-/*\r
-\r
- * jdapimin.c\r
-\r
- *\r
-\r
- * Copyright (C) 1994-1995, Thomas G. Lane.\r
-\r
- * This file is part of the Independent JPEG Group's software.\r
-\r
- * For conditions of distribution and use, see the accompanying README file.\r
-\r
- *\r
-\r
- * This file contains application interface code for the decompression half\r
-\r
- * of the JPEG library. These are the "minimum" API routines that may be\r
-\r
- * needed in either the normal full-decompression case or the\r
-\r
- * transcoding-only case.\r
-\r
- *\r
-\r
- * Most of the routines intended to be called directly by an application\r
-\r
- * are in this file or in jdapistd.c. But also see jcomapi.c for routines\r
-\r
- * shared by compression and decompression, and jdtrans.c for the transcoding\r
-\r
- * case.\r
-\r
- */\r
-\r
-\r
-\r
-#define JPEG_INTERNALS\r
-\r
-#include "jinclude.h"\r
-\r
-#include "radiant_jpeglib.h"\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Initialization of a JPEG decompression object.\r
-\r
- * The error manager must already be set up (in case memory manager fails).\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL void\r
-\r
-jpeg_create_decompress (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- int i;\r
-\r
-\r
-\r
- /* For debugging purposes, zero the whole master structure.\r
-\r
- * But error manager pointer is already there, so save and restore it.\r
-\r
- */\r
-\r
- {\r
-\r
- struct jpeg_error_mgr * err = cinfo->err;\r
-\r
- i = sizeof(struct jpeg_decompress_struct);\r
-\r
- i = SIZEOF(struct jpeg_decompress_struct);\r
-\r
- MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));\r
-\r
- cinfo->err = err;\r
-\r
- }\r
-\r
- cinfo->is_decompressor = TRUE;\r
-\r
-\r
-\r
- /* Initialize a memory manager instance for this object */\r
-\r
- jinit_memory_mgr((j_common_ptr) cinfo);\r
-\r
-\r
-\r
- /* Zero out pointers to permanent structures. */\r
-\r
- cinfo->progress = NULL;\r
-\r
- cinfo->src = NULL;\r
-\r
-\r
-\r
- for (i = 0; i < NUM_QUANT_TBLS; i++)\r
-\r
- cinfo->quant_tbl_ptrs[i] = NULL;\r
-\r
-\r
-\r
- for (i = 0; i < NUM_HUFF_TBLS; i++) {\r
-\r
- cinfo->dc_huff_tbl_ptrs[i] = NULL;\r
-\r
- cinfo->ac_huff_tbl_ptrs[i] = NULL;\r
-\r
- }\r
-\r
-\r
-\r
- /* Initialize marker processor so application can override methods\r
-\r
- * for COM, APPn markers before calling jpeg_read_header.\r
-\r
- */\r
-\r
- jinit_marker_reader(cinfo);\r
-\r
-\r
-\r
- /* And initialize the overall input controller. */\r
-\r
- jinit_input_controller(cinfo);\r
-\r
-\r
-\r
- /* OK, I'm ready */\r
-\r
- cinfo->global_state = DSTATE_START;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Destruction of a JPEG decompression object\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL void\r
-\r
-jpeg_destroy_decompress (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- jpeg_destroy((j_common_ptr) cinfo); /* use common routine */\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Abort processing of a JPEG decompression operation,\r
-\r
- * but don't destroy the object itself.\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL void\r
-\r
-jpeg_abort_decompress (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- jpeg_abort((j_common_ptr) cinfo); /* use common routine */\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Install a special processing method for COM or APPn markers.\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL void\r
-\r
-jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,\r
-\r
- jpeg_marker_parser_method routine)\r
-\r
-{\r
-\r
- if (marker_code == JPEG_COM)\r
-\r
- cinfo->marker->process_COM = routine;\r
-\r
- else if (marker_code >= JPEG_APP0 && marker_code <= JPEG_APP0+15)\r
-\r
- cinfo->marker->process_APPn[marker_code-JPEG_APP0] = routine;\r
-\r
- else\r
-\r
- ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Set default decompression parameters.\r
-\r
- */\r
-\r
-\r
-\r
-LOCAL void\r
-\r
-default_decompress_parms (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- /* Guess the input colorspace, and set output colorspace accordingly. */\r
-\r
