  cinfo->progress = NULL;
  cinfo->dest = NULL;

  cinfo->comp_info = NULL;

  for (i = 0; i < NUM_QUANT_TBLS; i++)
    cinfo->quant_tbl_ptrs[i] = NULL;

  for (i = 0; i < NUM_HUFF_TBLS; i++) {
    cinfo->dc_huff_tbl_ptrs[i] = NULL;
    cinfo->ac_huff_tbl_ptrs[i] = NULL;
  }

  cinfo->script_space = NULL;

  cinfo->input_gamma = 1.0; /* in case application forgets */

  /* OK, I'm ready */
  cinfo->global_state = CSTATE_START;
}

void jpeg_CreateDecompress	(	j_decompress_ptr	cinfo,
		int	version,
		size_t	structsize
	)

{
  int i;

  /* Guard against version mismatches between library and caller. */
  cinfo->mem = NULL;        /* so jpeg_destroy knows mem mgr not called */
  if (version != JPEG_LIB_VERSION)
    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
  if (structsize != SIZEOF(struct jpeg_decompress_struct))
    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, 
         (int) SIZEOF(struct jpeg_decompress_struct), (int) structsize);

  /* For debugging purposes, we zero the whole master structure.
   * But the application has already set the err pointer, and may have set
   * client_data, so we have to save and restore those fields.
   * Note: if application hasn't set client_data, tools like Purify may
   * complain here.
   */
  {
    struct jpeg_error_mgr * err = cinfo->err;
    void * client_data = cinfo->client_data; /* ignore Purify complaint here */
    MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
    cinfo->err = err;
    cinfo->client_data = client_data;
  }
  cinfo->is_decompressor = TRUE;

  /* Initialize a memory manager instance for this object */
  jinit_memory_mgr((j_common_ptr) cinfo);

  /* Zero out pointers to permanent structures. */
  cinfo->progress = NULL;
  cinfo->src = NULL;

  for (i = 0; i < NUM_QUANT_TBLS; i++)
    cinfo->quant_tbl_ptrs[i] = NULL;

  for (i = 0; i < NUM_HUFF_TBLS; i++) {
    cinfo->dc_huff_tbl_ptrs[i] = NULL;
    cinfo->ac_huff_tbl_ptrs[i] = NULL;
  }

  /* Initialize marker processor so application can override methods
   * for COM, APPn markers before calling jpeg_read_header.
   */
  cinfo->marker_list = NULL;
  jinit_marker_reader(cinfo);

  /* And initialize the overall input controller. */
  jinit_input_controller(cinfo);

  /* OK, I'm ready */
  cinfo->global_state = DSTATE_START;
}

void jpeg_destroy_compress

(

j_compress_ptr

cinfo

)

{
  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
}

void jpeg_destroy_decompress

(

j_decompress_ptr

cinfo

)

{
  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
}

void jpeg_stdio_dest	(	j_compress_ptr	cinfo,
		FILE *	outfile
	)

{
  my_dest_ptr dest;

  /* The destination object is made permanent so that multiple JPEG images
   * can be written to the same file without re-executing jpeg_stdio_dest.
   * This makes it dangerous to use this manager and a different destination
   * manager serially with the same JPEG object, because their private object
   * sizes may be different.  Caveat programmer.
   */
  if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
    cinfo->dest = (struct jpeg_destination_mgr *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                  SIZEOF(my_destination_mgr));
  }

  dest = (my_dest_ptr) cinfo->dest;
  dest->pub.init_destination = init_destination;
  dest->pub.empty_output_buffer = empty_output_buffer;
  dest->pub.term_destination = term_destination;
  dest->outfile = outfile;
}

void jpeg_stdio_src	(	j_decompress_ptr	cinfo,
		FILE *	infile
	)

{
  my_src_ptr src;

  /* The source object and input buffer are made permanent so that a series
   * of JPEG images can be read from the same file by calling jpeg_stdio_src
   * only before the first one.  (If we discarded the buffer at the end of
   * one image, we'd likely lose the start of the next one.)
   * This makes it unsafe to use this manager and a different source
   * manager serially with the same JPEG object.  Caveat programmer.
   */
  if (cinfo->src == NULL) { /* first time for this JPEG object? */
    cinfo->src = (struct jpeg_source_mgr *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                  SIZEOF(my_source_mgr));
    src = (my_src_ptr) cinfo->src;
    src->buffer = (JOCTET *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                  INPUT_BUF_SIZE * SIZEOF(JOCTET));
  }

  src = (my_src_ptr) cinfo->src;
  src->pub.init_source = init_source;
  src->pub.fill_input_buffer = fill_input_buffer;
  src->pub.skip_input_data = skip_input_data;
  src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
  src->pub.term_source = term_source;
  src->infile = infile;
  src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
  src->pub.next_input_byte = NULL; /* until buffer loaded */
}

void jpeg_set_defaults

(

j_compress_ptr

cinfo

)

{
  int i;

  /* Safety check to ensure start_compress not called yet. */
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  /* Allocate comp_info array large enough for maximum component count.
   * Array is made permanent in case application wants to compress
   * multiple images at same param settings.
   */
  if (cinfo->comp_info == NULL)
    cinfo->comp_info = (jpeg_component_info *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                  MAX_COMPONENTS * SIZEOF(jpeg_component_info));

  /* Initialize everything not dependent on the color space */

  cinfo->data_precision = BITS_IN_JSAMPLE;
  /* Set up two quantization tables using default quality of 75 */
  jpeg_set_quality(cinfo, 75, TRUE);
  /* Set up two Huffman tables */
  std_huff_tables(cinfo);

  /* Initialize default arithmetic coding conditioning */
  for (i = 0; i < NUM_ARITH_TBLS; i++) {
    cinfo->arith_dc_L[i] = 0;
    cinfo->arith_dc_U[i] = 1;
    cinfo->arith_ac_K[i] = 5;
  }

  /* Default is no multiple-scan output */
  cinfo->scan_info = NULL;
  cinfo->num_scans = 0;

  /* Expect normal source image, not raw downsampled data */
  cinfo->raw_data_in = FALSE;

  /* Use Huffman coding, not arithmetic coding, by default */
  cinfo->arith_code = FALSE;

  /* By default, don't do extra passes to optimize entropy coding */
  cinfo->optimize_coding = FALSE;
  /* The standard Huffman tables are only valid for 8-bit data precision.
   * If the precision is higher, force optimization on so that usable
   * tables will be computed.  This test can be removed if default tables
   * are supplied that are valid for the desired precision.
   */
  if (cinfo->data_precision > 8)
    cinfo->optimize_coding = TRUE;

