summaryrefslogtreecommitdiff
path: root/jpg/jdcoefct.c
diff options
context:
space:
mode:
authorJörg Frings-Fürst <debian@jff-webhosting.net>2015-05-01 16:13:57 +0200
committerJörg Frings-Fürst <debian@jff-webhosting.net>2015-05-01 16:13:57 +0200
commit094535c010320967639e8e86f974d878e80baa72 (patch)
treeefc3094b20355dcbeebb2c4ece4fcfc69bffedb5 /jpg/jdcoefct.c
parentc07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 (diff)
Imported Upstream version 1.7.0upstream/1.7.0
Diffstat (limited to 'jpg/jdcoefct.c')
-rw-r--r--jpg/jdcoefct.c741
1 files changed, 0 insertions, 741 deletions
diff --git a/jpg/jdcoefct.c b/jpg/jdcoefct.c
deleted file mode 100644
index ed02fc3..0000000
--- a/jpg/jdcoefct.c
+++ /dev/null
@@ -1,741 +0,0 @@
-/*
- * jdcoefct.c
- *
- * Copyright (C) 1994-1997, Thomas G. Lane.
- * Modified 2002-2011 by Guido Vollbeding.
- * 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 the coefficient buffer controller for decompression.
- * This controller is the top level of the JPEG decompressor proper.
- * The coefficient buffer lies between entropy decoding and inverse-DCT steps.
- *
- * In buffered-image mode, this controller is the interface between
- * input-oriented processing and output-oriented processing.
- * Also, the input side (only) is used when reading a file for transcoding.
- */
-
-#define JPEG_INTERNALS
-#include "jinclude.h"
-#include "jpeglib.h"
-
-/* Block smoothing is only applicable for progressive JPEG, so: */
-#ifndef D_PROGRESSIVE_SUPPORTED
-#undef BLOCK_SMOOTHING_SUPPORTED
-#endif
-
-/* Private buffer controller object */
-
-typedef struct {
- struct jpeg_d_coef_controller pub; /* public fields */
-
- /* These variables keep track of the current location of the input side. */
- /* cinfo->input_iMCU_row is also used for this. */
- JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
- int MCU_vert_offset; /* counts MCU rows within iMCU row */
- int MCU_rows_per_iMCU_row; /* number of such rows needed */
-
- /* The output side's location is represented by cinfo->output_iMCU_row. */
-
- /* In single-pass modes, it's sufficient to buffer just one MCU.
- * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
- * and let the entropy decoder write into that workspace each time.
- * (On 80x86, the workspace is FAR even though it's not really very big;
- * this is to keep the module interfaces unchanged when a large coefficient
- * buffer is necessary.)
- * In multi-pass modes, this array points to the current MCU's blocks
- * within the virtual arrays; it is used only by the input side.
- */
- JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
-
-#ifdef D_MULTISCAN_FILES_SUPPORTED
- /* In multi-pass modes, we need a virtual block array for each component. */
- jvirt_barray_ptr whole_image[MAX_COMPONENTS];
-#endif
-
-#ifdef BLOCK_SMOOTHING_SUPPORTED
- /* When doing block smoothing, we latch coefficient Al values here */
- int * coef_bits_latch;
-#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
-#endif
-} my_coef_controller;
-
-typedef my_coef_controller * my_coef_ptr;
-
-/* Forward declarations */
-METHODDEF(int) decompress_onepass
- JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
-#ifdef D_MULTISCAN_FILES_SUPPORTED
-METHODDEF(int) decompress_data
- JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
-#endif
-#ifdef BLOCK_SMOOTHING_SUPPORTED
-LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo));
-METHODDEF(int) decompress_smooth_data
- JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
-#endif
-
-
-LOCAL(void)
-start_iMCU_row (j_decompress_ptr cinfo)
-/* Reset within-iMCU-row counters for a new row (input side) */
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
-
- /* In an interleaved scan, an MCU row is the same as an iMCU row.
- * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
- * But at the bottom of the image, process only what's left.
- */
- if (cinfo->comps_in_scan > 1) {
- coef->MCU_rows_per_iMCU_row = 1;
- } else {
- if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
- coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
- else
- coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
- }
-
- coef->MCU_ctr = 0;
- coef->MCU_vert_offset = 0;
-}
-
-
-/*
- * Initialize for an input processing pass.
