<html><!-- Created using the cpp_pretty_printer from the dlib C++ library. See http://dlib.net for updates. --><head><title>dlib C++ Library - jddctmgr.c</title></head><body bgcolor='white'><pre>
<font color='#009900'>/*
* jddctmgr.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* Modified 2002-2010 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 inverse-DCT management logic.
* This code selects a particular IDCT implementation to be used,
* and it performs related housekeeping chores. No code in this file
* is executed per IDCT step, only during output pass setup.
*
* Note that the IDCT routines are responsible for performing coefficient
* dequantization as well as the IDCT proper. This module sets up the
* dequantization multiplier table needed by the IDCT routine.
*/</font>
<font color='#0000FF'>#define</font> JPEG_INTERNALS
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='jinclude.h.html'>jinclude.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='jpeglib.h.html'>jpeglib.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='jdct.h.html'>jdct.h</a>" <font color='#009900'>/* Private declarations for DCT subsystem */</font>
<font color='#009900'>/*
* The decompressor input side (jdinput.c) saves away the appropriate
* quantization table for each component at the start of the first scan
* involving that component. (This is necessary in order to correctly
* decode files that reuse Q-table slots.)
* When we are ready to make an output pass, the saved Q-table is converted
* to a multiplier table that will actually be used by the IDCT routine.
* The multiplier table contents are IDCT-method-dependent. To support
* application changes in IDCT method between scans, we can remake the
* multiplier tables if necessary.
* In buffered-image mode, the first output pass may occur before any data
* has been seen for some components, and thus before their Q-tables have
* been saved away. To handle this case, multiplier tables are preset
* to zeroes; the result of the IDCT will be a neutral gray level.
*/</font>
<font color='#009900'>/* Private subobject for this module */</font>
<font color='#0000FF'>typedef</font> <font color='#0000FF'>struct</font> <b>{</b>
<font color='#0000FF'>struct</font> jpeg_inverse_dct pub; <font color='#009900'>/* public fields */</font>
<font color='#009900'>/* This array contains the IDCT method code that each multiplier table
* is currently set up for, or -1 if it's not yet set up.
* The actual multiplier tables are pointed to by dct_table in the
* per-component comp_info structures.
*/</font>
<font color='#0000FF'><u>int</u></font> cur_method[MAX_COMPONENTS];
<b>}</b> my_idct_controller;
<font color='#0000FF'>typedef</font> my_idct_controller <font color='#5555FF'>*</font> my_idct_ptr;
<font color='#009900'>/* Allocated multiplier tables: big enough for any supported variant */</font>
<font color='#0000FF'>typedef</font> <font color='#0000FF'>union</font> <b>{</b>
ISLOW_MULT_TYPE islow_array[DCTSIZE2];
<font color='#0000FF'>#ifdef</font> DCT_IFAST_SUPPORTED
IFAST_MULT_TYPE ifast_array[DCTSIZE2];
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#ifdef</font> DCT_FLOAT_SUPPORTED
FLOAT_MULT_TYPE float_array[DCTSIZE2];
<font color='#0000FF'>#endif</font>
<b>}</b> multiplier_table;
<font color='#009900'>/* The current scaled-IDCT routines require ISLOW-style multiplier tables,
* so be sure to compile that code if either ISLOW or SCALING is requested.
*/</font>
<font color='#0000FF'>#ifdef</font> DCT_ISLOW_SUPPORTED
<font color='#0000FF'>#define</font> PROVIDE_ISLOW_TABLES
<font color='#0000FF'>#else</font>
<font color='#0000FF'>#ifdef</font> IDCT_SCALING_SUPPORTED
<font color='#0000FF'>#define</font> PROVIDE_ISLOW_TABLES
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#endif</font>
<font color='#009900'>/*
* Prepare for an output pass.
* Here we select the proper IDCT routine for each component and build
* a matching multiplier table.
