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- /*
- * jdapimin.c
- *
- * This file was part of the Independent JPEG Group's software:
- * Copyright (C) 1994-1998, Thomas G. Lane.
- * libjpeg-turbo Modifications:
- * Copyright (C) 2016, 2022, D. R. Commander.
- * For conditions of distribution and use, see the accompanying README.ijg
- * file.
- *
- * This file contains application interface code for the decompression half
- * of the JPEG library. These are the "minimum" API routines that may be
- * needed in either the normal full-decompression case or the
- * transcoding-only case.
- *
- * Most of the routines intended to be called directly by an application
- * are in this file or in jdapistd.c. But also see jcomapi.c for routines
- * shared by compression and decompression, and jdtrans.c for the transcoding
- * case.
- */
- #define JPEG_INTERNALS
- #include "jinclude.h"
- #include "jpeglib.h"
- #include "jdmaster.h"
- #include "jconfigint.h"
- /*
- * Initialization of a JPEG decompression object.
- * The error manager must already be set up (in case memory manager fails).
- */
- GLOBAL(void)
- jpeg_CreateDecompress(j_decompress_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_decompress_struct))
- ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
- (int)sizeof(struct jpeg_decompress_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 */
- memset(cinfo, 0, sizeof(struct jpeg_decompress_struct));
- cinfo->err = err;
- cinfo->client_data = client_data;
- }
- cinfo->is_decompressor = TRUE;
- /* 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->src = 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;
- }
- /* Initialize marker processor so application can override methods
- * for COM, APPn markers before calling jpeg_read_header.
- */
- cinfo->marker_list = NULL;
- jinit_marker_reader(cinfo);
- /* And initialize the overall input controller. */
- jinit_input_controller(cinfo);
- /* OK, I'm ready */
- cinfo->global_state = DSTATE_START;
- /* The master struct is used to store extension parameters, so we allocate it
- * here.
- */
- cinfo->master = (struct jpeg_decomp_master *)
- (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
- sizeof(my_decomp_master));
- memset(cinfo->master, 0, sizeof(my_decomp_master));
- }
- /*
- * Destruction of a JPEG decompression object
- */
- GLOBAL(void)
- jpeg_destroy_decompress(j_decompress_ptr cinfo)
- {
- jpeg_destroy((j_common_ptr)cinfo); /* use common routine */
- }
- /*
- * Abort processing of a JPEG decompression operation,
- * but don't destroy the object itself.
- */
- GLOBAL(void)
- jpeg_abort_decompress(j_decompress_ptr cinfo)
- {
- jpeg_abort((j_common_ptr)cinfo); /* use common routine */
- }
- /*
- * Set default decompression parameters.
- */
- LOCAL(void)
- default_decompress_parms(j_decompress_ptr cinfo)
- {
- /* Guess the input colorspace, and set output colorspace accordingly. */
- /* (Wish JPEG committee had provided a real way to specify this...) */
- /* Note application may override our guesses. */
- switch (cinfo->num_components) {
- case 1:
- cinfo->jpeg_color_space = JCS_GRAYSCALE;
- cinfo->out_color_space = JCS_GRAYSCALE;
- break;
- case 3:
- if (cinfo->saw_JFIF_marker) {
- cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */
- } else if (cinfo->saw_Adobe_marker) {
- switch (cinfo->Adobe_transform) {
- case 0:
- cinfo->jpeg_color_space = JCS_RGB;
- break;
- case 1:
- cinfo->jpeg_color_space = JCS_YCbCr;
- break;
- default:
- WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
- break;
- }
- } else {
- /* Saw no special markers, try to guess from the component IDs */
- int cid0 = cinfo->comp_info[0].component_id;
- int cid1 = cinfo->comp_info[1].component_id;
- int cid2 = cinfo->comp_info[2].component_id;
- if (cid0 == 1 && cid1 == 2 && cid2 == 3)
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */
- else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
- cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
- else {
- TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
