+++ /dev/null
-/*
- * jdinput.c
- *
- * Copyright (C) 1991-1995, 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 input control logic for the JPEG decompressor.
- * These routines are concerned with controlling the decompressor's input
- * processing (marker reading and coefficient decoding). The actual input
- * reading is done in jdmarker.c, jdhuff.c, and jdphuff.c.
- */
-
-#define JPEG_INTERNALS
-#include "jinclude.h"
-#include "radiant_jpeglib.h"
-
-
-/* Private state */
-
-typedef struct {
- struct jpeg_input_controller pub; /* public fields */
-
- boolean inheaders; /* TRUE until first SOS is reached */
-} my_input_controller;
-
-typedef my_input_controller * my_inputctl_ptr;
-
-
-/* Forward declarations */
-METHODDEF int consume_markers JPP((j_decompress_ptr cinfo));
-
-
-/*
- * Routines to calculate various quantities related to the size of the image.
- */
-
-LOCAL void
-initial_setup (j_decompress_ptr cinfo)
-/* Called once, when first SOS marker is reached */
-{
- int ci;
- jpeg_component_info *compptr;
-
- /* Make sure image isn't bigger than I can handle */
- if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
- (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
- ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
-
- /* For now, precision must match compiled-in value... */
- if (cinfo->data_precision != BITS_IN_JSAMPLE)
- ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
-
- /* Check that number of components won't exceed internal array sizes */
- if (cinfo->num_components > MAX_COMPONENTS)
- ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
- MAX_COMPONENTS);
-
- /* Compute maximum sampling factors; check factor validity */
- cinfo->max_h_samp_factor = 1;
- cinfo->max_v_samp_factor = 1;
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
- compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
- ERREXIT(cinfo, JERR_BAD_SAMPLING);
- cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
- compptr->h_samp_factor);
- cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
- compptr->v_samp_factor);
- }
-
- /* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
- * In the full decompressor, this will be overridden by jdmaster.c;
- * but in the transcoder, jdmaster.c is not used, so we must do it here.
- */
- cinfo->min_DCT_scaled_size = DCTSIZE;
-
- /* Compute dimensions of components */
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- compptr->DCT_scaled_size = DCTSIZE;
- /* Size in DCT blocks */
- compptr->width_in_blocks = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
- (long) (cinfo->max_h_samp_factor * DCTSIZE));
- compptr->height_in_blocks = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
- (long) (cinfo->max_v_samp_factor * DCTSIZE));
- /* downsampled_width and downsampled_height will also be overridden by
- * jdmaster.c if we are doing full decompression. The transcoder library
- * doesn't use these values, but the calling application might.
- */
- /* Size in samples */
- compptr->downsampled_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
- (long) cinfo->max_h_samp_factor);
- compptr->downsampled_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
- (long) cinfo->max_v_samp_factor);
- /* Mark component needed, until color conversion says otherwise */
- compptr->component_needed = TRUE;
- /* Mark no quantization table yet saved for component */
- compptr->quant_table = NULL;
- }
-
- /* Compute number of fully interleaved MCU rows. */
- cinfo->total_iMCU_rows = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
-
- /* Decide whether file contains multiple scans */
- if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode)
- cinfo->inputctl->has_multiple_scans = TRUE;
- else
- cinfo->inputctl->has_multiple_scans = FALSE;
-}
-
-
-LOCAL void
-per_scan_setup (j_decompress_ptr cinfo)
-/* Do computations that are needed before processing a JPEG scan */
-/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */
-{
- int ci, mcublks, tmp;
- jpeg_component_info *compptr;
-
- if (cinfo->comps_in_scan == 1) {
-
- /* Noninterleaved (single-component) scan */
- compptr = cinfo->cur_comp_info[0];
-
- /* Overall image size in MCUs */
- cinfo->MCUs_per_row = compptr->width_in_blocks;
- cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
-
- /* For noninterleaved scan, always one block per MCU */
- compptr->MCU_width = 1;
- compptr->MCU_height = 1;
- compptr->MCU_blocks = 1;
- compptr->MCU_sample_width = compptr->DCT_scaled_size;
- compptr->last_col_width = 1;
- /* For noninterleaved scans, it is convenient to define last_row_height
- * as the number of block rows present in the last iMCU row.
