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718112a8fe
Currently none of these is being used, but eventually they will, once more code gets ported over. So it's better to have them right away and avoid editing the project file too much, only to revert that later.
741 lines
25 KiB
C
741 lines
25 KiB
C
/*
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* jdcoefct.c
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*
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* Copyright (C) 1994-1997, Thomas G. Lane.
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* Modified 2002-2011 by Guido Vollbeding.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This file contains the coefficient buffer controller for decompression.
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* This controller is the top level of the JPEG decompressor proper.
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* The coefficient buffer lies between entropy decoding and inverse-DCT steps.
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*
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* In buffered-image mode, this controller is the interface between
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* input-oriented processing and output-oriented processing.
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* Also, the input side (only) is used when reading a file for transcoding.
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*/
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#define JPEG_INTERNALS
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#include "jinclude.h"
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#include "jpeglib.h"
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/* Block smoothing is only applicable for progressive JPEG, so: */
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#ifndef D_PROGRESSIVE_SUPPORTED
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#undef BLOCK_SMOOTHING_SUPPORTED
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#endif
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/* Private buffer controller object */
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typedef struct {
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struct jpeg_d_coef_controller pub; /* public fields */
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/* These variables keep track of the current location of the input side. */
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/* cinfo->input_iMCU_row is also used for this. */
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JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
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int MCU_vert_offset; /* counts MCU rows within iMCU row */
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int MCU_rows_per_iMCU_row; /* number of such rows needed */
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/* The output side's location is represented by cinfo->output_iMCU_row. */
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/* In single-pass modes, it's sufficient to buffer just one MCU.
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* We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
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* and let the entropy decoder write into that workspace each time.
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* (On 80x86, the workspace is FAR even though it's not really very big;
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* this is to keep the module interfaces unchanged when a large coefficient
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* buffer is necessary.)
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* In multi-pass modes, this array points to the current MCU's blocks
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* within the virtual arrays; it is used only by the input side.
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*/
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JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
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#ifdef D_MULTISCAN_FILES_SUPPORTED
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/* In multi-pass modes, we need a virtual block array for each component. */
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jvirt_barray_ptr whole_image[MAX_COMPONENTS];
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#endif
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#ifdef BLOCK_SMOOTHING_SUPPORTED
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/* When doing block smoothing, we latch coefficient Al values here */
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int * coef_bits_latch;
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#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
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#endif
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} my_coef_controller;
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typedef my_coef_controller * my_coef_ptr;
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/* Forward declarations */
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METHODDEF(int) decompress_onepass
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JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
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#ifdef D_MULTISCAN_FILES_SUPPORTED
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METHODDEF(int) decompress_data
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JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
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#endif
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#ifdef BLOCK_SMOOTHING_SUPPORTED
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LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo));
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METHODDEF(int) decompress_smooth_data
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JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
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#endif
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LOCAL(void)
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start_iMCU_row (j_decompress_ptr cinfo)
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/* Reset within-iMCU-row counters for a new row (input side) */
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{
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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/* In an interleaved scan, an MCU row is the same as an iMCU row.
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* In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
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* But at the bottom of the image, process only what's left.
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*/
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if (cinfo->comps_in_scan > 1) {
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coef->MCU_rows_per_iMCU_row = 1;
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} else {
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if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
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coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
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else
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coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
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}
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coef->MCU_ctr = 0;
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coef->MCU_vert_offset = 0;
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}
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/*
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* Initialize for an input processing pass.
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*/
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METHODDEF(void)
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start_input_pass (j_decompress_ptr cinfo)
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{
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cinfo->input_iMCU_row = 0;
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start_iMCU_row(cinfo);
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}
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/*
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* Initialize for an output processing pass.
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*/
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METHODDEF(void)
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start_output_pass (j_decompress_ptr cinfo)
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{
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#ifdef BLOCK_SMOOTHING_SUPPORTED
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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/* If multipass, check to see whether to use block smoothing on this pass */
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if (coef->pub.coef_arrays != NULL) {
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if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
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coef->pub.decompress_data = decompress_smooth_data;
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else
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coef->pub.decompress_data = decompress_data;
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}
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#endif
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cinfo->output_iMCU_row = 0;
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}
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/*
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* Decompress and return some data in the single-pass case.
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* Always attempts to emit one fully interleaved MCU row ("iMCU" row).
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* Input and output must run in lockstep since we have only a one-MCU buffer.
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* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
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*
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* NB: output_buf contains a plane for each component in image,
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* which we index according to the component's SOF position.
