jpeglib.h

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	virtual void output_message(void);
  
	// Format a message string for the most recent JPEG error or message
	virtual void format_message(char * buffer);

	// Reset error state variables at start of a new image
	virtual void reset_error_mgr(void);

#define JMSG_LENGTH_MAX  200	/* recommended size of format_message buffer */
  
  /* The message ID code and any parameters are saved here.
   * A message can have one string parameter or up to 8 int parameters.
   */
  int msg_code;
#define JMSG_STR_PARM_MAX  80
  union {
    int i[8];
    char s[JMSG_STR_PARM_MAX];
  } msg_parm;
  
  /* Standard state variables for error facility */
  int trace_level;		/* max msg_level that will be displayed */

private:
  
  /* For recoverable corrupt-data errors, we emit a warning message,
   * but keep going unless emit_message chooses to abort.  emit_message
   * should count warnings in num_warnings.  The surrounding application
   * can check for bad data by seeing if num_warnings is nonzero at the
   * end of processing.
   */
  long num_warnings;		/* number of corrupt-data warnings */

  /* These fields point to the table(s) of error message strings.
   * An application can change the table pointer to switch to a different
   * message list (typically, to change the language in which errors are
   * reported).  Some applications may wish to add additional error codes
   * that will be handled by the JPEG library error mechanism; the second
   * table pointer is used for this purpose.
   *
   * First table includes all errors generated by JPEG library itself.
   * Error code 0 is reserved for a "no such error string" message.
   */
  const char * const * jpeg_message_table; /* Library errors */
  int last_jpeg_message;    /* Table contains strings 0..last_jpeg_message */
  /* Second table can be added by application (see cjpeg/djpeg for example).
   * It contains strings numbered first_addon_message..last_addon_message.
   */
  const char * const * addon_message_table; /* Non-library errors */
  int first_addon_message;	/* code for first string in addon table */
  int last_addon_message;	/* code for last string in addon table */
};


/* Progress monitor object */

struct jpeg_progress_mgr {
  JMETHOD(void, progress_monitor, (j_common_ptr cinfo));

  long pass_counter;		/* work units completed in this pass */
  long pass_limit;		/* total number of work units in this pass */
  int completed_passes;		/* passes completed so far */
  int total_passes;		/* total number of passes expected */
};


/* Data destination object for compression */

struct jpeg_destination_mgr {
  JOCTET * next_output_byte;	/* => next byte to write in buffer */
  size_t free_in_buffer;	/* # of byte spaces remaining in buffer */

  JMETHOD(void, init_destination, (j_compress_ptr cinfo));
  JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
  JMETHOD(void, term_destination, (j_compress_ptr cinfo));
};


// Generic Data source object for decompression 
class jpeg_source_mgr 
{
public:
	const JOCTET * next_input_byte; /* => next byte to read from buffer */
	size_t bytes_in_buffer;	/* # of bytes remaining in buffer */

	virtual void     init_source(j_decompress_ptr cinfo);
	virtual boolean  fill_input_buffer(j_decompress_ptr cinfo);
	virtual void     skip_input_data(j_decompress_ptr cinfo, long num_bytes);
	virtual boolean  resync_to_restart(j_decompress_ptr cinfo, int desired);
	virtual void     term_source(j_decompress_ptr cinfo);
};


/* Memory manager object.
 * Allocates "small" objects (a few K total), "large" objects (tens of K),
 * and "really big" objects (virtual arrays with backing store if needed).
 * The memory manager does not allow individual objects to be freed; rather,
 * each created object is assigned to a pool, and whole pools can be freed
 * at once.  This is faster and more convenient than remembering exactly what
 * to free, especially where malloc()/free() are not too speedy.
 * NB: alloc routines never return NULL.  They exit to error_exit if not
 * successful.
 */

#define JPOOL_PERMANENT	0	/* lasts until master record is destroyed */
#define JPOOL_IMAGE	1	/* lasts until done with image/datastream */
#define JPOOL_NUMPOOLS	2

typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
typedef struct jvirt_barray_control * jvirt_barray_ptr;


class jpeg_memory_mgr 
{
  /* Method pointers */
public:
	virtual ~jpeg_memory_mgr()
	{
	}

	virtual void * alloc_small(int pool_id, size_t sizeofobject) = 0;

	virtual void * alloc_large(int pool_id, size_t sizeofobject) = 0;

	virtual JSAMPARRAY alloc_sarray(int pool_id, JDIMENSION samplesperrow, JDIMENSION numrows) = 0;
  
	virtual JBLOCKARRAY alloc_barray(int pool_id, JDIMENSION blocksperrow, JDIMENSION numrows) = 0;
  
	virtual jvirt_sarray_ptr request_virt_sarray(
						  int pool_id,
						  boolean pre_zero,
						  JDIMENSION samplesperrow,
						  JDIMENSION numrows,
						  JDIMENSION maxaccess) = 0;
  
	virtual jvirt_barray_ptr request_virt_barray(
						  int pool_id,
						  boolean pre_zero,
						  JDIMENSION blocksperrow,
						  JDIMENSION numrows,
						  JDIMENSION maxaccess) = 0;
  
	virtual void realize_virt_arrays(void) = 0;
  
	virtual JSAMPARRAY access_virt_sarray(
					   jvirt_sarray_ptr ptr,
					   JDIMENSION start_row,
					   JDIMENSION num_rows,
					   boolean writable) = 0;
  
	virtual JBLOCKARRAY access_virt_barray(
					    jvirt_barray_ptr ptr,
					    JDIMENSION start_row,
					    JDIMENSION num_rows,
					    boolean writable) = 0;
  
	virtual void free_pool(int pool_id) = 0;

