| /* |
| * jdapimin.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1994-1998, Thomas G. Lane. |
| * Lossless JPEG Modifications: |
| * Copyright (C) 1999, Ken Murchison. |
| * 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" |
| |
| |
| /* |
| * 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); |
| |
| cinfo->data_precision = BITS_IN_JSAMPLE; |
| |
| /* 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); |
| if (cinfo->master->lossless) |
| cinfo->jpeg_color_space = JCS_RGB; /* assume it's RGB */ |
| else |
| 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; |
| } |