- }
- }
- /* Always guess RGB is proper output colorspace. */
- cinfo->out_color_space = JCS_RGB;
- break;
- case 4:
- if (cinfo->saw_Adobe_marker) {
- switch (cinfo->Adobe_transform) {
- case 0:
- cinfo->jpeg_color_space = JCS_CMYK;
- break;
- case 2:
- cinfo->jpeg_color_space = JCS_YCCK;
- break;
- default:
- WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
- cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
- break;
- }
- } else {
- /* No special markers, assume straight CMYK. */
- cinfo->jpeg_color_space = JCS_CMYK;
- }
- cinfo->out_color_space = JCS_CMYK;
- break;
- default:
- cinfo->jpeg_color_space = JCS_UNKNOWN;
- cinfo->out_color_space = JCS_UNKNOWN;
- break;
- }
- /* Set defaults for other decompression parameters. */
- cinfo->scale_num = 1; /* 1:1 scaling */
- cinfo->scale_denom = 1;
- cinfo->output_gamma = 1.0;
- cinfo->buffered_image = FALSE;
- cinfo->raw_data_out = FALSE;
- cinfo->dct_method = JDCT_DEFAULT;
- cinfo->do_fancy_upsampling = TRUE;
- cinfo->do_block_smoothing = TRUE;
- cinfo->quantize_colors = FALSE;
- /* We set these in case application only sets quantize_colors. */
- cinfo->dither_mode = JDITHER_FS;
- #ifdef QUANT_2PASS_SUPPORTED
- cinfo->two_pass_quantize = TRUE;
- #else
- cinfo->two_pass_quantize = FALSE;
- #endif
- cinfo->desired_number_of_colors = 256;
- cinfo->colormap = NULL;
- /* Initialize for no mode change in buffered-image mode. */
- cinfo->enable_1pass_quant = FALSE;
- cinfo->enable_external_quant = FALSE;
- cinfo->enable_2pass_quant = FALSE;
- }
- /*
- * Decompression startup: read start of JPEG datastream to see what's there.
- * Need only initialize JPEG object and supply a data source before calling.
- *
- * This routine will read as far as the first SOS marker (ie, actual start of
- * compressed data), and will save all tables and parameters in the JPEG
- * object. It will also initialize the decompression parameters to default
- * values, and finally return JPEG_HEADER_OK. On return, the application may
- * adjust the decompression parameters and then call jpeg_start_decompress.
- * (Or, if the application only wanted to determine the image parameters,
- * the data need not be decompressed. In that case, call jpeg_abort or
- * jpeg_destroy to release any temporary space.)
- * If an abbreviated (tables only) datastream is presented, the routine will
- * return JPEG_HEADER_TABLES_ONLY upon reaching EOI. The application may then
- * re-use the JPEG object to read the abbreviated image datastream(s).
- * It is unnecessary (but OK) to call jpeg_abort in this case.
- * The JPEG_SUSPENDED return code only occurs if the data source module
- * requests suspension of the decompressor. In this case the application
- * should load more source data and then re-call jpeg_read_header to resume
- * processing.
- * If a non-suspending data source is used and require_image is TRUE, then the
- * return code need not be inspected since only JPEG_HEADER_OK is possible.
- *
- * This routine is now just a front end to jpeg_consume_input, with some
- * extra error checking.
- */
- GLOBAL(int)
- jpeg_read_header(j_decompress_ptr cinfo, boolean require_image)
- {
- int retcode;
- if (cinfo->global_state != DSTATE_START &&
- cinfo->global_state != DSTATE_INHEADER)
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
- retcode = jpeg_consume_input(cinfo);
- switch (retcode) {
- case JPEG_REACHED_SOS:
- retcode = JPEG_HEADER_OK;
- break;
- case JPEG_REACHED_EOI:
- if (require_image) /* Complain if application wanted an image */
- ERREXIT(cinfo, JERR_NO_IMAGE);
- /* Reset to start state; it would be safer to require the application to
- * call jpeg_abort, but we can't change it now for compatibility reasons.
- * A side effect is to free any temporary memory (there shouldn't be any).
- */
- jpeg_abort((j_common_ptr)cinfo); /* sets state = DSTATE_START */
- retcode = JPEG_HEADER_TABLES_ONLY;
- break;
- case JPEG_SUSPENDED:
- /* no work */
- break;
- }
- return retcode;
- }
- /*
- * Consume data in advance of what the decompressor requires.
