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/*
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 * jcapimin.c
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 *
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 * Copyright (C) 1994-1998, Thomas G. Lane.
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 * This file is part of the Independent JPEG Group's software.
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 * For conditions of distribution and use, see the accompanying README file.
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 *
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 * This file contains application interface code for the compression half
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 * of the JPEG library.  These are the "minimum" API routines that may be
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 * needed in either the normal full-compression case or the transcoding-only
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 * case.
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 *
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 * Most of the routines intended to be called directly by an application
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 * are in this file or in jcapistd.c.  But also see jcparam.c for
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 * parameter-setup helper routines, jcomapi.c for routines shared by
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 * compression and decompression, and jctrans.c for the transcoding case.
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 */
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#define JPEG_INTERNALS
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#include "jinclude.h"
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#include "jpeglib.h"
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/*
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 * Initialization of a JPEG compression object.
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 * The error manager must already be set up (in case memory manager fails).
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 */
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GLOBAL(void)
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jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
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{
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  int i;
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  /* Guard against version mismatches between library and caller. */
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  cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */
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  if (version != JPEG_LIB_VERSION)
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    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
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  if (structsize != SIZEOF(struct jpeg_compress_struct))
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    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, 
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	     (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
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  /* For debugging purposes, we zero the whole master structure.
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   * But the application has already set the err pointer, and may have set
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   * client_data, so we have to save and restore those fields.
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   * Note: if application hasn't set client_data, tools like Purify may
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   * complain here.
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   */
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  {
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    struct jpeg_error_mgr * err = cinfo->err;
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    void * client_data = cinfo->client_data; /* ignore Purify complaint here */
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    MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
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    cinfo->err = err;
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    cinfo->client_data = client_data;
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  }
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  cinfo->is_decompressor = FALSE;
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  /* Initialize a memory manager instance for this object */
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  jinit_memory_mgr((j_common_ptr) cinfo);
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  /* Zero out pointers to permanent structures. */
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  cinfo->progress = NULL;
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  cinfo->dest = NULL;
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  cinfo->comp_info = NULL;
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  for (i = 0; i < NUM_QUANT_TBLS; i++)
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    cinfo->quant_tbl_ptrs[i] = NULL;
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  for (i = 0; i < NUM_HUFF_TBLS; i++) {
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    cinfo->dc_huff_tbl_ptrs[i] = NULL;
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    cinfo->ac_huff_tbl_ptrs[i] = NULL;
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  }
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  cinfo->script_space = NULL;
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  cinfo->input_gamma = 1.0;	/* in case application forgets */
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  /* OK, I'm ready */
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  cinfo->global_state = CSTATE_START;
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}
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/*
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 * Destruction of a JPEG compression object
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 */
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GLOBAL(void)
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jpeg_destroy_compress (j_compress_ptr cinfo)
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{
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  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
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}
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/*
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 * Abort processing of a JPEG compression operation,
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 * but don't destroy the object itself.
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 */
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GLOBAL(void)
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jpeg_abort_compress (j_compress_ptr cinfo)
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{
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  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
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}
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/*
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 * Forcibly suppress or un-suppress all quantization and Huffman tables.
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 * Marks all currently defined tables as already written (if suppress)
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 * or not written (if !suppress).  This will control whether they get emitted
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 * by a subsequent jpeg_start_compress call.
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 *
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 * This routine is exported for use by applications that want to produce
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 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
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 * since it is called by jpeg_start_compress, we put it here --- otherwise
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 * jcparam.o would be linked whether the application used it or not.
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 */
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GLOBAL(void)
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jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
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{
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  int i;
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  JQUANT_TBL * qtbl;
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  JHUFF_TBL * htbl;
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  for (i = 0; i < NUM_QUANT_TBLS; i++) {
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    if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
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      qtbl->sent_table = suppress;
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  }
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  for (i = 0; i < NUM_HUFF_TBLS; i++) {
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    if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
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      htbl->sent_table = suppress;
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    if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
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      htbl->sent_table = suppress;
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  }
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}
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/*
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 * Finish JPEG compression.
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 *
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 * If a multipass operating mode was selected, this may do a great deal of
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 * work including most of the actual output.