  /* By default, use the simpler non-cosited sampling alignment */
  cinfo->CCIR601_sampling = FALSE;

  /* No input smoothing */
  cinfo->smoothing_factor = 0;

  /* DCT algorithm preference */
  cinfo->dct_method = JDCT_DEFAULT;

  /* No restart markers */
  cinfo->restart_interval = 0;
  cinfo->restart_in_rows = 0;

  /* Fill in default JFIF marker parameters.  Note that whether the marker
   * will actually be written is determined by jpeg_set_colorspace.
   *
   * By default, the library emits JFIF version code 1.01.
   * An application that wants to emit JFIF 1.02 extension markers should set
   * JFIF_minor_version to 2.  We could probably get away with just defaulting
   * to 1.02, but there may still be some decoders in use that will complain
   * about that; saying 1.01 should minimize compatibility problems.
   */
  cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
  cinfo->JFIF_minor_version = 1;
  cinfo->density_unit = 0;  /* Pixel size is unknown by default */
  cinfo->X_density = 1;     /* Pixel aspect ratio is square by default */
  cinfo->Y_density = 1;

  /* Choose JPEG colorspace based on input space, set defaults accordingly */

  jpeg_default_colorspace(cinfo);
}

void jpeg_set_colorspace	(	j_compress_ptr	cinfo,
		J_COLOR_SPACE	colorspace
	)

{
  jpeg_component_info * compptr;
  int ci;

#define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl)  \
  (compptr = &cinfo->comp_info[index], \
   compptr->component_id = (id), \
   compptr->h_samp_factor = (hsamp), \
   compptr->v_samp_factor = (vsamp), \
   compptr->quant_tbl_no = (quant), \
   compptr->dc_tbl_no = (dctbl), \
   compptr->ac_tbl_no = (actbl) )

  /* Safety check to ensure start_compress not called yet. */
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
   * tables 1 for chrominance components.
   */

  cinfo->jpeg_color_space = colorspace;

  cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
  cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */

  switch (colorspace) {
  case JCS_GRAYSCALE:
    cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
    cinfo->num_components = 1;
    /* JFIF specifies component ID 1 */
    SET_COMP(0, 1, 1,1, 0, 0,0);
    break;
  case JCS_RGB:
    cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
    cinfo->num_components = 3;
    SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0);
    SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
    SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0);
    break;
  case JCS_YCbCr:
    cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
    cinfo->num_components = 3;
    /* JFIF specifies component IDs 1,2,3 */
    /* We default to 2x2 subsamples of chrominance */
    SET_COMP(0, 1, 2,2, 0, 0,0);
    SET_COMP(1, 2, 1,1, 1, 1,1);
    SET_COMP(2, 3, 1,1, 1, 1,1);
    break;
  case JCS_CMYK:
    cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
    cinfo->num_components = 4;
    SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
    SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
    SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
    SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
    break;
  case JCS_YCCK:
    cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
    cinfo->num_components = 4;
    SET_COMP(0, 1, 2,2, 0, 0,0);
    SET_COMP(1, 2, 1,1, 1, 1,1);
    SET_COMP(2, 3, 1,1, 1, 1,1);
    SET_COMP(3, 4, 2,2, 0, 0,0);
    break;
  case JCS_UNKNOWN:
    cinfo->num_components = cinfo->input_components;
    if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
      ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
           MAX_COMPONENTS);
    for (ci = 0; ci < cinfo->num_components; ci++) {
      SET_COMP(ci, ci, 1,1, 0, 0,0);
    }
    break;
  default:
    ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
  }
}

void jpeg_default_colorspace

(

j_compress_ptr

cinfo

)

{
  switch (cinfo->in_color_space) {
  case JCS_GRAYSCALE:
    jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
    break;
  case JCS_RGB:
    jpeg_set_colorspace(cinfo, JCS_YCbCr);
    break;
  case JCS_YCbCr:
    jpeg_set_colorspace(cinfo, JCS_YCbCr);
    break;
  case JCS_CMYK:
    jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
    break;
  case JCS_YCCK:
    jpeg_set_colorspace(cinfo, JCS_YCCK);
    break;
  case JCS_UNKNOWN:
    jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
    break;
  default:
    ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
  }
}

void jpeg_set_quality	(	j_compress_ptr	cinfo,
		int	quality,
		boolean	force_baseline
	)

{
  /* Convert user 0-100 rating to percentage scaling */
  quality = jpeg_quality_scaling(quality);

  /* Set up standard quality tables */
  jpeg_set_linear_quality(cinfo, quality, force_baseline);
}

void jpeg_set_linear_quality	(	j_compress_ptr	cinfo,
		int	scale_factor,
		boolean	force_baseline
	)

{
  /* These are the sample quantization tables given in JPEG spec section K.1.
   * The spec says that the values given produce "good" quality, and
   * when divided by 2, "very good" quality.
   */
  static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
    16,  11,  10,  16,  24,  40,  51,  61,
    12,  12,  14,  19,  26,  58,  60,  55,
    14,  13,  16,  24,  40,  57,  69,  56,
    14,  17,  22,  29,  51,  87,  80,  62,
    18,  22,  37,  56,  68, 109, 103,  77,
    24,  35,  55,  64,  81, 104, 113,  92,
    49,  64,  78,  87, 103, 121, 120, 101,
    72,  92,  95,  98, 112, 100, 103,  99
  };
  static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
    17,  18,  24,  47,  99,  99,  99,  99,
    18,  21,  26,  66,  99,  99,  99,  99,
    24,  26,  56,  99,  99,  99,  99,  99,
    47,  66,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99
  };

  /* Set up two quantization tables using the specified scaling */
  jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
               scale_factor, force_baseline);
  jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
               scale_factor, force_baseline);
}

void jpeg_add_quant_table	(	j_compress_ptr	cinfo,
		int	which_tbl,
		const unsigned int *	basic_table,
		int	scale_factor,
		boolean	force_baseline
	)

{
  JQUANT_TBL ** qtblptr;
  int i;
  long temp;

  /* Safety check to ensure start_compress not called yet. */
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
    ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);

  qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];

  if (*qtblptr == NULL)
    *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);

  for (i = 0; i < DCTSIZE2; i++) {
    temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
    /* limit the values to the valid range */
    if (temp <= 0L) temp = 1L;
    if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
    if (force_baseline && temp > 255L)
      temp = 255L;      /* limit to baseline range if requested */
    (*qtblptr)->quantval[i] = (uint16_t) temp;
  }