- */
-
-METHODDEF(void)
-start_input_pass (j_decompress_ptr cinfo)
-{
- cinfo->input_iMCU_row = 0;
- start_iMCU_row(cinfo);
-}
-
-
-/*
- * Initialize for an output processing pass.
- */
-
-METHODDEF(void)
-start_output_pass (j_decompress_ptr cinfo)
-{
-#ifdef BLOCK_SMOOTHING_SUPPORTED
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
-
- /* If multipass, check to see whether to use block smoothing on this pass */
- if (coef->pub.coef_arrays != NULL) {
- if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
- coef->pub.decompress_data = decompress_smooth_data;
- else
- coef->pub.decompress_data = decompress_data;
- }
-#endif
- cinfo->output_iMCU_row = 0;
-}
-
-
-/*
- * Decompress and return some data in the single-pass case.
- * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
- * Input and output must run in lockstep since we have only a one-MCU buffer.
- * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
- *
- * NB: output_buf contains a plane for each component in image,
- * which we index according to the component's SOF position.
- */
-
-METHODDEF(int)
-decompress_onepass (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
- JDIMENSION MCU_col_num; /* index of current MCU within row */
- JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
- JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
- int blkn, ci, xindex, yindex, yoffset, useful_width;
- JSAMPARRAY output_ptr;
- JDIMENSION start_col, output_col;
- jpeg_component_info *compptr;
- inverse_DCT_method_ptr inverse_DCT;
-
- /* Loop to process as much as one whole iMCU row */
- for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
- yoffset++) {
- for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
- MCU_col_num++) {
- /* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */
- if (cinfo->lim_Se) /* can bypass in DC only case */
- FMEMZERO((void FAR *) coef->MCU_buffer[0],
- (size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK)));
- if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
- /* Suspension forced; update state counters and exit */
- coef->MCU_vert_offset = yoffset;
- coef->MCU_ctr = MCU_col_num;
- return JPEG_SUSPENDED;
- }
- /* Determine where data should go in output_buf and do the IDCT thing.
- * We skip dummy blocks at the right and bottom edges (but blkn gets
- * incremented past them!). Note the inner loop relies on having
- * allocated the MCU_buffer[] blocks sequentially.
- */
- blkn = 0; /* index of current DCT block within MCU */
- for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
- compptr = cinfo->cur_comp_info[ci];
- /* Don't bother to IDCT an uninteresting component. */
- if (! compptr->component_needed) {
- blkn += compptr->MCU_blocks;
- continue;
- }
- inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
- useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
- : compptr->last_col_width;
- output_ptr = output_buf[compptr->component_index] +
- yoffset * compptr->DCT_v_scaled_size;
- start_col = MCU_col_num * compptr->MCU_sample_width;
- for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
- if (cinfo->input_iMCU_row < last_iMCU_row ||
- yoffset+yindex < compptr->last_row_height) {
- output_col = start_col;
- for (xindex = 0; xindex < useful_width; xindex++) {
- (*inverse_DCT) (cinfo, compptr,
- (JCOEFPTR) coef->MCU_buffer[blkn+xindex],
- output_ptr, output_col);
- output_col += compptr->DCT_h_scaled_size;
- }
- }
- blkn += compptr->MCU_width;
- output_ptr += compptr->DCT_v_scaled_size;
- }
- }
- }
- /* Completed an MCU row, but perhaps not an iMCU row */
- coef->MCU_ctr = 0;
- }
- /* Completed the iMCU row, advance counters for next one */
- cinfo->output_iMCU_row++;
- if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
- start_iMCU_row(cinfo);
- return JPEG_ROW_COMPLETED;
- }
- /* Completed the scan */
- (*cinfo->inputctl->finish_input_pass) (cinfo);
- return JPEG_SCAN_COMPLETED;
-}
-
-
-/*
- * Dummy consume-input routine for single-pass operation.
