ref: b818f48f41895754dd9b470be407ba85cfea45bd
dir: /sys/src/cmd/gs/jpeg/jcapimin.c/
/*
* 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--) {
(*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().
*/
}