	/* Limit on memory allocation for this JPEG object.  (Note that this is
	* merely advisory, not a guaranteed maximum; it only affects the space
	* used for virtual-array buffers.)  May be changed by outer application
	* after creating the JPEG object.
	*/
	long max_memory_to_use;

	/* Maximum allocation request accepted by alloc_large. */
	long max_alloc_chunk;
};


/* Routine signature for application-supplied marker processing methods.
 * Need not pass marker code since it is stored in cinfo->unread_marker.
 */
typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));

/* Short forms of external names for systems with brain-damaged linkers.
 * We shorten external names to be unique in the first six letters, which
 * is good enough for all known systems.
 * (If your compiler itself needs names to be unique in less than 15 
 * characters, you are out of luck.  Get a better compiler.)
 */

/* Initialization of JPEG compression objects.
 * jpeg_create_compress() and jpeg_create_decompress() are the exported
 * names that applications should call.  These expand to calls on
 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
 * passed for version mismatch checking.
 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
 */
#define jpeg_create_compress(cinfo) \
    jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
			(size_t) sizeof(jpeg_compress_struct))

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

/* Destruction of JPEG compression objects */
void jpeg_destroy_compress (j_compress_ptr cinfo);


/* Standard data source and destination managers: stdio streams. */
/* Caller is responsible for opening the file before and closing after. */
void jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile);
void jpeg_stdio_src  (j_decompress_ptr cinfo, FILE * infile);
void jpeg_const_src  (j_decompress_ptr cinfo, const unsigned char * buffer, int len);

/* Default parameter setup for compression */
void jpeg_set_defaults (j_compress_ptr cinfo);
/* Compression parameter setup aids */
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);

/* Main entry points for compression */
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);

/* Replaces jpeg_write_scanlines when writing raw downsampled data. */
JDIMENSION jpeg_write_raw_data (j_compress_ptr cinfo,
					    JSAMPIMAGE data,
					    JDIMENSION num_lines);

/* Write a special marker.  See libjpeg.doc concerning safe usage. */
void jpeg_write_marker
	(j_compress_ptr cinfo, int marker,
	     const JOCTET * dataptr, unsigned int datalen);
/* Same, but piecemeal. */
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);

/* Alternate compression function: just write an abbreviated table file */
void jpeg_write_tables (j_compress_ptr cinfo);

/* Decompression startup: read start of JPEG datastream to see what's there */

/* Return value is one of: */
#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 */
/* If you pass require_image = TRUE (normal case), you need not check for
 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
 * JPEG_SUSPENDED is only possible if you use a data source module that can
 * give a suspension return (the stdio source module doesn't).
 */

/* Main entry points for decompression */

/* Replaces jpeg_read_scanlines when reading raw downsampled data. */
JDIMENSION jpeg_read_raw_data (j_decompress_ptr cinfo,
					   JSAMPIMAGE data,
					   JDIMENSION max_lines);

/* Additional entry points for buffered-image mode. */

boolean jpeg_start_output (j_decompress_ptr cinfo,
				       int scan_number);
boolean jpeg_finish_output (j_decompress_ptr cinfo);

void jpeg_new_colormap (j_decompress_ptr cinfo);

/* Return value is one of: */
/* #define JPEG_SUSPENDED	0    Suspended due to lack of input data */
#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 */

/* Precalculate output dimensions for current decompression parameters. */
void jpeg_calc_output_dimensions (j_decompress_ptr cinfo);

/* Control saving of COM and APPn markers into marker_list. */
void jpeg_save_markers
	(j_decompress_ptr cinfo, int marker_code,
	     unsigned int length_limit);

/* Install a special processing method for COM or APPn markers. */
void jpeg_set_marker_processor
	(j_decompress_ptr cinfo, int marker_code,
	     jpeg_marker_parser_method routine);

/* Read or write raw DCT coefficients --- useful for lossless transcoding. */
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);

/* If you choose to abort compression or decompression before completing
 * jpeg_finish_(de)compress, then you need to clean up to release memory,
 * temporary files, etc.  You can just call jpeg_destroy_(de)compress
 * if you're done with the JPEG object, but if you want to clean it up and
 * reuse it, call this:
 */
void jpeg_abort_compress (j_compress_ptr cinfo);

/* Generic versions of jpeg_abort and jpeg_destroy that work on either
 * flavor of JPEG object.  These may be more convenient in some places.
 */
void jpeg_abort (j_common_ptr cinfo);

/* Default restart-marker-resync procedure for use by data source modules */
boolean jpeg_resync_to_restart (j_decompress_ptr cinfo,
					    int desired);


/* These marker codes are exported since applications and data source modules
 * are likely to want to use them.
 */

#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 */



/*
 * The JPEG library modules define JPEG_INTERNALS before including this file.
 * The internal structure declarations are read only when that is true.
 * Applications using the library should not include jpegint.h, but may wish
 * to include jerror.h.
 */

#ifdef JPEG_INTERNALS
#include "jpegint.h"		/* fetch private declarations */
#include "jerror.h"		/* fetch error codes too */
#endif

#endif /* JPEGLIB_H */