  /* Initialize sent_table FALSE so table will be written to JPEG file. */
  (*qtblptr)->sent_table = FALSE;
}

int jpeg_quality_scaling

(

int

quality

)

{
  /* Safety limit on quality factor.  Convert 0 to 1 to avoid zero divide. */
  if (quality <= 0) quality = 1;
  if (quality > 100) quality = 100;

  /* The basic table is used as-is (scaling 100) for a quality of 50.
   * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
   * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
   * to make all the table entries 1 (hence, minimum quantization loss).
   * Qualities 1..50 are converted to scaling percentage 5000/Q.
   */
  if (quality < 50)
    quality = 5000 / quality;
  else
    quality = 200 - quality*2;

  return quality;
}

void jpeg_simple_progression

(

j_compress_ptr

cinfo

)

{
  int ncomps = cinfo->num_components;
  int nscans;
  jpeg_scan_info * scanptr;

  /* Safety check to ensure start_compress not called yet. */
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  /* Figure space needed for script.  Calculation must match code below! */
  if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
    /* Custom script for YCbCr color images. */
    nscans = 10;
  } else {
    /* All-purpose script for other color spaces. */
    if (ncomps > MAX_COMPS_IN_SCAN)
      nscans = 6 * ncomps;  /* 2 DC + 4 AC scans per component */
    else
      nscans = 2 + 4 * ncomps;  /* 2 DC scans; 4 AC scans per component */
  }

  /* Allocate space for script.
   * We need to put it in the permanent pool in case the application performs
   * multiple compressions without changing the settings.  To avoid a memory
   * leak if jpeg_simple_progression is called repeatedly for the same JPEG
   * object, we try to re-use previously allocated space, and we allocate
   * enough space to handle YCbCr even if initially asked for grayscale.
   */
  if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
    cinfo->script_space_size = MAX(nscans, 10);
    cinfo->script_space = (jpeg_scan_info *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
            cinfo->script_space_size * SIZEOF(jpeg_scan_info));
  }
  scanptr = cinfo->script_space;
  cinfo->scan_info = scanptr;
  cinfo->num_scans = nscans;

  if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
    /* Custom script for YCbCr color images. */
    /* Initial DC scan */
    scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
    /* Initial AC scan: get some luma data out in a hurry */
    scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
    /* Chroma data is too small to be worth expending many scans on */
    scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
    scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
    /* Complete spectral selection for luma AC */
    scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
    /* Refine next bit of luma AC */
    scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
    /* Finish DC successive approximation */
    scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
    /* Finish AC successive approximation */
    scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
    scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
    /* Luma bottom bit comes last since it's usually largest scan */
    scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
  } else {
    /* All-purpose script for other color spaces. */
    /* Successive approximation first pass */
    scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
    scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
    scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
    /* Successive approximation second pass */
    scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
    /* Successive approximation final pass */
    scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
    scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
  }
}

void jpeg_suppress_tables	(	j_compress_ptr	cinfo,
		boolean	suppress
	)

{
  int i;
  JQUANT_TBL * qtbl;
  JHUFF_TBL * htbl;

  for (i = 0; i < NUM_QUANT_TBLS; i++) {
    if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
      qtbl->sent_table = suppress;
  }

  for (i = 0; i < NUM_HUFF_TBLS; i++) {
    if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
      htbl->sent_table = suppress;
    if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
      htbl->sent_table = suppress;
  }
}

JQUANT_TBL* jpeg_alloc_quant_table

(

j_common_ptr

cinfo

)

{
  JQUANT_TBL *tbl;

  tbl = (JQUANT_TBL *)
    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
  tbl->sent_table = FALSE;  /* make sure this is false in any new table */
  return tbl;
}

JHUFF_TBL* jpeg_alloc_huff_table

(

j_common_ptr

cinfo

)

{
  JHUFF_TBL *tbl;

  tbl = (JHUFF_TBL *)
    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
  tbl->sent_table = FALSE;  /* make sure this is false in any new table */
  return tbl;
}

void jpeg_start_compress	(	j_compress_ptr	cinfo,
		boolean	write_all_tables
	)

{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (write_all_tables)
    jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */

  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Perform master selection of active modules */
  jinit_compress_master(cinfo);
  /* Set up for the first pass */
  (*cinfo->master->prepare_for_pass) (cinfo);
  /* Ready for application to drive first pass through jpeg_write_scanlines
   * or jpeg_write_raw_data.
   */
  cinfo->next_scanline = 0;
  cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
}

JDIMENSION jpeg_write_scanlines	(	j_compress_ptr	cinfo,
		JSAMPARRAY	scanlines,
		JDIMENSION	num_lines
	)

{
  JDIMENSION row_ctr, rows_left;

  if (cinfo->global_state != CSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_height)
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_scanlines.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_scanlines.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Ignore any extra scanlines at bottom of image. */
  rows_left = cinfo->image_height - cinfo->next_scanline;
  if (num_lines > rows_left)
    num_lines = rows_left;

  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
  cinfo->next_scanline += row_ctr;
  return row_ctr;
}

void jpeg_finish_compress

(

j_compress_ptr

cinfo

)

{
  JDIMENSION iMCU_row;

  if (cinfo->global_state == CSTATE_SCANNING ||
      cinfo->global_state == CSTATE_RAW_OK) {
    /* Terminate first pass */
    if (cinfo->next_scanline < cinfo->image_height)
      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
    (*cinfo->master->finish_pass) (cinfo);
  } else if (cinfo->global_state != CSTATE_WRCOEFS)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Perform any remaining passes */
  while (! cinfo->master->is_last_pass) {
    (*cinfo->master->prepare_for_pass) (cinfo);
    for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
      if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) iMCU_row;
    cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      }
      /* We bypass the main controller and invoke coef controller directly;
       * all work is being done from the coefficient buffer.
       */
      if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
    ERREXIT(cinfo, JERR_CANT_SUSPEND);
    }
    (*cinfo->master->finish_pass) (cinfo);
  }
  /* Write EOI, do final cleanup */
  (*cinfo->marker->write_file_trailer) (cinfo);
  (*cinfo->dest->term_destination) (cinfo);
  /* We can use jpeg_abort to release memory and reset global_state */
  jpeg_abort((j_common_ptr) cinfo);
}

JDIMENSION jpeg_write_raw_data	(	j_compress_ptr	cinfo,
		JSAMPIMAGE	data,
		JDIMENSION	num_lines
	)