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*/
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METHODDEF(int)
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decompress_onepass (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
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{
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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JDIMENSION MCU_col_num; /* index of current MCU within row */
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JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
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JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
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int blkn, ci, xindex, yindex, yoffset, useful_width;
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JSAMPARRAY output_ptr;
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JDIMENSION start_col, output_col;
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jpeg_component_info *compptr;
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inverse_DCT_method_ptr inverse_DCT;
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/* Loop to process as much as one whole iMCU row */
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for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
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yoffset++) {
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for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
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MCU_col_num++) {
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/* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */
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if (cinfo->lim_Se) /* can bypass in DC only case */
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FMEMZERO((void FAR *) coef->MCU_buffer[0],
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(size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK)));
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if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
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/* Suspension forced; update state counters and exit */
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coef->MCU_vert_offset = yoffset;
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coef->MCU_ctr = MCU_col_num;
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return JPEG_SUSPENDED;
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}
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/* Determine where data should go in output_buf and do the IDCT thing.
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* We skip dummy blocks at the right and bottom edges (but blkn gets
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* incremented past them!). Note the inner loop relies on having
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* allocated the MCU_buffer[] blocks sequentially.
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*/
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blkn = 0; /* index of current DCT block within MCU */
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for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
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compptr = cinfo->cur_comp_info[ci];
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/* Don't bother to IDCT an uninteresting component. */
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if (! compptr->component_needed) {
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blkn += compptr->MCU_blocks;
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continue;
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}
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inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
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useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
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: compptr->last_col_width;
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output_ptr = output_buf[compptr->component_index] +
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yoffset * compptr->DCT_v_scaled_size;
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start_col = MCU_col_num * compptr->MCU_sample_width;
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for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
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if (cinfo->input_iMCU_row < last_iMCU_row ||
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yoffset+yindex < compptr->last_row_height) {
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output_col = start_col;
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for (xindex = 0; xindex < useful_width; xindex++) {
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(*inverse_DCT) (cinfo, compptr,
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(JCOEFPTR) coef->MCU_buffer[blkn+xindex],
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output_ptr, output_col);
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output_col += compptr->DCT_h_scaled_size;
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}
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}
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blkn += compptr->MCU_width;
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output_ptr += compptr->DCT_v_scaled_size;
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}
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}
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}
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/* Completed an MCU row, but perhaps not an iMCU row */
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coef->MCU_ctr = 0;
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}
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/* Completed the iMCU row, advance counters for next one */
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cinfo->output_iMCU_row++;
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if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
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start_iMCU_row(cinfo);
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return JPEG_ROW_COMPLETED;
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}
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/* Completed the scan */
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(*cinfo->inputctl->finish_input_pass) (cinfo);
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return JPEG_SCAN_COMPLETED;
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}
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/*
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* Dummy consume-input routine for single-pass operation.
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*/
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METHODDEF(int)
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dummy_consume_data (j_decompress_ptr cinfo)
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{
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return JPEG_SUSPENDED; /* Always indicate nothing was done */
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}
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#ifdef D_MULTISCAN_FILES_SUPPORTED
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/*
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* Consume input data and store it in the full-image coefficient buffer.
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* We read as much as one fully interleaved MCU row ("iMCU" row) per call,
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* ie, v_samp_factor block rows for each component in the scan.
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* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
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*/
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METHODDEF(int)
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consume_data (j_decompress_ptr cinfo)
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{
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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JDIMENSION MCU_col_num; /* index of current MCU within row */
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int blkn, ci, xindex, yindex, yoffset;
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JDIMENSION start_col;
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JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
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JBLOCKROW buffer_ptr;
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jpeg_component_info *compptr;
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/* Align the virtual buffers for the components used in this scan. */
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for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
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compptr = cinfo->cur_comp_info[ci];
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buffer[ci] = (*cinfo->mem->access_virt_barray)
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((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
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cinfo->input_iMCU_row * compptr->v_samp_factor,
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(JDIMENSION) compptr->v_samp_factor, TRUE);
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/* Note: entropy decoder expects buffer to be zeroed,
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* but this is handled automatically by the memory manager
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* because we requested a pre-zeroed array.
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*/
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}
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/* Loop to process one whole iMCU row */
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for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
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yoffset++) {
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for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
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MCU_col_num++) {
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/* Construct list of pointers to DCT blocks belonging to this MCU */
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blkn = 0; /* index of current DCT block within MCU */
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for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
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compptr = cinfo->cur_comp_info[ci];
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start_col = MCU_col_num * compptr->MCU_width;
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for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
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buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
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for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
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coef->MCU_buffer[blkn++] = buffer_ptr++;
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}
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}
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}
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/* Try to fetch the MCU. */
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if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
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/* Suspension forced; update state counters and exit */
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coef->MCU_vert_offset = yoffset;
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coef->MCU_ctr = MCU_col_num;
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return JPEG_SUSPENDED;
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}
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}
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/* Completed an MCU row, but perhaps not an iMCU row */
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coef->MCU_ctr = 0;
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}
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/* Completed the iMCU row, advance counters for next one */
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if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
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start_iMCU_row(cinfo);
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return JPEG_ROW_COMPLETED;
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}
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/* Completed the scan */
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(*cinfo->inputctl->finish_input_pass) (cinfo);
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return JPEG_SCAN_COMPLETED;
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}
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/*
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* Decompress and return some data in the multi-pass case.