*/</font>
<b><a name='METHODDEF'></a>METHODDEF</b><font face='Lucida Console'>(</font><font color='#0000FF'><u>void</u></font><font face='Lucida Console'>)</font>
<b><a name='start_pass'></a>start_pass</b> <font face='Lucida Console'>(</font>j_decompress_ptr cinfo<font face='Lucida Console'>)</font>
<b>{</b>
my_idct_ptr idct <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>my_idct_ptr<font face='Lucida Console'>)</font> cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>idct;
<font color='#0000FF'><u>int</u></font> ci, i;
jpeg_component_info <font color='#5555FF'>*</font>compptr;
<font color='#0000FF'><u>int</u></font> method <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
inverse_DCT_method_ptr method_ptr <font color='#5555FF'>=</font> NULL;
JQUANT_TBL <font color='#5555FF'>*</font> qtbl;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>ci <font color='#5555FF'>=</font> <font color='#979000'>0</font>, compptr <font color='#5555FF'>=</font> cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>comp_info; ci <font color='#5555FF'><</font> cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>num_components;
ci<font color='#5555FF'>+</font><font color='#5555FF'>+</font>, compptr<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
<font color='#009900'>/* Select the proper IDCT routine for this component's scaling */</font>
<font color='#0000FF'>switch</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font>compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>DCT_h_scaled_size <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>DCT_v_scaled_size<font face='Lucida Console'>)</font> <b>{</b>
<font color='#0000FF'>#ifdef</font> IDCT_SCALING_SUPPORTED
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>1</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>1</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_1x1;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>2</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>2</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_2x2;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>3</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>3</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_3x3;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>4</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>4</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_4x4;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>5</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>5</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_5x5;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>6</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>6</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_6x6;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>7</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>7</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_7x7;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>9</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>9</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_9x9;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>10</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>10</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_10x10;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>11</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>11</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_11x11;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>12</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>12</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_12x12;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>13</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>13</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_13x13;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>14</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>14</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_14x14;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>15</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>15</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_15x15;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>16</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>16</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_16x16;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>16</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_16x8;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>14</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>7</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_14x7;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>12</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>6</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_12x6;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>10</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>5</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_10x5;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>8</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>4</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_8x4;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>6</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>3</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_6x3;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>4</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>2</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_4x2;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>2</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>1</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_2x1;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>8</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>16</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_8x16;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>7</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>14</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_7x14;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>6</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>12</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_6x12;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>5</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>10</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_5x10;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>4</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_4x8;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>3</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>6</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_3x6;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>2</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>4</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_2x4;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#979000'>1</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> <font color='#979000'>2</font><font face='Lucida Console'>)</font>:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_1x2;
method <font color='#5555FF'>=</font> JDCT_ISLOW; <font color='#009900'>/* jidctint uses islow-style table */</font>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>case</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font>DCTSIZE <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#979000'>8</font><font face='Lucida Console'>)</font> <font color='#5555FF'>+</font> DCTSIZE<font face='Lucida Console'>)</font>:
<font color='#0000FF'>switch</font> <font face='Lucida Console'>(</font>cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_method<font face='Lucida Console'>)</font> <b>{</b>
<font color='#0000FF'>#ifdef</font> DCT_ISLOW_SUPPORTED
<font color='#0000FF'>case</font> JDCT_ISLOW:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_islow;
method <font color='#5555FF'>=</font> JDCT_ISLOW;
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#ifdef</font> DCT_IFAST_SUPPORTED
<font color='#0000FF'>case</font> JDCT_IFAST:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_ifast;
method <font color='#5555FF'>=</font> JDCT_IFAST;
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#ifdef</font> DCT_FLOAT_SUPPORTED
<font color='#0000FF'>case</font> JDCT_FLOAT:
method_ptr <font color='#5555FF'>=</font> jpeg_idct_float;
method <font color='#5555FF'>=</font> JDCT_FLOAT;
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>default</font>:
<font color='#BB00BB'>ERREXIT</font><font face='Lucida Console'>(</font>cinfo, JERR_NOT_COMPILED<font face='Lucida Console'>)</font>;
<font color='#0000FF'>break</font>;
<b>}</b>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>default</font>:
<font color='#BB00BB'>ERREXIT2</font><font face='Lucida Console'>(</font>cinfo, JERR_BAD_DCTSIZE,
compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>DCT_h_scaled_size, compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>DCT_v_scaled_size<font face='Lucida Console'>)</font>;
<font color='#0000FF'>break</font>;
<b>}</b>
idct<font color='#5555FF'>-</font><font color='#5555FF'>></font>pub.inverse_DCT[ci] <font color='#5555FF'>=</font> method_ptr;
<font color='#009900'>/* Create multiplier table from quant table.