- */
-
-METHODDEF(int)
-dummy_consume_data (j_decompress_ptr cinfo)
-{
- return JPEG_SUSPENDED; /* Always indicate nothing was done */
-}
-
-
-#ifdef D_MULTISCAN_FILES_SUPPORTED
-
-/*
- * Consume input data and store it in the full-image coefficient buffer.
- * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
- * ie, v_samp_factor block rows for each component in the scan.
- * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
- */
-
-METHODDEF(int)
-consume_data (j_decompress_ptr cinfo)
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
- JDIMENSION MCU_col_num; /* index of current MCU within row */
- int blkn, ci, xindex, yindex, yoffset;
- JDIMENSION start_col;
- JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
- JBLOCKROW buffer_ptr;
- jpeg_component_info *compptr;
-
- /* Align the virtual buffers for the components used in this scan. */
- for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
- compptr = cinfo->cur_comp_info[ci];
- buffer[ci] = (*cinfo->mem->access_virt_barray)
- ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
- cinfo->input_iMCU_row * compptr->v_samp_factor,
- (JDIMENSION) compptr->v_samp_factor, TRUE);
- /* Note: entropy decoder expects buffer to be zeroed,
- * but this is handled automatically by the memory manager
- * because we requested a pre-zeroed array.
- */
- }
-
- /* Loop to process one whole iMCU row */
- for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
- yoffset++) {
- for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
- MCU_col_num++) {
- /* Construct list of pointers to DCT blocks belonging to this MCU */
- blkn = 0; /* index of current DCT block within MCU */
- for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
- compptr = cinfo->cur_comp_info[ci];
- start_col = MCU_col_num * compptr->MCU_width;
- for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
- buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
- for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
- coef->MCU_buffer[blkn++] = buffer_ptr++;
- }
- }
- }
- /* Try to fetch the MCU. */
- if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
- /* Suspension forced; update state counters and exit */
- coef->MCU_vert_offset = yoffset;
- coef->MCU_ctr = MCU_col_num;
- return JPEG_SUSPENDED;
- }
- }
- /* Completed an MCU row, but perhaps not an iMCU row */
- coef->MCU_ctr = 0;
- }
- /* Completed the iMCU row, advance counters for next one */
- if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
- start_iMCU_row(cinfo);
- return JPEG_ROW_COMPLETED;
- }
- /* Completed the scan */
- (*cinfo->inputctl->finish_input_pass) (cinfo);
- return JPEG_SCAN_COMPLETED;
-}
-
-
-/*
- * Decompress and return some data in the multi-pass case.
- * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
- * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
- *
- * NB: output_buf contains a plane for each component in image.
- */
-
-METHODDEF(int)
-decompress_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
- JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
- JDIMENSION block_num;
- int ci, block_row, block_rows;
- JBLOCKARRAY buffer;
- JBLOCKROW buffer_ptr;
- JSAMPARRAY output_ptr;
- JDIMENSION output_col;
- jpeg_component_info *compptr;
- inverse_DCT_method_ptr inverse_DCT;
-
- /* Force some input to be done if we are getting ahead of the input. */
- while (cinfo->input_scan_number < cinfo->output_scan_number ||
- (cinfo->input_scan_number == cinfo->output_scan_number &&
- cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
- if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
- return JPEG_SUSPENDED;
- }
-
- /* OK, output from the virtual arrays. */
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- /* Don't bother to IDCT an uninteresting component. */
- if (! compptr->component_needed)
- continue;
- /* Align the virtual buffer for this component. */
- buffer = (*cinfo->mem->access_virt_barray)
- ((j_common_ptr) cinfo, coef->whole_image[ci],
- cinfo->output_iMCU_row * compptr->v_samp_factor,
- (JDIMENSION) compptr->v_samp_factor, FALSE);
- /* Count non-dummy DCT block rows in this iMCU row. */
- if (cinfo->output_iMCU_row < last_iMCU_row)
- block_rows = compptr->v_samp_factor;
- else {
- /* NB: can't use last_row_height here; it is input-side-dependent! */
- block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
- if (block_rows == 0) block_rows = compptr->v_samp_factor;
- }
- inverse_DCT = cinfo->idct->inverse_DCT[ci];
- output_ptr = output_buf[ci];
- /* Loop over all DCT blocks to be processed. */
- for (block_row = 0; block_row < block_rows; block_row++) {
- buffer_ptr = buffer[block_row];
- output_col = 0;
- for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) {
- (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr,
- output_ptr, output_col);
- buffer_ptr++;
- output_col += compptr->DCT_h_scaled_size;
- }
- output_ptr += compptr->DCT_v_scaled_size;
- }
- }
-
- if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
- return JPEG_ROW_COMPLETED;
- return JPEG_SCAN_COMPLETED;
-}
-
-#endif /* D_MULTISCAN_FILES_SUPPORTED */
-
-
-#ifdef BLOCK_SMOOTHING_SUPPORTED
-
-/*
- * This code applies interblock smoothing as described by section K.8
- * of the JPEG standard: the first 5 AC coefficients are estimated from
- * the DC values of a DCT block and its 8 neighboring blocks.