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* Always attempts to emit one fully interleaved MCU row ("iMCU" row).
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* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
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*
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* NB: output_buf contains a plane for each component in image.
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*/
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METHODDEF(int)
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decompress_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
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{
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
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JDIMENSION block_num;
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int ci, block_row, block_rows;
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JBLOCKARRAY buffer;
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JBLOCKROW buffer_ptr;
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JSAMPARRAY output_ptr;
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JDIMENSION output_col;
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jpeg_component_info *compptr;
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inverse_DCT_method_ptr inverse_DCT;
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/* Force some input to be done if we are getting ahead of the input. */
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while (cinfo->input_scan_number < cinfo->output_scan_number ||
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(cinfo->input_scan_number == cinfo->output_scan_number &&
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cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
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if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
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return JPEG_SUSPENDED;
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}
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/* OK, output from the virtual arrays. */
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for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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ci++, compptr++) {
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/* Don't bother to IDCT an uninteresting component. */
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if (! compptr->component_needed)
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continue;
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/* Align the virtual buffer for this component. */
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buffer = (*cinfo->mem->access_virt_barray)
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((j_common_ptr) cinfo, coef->whole_image[ci],
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cinfo->output_iMCU_row * compptr->v_samp_factor,
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(JDIMENSION) compptr->v_samp_factor, FALSE);
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/* Count non-dummy DCT block rows in this iMCU row. */
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if (cinfo->output_iMCU_row < last_iMCU_row)
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block_rows = compptr->v_samp_factor;
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else {
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/* NB: can't use last_row_height here; it is input-side-dependent! */
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block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
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if (block_rows == 0) block_rows = compptr->v_samp_factor;
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}
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inverse_DCT = cinfo->idct->inverse_DCT[ci];
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output_ptr = output_buf[ci];
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/* Loop over all DCT blocks to be processed. */
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for (block_row = 0; block_row < block_rows; block_row++) {
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buffer_ptr = buffer[block_row];
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output_col = 0;
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for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) {
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(*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr,
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output_ptr, output_col);
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buffer_ptr++;
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output_col += compptr->DCT_h_scaled_size;
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}
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output_ptr += compptr->DCT_v_scaled_size;
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}
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}
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if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
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return JPEG_ROW_COMPLETED;
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return JPEG_SCAN_COMPLETED;
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}
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#endif /* D_MULTISCAN_FILES_SUPPORTED */
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#ifdef BLOCK_SMOOTHING_SUPPORTED
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/*
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* This code applies interblock smoothing as described by section K.8
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* of the JPEG standard: the first 5 AC coefficients are estimated from
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* the DC values of a DCT block and its 8 neighboring blocks.
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* We apply smoothing only for progressive JPEG decoding, and only if
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* the coefficients it can estimate are not yet known to full precision.
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*/
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/* Natural-order array positions of the first 5 zigzag-order coefficients */
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#define Q01_POS 1
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#define Q10_POS 8
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#define Q20_POS 16
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#define Q11_POS 9
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#define Q02_POS 2
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/*
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* Determine whether block smoothing is applicable and safe.
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* We also latch the current states of the coef_bits[] entries for the
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* AC coefficients; otherwise, if the input side of the decompressor
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* advances into a new scan, we might think the coefficients are known
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* more accurately than they really are.
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*/
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LOCAL(boolean)
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smoothing_ok (j_decompress_ptr cinfo)
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{
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my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
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boolean smoothing_useful = FALSE;
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int ci, coefi;
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jpeg_component_info *compptr;
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JQUANT_TBL * qtable;
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int * coef_bits;
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int * coef_bits_latch;
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if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)
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return FALSE;
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/* Allocate latch area if not already done */
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if (coef->coef_bits_latch == NULL)
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coef->coef_bits_latch = (int *)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
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cinfo->num_components *
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(SAVED_COEFS * SIZEOF(int)));
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coef_bits_latch = coef->coef_bits_latch;
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for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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ci++, compptr++) {
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/* All components' quantization values must already be latched. */
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if ((qtable = compptr->quant_table) == NULL)
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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 */
|
|
}
|
|
}
|