{
  JDIMENSION lines_per_iMCU_row;

  if (cinfo->global_state != CSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_raw_data.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_raw_data.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Verify that at least one iMCU row has been passed. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
  if (num_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);

  /* Directly compress the row. */
  if (! (*cinfo->coef->compress_data) (cinfo, data)) {
    /* If compressor did not consume the whole row, suspend processing. */
    return 0;
  }

  /* OK, we processed one iMCU row. */
  cinfo->next_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}

void jpeg_write_marker	(	j_compress_ptr	cinfo,
		int	marker,
		const JOCTET *	dataptr,
		unsigned int	datalen
	)

{
  JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));

  if (cinfo->next_scanline != 0 ||
      (cinfo->global_state != CSTATE_SCANNING &&
       cinfo->global_state != CSTATE_RAW_OK &&
       cinfo->global_state != CSTATE_WRCOEFS))
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
  write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
  while (datalen--) {
    (*write_marker_byte) (cinfo, *dataptr);
    dataptr++;
  }
}

void jpeg_write_m_header	(	j_compress_ptr	cinfo,
		int	marker,
		unsigned int	datalen
	)

{
  if (cinfo->next_scanline != 0 ||
      (cinfo->global_state != CSTATE_SCANNING &&
       cinfo->global_state != CSTATE_RAW_OK &&
       cinfo->global_state != CSTATE_WRCOEFS))
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
}

void jpeg_write_m_byte	(	j_compress_ptr	cinfo,
		int	val
	)

{
  (*cinfo->marker->write_marker_byte) (cinfo, val);
}

void jpeg_write_tables

(

j_compress_ptr

cinfo

)

{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Initialize the marker writer ... bit of a crock to do it here. */
  jinit_marker_writer(cinfo);
  /* Write them tables! */
  (*cinfo->marker->write_tables_only) (cinfo);
  /* And clean up. */
  (*cinfo->dest->term_destination) (cinfo);
  /*
   * In library releases up through v6a, we called jpeg_abort() here to free
   * any working memory allocated by the destination manager and marker
   * writer.  Some applications had a problem with that: they allocated space
   * of their own from the library memory manager, and didn't want it to go
   * away during write_tables.  So now we do nothing.  This will cause a
   * memory leak if an app calls write_tables repeatedly without doing a full
   * compression cycle or otherwise resetting the JPEG object.  However, that
   * seems less bad than unexpectedly freeing memory in the normal case.
   * An app that prefers the old behavior can call jpeg_abort for itself after
   * each call to jpeg_write_tables().
   */
}

int jpeg_read_header	(	j_decompress_ptr	cinfo,
		boolean	require_image
	)

{
  int retcode;

  if (cinfo->global_state != DSTATE_START &&
      cinfo->global_state != DSTATE_INHEADER)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  retcode = jpeg_consume_input(cinfo);

  switch (retcode) {
  case JPEG_REACHED_SOS:
    retcode = JPEG_HEADER_OK;
    break;
  case JPEG_REACHED_EOI:
    if (require_image)      /* Complain if application wanted an image */
      ERREXIT(cinfo, JERR_NO_IMAGE);
    /* Reset to start state; it would be safer to require the application to
     * call jpeg_abort, but we can't change it now for compatibility reasons.
     * A side effect is to free any temporary memory (there shouldn't be any).
     */
    jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */
    retcode = JPEG_HEADER_TABLES_ONLY;
    break;
  case JPEG_SUSPENDED:
    /* no work */
    break;
  }

  return retcode;
}

boolean jpeg_start_decompress

(

j_decompress_ptr

cinfo

)

{
  if (cinfo->global_state == DSTATE_READY) {
    /* First call: initialize master control, select active modules */
    jinit_master_decompress(cinfo);
    if (cinfo->buffered_image) {
      /* No more work here; expecting jpeg_start_output next */
      cinfo->global_state = DSTATE_BUFIMAGE;
      return TRUE;
    }
    cinfo->global_state = DSTATE_PRELOAD;
  }
  if (cinfo->global_state == DSTATE_PRELOAD) {
    /* If file has multiple scans, absorb them all into the coef buffer */
    if (cinfo->inputctl->has_multiple_scans) {
#ifdef D_MULTISCAN_FILES_SUPPORTED
      for (;;) {
    int retcode;
    /* Call progress monitor hook if present */
    if (cinfo->progress != NULL)
      (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
    /* Absorb some more input */
    retcode = (*cinfo->inputctl->consume_input) (cinfo);
    if (retcode == JPEG_SUSPENDED)
      return FALSE;
    if (retcode == JPEG_REACHED_EOI)
      break;
    /* Advance progress counter if appropriate */
    if (cinfo->progress != NULL &&
        (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
      if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
        /* jdmaster underestimated number of scans; ratchet up one scan */
        cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
      }
    }
      }
#else
      ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* D_MULTISCAN_FILES_SUPPORTED */
    }
    cinfo->output_scan_number = cinfo->input_scan_number;
  } else if (cinfo->global_state != DSTATE_PRESCAN)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Perform any dummy output passes, and set up for the final pass */
  return output_pass_setup(cinfo);
}

JDIMENSION jpeg_read_scanlines	(	j_decompress_ptr	cinfo,
		JSAMPARRAY	scanlines,
		JDIMENSION	max_lines
	)

{
  JDIMENSION row_ctr;

  if (cinfo->global_state != DSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Process some data */
  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
  cinfo->output_scanline += row_ctr;
  return row_ctr;
}

boolean jpeg_finish_decompress

(

j_decompress_ptr

cinfo

)

{
  if ((cinfo->global_state == DSTATE_SCANNING ||
       cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {
    /* Terminate final pass of non-buffered mode */
    if (cinfo->output_scanline < cinfo->output_height)
      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
    (*cinfo->master->finish_output_pass) (cinfo);
    cinfo->global_state = DSTATE_STOPPING;
  } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
    /* Finishing after a buffered-image operation */
    cinfo->global_state = DSTATE_STOPPING;
  } else if (cinfo->global_state != DSTATE_STOPPING) {
    /* STOPPING = repeat call after a suspension, anything else is error */
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  }
  /* Read until EOI */
  while (! cinfo->inputctl->eoi_reached) {
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
      return FALSE;     /* Suspend, come back later */
  }
  /* Do final cleanup */
  (*cinfo->src->term_source) (cinfo);
  /* We can use jpeg_abort to release memory and reset global_state */
  jpeg_abort((j_common_ptr) cinfo);
  return TRUE;
}