- * We apply smoothing only for progressive JPEG decoding, and only if
- * the coefficients it can estimate are not yet known to full precision.
- */
-
-/* Natural-order array positions of the first 5 zigzag-order coefficients */
-#define Q01_POS 1
-#define Q10_POS 8
-#define Q20_POS 16
-#define Q11_POS 9
-#define Q02_POS 2
-
-/*
- * Determine whether block smoothing is applicable and safe.
- * We also latch the current states of the coef_bits[] entries for the
- * AC coefficients; otherwise, if the input side of the decompressor
- * advances into a new scan, we might think the coefficients are known
- * more accurately than they really are.
- */
-
-LOCAL(boolean)
-smoothing_ok (j_decompress_ptr cinfo)
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
- boolean smoothing_useful = FALSE;
- int ci, coefi;
- jpeg_component_info *compptr;
- JQUANT_TBL * qtable;
- int * coef_bits;
- int * coef_bits_latch;
-
- if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)
- return FALSE;
-
- /* Allocate latch area if not already done */
- if (coef->coef_bits_latch == NULL)
- coef->coef_bits_latch = (int *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- cinfo->num_components *
- (SAVED_COEFS * SIZEOF(int)));
- coef_bits_latch = coef->coef_bits_latch;
-
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- /* All components' quantization values must already be latched. */
- if ((qtable = compptr->quant_table) == NULL)
- return FALSE;
- /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
- if (qtable->quantval[0] == 0 ||
- qtable->quantval[Q01_POS] == 0 ||
- qtable->quantval[Q10_POS] == 0 ||
- qtable->quantval[Q20_POS] == 0 ||
- qtable->quantval[Q11_POS] == 0 ||
- qtable->quantval[Q02_POS] == 0)
- return FALSE;
- /* DC values must be at least partly known for all components. */
- coef_bits = cinfo->coef_bits[ci];
- if (coef_bits[0] < 0)
- return FALSE;
- /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
- for (coefi = 1; coefi <= 5; coefi++) {
- coef_bits_latch[coefi] = coef_bits[coefi];
- if (coef_bits[coefi] != 0)
- smoothing_useful = TRUE;
- }
- coef_bits_latch += SAVED_COEFS;
- }
-
- return smoothing_useful;
-}
-
-
-/*
- * Variant of decompress_data for use when doing block smoothing.
- */
-
-METHODDEF(int)
-decompress_smooth_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
-{
- my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
- JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
- JDIMENSION block_num, last_block_column;
- int ci, block_row, block_rows, access_rows;
- JBLOCKARRAY buffer;
- JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
- JSAMPARRAY output_ptr;
- JDIMENSION output_col;
- jpeg_component_info *compptr;
- inverse_DCT_method_ptr inverse_DCT;
- boolean first_row, last_row;
- JBLOCK workspace;
- int *coef_bits;
- JQUANT_TBL *quanttbl;
- INT32 Q00,Q01,Q02,Q10,Q11,Q20, num;
- int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9;
- int Al, pred;
-
- /* Force some input to be done if we are getting ahead of the input. */
- while (cinfo->input_scan_number <= cinfo->output_scan_number &&
- ! cinfo->inputctl->eoi_reached) {
- if (cinfo->input_scan_number == cinfo->output_scan_number) {
- /* If input is working on current scan, we ordinarily want it to
- * have completed the current row. But if input scan is DC,
- * we want it to keep one row ahead so that next block row's DC
- * values are up to date.
