--- /dev/null
+/*
+ * jdapimin.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 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"
+
+
+/*
+ * 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 */
+ MEMZERO(cinfo, 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;
+}
+
+
+/*
+ * 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*/
+ 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;
+}
projects / opencv / blobdiff