JDIMENSION jpeg_read_raw_data	(	j_decompress_ptr	cinfo,
		JSAMPIMAGE	data,
		JDIMENSION	max_lines
	)

{
  JDIMENSION lines_per_iMCU_row;

  if (cinfo->global_state != DSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Verify that at least one iMCU row can be returned. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
  if (max_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);

  /* Decompress directly into user's buffer. */
  if (! (*cinfo->coef->decompress_data) (cinfo, data))
    return 0;           /* suspension forced, can do nothing more */

  /* OK, we processed one iMCU row. */
  cinfo->output_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}

boolean jpeg_has_multiple_scans

(

j_decompress_ptr

cinfo

)

{
  /* Only valid after jpeg_read_header completes */
  if (cinfo->global_state < DSTATE_READY ||
      cinfo->global_state > DSTATE_STOPPING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  return cinfo->inputctl->has_multiple_scans;
}

boolean jpeg_start_output	(	j_decompress_ptr	cinfo,
		int	scan_number
	)

{
  if (cinfo->global_state != DSTATE_BUFIMAGE &&
      cinfo->global_state != DSTATE_PRESCAN)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Limit scan number to valid range */
  if (scan_number <= 0)
    scan_number = 1;
  if (cinfo->inputctl->eoi_reached &&
      scan_number > cinfo->input_scan_number)
    scan_number = cinfo->input_scan_number;
  cinfo->output_scan_number = scan_number;
  /* Perform any dummy output passes, and set up for the real pass */
  return output_pass_setup(cinfo);
}

boolean jpeg_finish_output

(

j_decompress_ptr

cinfo

)

{
  if ((cinfo->global_state == DSTATE_SCANNING ||
       cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
    /* Terminate this pass. */
    /* We do not require the whole pass to have been completed. */
    (*cinfo->master->finish_output_pass) (cinfo);
    cinfo->global_state = DSTATE_BUFPOST;
  } else if (cinfo->global_state != DSTATE_BUFPOST) {
    /* BUFPOST = repeat call after a suspension, anything else is error */
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  }
  /* Read markers looking for SOS or EOI */
  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
     ! cinfo->inputctl->eoi_reached) {
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
      return FALSE;     /* Suspend, come back later */
  }
  cinfo->global_state = DSTATE_BUFIMAGE;
  return TRUE;
}

boolean jpeg_input_complete

(

j_decompress_ptr

cinfo

)

{
  /* Check for valid jpeg object */
  if (cinfo->global_state < DSTATE_START ||
      cinfo->global_state > DSTATE_STOPPING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  return cinfo->inputctl->eoi_reached;
}

void jpeg_new_colormap

(

j_decompress_ptr

cinfo

)

{
  my_master_ptr master = (my_master_ptr) cinfo->master;

  /* Prevent application from calling me at wrong times */
  if (cinfo->global_state != DSTATE_BUFIMAGE)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (cinfo->quantize_colors && cinfo->enable_external_quant &&
      cinfo->colormap != NULL) {
    /* Select 2-pass quantizer for external colormap use */
    cinfo->cquantize = master->quantizer_2pass;
    /* Notify quantizer of colormap change */
    (*cinfo->cquantize->new_color_map) (cinfo);
    master->pub.is_dummy_pass = FALSE; /* just in case */
  } else
    ERREXIT(cinfo, JERR_MODE_CHANGE);
}

int jpeg_consume_input

(

j_decompress_ptr

cinfo

)

{
  int retcode = JPEG_SUSPENDED;

  /* NB: every possible DSTATE value should be listed in this switch */
  switch (cinfo->global_state) {
  case DSTATE_START:
    /* Start-of-datastream actions: reset appropriate modules */
    (*cinfo->inputctl->reset_input_controller) (cinfo);
    /* Initialize application's data source module */
    (*cinfo->src->init_source) (cinfo);
    cinfo->global_state = DSTATE_INHEADER;
    /*FALLTHROUGH*/
  case DSTATE_INHEADER:
    retcode = (*cinfo->inputctl->consume_input) (cinfo);
    if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
      /* Set up default parameters based on header data */
      default_decompress_parms(cinfo);
      /* Set global state: ready for start_decompress */
      cinfo->global_state = DSTATE_READY;
    }
    break;
  case DSTATE_READY:
    /* Can't advance past first SOS until start_decompress is called */
    retcode = JPEG_REACHED_SOS;
    break;
  case DSTATE_PRELOAD:
  case DSTATE_PRESCAN:
  case DSTATE_SCANNING:
  case DSTATE_RAW_OK:
  case DSTATE_BUFIMAGE:
  case DSTATE_BUFPOST:
  case DSTATE_STOPPING:
    retcode = (*cinfo->inputctl->consume_input) (cinfo);
    break;
  default:
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  }
  return retcode;
}

void jpeg_calc_output_dimensions

(

j_decompress_ptr

cinfo

)

{
#ifdef IDCT_SCALING_SUPPORTED
  int ci;
  jpeg_component_info *compptr;
#endif

  /* Prevent application from calling me at wrong times */
  if (cinfo->global_state != DSTATE_READY)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

#ifdef IDCT_SCALING_SUPPORTED

  /* Compute actual output image dimensions and DCT scaling choices. */
  if (cinfo->scale_num * 8 <= cinfo->scale_denom) {
    /* Provide 1/8 scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width, 8L);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height, 8L);
    cinfo->min_DCT_scaled_size = 1;
  } else if (cinfo->scale_num * 4 <= cinfo->scale_denom) {
    /* Provide 1/4 scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width, 4L);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height, 4L);
    cinfo->min_DCT_scaled_size = 2;
  } else if (cinfo->scale_num * 2 <= cinfo->scale_denom) {
    /* Provide 1/2 scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width, 2L);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height, 2L);
    cinfo->min_DCT_scaled_size = 4;
  } else {
    /* Provide 1/1 scaling */
    cinfo->output_width = cinfo->image_width;
    cinfo->output_height = cinfo->image_height;
    cinfo->min_DCT_scaled_size = DCTSIZE;
  }
  /* In selecting the actual DCT scaling for each component, we try to
   * scale up the chroma components via IDCT scaling rather than upsampling.
   * This saves time if the upsampler gets to use 1:1 scaling.
   * Note this code assumes that the supported DCT scalings are powers of 2.
   */
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    int ssize = cinfo->min_DCT_scaled_size;
    while (ssize < DCTSIZE &&
       (compptr->h_samp_factor * ssize * 2 <=
        cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size) &&
       (compptr->v_samp_factor * ssize * 2 <=
        cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size)) {
      ssize = ssize * 2;
    }
    compptr->DCT_scaled_size = ssize;
  }