- /* (Wish JPEG committee had provided a real way to specify this...) */\r
-\r
- /* Note application may override our guesses. */\r
-\r
- switch (cinfo->num_components) {\r
-\r
- case 1:\r
-\r
- cinfo->jpeg_color_space = JCS_GRAYSCALE;\r
-\r
- cinfo->out_color_space = JCS_GRAYSCALE;\r
-\r
- break;\r
-\r
- \r
-\r
- case 3:\r
-\r
- if (cinfo->saw_JFIF_marker) {\r
-\r
- cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */\r
-\r
- } else if (cinfo->saw_Adobe_marker) {\r
-\r
- switch (cinfo->Adobe_transform) {\r
-\r
- case 0:\r
-\r
- cinfo->jpeg_color_space = JCS_RGB;\r
-\r
- break;\r
-\r
- case 1:\r
-\r
- cinfo->jpeg_color_space = JCS_YCbCr;\r
-\r
- break;\r
-\r
- default:\r
-\r
- WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);\r
-\r
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */\r
-\r
- break;\r
-\r
- }\r
-\r
- } else {\r
-\r
- /* Saw no special markers, try to guess from the component IDs */\r
-\r
- int cid0 = cinfo->comp_info[0].component_id;\r
-\r
- int cid1 = cinfo->comp_info[1].component_id;\r
-\r
- int cid2 = cinfo->comp_info[2].component_id;\r
-\r
-\r
-\r
- if (cid0 == 1 && cid1 == 2 && cid2 == 3)\r
-\r
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */\r
-\r
- else if (cid0 == 82 && cid1 == 71 && cid2 == 66)\r
-\r
- cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */\r
-\r
- else {\r
-\r
- TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);\r
-\r
- cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */\r
-\r
- }\r
-\r
- }\r
-\r
- /* Always guess RGB is proper output colorspace. */\r
-\r
- cinfo->out_color_space = JCS_RGB;\r
-\r
- break;\r
-\r
- \r
-\r
- case 4:\r
-\r
- if (cinfo->saw_Adobe_marker) {\r
-\r
- switch (cinfo->Adobe_transform) {\r
-\r
- case 0:\r
-\r
- cinfo->jpeg_color_space = JCS_CMYK;\r
-\r
- break;\r
-\r
- case 2:\r
-\r
- cinfo->jpeg_color_space = JCS_YCCK;\r
-\r
- break;\r
-\r
- default:\r
-\r
- WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);\r
-\r
- cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */\r
-\r
- break;\r
-\r
- }\r
-\r
- } else {\r
-\r
- /* No special markers, assume straight CMYK. */\r
-\r
- cinfo->jpeg_color_space = JCS_CMYK;\r
-\r
- }\r
-\r
- cinfo->out_color_space = JCS_CMYK;\r
-\r
- break;\r
-\r
- \r
-\r
- default:\r
-\r
- cinfo->jpeg_color_space = JCS_UNKNOWN;\r
-\r
- cinfo->out_color_space = JCS_UNKNOWN;\r
-\r
- break;\r
-\r
- }\r
-\r
-\r
-\r
- /* Set defaults for other decompression parameters. */\r
-\r
- cinfo->scale_num = 1; /* 1:1 scaling */\r
-\r
- cinfo->scale_denom = 1;\r
-\r
- cinfo->output_gamma = 1.0;\r
-\r
- cinfo->buffered_image = FALSE;\r
-\r
- cinfo->raw_data_out = FALSE;\r
-\r
- cinfo->dct_method = JDCT_DEFAULT;\r
-\r
- cinfo->do_fancy_upsampling = TRUE;\r
-\r
- cinfo->do_block_smoothing = TRUE;\r
-\r
- cinfo->quantize_colors = FALSE;\r
-\r
- /* We set these in case application only sets quantize_colors. */\r
-\r
- cinfo->dither_mode = JDITHER_FS;\r
-\r
-#ifdef QUANT_2PASS_SUPPORTED\r
-\r
- cinfo->two_pass_quantize = TRUE;\r
-\r
-#else\r
-\r
- cinfo->two_pass_quantize = FALSE;\r
-\r
-#endif\r
-\r
- cinfo->desired_number_of_colors = 256;\r
-\r
- cinfo->colormap = NULL;\r
-\r
- /* Initialize for no mode change in buffered-image mode. */\r
-\r
- cinfo->enable_1pass_quant = FALSE;\r
-\r
- cinfo->enable_external_quant = FALSE;\r
-\r
- cinfo->enable_2pass_quant = FALSE;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Decompression startup: read start of JPEG datastream to see what's there.\r
-\r
- * Need only initialize JPEG object and supply a data source before calling.\r
-\r
- *\r
-\r
- * This routine will read as far as the first SOS marker (ie, actual start of\r
-\r
- * compressed data), and will save all tables and parameters in the JPEG\r
-\r
- * object. It will also initialize the decompression parameters to default\r
-\r
- * values, and finally return JPEG_HEADER_OK. On return, the application may\r
-\r
- * adjust the decompression parameters and then call jpeg_start_decompress.\r
-\r
- * (Or, if the application only wanted to determine the image parameters,\r
-\r
- * the data need not be decompressed. In that case, call jpeg_abort or\r
-\r
