/*

 * jcapimin.c

 *

 * Copyright (C) 1994-1998, 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 contains application interface code for the compression half

 * of the JPEG library.  These are the "minimum" API routines that may be

 * needed in either the normal full-compression case or the transcoding-only

 * case.

 *

 * Most of the routines intended to be called directly by an application

 * are in this file or in jcapistd.c.  But also see jcparam.c for

 * parameter-setup helper routines, jcomapi.c for routines shared by

 * compression and decompression, and jctrans.c for the transcoding case.

 */

#define JPEG_INTERNALS

#include "jinclude.h"

#include "jpeglib.h"

/*

 * Initialization of a JPEG compression object.

 * The error manager must already be set up (in case memory manager fails).

 */

GLOBAL(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;

}

/*

 * Destruction of a JPEG compression object

 */

GLOBAL(void)

jpeg_destroy_compress (j_compress_ptr cinfo)

{

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

}

/*

 * Abort processing of a JPEG compression operation,

 * but don't destroy the object itself.

 */

GLOBAL(void)

jpeg_abort_compress (j_compress_ptr cinfo)

{

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

}

/*

 * Forcibly suppress or un-suppress all quantization and Huffman tables.

 * Marks all currently defined tables as already written (if suppress)

 * or not written (if !suppress).  This will control whether they get emitted

 * by a subsequent jpeg_start_compress call.

 *

 * This routine is exported for use by applications that want to produce

 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but

 * since it is called by jpeg_start_compress, we put it here --- otherwise

 * jcparam.o would be linked whether the application used it or not.

 */

GLOBAL(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;

  }

}

/*

 * Finish JPEG compression.

 *

 * If a multipass operating mode was selected, this may do a great deal of

 * work including most of the actual output.

 */

GLOBAL(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);

}

/*

 * Write a special marker.

 * This is only recommended for writing COM or APPn markers.

 * Must be called after jpeg_start_compress() and before

 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().

 */

GLOBAL(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) {

    datalen --;

    (*write_marker_byte) (cinfo, *dataptr);

    dataptr++;

  }

}

/* Same, but piecemeal. */

GLOBAL(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);

}

GLOBAL(void)

jpeg_write_m_byte (j_compress_ptr cinfo, int val)

{

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

}

/*

 * Alternate compression function: just write an abbreviated table file.

 * Before calling this, all parameters and a data destination must be set up.

 *

 * To produce a pair of files containing abbreviated tables and abbreviated

 * image data, one would proceed as follows:

 *

 *    initialize JPEG object

 *    set JPEG parameters

 *    set destination to table file

 *    jpeg_write_tables(cinfo);

 *    set destination to image file

 *    jpeg_start_compress(cinfo, FALSE);

 *    write data...

 *    jpeg_finish_compress(cinfo);

 *

 * jpeg_write_tables has the side effect of marking all tables written

 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress

 * will not re-emit the tables unless it is passed write_all_tables=TRUE.

 */

GLOBAL(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().

   */

}