  /* Recompute downsampled dimensions of components;
   * application needs to know these if using raw downsampled data.
   */
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    /* Size in samples, after IDCT scaling */
    compptr->downsampled_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width *
            (long) (compptr->h_samp_factor * compptr->DCT_scaled_size),
            (long) (cinfo->max_h_samp_factor * DCTSIZE));
    compptr->downsampled_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height *
            (long) (compptr->v_samp_factor * compptr->DCT_scaled_size),
            (long) (cinfo->max_v_samp_factor * DCTSIZE));
  }

#else /* !IDCT_SCALING_SUPPORTED */

  /* Hardwire it to "no scaling" */
  cinfo->output_width = cinfo->image_width;
  cinfo->output_height = cinfo->image_height;
  /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
   * and has computed unscaled downsampled_width and downsampled_height.
   */

#endif /* IDCT_SCALING_SUPPORTED */

  /* Report number of components in selected colorspace. */
  /* Probably this should be in the color conversion module... */
  switch (cinfo->out_color_space) {
  case JCS_GRAYSCALE:
    cinfo->out_color_components = 1;
    break;
  case JCS_RGB:
#if RGB_PIXELSIZE != 3
    cinfo->out_color_components = RGB_PIXELSIZE;
    break;
#endif /* else share code with YCbCr */
  case JCS_YCbCr:
    cinfo->out_color_components = 3;
    break;
  case JCS_CMYK:
  case JCS_YCCK:
    cinfo->out_color_components = 4;
    break;
  default:          /* else must be same colorspace as in file */
    cinfo->out_color_components = cinfo->num_components;
    break;
  }
  cinfo->output_components = (cinfo->quantize_colors ? 1 :
                  cinfo->out_color_components);

  /* See if upsampler will want to emit more than one row at a time */
  if (use_merged_upsample(cinfo))
    cinfo->rec_outbuf_height = cinfo->max_v_samp_factor;
  else
    cinfo->rec_outbuf_height = 1;
}

void jpeg_save_markers	(	j_decompress_ptr	cinfo,
		int	marker_code,
		unsigned int	length_limit
	)

{
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
  long maxlength;
  jpeg_marker_parser_method processor;

  /* Length limit mustn't be larger than what we can allocate
   * (should only be a concern in a 16-bit environment).
   */
  maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
  if (((long) length_limit) > maxlength)
    length_limit = (unsigned int) maxlength;

  /* Choose processor routine to use.
   * APP0/APP14 have special requirements.
   */
  if (length_limit) {
    processor = save_marker;
    /* If saving APP0/APP14, save at least enough for our internal use. */
    if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
      length_limit = APP0_DATA_LEN;
    else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
      length_limit = APP14_DATA_LEN;
  } else {
    processor = skip_variable;
    /* If discarding APP0/APP14, use our regular on-the-fly processor. */
    if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
      processor = get_interesting_appn;
  }

  if (marker_code == (int) M_COM) {
    marker->process_COM = processor;
    marker->length_limit_COM = length_limit;
  } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
    marker->process_APPn[marker_code - (int) M_APP0] = processor;
    marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
  } else
    ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
}

void jpeg_set_marker_processor	(	j_decompress_ptr	cinfo,
		int	marker_code,
		jpeg_marker_parser_method	routine
	)

{
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;

  if (marker_code == (int) M_COM)
    marker->process_COM = routine;
  else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
    marker->process_APPn[marker_code - (int) M_APP0] = routine;
  else
    ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
}

jvirt_barray_ptr* jpeg_read_coefficients

(

j_decompress_ptr

cinfo

)

{
  if (cinfo->global_state == DSTATE_READY) {
    /* First call: initialize active modules */
    transdecode_master_selection(cinfo);
    cinfo->global_state = DSTATE_RDCOEFS;
  }
  if (cinfo->global_state == DSTATE_RDCOEFS) {
    /* Absorb whole file into the coef buffer */
    for (;;) {
      int retcode;
      /* Call progress monitor hook if present */
      if (cinfo->progress != NULL)
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      /* Absorb some more input */
      retcode = (*cinfo->inputctl->consume_input) (cinfo);
      if (retcode == JPEG_SUSPENDED)
    return NULL;
      if (retcode == JPEG_REACHED_EOI)
    break;
      /* Advance progress counter if appropriate */
      if (cinfo->progress != NULL &&
      (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
    if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
      /* startup underestimated number of scans; ratchet up one scan */
      cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
    }
      }
    }
    /* Set state so that jpeg_finish_decompress does the right thing */
    cinfo->global_state = DSTATE_STOPPING;
  }
  /* At this point we should be in state DSTATE_STOPPING if being used
   * standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
   * to the coefficients during a full buffered-image-mode decompression.
   */
  if ((cinfo->global_state == DSTATE_STOPPING ||
       cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
    return cinfo->coef->coef_arrays;
  }
  /* Oops, improper usage */
  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  return NULL;          /* keep compiler happy */
}

void jpeg_write_coefficients	(	j_compress_ptr	cinfo,
		jvirt_barray_ptr *	coef_arrays
	)

{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Mark all tables to be written */
  jpeg_suppress_tables(cinfo, FALSE);
  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Perform master selection of active modules */
  transencode_master_selection(cinfo, coef_arrays);
  /* Wait for jpeg_finish_compress() call */
  cinfo->next_scanline = 0; /* so jpeg_write_marker works */
  cinfo->global_state = CSTATE_WRCOEFS;
}

void jpeg_copy_critical_parameters	(	j_decompress_ptr	srcinfo,
		j_compress_ptr	dstinfo
	)

{
  JQUANT_TBL ** qtblptr;
  jpeg_component_info *incomp, *outcomp;
  JQUANT_TBL *c_quant, *slot_quant;
  int tblno, ci, coefi;

