michael@0: /*
michael@0:  * jcapimin.c
michael@0:  *
michael@0:  * Copyright (C) 1994-1998, Thomas G. Lane.
michael@0:  * Modified 2003-2010 by Guido Vollbeding.
michael@0:  * This file is part of the Independent JPEG Group's software.
michael@0:  * For conditions of distribution and use, see the accompanying README file.
michael@0:  *
michael@0:  * This file contains application interface code for the compression half
michael@0:  * of the JPEG library.  These are the "minimum" API routines that may be
michael@0:  * needed in either the normal full-compression case or the transcoding-only
michael@0:  * case.
michael@0:  *
michael@0:  * Most of the routines intended to be called directly by an application
michael@0:  * are in this file or in jcapistd.c.  But also see jcparam.c for
michael@0:  * parameter-setup helper routines, jcomapi.c for routines shared by
michael@0:  * compression and decompression, and jctrans.c for the transcoding case.
michael@0:  */
michael@0: 
michael@0: #define JPEG_INTERNALS
michael@0: #include "jinclude.h"
michael@0: #include "jpeglib.h"
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Initialization of a JPEG compression object.
michael@0:  * The error manager must already be set up (in case memory manager fails).
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
michael@0: {
michael@0:   int i;
michael@0: 
michael@0:   /* Guard against version mismatches between library and caller. */
michael@0:   cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */
michael@0:   if (version != JPEG_LIB_VERSION)
michael@0:     ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
michael@0:   if (structsize != SIZEOF(struct jpeg_compress_struct))
michael@0:     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, 
michael@0: 	     (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
michael@0: 
michael@0:   /* For debugging purposes, we zero the whole master structure.
michael@0:    * But the application has already set the err pointer, and may have set
michael@0:    * client_data, so we have to save and restore those fields.
michael@0:    * Note: if application hasn't set client_data, tools like Purify may
michael@0:    * complain here.
michael@0:    */
michael@0:   {
michael@0:     struct jpeg_error_mgr * err = cinfo->err;
michael@0:     void * client_data = cinfo->client_data; /* ignore Purify complaint here */
michael@0:     MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
michael@0:     cinfo->err = err;
michael@0:     cinfo->client_data = client_data;
michael@0:   }
michael@0:   cinfo->is_decompressor = FALSE;
michael@0: 
michael@0:   /* Initialize a memory manager instance for this object */
michael@0:   jinit_memory_mgr((j_common_ptr) cinfo);
michael@0: 
michael@0:   /* Zero out pointers to permanent structures. */
michael@0:   cinfo->progress = NULL;
michael@0:   cinfo->dest = NULL;
michael@0: 
michael@0:   cinfo->comp_info = NULL;
michael@0: 
michael@0:   for (i = 0; i < NUM_QUANT_TBLS; i++) {
michael@0:     cinfo->quant_tbl_ptrs[i] = NULL;
michael@0: #if JPEG_LIB_VERSION >= 70
michael@0:     cinfo->q_scale_factor[i] = 100;
michael@0: #endif
michael@0:   }
michael@0: 
michael@0:   for (i = 0; i < NUM_HUFF_TBLS; i++) {
michael@0:     cinfo->dc_huff_tbl_ptrs[i] = NULL;
michael@0:     cinfo->ac_huff_tbl_ptrs[i] = NULL;
michael@0:   }
michael@0: 
michael@0: #if JPEG_LIB_VERSION >= 80
michael@0:   /* Must do it here for emit_dqt in case jpeg_write_tables is used */
michael@0:   cinfo->block_size = DCTSIZE;
michael@0:   cinfo->natural_order = jpeg_natural_order;
michael@0:   cinfo->lim_Se = DCTSIZE2-1;
michael@0: #endif
michael@0: 
michael@0:   cinfo->script_space = NULL;
michael@0: 
michael@0:   cinfo->input_gamma = 1.0;	/* in case application forgets */
michael@0: 
michael@0:   /* OK, I'm ready */
michael@0:   cinfo->global_state = CSTATE_START;
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Destruction of a JPEG compression object
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_destroy_compress (j_compress_ptr cinfo)
michael@0: {
michael@0:   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Abort processing of a JPEG compression operation,
michael@0:  * but don't destroy the object itself.
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_abort_compress (j_compress_ptr cinfo)
michael@0: {
michael@0:   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Forcibly suppress or un-suppress all quantization and Huffman tables.
michael@0:  * Marks all currently defined tables as already written (if suppress)
michael@0:  * or not written (if !suppress).  This will control whether they get emitted
michael@0:  * by a subsequent jpeg_start_compress call.
michael@0:  *
michael@0:  * This routine is exported for use by applications that want to produce
michael@0:  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
michael@0:  * since it is called by jpeg_start_compress, we put it here --- otherwise
michael@0:  * jcparam.o would be linked whether the application used it or not.
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
michael@0: {
michael@0:   int i;
michael@0:   JQUANT_TBL * qtbl;
michael@0:   JHUFF_TBL * htbl;
michael@0: 
michael@0:   for (i = 0; i < NUM_QUANT_TBLS; i++) {
michael@0:     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
michael@0:       qtbl->sent_table = suppress;
michael@0:   }
michael@0: 
michael@0:   for (i = 0; i < NUM_HUFF_TBLS; i++) {
michael@0:     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
michael@0:       htbl->sent_table = suppress;
michael@0:     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
michael@0:       htbl->sent_table = suppress;
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Finish JPEG compression.
michael@0:  *
michael@0:  * If a multipass operating mode was selected, this may do a great deal of
michael@0:  * work including most of the actual output.