- */
- tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
- if (tmp == 0) tmp = compptr->v_samp_factor;
- compptr->last_row_height = tmp;
-
- /* Prepare array describing MCU composition */
- cinfo->blocks_in_MCU = 1;
- cinfo->MCU_membership[0] = 0;
-
- } else {
-
- /* Interleaved (multi-component) scan */
- if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
- ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
- MAX_COMPS_IN_SCAN);
-
- /* Overall image size in MCUs */
- cinfo->MCUs_per_row = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width,
- (long) (cinfo->max_h_samp_factor*DCTSIZE));
- cinfo->MCU_rows_in_scan = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
-
- cinfo->blocks_in_MCU = 0;
-
- for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
- compptr = cinfo->cur_comp_info[ci];
- /* Sampling factors give # of blocks of component in each MCU */
- compptr->MCU_width = compptr->h_samp_factor;
- compptr->MCU_height = compptr->v_samp_factor;
- compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
- compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
- /* Figure number of non-dummy blocks in last MCU column & row */
- tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
- if (tmp == 0) tmp = compptr->MCU_width;
- compptr->last_col_width = tmp;
- tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
- if (tmp == 0) tmp = compptr->MCU_height;
- compptr->last_row_height = tmp;
- /* Prepare array describing MCU composition */
- mcublks = compptr->MCU_blocks;
- if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU)
- ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
- while (mcublks-- > 0) {
- cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
- }
- }
-
- }
-}
-
-
-/*
- * Save away a copy of the Q-table referenced by each component present
- * in the current scan, unless already saved during a prior scan.
- *
- * In a multiple-scan JPEG file, the encoder could assign different components
- * the same Q-table slot number, but change table definitions between scans
- * so that each component uses a different Q-table. (The IJG encoder is not
- * currently capable of doing this, but other encoders might.) Since we want
- * to be able to dequantize all the components at the end of the file, this
- * means that we have to save away the table actually used for each component.
- * We do this by copying the table at the start of the first scan containing
- * the component.
- * The JPEG spec prohibits the encoder from changing the contents of a Q-table
- * slot between scans of a component using that slot. If the encoder does so
- * anyway, this decoder will simply use the Q-table values that were current
- * at the start of the first scan for the component.
- *
- * The decompressor output side looks only at the saved quant tables,
- * not at the current Q-table slots.
- */
-
-LOCAL void
-latch_quant_tables (j_decompress_ptr cinfo)
-{
- int ci, qtblno;
- jpeg_component_info *compptr;
- JQUANT_TBL * qtbl;
-
- for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
- compptr = cinfo->cur_comp_info[ci];
- /* No work if we already saved Q-table for this component */
- if (compptr->quant_table != NULL)
- continue;
- /* Make sure specified quantization table is present */
- qtblno = compptr->quant_tbl_no;
- if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
- cinfo->quant_tbl_ptrs[qtblno] == NULL)
- ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
- /* OK, save away the quantization table */
- qtbl = (JQUANT_TBL *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(JQUANT_TBL));
- MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL));
- compptr->quant_table = qtbl;
- }
-}
-
-
-/*
- * Initialize the input modules to read a scan of compressed data.
- * The first call to this is done by jdmaster.c after initializing
- * the entire decompressor (during jpeg_start_decompress).
- * Subsequent calls come from consume_markers, below.