- */
- JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;
- if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta)
- break;
- }
- if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
- return JPEG_SUSPENDED;
- }
-
- /* OK, output from the virtual arrays. */
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- /* Don't bother to IDCT an uninteresting component. */
- if (! compptr->component_needed)
- continue;
- /* Count non-dummy DCT block rows in this iMCU row. */
- if (cinfo->output_iMCU_row < last_iMCU_row) {
- block_rows = compptr->v_samp_factor;
- access_rows = block_rows * 2; /* this and next iMCU row */
- last_row = FALSE;
- } else {
- /* NB: can't use last_row_height here; it is input-side-dependent! */
- block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
- if (block_rows == 0) block_rows = compptr->v_samp_factor;
- access_rows = block_rows; /* this iMCU row only */
- last_row = TRUE;
- }
- /* Align the virtual buffer for this component. */
- if (cinfo->output_iMCU_row > 0) {
- access_rows += compptr->v_samp_factor; /* prior iMCU row too */
- buffer = (*cinfo->mem->access_virt_barray)
- ((j_common_ptr) cinfo, coef->whole_image[ci],
- (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
- (JDIMENSION) access_rows, FALSE);
- buffer += compptr->v_samp_factor; /* point to current iMCU row */
- first_row = FALSE;
- } else {
- buffer = (*cinfo->mem->access_virt_barray)
- ((j_common_ptr) cinfo, coef->whole_image[ci],
- (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE);
- first_row = TRUE;
- }
- /* Fetch component-dependent info */
- coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
- quanttbl = compptr->quant_table;
- Q00 = quanttbl->quantval[0];
- Q01 = quanttbl->quantval[Q01_POS];
- Q10 = quanttbl->quantval[Q10_POS];
- Q20 = quanttbl->quantval[Q20_POS];
- Q11 = quanttbl->quantval[Q11_POS];
- Q02 = quanttbl->quantval[Q02_POS];
- inverse_DCT = cinfo->idct->inverse_DCT[ci];
- output_ptr = output_buf[ci];
- /* Loop over all DCT blocks to be processed. */
- for (block_row = 0; block_row < block_rows; block_row++) {
- buffer_ptr = buffer[block_row];
- if (first_row && block_row == 0)
- prev_block_row = buffer_ptr;
- else
- prev_block_row = buffer[block_row-1];
- if (last_row && block_row == block_rows-1)
- next_block_row = buffer_ptr;
- else
- next_block_row = buffer[block_row+1];
- /* We fetch the surrounding DC values using a sliding-register approach.
- * Initialize all nine here so as to do the right thing on narrow pics.
- */
- DC1 = DC2 = DC3 = (int) prev_block_row[0][0];
- DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];
- DC7 = DC8 = DC9 = (int) next_block_row[0][0];
- output_col = 0;
- last_block_column = compptr->width_in_blocks - 1;
- for (block_num = 0; block_num <= last_block_column; block_num++) {
- /* Fetch current DCT block into workspace so we can modify it. */
- jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1);
- /* Update DC values */
- if (block_num < last_block_column) {
- DC3 = (int) prev_block_row[1][0];
- DC6 = (int) buffer_ptr[1][0];
- DC9 = (int) next_block_row[1][0];
- }
- /* Compute coefficient estimates per K.8.
- * An estimate is applied only if coefficient is still zero,
- * and is not known to be fully accurate.