  /* Safety check to ensure start_compress not called yet. */
  if (dstinfo->global_state != CSTATE_START)
    ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
  /* Copy fundamental image dimensions */
  dstinfo->image_width = srcinfo->image_width;
  dstinfo->image_height = srcinfo->image_height;
  dstinfo->input_components = srcinfo->num_components;
  dstinfo->in_color_space = srcinfo->jpeg_color_space;
  /* Initialize all parameters to default values */
  jpeg_set_defaults(dstinfo);
  /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
   * Fix it to get the right header markers for the image colorspace.
   */
  jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
  dstinfo->data_precision = srcinfo->data_precision;
  dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
  /* Copy the source's quantization tables. */
  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
    if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
      qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
      if (*qtblptr == NULL)
    *qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
      MEMCOPY((*qtblptr)->quantval,
          srcinfo->quant_tbl_ptrs[tblno]->quantval,
          SIZEOF((*qtblptr)->quantval));
      (*qtblptr)->sent_table = FALSE;
    }
  }
  /* Copy the source's per-component info.
   * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
   */
  dstinfo->num_components = srcinfo->num_components;
  if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
    ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
         MAX_COMPONENTS);
  for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
       ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
    outcomp->component_id = incomp->component_id;
    outcomp->h_samp_factor = incomp->h_samp_factor;
    outcomp->v_samp_factor = incomp->v_samp_factor;
    outcomp->quant_tbl_no = incomp->quant_tbl_no;
    /* Make sure saved quantization table for component matches the qtable
     * slot.  If not, the input file re-used this qtable slot.
     * IJG encoder currently cannot duplicate this.
     */
    tblno = outcomp->quant_tbl_no;
    if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
    srcinfo->quant_tbl_ptrs[tblno] == NULL)
      ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
    slot_quant = srcinfo->quant_tbl_ptrs[tblno];
    c_quant = incomp->quant_table;
    if (c_quant != NULL) {
      for (coefi = 0; coefi < DCTSIZE2; coefi++) {
    if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
      ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
      }
    }
    /* Note: we do not copy the source's Huffman table assignments;
     * instead we rely on jpeg_set_colorspace to have made a suitable choice.
     */
  }
  /* Also copy JFIF version and resolution information, if available.
   * Strictly speaking this isn't "critical" info, but it's nearly
   * always appropriate to copy it if available.  In particular,
   * if the application chooses to copy JFIF 1.02 extension markers from
   * the source file, we need to copy the version to make sure we don't
   * emit a file that has 1.02 extensions but a claimed version of 1.01.
   * We will *not*, however, copy version info from mislabeled "2.01" files.
   */
  if (srcinfo->saw_JFIF_marker) {
    if (srcinfo->JFIF_major_version == 1) {
      dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
      dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
    }
    dstinfo->density_unit = srcinfo->density_unit;
    dstinfo->X_density = srcinfo->X_density;
    dstinfo->Y_density = srcinfo->Y_density;
  }
}

void jpeg_abort_compress

(

j_compress_ptr

cinfo

)

{
  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
}

void jpeg_abort_decompress

(

j_decompress_ptr

cinfo

)

{
  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
}

void jpeg_abort

(

j_common_ptr

cinfo

)

{
  int pool;

  /* Do nothing if called on a not-initialized or destroyed JPEG object. */
  if (cinfo->mem == NULL)
    return;

  /* Releasing pools in reverse order might help avoid fragmentation
   * with some (brain-damaged) malloc libraries.
   */
  for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
    (*cinfo->mem->free_pool) (cinfo, pool);
  }

  /* Reset overall state for possible reuse of object */
  if (cinfo->is_decompressor) {
    cinfo->global_state = DSTATE_START;
    /* Try to keep application from accessing now-deleted marker list.
     * A bit kludgy to do it here, but this is the most central place.
     */
    ((j_decompress_ptr) cinfo)->marker_list = NULL;
  } else {
    cinfo->global_state = CSTATE_START;
  }
}

void jpeg_destroy

(

j_common_ptr

cinfo

)

{
  /* We need only tell the memory manager to release everything. */
  /* NB: mem pointer is NULL if memory mgr failed to initialize. */
  if (cinfo->mem != NULL)
    (*cinfo->mem->self_destruct) (cinfo);
  cinfo->mem = NULL;        /* be safe if jpeg_destroy is called twice */
  cinfo->global_state = 0;  /* mark it destroyed */
}

boolean jpeg_resync_to_restart	(	j_decompress_ptr	cinfo,
		int	desired
	)

{
  int marker = cinfo->unread_marker;
  int action = 1;
  
  /* Always put up a warning. */
  WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
  
  /* Outer loop handles repeated decision after scanning forward. */
  for (;;) {
    if (marker < (int) M_SOF0)
      action = 2;       /* invalid marker */
    else if (marker < (int) M_RST0 || marker > (int) M_RST7)
      action = 3;       /* valid non-restart marker */
    else {
      if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
      marker == ((int) M_RST0 + ((desired+2) & 7)))
    action = 3;     /* one of the next two expected restarts */
      else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
           marker == ((int) M_RST0 + ((desired-2) & 7)))
    action = 2;     /* a prior restart, so advance */
      else
    action = 1;     /* desired restart or too far away */
    }
    TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
    switch (action) {
    case 1:
      /* Discard marker and let entropy decoder resume processing. */
      cinfo->unread_marker = 0;
      return TRUE;
    case 2:
      /* Scan to the next marker, and repeat the decision loop. */
      if (! next_marker(cinfo))
    return FALSE;
      marker = cinfo->unread_marker;
      break;
    case 3:
      /* Return without advancing past this marker. */
      /* Entropy decoder will be forced to process an empty segment. */
      return TRUE;
    }
  } /* end loop */
}

int read_JPEG_file	(	const char *	filename,
		vector< vector< uint8_t > > &	image_buffer
	)

{
    FILE *infile;
/* This struct contains the JPEG decompression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   */
    struct jpeg_decompress_struct cinfo;
    /* We use our private extension JPEG error handler.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
    struct my_error_mgr jerr;
    /* More stuff */
    JSAMPARRAY buffer;      /* Output row buffer */
    int row_stride;     /* physical row width in output buffer */

    /* In this example we want to open the input file before doing anything else,
     * so that the setjmp() error recovery below can assume the file is open.
     * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
     * requires it in order to read binary files.
     */

    if ((infile = fopen(filename, "rb")) == NULL) {
        fprintf(stderr, "can't open %s\n", filename);
        return 0;
    }

    /* Step 1: allocate and initialize JPEG decompression object */

    /* We set up the normal JPEG error routines, then override error_exit. */
    cinfo.err = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer))
    {
        /* If we get here, the JPEG code has signaled an error.
     * We need to clean up the JPEG object, close the input file, and return.
     */
        jpeg_destroy_decompress(&cinfo);
        fclose(infile);
        return 0;
    }
    /* Now we can initialize the JPEG decompression object. */
    jpeg_create_decompress(&cinfo);

    /* Step 2: specify data source (eg, a file) */

    jpeg_stdio_src(&cinfo, infile);