* However, we can skip this if the component is uninteresting
* or if we already built the table. Also, if no quant table
* has yet been saved for the component, we leave the
* multiplier table all-zero; we'll be reading zeroes from the
* coefficient controller's buffer anyway.
*/</font>
<font color='#0000FF'>if</font> <font face='Lucida Console'>(</font><font color='#5555FF'>!</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>component_needed <font color='#5555FF'>|</font><font color='#5555FF'>|</font> idct<font color='#5555FF'>-</font><font color='#5555FF'>></font>cur_method[ci] <font color='#5555FF'>=</font><font color='#5555FF'>=</font> method<font face='Lucida Console'>)</font>
<font color='#0000FF'>continue</font>;
qtbl <font color='#5555FF'>=</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>quant_table;
<font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>qtbl <font color='#5555FF'>=</font><font color='#5555FF'>=</font> NULL<font face='Lucida Console'>)</font> <font color='#009900'>/* happens if no data yet for component */</font>
<font color='#0000FF'>continue</font>;
idct<font color='#5555FF'>-</font><font color='#5555FF'>></font>cur_method[ci] <font color='#5555FF'>=</font> method;
<font color='#0000FF'>switch</font> <font face='Lucida Console'>(</font>method<font face='Lucida Console'>)</font> <b>{</b>
<font color='#0000FF'>#ifdef</font> PROVIDE_ISLOW_TABLES
<font color='#0000FF'>case</font> JDCT_ISLOW:
<b>{</b>
<font color='#009900'>/* For LL&M IDCT method, multipliers are equal to raw quantization
* coefficients, but are stored as ints to ensure access efficiency.
*/</font>
ISLOW_MULT_TYPE <font color='#5555FF'>*</font> ismtbl <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>ISLOW_MULT_TYPE <font color='#5555FF'>*</font><font face='Lucida Console'>)</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_table;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> DCTSIZE2; i<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
ismtbl[i] <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>ISLOW_MULT_TYPE<font face='Lucida Console'>)</font> qtbl<font color='#5555FF'>-</font><font color='#5555FF'>></font>quantval[i];
<b>}</b>
<b>}</b>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#ifdef</font> DCT_IFAST_SUPPORTED
<font color='#0000FF'>case</font> JDCT_IFAST:
<b>{</b>
<font color='#009900'>/* For AA&N IDCT method, multipliers are equal to quantization
* coefficients scaled by scalefactor[row]*scalefactor[col], where
* scalefactor[0] = 1
* scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
* For integer operation, the multiplier table is to be scaled by
* IFAST_SCALE_BITS.
*/</font>
IFAST_MULT_TYPE <font color='#5555FF'>*</font> ifmtbl <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>IFAST_MULT_TYPE <font color='#5555FF'>*</font><font face='Lucida Console'>)</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_table;
<font color='#0000FF'>#define</font> CONST_BITS <font color='#979000'>14</font>
<font color='#0000FF'>static</font> <font color='#0000FF'>const</font> INT16 aanscales[DCTSIZE2] <font color='#5555FF'>=</font> <b>{</b>
<font color='#009900'>/* precomputed values scaled up by 14 bits */</font>
<font color='#979000'>16384</font>, <font color='#979000'>22725</font>, <font color='#979000'>21407</font>, <font color='#979000'>19266</font>, <font color='#979000'>16384</font>, <font color='#979000'>12873</font>, <font color='#979000'>8867</font>, <font color='#979000'>4520</font>,