- */
- /* AC01 */
- if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) {
- num = 36 * Q00 * (DC4 - DC6);
- if (num >= 0) {
- pred = (int) (((Q01<<7) + num) / (Q01<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- } else {
- pred = (int) (((Q01<<7) - num) / (Q01<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- pred = -pred;
- }
- workspace[1] = (JCOEF) pred;
- }
- /* AC10 */
- if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) {
- num = 36 * Q00 * (DC2 - DC8);
- if (num >= 0) {
- pred = (int) (((Q10<<7) + num) / (Q10<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- } else {
- pred = (int) (((Q10<<7) - num) / (Q10<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- pred = -pred;
- }
- workspace[8] = (JCOEF) pred;
- }
- /* AC20 */
- if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) {
- num = 9 * Q00 * (DC2 + DC8 - 2*DC5);
- if (num >= 0) {
- pred = (int) (((Q20<<7) + num) / (Q20<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- } else {
- pred = (int) (((Q20<<7) - num) / (Q20<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- pred = -pred;
- }
- workspace[16] = (JCOEF) pred;
- }
- /* AC11 */
- if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) {
- num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
- if (num >= 0) {
- pred = (int) (((Q11<<7) + num) / (Q11<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- } else {
- pred = (int) (((Q11<<7) - num) / (Q11<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- pred = -pred;
- }
- workspace[9] = (JCOEF) pred;
- }
- /* AC02 */
- if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) {
- num = 9 * Q00 * (DC4 + DC6 - 2*DC5);
- if (num >= 0) {
- pred = (int) (((Q02<<7) + num) / (Q02<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- } else {
- pred = (int) (((Q02<<7) - num) / (Q02<<8));
- if (Al > 0 && pred >= (1<<Al))
- pred = (1<<Al)-1;
- pred = -pred;
- }
- workspace[2] = (JCOEF) pred;
- }
- /* OK, do the IDCT */
- (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace,
- output_ptr, output_col);
- /* Advance for next column */
- DC1 = DC2; DC2 = DC3;
- DC4 = DC5; DC5 = DC6;
- DC7 = DC8; DC8 = DC9;
- buffer_ptr++, prev_block_row++, next_block_row++;
- output_col += compptr->DCT_h_scaled_size;
- }
- output_ptr += compptr->DCT_v_scaled_size;
- }
- }
-
- if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
- return JPEG_ROW_COMPLETED;
- return JPEG_SCAN_COMPLETED;
-}
-
-#endif /* BLOCK_SMOOTHING_SUPPORTED */
-
-
-/*
- * Initialize coefficient buffer controller.
- */
-
-GLOBAL(void)
-jinit_d_coef_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
-{
- my_coef_ptr coef;
-
- coef = (my_coef_ptr)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(my_coef_controller));
- cinfo->coef = (struct jpeg_d_coef_controller *) coef;
- coef->pub.start_input_pass = start_input_pass;
- coef->pub.start_output_pass = start_output_pass;
-#ifdef BLOCK_SMOOTHING_SUPPORTED
- coef->coef_bits_latch = NULL;
-#endif
-
- /* Create the coefficient buffer. */
- if (need_full_buffer) {
-#ifdef D_MULTISCAN_FILES_SUPPORTED
- /* Allocate a full-image virtual array for each component, */
- /* padded to a multiple of samp_factor DCT blocks in each direction. */
- /* Note we ask for a pre-zeroed array. */
- int ci, access_rows;
- jpeg_component_info *compptr;
-
- for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
- ci++, compptr++) {
- access_rows = compptr->v_samp_factor;
-#ifdef BLOCK_SMOOTHING_SUPPORTED
- /* If block smoothing could be used, need a bigger window */
- if (cinfo->progressive_mode)
- access_rows *= 3;
-#endif
- coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
- ((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,
- (JDIMENSION) jround_up((long) compptr->width_in_blocks,
- (long) compptr->h_samp_factor),
- (JDIMENSION) jround_up((long) compptr->height_in_blocks,
- (long) compptr->v_samp_factor),
- (JDIMENSION) access_rows);
- }
- coef->pub.consume_data = consume_data;
- coef->pub.decompress_data = decompress_data;
- coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
-#else
- ERREXIT(cinfo, JERR_NOT_COMPILED);
-#endif
- } else {
- /* We only need a single-MCU buffer. */
- JBLOCKROW buffer;
- int i;
-
- buffer = (JBLOCKROW)
- (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
- for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
- coef->MCU_buffer[i] = buffer + i;
- }
- if (cinfo->lim_Se == 0) /* DC only case: want to bypass later */
- FMEMZERO((void FAR *) buffer,
- (size_t) (D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)));
- coef->pub.consume_data = dummy_consume_data;
- coef->pub.decompress_data = decompress_onepass;
- coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
- }
-}