- * jpeg_destroy to release any temporary space.)\r
-\r
- * If an abbreviated (tables only) datastream is presented, the routine will\r
-\r
- * return JPEG_HEADER_TABLES_ONLY upon reaching EOI. The application may then\r
-\r
- * re-use the JPEG object to read the abbreviated image datastream(s).\r
-\r
- * It is unnecessary (but OK) to call jpeg_abort in this case.\r
-\r
- * The JPEG_SUSPENDED return code only occurs if the data source module\r
-\r
- * requests suspension of the decompressor. In this case the application\r
-\r
- * should load more source data and then re-call jpeg_read_header to resume\r
-\r
- * processing.\r
-\r
- * If a non-suspending data source is used and require_image is TRUE, then the\r
-\r
- * return code need not be inspected since only JPEG_HEADER_OK is possible.\r
-\r
- *\r
-\r
- * This routine is now just a front end to jpeg_consume_input, with some\r
-\r
- * extra error checking.\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL int\r
-\r
-jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)\r
-\r
-{\r
-\r
- int retcode;\r
-\r
-\r
-\r
- if (cinfo->global_state != DSTATE_START &&\r
-\r
- cinfo->global_state != DSTATE_INHEADER)\r
-\r
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);\r
-\r
-\r
-\r
- retcode = jpeg_consume_input(cinfo);\r
-\r
-\r
-\r
- switch (retcode) {\r
-\r
- case JPEG_REACHED_SOS:\r
-\r
- retcode = JPEG_HEADER_OK;\r
-\r
- break;\r
-\r
- case JPEG_REACHED_EOI:\r
-\r
- if (require_image) /* Complain if application wanted an image */\r
-\r
- ERREXIT(cinfo, JERR_NO_IMAGE);\r
-\r
- /* Reset to start state; it would be safer to require the application to\r
-\r
- * call jpeg_abort, but we can't change it now for compatibility reasons.\r
-\r
- * A side effect is to free any temporary memory (there shouldn't be any).\r
-\r
- */\r
-\r
- jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */\r
-\r
- retcode = JPEG_HEADER_TABLES_ONLY;\r
-\r
- break;\r
-\r
- case JPEG_SUSPENDED:\r
-\r
- /* no work */\r
-\r
- break;\r
-\r
- }\r
-\r
-\r
-\r
- return retcode;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Consume data in advance of what the decompressor requires.\r
-\r
- * This can be called at any time once the decompressor object has\r
-\r
- * been created and a data source has been set up.\r
-\r
- *\r
-\r
- * This routine is essentially a state machine that handles a couple\r
-\r
- * of critical state-transition actions, namely initial setup and\r
-\r
- * transition from header scanning to ready-for-start_decompress.\r
-\r
- * All the actual input is done via the input controller's consume_input\r
-\r
- * method.\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL int\r
-\r
-jpeg_consume_input (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- int retcode = JPEG_SUSPENDED;\r
-\r
-\r
-\r
- /* NB: every possible DSTATE value should be listed in this switch */\r
-\r
- switch (cinfo->global_state) {\r
-\r
- case DSTATE_START:\r
-\r
- /* Start-of-datastream actions: reset appropriate modules */\r
-\r
- (*cinfo->inputctl->reset_input_controller) (cinfo);\r
-\r
- /* Initialize application's data source module */\r
-\r
- (*cinfo->src->init_source) (cinfo);\r
-\r
- cinfo->global_state = DSTATE_INHEADER;\r
-\r
- /*FALLTHROUGH*/\r
-\r
- case DSTATE_INHEADER:\r
-\r
- retcode = (*cinfo->inputctl->consume_input) (cinfo);\r
-\r
- if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */\r
-\r
- /* Set up default parameters based on header data */\r
-\r
- default_decompress_parms(cinfo);\r
-\r
- /* Set global state: ready for start_decompress */\r
-\r
- cinfo->global_state = DSTATE_READY;\r
-\r
- }\r
-\r
- break;\r
-\r
- case DSTATE_READY:\r
-\r
- /* Can't advance past first SOS until start_decompress is called */\r
-\r
- retcode = JPEG_REACHED_SOS;\r
-\r
- break;\r
-\r
- case DSTATE_PRELOAD:\r
-\r
- case DSTATE_PRESCAN:\r
-\r
- case DSTATE_SCANNING:\r
-\r
- case DSTATE_RAW_OK:\r
-\r
- case DSTATE_BUFIMAGE:\r
-\r
- case DSTATE_BUFPOST:\r
-\r
- case DSTATE_STOPPING:\r
-\r
- retcode = (*cinfo->inputctl->consume_input) (cinfo);\r
-\r
- break;\r
-\r
- default:\r
-\r
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);\r
