2e8360e061
Patch obtained from: https://sourceforge.net/projects/jpeg/files/ftp.oceana.com Author date taken from original announcement and timestamp of patch tarball: https://groups.google.com/g/comp.protocols.dicom/c/rrkP8BxoMRk/m/Ij4dfprggp8J
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/*
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* jdlossls.c
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*
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* Copyright (C) 1998, Thomas G. Lane.
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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 control logic for the lossless JPEG decompressor.
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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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#include "jlossls.h"
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#ifdef D_LOSSLESS_SUPPORTED
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/*
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* Compute output image dimensions and related values.
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*/
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METHODDEF(void)
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calc_output_dimensions (j_decompress_ptr cinfo)
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{
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/* Hardwire it to "no scaling" */
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cinfo->output_width = cinfo->image_width;
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cinfo->output_height = cinfo->image_height;
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/* jdinput.c has already initialized codec_data_unit to 1,
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* and has computed unscaled downsampled_width and downsampled_height.
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*/
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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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j_lossless_d_ptr losslsd = (j_lossless_d_ptr) cinfo->codec;
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(*losslsd->entropy_start_pass) (cinfo);
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(*losslsd->predict_start_pass) (cinfo);
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(*losslsd->scaler_start_pass) (cinfo);
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(*losslsd->diff_start_input_pass) (cinfo);
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}
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/*
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* Initialize the lossless decompression codec.
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* This is called only once, during master selection.
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*/
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GLOBAL(void)
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jinit_lossless_d_codec(j_decompress_ptr cinfo)
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{
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j_lossless_d_ptr losslsd;
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boolean use_c_buffer;
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/* Create subobject in permanent pool */
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losslsd = (j_lossless_d_ptr)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
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SIZEOF(jpeg_lossless_d_codec));
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cinfo->codec = (struct jpeg_d_codec *) losslsd;
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/* Initialize sub-modules */
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/* Entropy decoding: either Huffman or arithmetic coding. */
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if (cinfo->arith_code) {
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ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
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} else {
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jinit_lhuff_decoder(cinfo);
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}
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/* Undifferencer */
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jinit_undifferencer(cinfo);
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/* Scaler */
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jinit_d_scaler(cinfo);
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use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image;
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jinit_d_diff_controller(cinfo, use_c_buffer);
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/* Initialize method pointers.
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*
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* Note: consume_data, start_output_pass and decompress_data are
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* assigned in jddiffct.c.
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*/
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losslsd->pub.calc_output_dimensions = calc_output_dimensions;
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losslsd->pub.start_input_pass = start_input_pass;
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}
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#endif /* D_LOSSLESS_SUPPORTED */
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