- */
-
-METHODDEF void
-start_input_pass (j_decompress_ptr cinfo)
-{
- per_scan_setup(cinfo);
- latch_quant_tables(cinfo);
- (*cinfo->entropy->start_pass) (cinfo);
- (*cinfo->coef->start_input_pass) (cinfo);
- cinfo->inputctl->consume_input = cinfo->coef->consume_data;
-}
-
-
-/*
- * Finish up after inputting a compressed-data scan.
- * This is called by the coefficient controller after it's read all
- * the expected data of the scan.
- */
-
-METHODDEF void
-finish_input_pass (j_decompress_ptr cinfo)
-{
- cinfo->inputctl->consume_input = consume_markers;
-}
-
-
-/*
- * Read JPEG markers before, between, or after compressed-data scans.
- * Change state as necessary when a new scan is reached.
- * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
- *
- * The consume_input method pointer points either here or to the
- * coefficient controller's consume_data routine, depending on whether
- * we are reading a compressed data segment or inter-segment markers.
- */
-
-METHODDEF int
-consume_markers (j_decompress_ptr cinfo)
-{
- my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
- int val;
-
- if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */
- return JPEG_REACHED_EOI;
-
- val = (*cinfo->marker->read_markers) (cinfo);
-
- switch (val) {
- case JPEG_REACHED_SOS: /* Found SOS */
- if (inputctl->inheaders) { /* 1st SOS */
- initial_setup(cinfo);
- inputctl->inheaders = FALSE;
- /* Note: start_input_pass must be called by jdmaster.c
- * before any more input can be consumed. jdapi.c is
- * responsible for enforcing this sequencing.
- */
- } else { /* 2nd or later SOS marker */
- if (! inputctl->pub.has_multiple_scans)
- ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */
- start_input_pass(cinfo);
- }
- break;
- case JPEG_REACHED_EOI: /* Found EOI */
- inputctl->pub.eoi_reached = TRUE;
- if (inputctl->inheaders) { /* Tables-only datastream, apparently */
- if (cinfo->marker->saw_SOF)
- ERREXIT(cinfo, JERR_SOF_NO_SOS);
- } else {
- /* Prevent infinite loop in coef ctlr's decompress_data routine
- * if user set output_scan_number larger than number of scans.
- */
- if (cinfo->output_scan_number > cinfo->input_scan_number)
- cinfo->output_scan_number = cinfo->input_scan_number;
- }
- break;
- case JPEG_SUSPENDED:
- break;
- }
-
- return val;
-}
-
-
-/*
- * Reset state to begin a fresh datastream.
- */
-
-METHODDEF void
-reset_input_controller (j_decompress_ptr cinfo)
-{
- my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
-
- inputctl->pub.consume_input = consume_markers;
- inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
- inputctl->pub.eoi_reached = FALSE;
- inputctl->inheaders = TRUE;
- /* Reset other modules */
- (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
- (*cinfo->marker->reset_marker_reader) (cinfo);
- /* Reset progression state -- would be cleaner if entropy decoder did this */
- cinfo->coef_bits = NULL;
-}
-
-
-/*
- * Initialize the input controller module.
- * This is called only once, when the decompression object is created.
- */
-
-GLOBAL void
-jinit_input_controller (j_decompress_ptr cinfo)
-{
- my_inputctl_ptr inputctl;
-
- /* Create subobject in permanent pool */
- inputctl = (my_inputctl_ptr)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
- SIZEOF(my_input_controller));
- cinfo->inputctl = (struct jpeg_input_controller *) inputctl;
- /* Initialize method pointers */
- inputctl->pub.consume_input = consume_markers;
- inputctl->pub.reset_input_controller = reset_input_controller;
- inputctl->pub.start_input_pass = start_input_pass;
- inputctl->pub.finish_input_pass = finish_input_pass;
- /* Initialize state: can't use reset_input_controller since we don't
- * want to try to reset other modules yet.
- */
- inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
- inputctl->pub.eoi_reached = FALSE;
- inputctl->inheaders = TRUE;
-}
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