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_finish_compress (j_compress_ptr cinfo)
michael@0: {
michael@0:   JDIMENSION iMCU_row;
michael@0: 
michael@0:   if (cinfo->global_state == CSTATE_SCANNING ||
michael@0:       cinfo->global_state == CSTATE_RAW_OK) {
michael@0:     /* Terminate first pass */
michael@0:     if (cinfo->next_scanline < cinfo->image_height)
michael@0:       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
michael@0:     (*cinfo->master->finish_pass) (cinfo);
michael@0:   } else if (cinfo->global_state != CSTATE_WRCOEFS)
michael@0:     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
michael@0:   /* Perform any remaining passes */
michael@0:   while (! cinfo->master->is_last_pass) {
michael@0:     (*cinfo->master->prepare_for_pass) (cinfo);
michael@0:     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
michael@0:       if (cinfo->progress != NULL) {
michael@0: 	cinfo->progress->pass_counter = (long) iMCU_row;
michael@0: 	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
michael@0: 	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
michael@0:       }
michael@0:       /* We bypass the main controller and invoke coef controller directly;
michael@0:        * all work is being done from the coefficient buffer.
michael@0:        */
michael@0:       if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
michael@0: 	ERREXIT(cinfo, JERR_CANT_SUSPEND);
michael@0:     }
michael@0:     (*cinfo->master->finish_pass) (cinfo);
michael@0:   }
michael@0:   /* Write EOI, do final cleanup */
michael@0:   (*cinfo->marker->write_file_trailer) (cinfo);
michael@0:   (*cinfo->dest->term_destination) (cinfo);
michael@0:   /* We can use jpeg_abort to release memory and reset global_state */
michael@0:   jpeg_abort((j_common_ptr) cinfo);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Write a special marker.
michael@0:  * This is only recommended for writing COM or APPn markers.
michael@0:  * Must be called after jpeg_start_compress() and before
michael@0:  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_write_marker (j_compress_ptr cinfo, int marker,
michael@0: 		   const JOCTET *dataptr, unsigned int datalen)
michael@0: {
michael@0:   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
michael@0: 
michael@0:   if (cinfo->next_scanline != 0 ||
michael@0:       (cinfo->global_state != CSTATE_SCANNING &&
michael@0:        cinfo->global_state != CSTATE_RAW_OK &&
michael@0:        cinfo->global_state != CSTATE_WRCOEFS))
michael@0:     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
michael@0: 
michael@0:   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
michael@0:   write_marker_byte = cinfo->marker->write_marker_byte;	/* copy for speed */
michael@0:   while (datalen--) {
michael@0:     (*write_marker_byte) (cinfo, *dataptr);
michael@0:     dataptr++;
michael@0:   }
michael@0: }
michael@0: 
michael@0: /* Same, but piecemeal. */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
michael@0: {
michael@0:   if (cinfo->next_scanline != 0 ||
michael@0:       (cinfo->global_state != CSTATE_SCANNING &&
michael@0:        cinfo->global_state != CSTATE_RAW_OK &&
michael@0:        cinfo->global_state != CSTATE_WRCOEFS))
michael@0:     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
michael@0: 
michael@0:   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
michael@0: }
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_write_m_byte (j_compress_ptr cinfo, int val)
michael@0: {
michael@0:   (*cinfo->marker->write_marker_byte) (cinfo, val);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Alternate compression function: just write an abbreviated table file.
michael@0:  * Before calling this, all parameters and a data destination must be set up.
michael@0:  *
michael@0:  * To produce a pair of files containing abbreviated tables and abbreviated
michael@0:  * image data, one would proceed as follows:
michael@0:  *
michael@0:  *		initialize JPEG object
michael@0:  *		set JPEG parameters
michael@0:  *		set destination to table file
michael@0:  *		jpeg_write_tables(cinfo);
michael@0:  *		set destination to image file
michael@0:  *		jpeg_start_compress(cinfo, FALSE);
michael@0:  *		write data...
michael@0:  *		jpeg_finish_compress(cinfo);
michael@0:  *
michael@0:  * jpeg_write_tables has the side effect of marking all tables written
michael@0:  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
michael@0:  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
michael@0:  */
michael@0: 
michael@0: GLOBAL(void)
michael@0: jpeg_write_tables (j_compress_ptr cinfo)
michael@0: {
michael@0:   if (cinfo->global_state != CSTATE_START)
michael@0:     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
michael@0: 
michael@0:   /* (Re)initialize error mgr and destination modules */
michael@0:   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
michael@0:   (*cinfo->dest->init_destination) (cinfo);
michael@0:   /* Initialize the marker writer ... bit of a crock to do it here. */
michael@0:   jinit_marker_writer(cinfo);
michael@0:   /* Write them tables! */
michael@0:   (*cinfo->marker->write_tables_only) (cinfo);
michael@0:   /* And clean up. */
michael@0:   (*cinfo->dest->term_destination) (cinfo);
michael@0:   /*
michael@0:    * In library releases up through v6a, we called jpeg_abort() here to free
michael@0:    * any working memory allocated by the destination manager and marker
michael@0:    * writer.  Some applications had a problem with that: they allocated space
michael@0:    * of their own from the library memory manager, and didn't want it to go
michael@0:    * away during write_tables.  So now we do nothing.  This will cause a
michael@0:    * memory leak if an app calls write_tables repeatedly without doing a full
michael@0:    * compression cycle or otherwise resetting the JPEG object.  However, that
michael@0:    * seems less bad than unexpectedly freeing memory in the normal case.
michael@0:    * An app that prefers the old behavior can call jpeg_abort for itself after
michael@0:    * each call to jpeg_write_tables().
michael@0:    */
michael@0: }