- * This can be called at any time once the decompressor object has
- * been created and a data source has been set up.
- *
- * This routine is essentially a state machine that handles a couple
- * of critical state-transition actions, namely initial setup and
- * transition from header scanning to ready-for-start_decompress.
- * All the actual input is done via the input controller's consume_input
- * method.
- */
- GLOBAL(int)
- jpeg_consume_input(j_decompress_ptr cinfo)
- {
- int retcode = JPEG_SUSPENDED;
- /* NB: every possible DSTATE value should be listed in this switch */
- switch (cinfo->global_state) {
- case DSTATE_START:
- /* Start-of-datastream actions: reset appropriate modules */
- (*cinfo->inputctl->reset_input_controller) (cinfo);
- /* Initialize application's data source module */
- (*cinfo->src->init_source) (cinfo);
- cinfo->global_state = DSTATE_INHEADER;
- FALLTHROUGH /*FALLTHROUGH*/
- case DSTATE_INHEADER:
- retcode = (*cinfo->inputctl->consume_input) (cinfo);
- if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
- /* Set up default parameters based on header data */
- default_decompress_parms(cinfo);
- /* Set global state: ready for start_decompress */
- cinfo->global_state = DSTATE_READY;
- }
- break;
- case DSTATE_READY:
- /* Can't advance past first SOS until start_decompress is called */
- retcode = JPEG_REACHED_SOS;
- break;
- case DSTATE_PRELOAD:
- case DSTATE_PRESCAN:
- case DSTATE_SCANNING:
- case DSTATE_RAW_OK:
- case DSTATE_BUFIMAGE:
- case DSTATE_BUFPOST:
- case DSTATE_STOPPING:
- retcode = (*cinfo->inputctl->consume_input) (cinfo);
- break;
- default:
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
- }
- return retcode;
- }
- /*
- * Have we finished reading the input file?
- */
- GLOBAL(boolean)
- jpeg_input_complete(j_decompress_ptr cinfo)
- {
- /* Check for valid jpeg object */
- if (cinfo->global_state < DSTATE_START ||
- cinfo->global_state > DSTATE_STOPPING)
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
- return cinfo->inputctl->eoi_reached;
- }
- /*
- * Is there more than one scan?
- */
- GLOBAL(boolean)
- jpeg_has_multiple_scans(j_decompress_ptr cinfo)
- {
- /* Only valid after jpeg_read_header completes */
- if (cinfo->global_state < DSTATE_READY ||
- cinfo->global_state > DSTATE_STOPPING)
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
- return cinfo->inputctl->has_multiple_scans;
- }
- /*
- * Finish JPEG decompression.
- *
- * This will normally just verify the file trailer and release temp storage.
- *
- * Returns FALSE if suspended. The return value need be inspected only if
- * a suspending data source is used.
- */
- GLOBAL(boolean)
- jpeg_finish_decompress(j_decompress_ptr cinfo)
- {
- if ((cinfo->global_state == DSTATE_SCANNING ||
- cinfo->global_state == DSTATE_RAW_OK) && !cinfo->buffered_image) {
- /* Terminate final pass of non-buffered mode */
- if (cinfo->output_scanline < cinfo->output_height)
- ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
- (*cinfo->master->finish_output_pass) (cinfo);
- cinfo->global_state = DSTATE_STOPPING;
- } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
- /* Finishing after a buffered-image operation */
- cinfo->global_state = DSTATE_STOPPING;
- } else if (cinfo->global_state != DSTATE_STOPPING) {
- /* STOPPING = repeat call after a suspension, anything else is error */
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
- }
- /* Read until EOI */
- while (!cinfo->inputctl->eoi_reached) {
- if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
- return FALSE; /* Suspend, come back later */
- }
- /* Do final cleanup */
- (*cinfo->src->term_source) (cinfo);
- /* We can use jpeg_abort to release memory and reset global_state */
- jpeg_abort((j_common_ptr)cinfo);
- return TRUE;
- }
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