jpegint.h

基于Linux的ffmepg decoder

/*
 * 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 */
} J_BUF_MODE;

/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
#define CSTATE_START	100	/* after create_compress */
#define CSTATE_SCANNING	101	/* start_compress done, write_scanlines OK */
#define CSTATE_RAW_OK	102	/* start_compress done, write_raw_data OK */
#define CSTATE_WRCOEFS	103	/* jpeg_write_coefficients done */
#define DSTATE_START	200	/* after create_decompress */
#define DSTATE_INHEADER	201	/* reading header markers, no SOS yet */
#define DSTATE_READY	202	/* found SOS, ready for start_decompress */
#define DSTATE_PRELOAD	203	/* reading multiscan file in start_decompress*/
#define DSTATE_PRESCAN	204	/* performing dummy pass for 2-pass quant */
#define DSTATE_SCANNING	205	/* start_decompress done, read_scanlines OK */
#define DSTATE_RAW_OK	206	/* start_decompress done, read_raw_data OK */
#define DSTATE_BUFIMAGE	207	/* expecting jpeg_start_output */
#define DSTATE_BUFPOST	208	/* looking for SOS/EOI in jpeg_finish_output */
#define DSTATE_RDCOEFS	209	/* reading file in jpeg_read_coefficients */
#define DSTATE_STOPPING	210	/* looking for EOI in jpeg_finish_decompress */


/* Declarations for compression modules */

/* Master control module */
struct jpeg_comp_master {
  JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
  JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));

  /* State variables made visible to other modules */
  boolean call_pass_startup;	/* True if pass_startup must be called */
  boolean is_last_pass;		/* True during last pass */
};

/* Main buffer control (downsampled-data buffer) */
struct jpeg_c_main_controller {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
//  JMETHOD(void, process_data, (j_compress_ptr cinfo,
//			       JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
//			       JDIMENSION in_rows_avail ));
};

/* Compression preprocessing (downsampling input buffer control) */
struct jpeg_c_prep_controller {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
/*  JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
				   JSAMPARRAY input_buf,
				   JDIMENSION *in_row_ctr,
				   JDIMENSION in_rows_avail,
				   JSAMPIMAGE output_buf,
				   JDIMENSION *out_row_group_ctr,
				   JDIMENSION out_row_groups_avail));
*/
};

/* Coefficient buffer control */
struct jpeg_c_coef_controller {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
//  JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
//				   JSAMPIMAGE input_buf));
};


/* Entropy encoding */
struct jpeg_entropy_encoder {
  JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
  //JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
};

/* Marker writing */
struct jpeg_marker_writer {
  JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
};



/* Miscellaneous useful macros */

#undef MAX
#define MAX(a,b)	((a) > (b) ? (a) : (b))
#undef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))


/* We assume that right shift corresponds to signed division by 2 with
 * rounding towards minus infinity.  This is correct for typical "arithmetic
 * shift" instructions that shift in copies of the sign bit.  But some
 * C compilers implement >> with an unsigned shift.  For these machines you
 * must define RIGHT_SHIFT_IS_UNSIGNED.
 * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
 * It is only applied with constant shift counts.  SHIFT_TEMPS must be
 * included in the variables of any routine using RIGHT_SHIFT.
 */

#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define SHIFT_TEMPS	INT32 shift_temp;
#define RIGHT_SHIFT(x,shft)  \
	((shift_temp = (x)) < 0 ? \
	 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
	 (shift_temp >> (shft)))
#else
#define SHIFT_TEMPS
#define RIGHT_SHIFT(x,shft)	((x) >> (shft))
#endif


/* Short forms of external names for systems with brain-damaged linkers. */

#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jinit_compress_master	jICompress
#define jinit_c_master_control	jICMaster
#define jinit_c_main_controller	jICMainC
#define jinit_c_prep_controller	jICPrepC
#define jinit_c_coef_controller	jICCoefC
#define jinit_color_converter	jICColor
#define jinit_downsampler	jIDownsampler
//#define jinit_forward_dct	jIFDCT
#define jinit_huff_encoder	jIHEncoder
//#define jinit_phuff_encoder	jIPHEncoder
#define jinit_marker_writer	jIMWriter
#define jinit_master_decompress	jIDMaster
#define jinit_d_main_controller	jIDMainC
#define jinit_d_coef_controller	jIDCoefC
#define jinit_d_post_controller	jIDPostC
#define jinit_input_controller	jIInCtlr
#define jinit_marker_reader	jIMReader
#define jinit_huff_decoder	jIHDecoder
#define jinit_phuff_decoder	jIPHDecoder
#define jinit_inverse_dct	jIIDCT
#define jinit_upsampler		jIUpsampler
#define jinit_color_deconverter	jIDColor
#define jinit_1pass_quantizer	jI1Quant
#define jinit_2pass_quantizer	jI2Quant
#define jinit_merged_upsampler	jIMUpsampler
#define jinit_memory_mgr	jIMemMgr
#define jdiv_round_up		jDivRound
#define jround_up		jRound
#define jcopy_sample_rows	jCopySamples
#define jcopy_block_row		jCopyBlocks
#define jzero_far		jZeroFar
#define jpeg_zigzag_order	jZIGTable
#define jpeg_natural_order	jZAGTable
#endif /* NEED_SHORT_EXTERNAL_NAMES */


/* Compression module initialization routines */
EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
					 boolean transcode_only));
EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
					  boolean need_full_buffer));

EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
					  boolean need_full_buffer));
EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));

EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));

/* Utility routines in jutils.c */
EXTERN(long) jdiv_round_up JPP((long a, long b));
EXTERN(long) jround_up JPP((long a, long b));

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

/* Suppress undefined-structure complaints if necessary. */

#ifdef INCOMPLETE_TYPES_BROKEN
#ifndef AM_MEMORY_MANAGER	/* only jmemmgr.c defines these */
struct jvirt_sarray_control { long dummy; };
struct jvirt_barray_control { long dummy; };
#endif
#endif /* INCOMPLETE_TYPES_BROKEN */