<font color='#979000'>22725</font>, <font color='#979000'>31521</font>, <font color='#979000'>29692</font>, <font color='#979000'>26722</font>, <font color='#979000'>22725</font>, <font color='#979000'>17855</font>, <font color='#979000'>12299</font>, <font color='#979000'>6270</font>,
<font color='#979000'>21407</font>, <font color='#979000'>29692</font>, <font color='#979000'>27969</font>, <font color='#979000'>25172</font>, <font color='#979000'>21407</font>, <font color='#979000'>16819</font>, <font color='#979000'>11585</font>, <font color='#979000'>5906</font>,
<font color='#979000'>19266</font>, <font color='#979000'>26722</font>, <font color='#979000'>25172</font>, <font color='#979000'>22654</font>, <font color='#979000'>19266</font>, <font color='#979000'>15137</font>, <font color='#979000'>10426</font>, <font color='#979000'>5315</font>,
<font color='#979000'>16384</font>, <font color='#979000'>22725</font>, <font color='#979000'>21407</font>, <font color='#979000'>19266</font>, <font color='#979000'>16384</font>, <font color='#979000'>12873</font>, <font color='#979000'>8867</font>, <font color='#979000'>4520</font>,
<font color='#979000'>12873</font>, <font color='#979000'>17855</font>, <font color='#979000'>16819</font>, <font color='#979000'>15137</font>, <font color='#979000'>12873</font>, <font color='#979000'>10114</font>, <font color='#979000'>6967</font>, <font color='#979000'>3552</font>,
<font color='#979000'>8867</font>, <font color='#979000'>12299</font>, <font color='#979000'>11585</font>, <font color='#979000'>10426</font>, <font color='#979000'>8867</font>, <font color='#979000'>6967</font>, <font color='#979000'>4799</font>, <font color='#979000'>2446</font>,
<font color='#979000'>4520</font>, <font color='#979000'>6270</font>, <font color='#979000'>5906</font>, <font color='#979000'>5315</font>, <font color='#979000'>4520</font>, <font color='#979000'>3552</font>, <font color='#979000'>2446</font>, <font color='#979000'>1247</font>
<b>}</b>;
SHIFT_TEMPS
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> DCTSIZE2; i<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
ifmtbl[i] <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>IFAST_MULT_TYPE<font face='Lucida Console'>)</font>
<font color='#BB00BB'>DESCALE</font><font face='Lucida Console'>(</font><font color='#BB00BB'>MULTIPLY16V16</font><font face='Lucida Console'>(</font><font face='Lucida Console'>(</font>INT32<font face='Lucida Console'>)</font> qtbl<font color='#5555FF'>-</font><font color='#5555FF'>></font>quantval[i],
<font face='Lucida Console'>(</font>INT32<font face='Lucida Console'>)</font> aanscales[i]<font face='Lucida Console'>)</font>,
CONST_BITS<font color='#5555FF'>-</font>IFAST_SCALE_BITS<font face='Lucida Console'>)</font>;
<b>}</b>
<b>}</b>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>#ifdef</font> DCT_FLOAT_SUPPORTED
<font color='#0000FF'>case</font> JDCT_FLOAT:
<b>{</b>
<font color='#009900'>/* For float AA&N IDCT method, multipliers are equal to quantization
* coefficients scaled by scalefactor[row]*scalefactor[col], where
* scalefactor[0] = 1
* scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
* We apply a further scale factor of 1/8.