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 */
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GLOBAL(void)
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jpeg_finish_compress (j_compress_ptr cinfo)
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{
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  JDIMENSION iMCU_row;
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  if (cinfo->global_state == CSTATE_SCANNING ||
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      cinfo->global_state == CSTATE_RAW_OK) {
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    /* Terminate first pass */
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    if (cinfo->next_scanline < cinfo->image_height)
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      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
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    (*cinfo->master->finish_pass) (cinfo);
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  } else if (cinfo->global_state != CSTATE_WRCOEFS)
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    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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  /* Perform any remaining passes */
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  while (! cinfo->master->is_last_pass) {
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    (*cinfo->master->prepare_for_pass) (cinfo);
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    for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
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      if (cinfo->progress != NULL) {
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	cinfo->progress->pass_counter = (long) iMCU_row;
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	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
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	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
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      }
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      /* We bypass the main controller and invoke coef controller directly;
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       * all work is being done from the coefficient buffer.
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       */
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      if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
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	ERREXIT(cinfo, JERR_CANT_SUSPEND);
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    }
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    (*cinfo->master->finish_pass) (cinfo);
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  }
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  /* Write EOI, do final cleanup */
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  (*cinfo->marker->write_file_trailer) (cinfo);
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  (*cinfo->dest->term_destination) (cinfo);
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  /* We can use jpeg_abort to release memory and reset global_state */
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  jpeg_abort((j_common_ptr) cinfo);
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}
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/*
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 * Write a special marker.
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 * This is only recommended for writing COM or APPn markers.
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 * Must be called after jpeg_start_compress() and before
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 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
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 */
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GLOBAL(void)
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jpeg_write_marker (j_compress_ptr cinfo, int marker,
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		   const JOCTET *dataptr, unsigned int datalen)
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{
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  JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
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  if (cinfo->next_scanline != 0 ||
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      (cinfo->global_state != CSTATE_SCANNING &&
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       cinfo->global_state != CSTATE_RAW_OK &&
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       cinfo->global_state != CSTATE_WRCOEFS))
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    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
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  write_marker_byte = cinfo->marker->write_marker_byte;	/* copy for speed */
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  while (datalen--) {
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    (*write_marker_byte) (cinfo, *dataptr);
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    dataptr++;
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  }
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}
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/* Same, but piecemeal. */
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GLOBAL(void)
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jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
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{
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  if (cinfo->next_scanline != 0 ||
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      (cinfo->global_state != CSTATE_SCANNING &&
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       cinfo->global_state != CSTATE_RAW_OK &&
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       cinfo->global_state != CSTATE_WRCOEFS))
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    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
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}
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GLOBAL(void)
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jpeg_write_m_byte (j_compress_ptr cinfo, int val)
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{
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  (*cinfo->marker->write_marker_byte) (cinfo, val);
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}
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/*
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 * Alternate compression function: just write an abbreviated table file.
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 * Before calling this, all parameters and a data destination must be set up.
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 *
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 * To produce a pair of files containing abbreviated tables and abbreviated
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 * image data, one would proceed as follows:
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 *
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 *		initialize JPEG object
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 *		set JPEG parameters
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 *		set destination to table file
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 *		jpeg_write_tables(cinfo);
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 *		set destination to image file
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 *		jpeg_start_compress(cinfo, FALSE);
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 *		write data...
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 *		jpeg_finish_compress(cinfo);
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 *
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 * jpeg_write_tables has the side effect of marking all tables written
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 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
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 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
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 */
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GLOBAL(void)
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jpeg_write_tables (j_compress_ptr cinfo)
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{
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  if (cinfo->global_state != CSTATE_START)
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    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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  /* (Re)initialize error mgr and destination modules */
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  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
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  (*cinfo->dest->init_destination) (cinfo);
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  /* Initialize the marker writer ... bit of a crock to do it here. */
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  jinit_marker_writer(cinfo);
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  /* Write them tables! */
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  (*cinfo->marker->write_tables_only) (cinfo);
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  /* And clean up. */
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  (*cinfo->dest->term_destination) (cinfo);
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  /*
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   * In library releases up through v6a, we called jpeg_abort() here to free
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   * any working memory allocated by the destination manager and marker
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   * writer.  Some applications had a problem with that: they allocated space
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   * of their own from the library memory manager, and didn't want it to go
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   * away during write_tables.  So now we do nothing.  This will cause a
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   * memory leak if an app calls write_tables repeatedly without doing a full
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   * compression cycle or otherwise resetting the JPEG object.  However, that
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   * seems less bad than unexpectedly freeing memory in the normal case.
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   * An app that prefers the old behavior can call jpeg_abort for itself after
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   * each call to jpeg_write_tables().
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   */
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}
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