-\r
- }\r
-\r
- return retcode;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Have we finished reading the input file?\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL boolean\r
-\r
-jpeg_input_complete (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- /* Check for valid jpeg object */\r
-\r
- if (cinfo->global_state < DSTATE_START ||\r
-\r
- cinfo->global_state > DSTATE_STOPPING)\r
-\r
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);\r
-\r
- return cinfo->inputctl->eoi_reached;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Is there more than one scan?\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL boolean\r
-\r
-jpeg_has_multiple_scans (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- /* Only valid after jpeg_read_header completes */\r
-\r
- if (cinfo->global_state < DSTATE_READY ||\r
-\r
- cinfo->global_state > DSTATE_STOPPING)\r
-\r
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);\r
-\r
- return cinfo->inputctl->has_multiple_scans;\r
-\r
-}\r
-\r
-\r
-\r
-\r
-\r
-/*\r
-\r
- * Finish JPEG decompression.\r
-\r
- *\r
-\r
- * This will normally just verify the file trailer and release temp storage.\r
-\r
- *\r
-\r
- * Returns FALSE if suspended. The return value need be inspected only if\r
-\r
- * a suspending data source is used.\r
-\r
- */\r
-\r
-\r
-\r
-GLOBAL boolean\r
-\r
-jpeg_finish_decompress (j_decompress_ptr cinfo)\r
-\r
-{\r
-\r
- if ((cinfo->global_state == DSTATE_SCANNING ||\r
-\r
- cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {\r
-\r
- /* Terminate final pass of non-buffered mode */\r
-\r
- if (cinfo->output_scanline < cinfo->output_height)\r
-\r
- ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);\r
-\r
- (*cinfo->master->finish_output_pass) (cinfo);\r
-\r
- cinfo->global_state = DSTATE_STOPPING;\r
-\r
- } else if (cinfo->global_state == DSTATE_BUFIMAGE) {\r
-\r
- /* Finishing after a buffered-image operation */\r
-\r
- cinfo->global_state = DSTATE_STOPPING;\r
-\r
- } else if (cinfo->global_state != DSTATE_STOPPING) {\r
-\r
- /* STOPPING = repeat call after a suspension, anything else is error */\r
-\r
- ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);\r
-\r
- }\r
-\r
- /* Read until EOI */\r
-\r
- while (! cinfo->inputctl->eoi_reached) {\r
-\r
- if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)\r
-\r
- return FALSE; /* Suspend, come back later */\r
-\r
- }\r
-\r
- /* Do final cleanup */\r
-\r
- (*cinfo->src->term_source) (cinfo);\r
-\r
- /* We can use jpeg_abort to release memory and reset global_state */\r
-\r
- jpeg_abort((j_common_ptr) cinfo);\r
-\r
- return TRUE;\r
-\r
-}\r
-\r
+/*
+
+ * jdapimin.c
+
+ *
+
+ * Copyright (C) 1994-1995, 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 "radiant_jpeglib.h"
+
+
+
+
+
+/*
+
+ * Initialization of a JPEG decompression object.
+
+ * The error manager must already be set up (in case memory manager fails).
+
+ */
+
+
+
+GLOBAL void
+
+jpeg_create_decompress (j_decompress_ptr cinfo)
+
+{
+
+ int i;
+
+
+
+ /* For debugging purposes, zero the whole master structure.
+
+ * But error manager pointer is already there, so save and restore it.
+
+ */
+
+ {
+
+ struct jpeg_error_mgr * err = cinfo->err;
+
+ i = sizeof(struct jpeg_decompress_struct);
+
+ i = SIZEOF(struct jpeg_decompress_struct);
+
+ MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
+
+ cinfo->err = err;
+
+ }
+
+ 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.
+
+ */
+
+ 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 */
+
+}
+
+
+
+
+
+/*
+
+ * Install a special processing method for COM or APPn markers.
+
+ */
+
+
+
+GLOBAL void
+
+jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
+
+ jpeg_marker_parser_method routine)
+
+{
+
+ if (marker_code == JPEG_COM)
+
+ cinfo->marker->process_COM = routine;
+
+ else if (marker_code >= JPEG_APP0 && marker_code <= JPEG_APP0+15)
+
+ cinfo->marker->process_APPn[marker_code-JPEG_APP0] = routine;
+
+ else
+
+ ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
+
+}
+
+
+
+
+
+/*
+
+ * 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;
+
+}
+