    /* Step 3: read file parameters with jpeg_read_header() */

    (void) jpeg_read_header(&cinfo, TRUE);
    /* We can ignore the return value from jpeg_read_header since
   *   (a) suspension is not possible with the stdio data source, and
   *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
   * See libjpeg.doc for more info.
   */

    /* Step 4: set parameters for decompression */

    /* In this example, we don't need to change any of the defaults set by
   * jpeg_read_header(), so we do nothing here.
   */

    /* Step 5: Start decompressor */

    (void) jpeg_start_decompress(&cinfo);
    /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

    /* We may need to do some setup of our own at this point before reading
   * the data.  After jpeg_start_decompress() we have the correct scaled
   * output image dimensions available, as well as the output colormap
   * if we asked for color quantization.
   * In this example, we need to make an output work buffer of the right size.
   */
    /* JSAMPLEs per row in output buffer */
    row_stride = cinfo.output_width * cinfo.output_components;
    /* Make a one-row-high sample array that will go away when done with image */
    buffer = (*cinfo.mem->alloc_sarray)
            ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);

    /* Step 6: while (scan lines remain to be read) */
    /*           jpeg_read_scanlines(...); */

    /* Here we use the library's state variable cinfo.output_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   */
//    while (cinfo.output_scanline < cinfo.output_height)
    image_buffer.resize(cinfo.output_height);
    for (size_t ih=0; ih<cinfo.output_height; ++ih)
    {
        /* jpeg_read_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could ask for
     * more than one scanline at a time if that's more convenient.
     */
        (void) jpeg_read_scanlines(&cinfo, buffer, 1);
        /* Assume put_scanline_someplace wants a pointer and sample count. */
        //put_scanline_someplace(buffer[0], row_stride);
        image_buffer[ih].resize(cinfo.output_width * cinfo.output_components);
        memcpy((void *)image_buffer[ih].data(), (const void *)buffer[0], row_stride);
    }

    /* Step 7: Finish decompression */

    (void) jpeg_finish_decompress(&cinfo);
    /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

    /* Step 8: Release JPEG decompression object */

    /* This is an important step since it will release a good deal of memory. */
    jpeg_destroy_decompress(&cinfo);

    /* After finish_decompress, we can close the input file.
   * Here we postpone it until after no more JPEG errors are possible,
   * so as to simplify the setjmp error logic above.  (Actually, I don't
   * think that jpeg_destroy can do an error exit, but why assume anything...)
   */
    fclose(infile);

    /* At this point you may want to check to see whether any corrupt-data
   * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
   */

    /* And we're done! */
    return 1;
}

int read_JPEG_file	(	const char *	filename,
		JSAMPLE *	image_buffer
	)

{
    FILE *infile;
/* This struct contains the JPEG decompression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   */
    struct jpeg_decompress_struct cinfo;
    /* We use our private extension JPEG error handler.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
    struct my_error_mgr jerr;
    /* More stuff */
    JSAMPARRAY buffer;      /* Output row buffer */
    int row_stride;     /* physical row width in output buffer */

    /* In this example we want to open the input file before doing anything else,
     * so that the setjmp() error recovery below can assume the file is open.
     * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
     * requires it in order to read binary files.
     */

    if ((infile = fopen(filename, "rb")) == NULL) {
        fprintf(stderr, "can't open %s\n", filename);
        return 0;
    }

    /* Step 1: allocate and initialize JPEG decompression object */

    /* We set up the normal JPEG error routines, then override error_exit. */
    cinfo.err = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer))
    {
        /* If we get here, the JPEG code has signaled an error.
     * We need to clean up the JPEG object, close the input file, and return.
     */
        jpeg_destroy_decompress(&cinfo);
        fclose(infile);
        return 0;
    }
    /* Now we can initialize the JPEG decompression object. */
    jpeg_create_decompress(&cinfo);

    /* Step 2: specify data source (eg, a file) */

    jpeg_stdio_src(&cinfo, infile);

    /* Step 3: read file parameters with jpeg_read_header() */

    (void) jpeg_read_header(&cinfo, TRUE);
    /* We can ignore the return value from jpeg_read_header since
   *   (a) suspension is not possible with the stdio data source, and
   *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
   * See libjpeg.doc for more info.
   */

    /* Step 4: set parameters for decompression */

    /* In this example, we don't need to change any of the defaults set by
   * jpeg_read_header(), so we do nothing here.
   */

    /* Step 5: Start decompressor */

    (void) jpeg_start_decompress(&cinfo);
    /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

    /* We may need to do some setup of our own at this point before reading
   * the data.  After jpeg_start_decompress() we have the correct scaled
   * output image dimensions available, as well as the output colormap
   * if we asked for color quantization.
   * In this example, we need to make an output work buffer of the right size.
   */
    /* JSAMPLEs per row in output buffer */
    row_stride = cinfo.output_width * cinfo.output_components;
    /* Make a one-row-high sample array that will go away when done with image */
    buffer = (*cinfo.mem->alloc_sarray)
            ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);

    /* Step 6: while (scan lines remain to be read) */
    /*           jpeg_read_scanlines(...); */

    /* Here we use the library's state variable cinfo.output_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   */
    while (cinfo.output_scanline < cinfo.output_height) {
        /* jpeg_read_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could ask for
     * more than one scanline at a time if that's more convenient.
     */
        (void) jpeg_read_scanlines(&cinfo, buffer, 1);
        /* Assume put_scanline_someplace wants a pointer and sample count. */
        //put_scanline_someplace(buffer[0], row_stride);
        memcpy((void *)image_buffer, (const void *)buffer[0], row_stride);
        image_buffer += row_stride;
    }

    /* Step 7: Finish decompression */

    (void) jpeg_finish_decompress(&cinfo);
    /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

    /* Step 8: Release JPEG decompression object */

    /* This is an important step since it will release a good deal of memory. */
    jpeg_destroy_decompress(&cinfo);

    /* After finish_decompress, we can close the input file.
   * Here we postpone it until after no more JPEG errors are possible,
   * so as to simplify the setjmp error logic above.  (Actually, I don't
   * think that jpeg_destroy can do an error exit, but why assume anything...)
   */
    fclose(infile);

    /* At this point you may want to check to see whether any corrupt-data
   * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
   */

    /* And we're done! */
    return 1;
}

void write_JPEG_file	(	const char *	filename,
		int	quality,
		J_COLOR_SPACE	in_color_space,
		int	image_width,
		int	image_height,
		JSAMPLE *	image_buffer
	)