*/</font>
FLOAT_MULT_TYPE <font color='#5555FF'>*</font> fmtbl <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>FLOAT_MULT_TYPE <font color='#5555FF'>*</font><font face='Lucida Console'>)</font> compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_table;
<font color='#0000FF'><u>int</u></font> row, col;
<font color='#0000FF'>static</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>double</u></font> aanscalefactor[DCTSIZE] <font color='#5555FF'>=</font> <b>{</b>
<font color='#979000'>1.0</font>, <font color='#979000'>1.387039845</font>, <font color='#979000'>1.306562965</font>, <font color='#979000'>1.175875602</font>,
<font color='#979000'>1.0</font>, <font color='#979000'>0.785694958</font>, <font color='#979000'>0.541196100</font>, <font color='#979000'>0.275899379</font>
<b>}</b>;
i <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>row <font color='#5555FF'>=</font> <font color='#979000'>0</font>; row <font color='#5555FF'><</font> DCTSIZE; row<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>col <font color='#5555FF'>=</font> <font color='#979000'>0</font>; col <font color='#5555FF'><</font> DCTSIZE; col<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
fmtbl[i] <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>FLOAT_MULT_TYPE<font face='Lucida Console'>)</font>
<font face='Lucida Console'>(</font><font face='Lucida Console'>(</font><font color='#0000FF'><u>double</u></font><font face='Lucida Console'>)</font> qtbl<font color='#5555FF'>-</font><font color='#5555FF'>></font>quantval[i] <font color='#5555FF'>*</font>
aanscalefactor[row] <font color='#5555FF'>*</font> aanscalefactor[col] <font color='#5555FF'>*</font> <font color='#979000'>0.125</font><font face='Lucida Console'>)</font>;
i<font color='#5555FF'>+</font><font color='#5555FF'>+</font>;
<b>}</b>
<b>}</b>
<b>}</b>
<font color='#0000FF'>break</font>;
<font color='#0000FF'>#endif</font>
<font color='#0000FF'>default</font>:
<font color='#BB00BB'>ERREXIT</font><font face='Lucida Console'>(</font>cinfo, JERR_NOT_COMPILED<font face='Lucida Console'>)</font>;
<font color='#0000FF'>break</font>;
<b>}</b>
<b>}</b>
<b>}</b>
<font color='#009900'>/*
* Initialize IDCT manager.
*/</font>
<b><a name='GLOBAL'></a>GLOBAL</b><font face='Lucida Console'>(</font><font color='#0000FF'><u>void</u></font><font face='Lucida Console'>)</font>
<b><a name='jinit_inverse_dct'></a>jinit_inverse_dct</b> <font face='Lucida Console'>(</font>j_decompress_ptr cinfo<font face='Lucida Console'>)</font>
<b>{</b>
my_idct_ptr idct;
<font color='#0000FF'><u>int</u></font> ci;
jpeg_component_info <font color='#5555FF'>*</font>compptr;
idct <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>my_idct_ptr<font face='Lucida Console'>)</font>
<font face='Lucida Console'>(</font><font color='#5555FF'>*</font>cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>mem<font color='#5555FF'>-</font><font color='#5555FF'>></font>alloc_small<font face='Lucida Console'>)</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font>j_common_ptr<font face='Lucida Console'>)</font> cinfo, JPOOL_IMAGE,
<font color='#BB00BB'>SIZEOF</font><font face='Lucida Console'>(</font>my_idct_controller<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>idct <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font><font color='#0000FF'>struct</font> jpeg_inverse_dct <font color='#5555FF'>*</font><font face='Lucida Console'>)</font> idct;
idct<font color='#5555FF'>-</font><font color='#5555FF'>></font>pub.start_pass <font color='#5555FF'>=</font> start_pass;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font>ci <font color='#5555FF'>=</font> <font color='#979000'>0</font>, compptr <font color='#5555FF'>=</font> cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>comp_info; ci <font color='#5555FF'><</font> cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>num_components;
ci<font color='#5555FF'>+</font><font color='#5555FF'>+</font>, compptr<font color='#5555FF'>+</font><font color='#5555FF'>+</font><font face='Lucida Console'>)</font> <b>{</b>
<font color='#009900'>/* Allocate and pre-zero a multiplier table for each component */</font>
compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_table <font color='#5555FF'>=</font>
<font face='Lucida Console'>(</font><font color='#5555FF'>*</font>cinfo<font color='#5555FF'>-</font><font color='#5555FF'>></font>mem<font color='#5555FF'>-</font><font color='#5555FF'>></font>alloc_small<font face='Lucida Console'>)</font> <font face='Lucida Console'>(</font><font face='Lucida Console'>(</font>j_common_ptr<font face='Lucida Console'>)</font> cinfo, JPOOL_IMAGE,
<font color='#BB00BB'>SIZEOF</font><font face='Lucida Console'>(</font>multiplier_table<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
<font color='#BB00BB'>MEMZERO</font><font face='Lucida Console'>(</font>compptr<font color='#5555FF'>-</font><font color='#5555FF'>></font>dct_table, <font color='#BB00BB'>SIZEOF</font><font face='Lucida Console'>(</font>multiplier_table<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
<font color='#009900'>/* Mark multiplier table not yet set up for any method */</font>
idct<font color='#5555FF'>-</font><font color='#5555FF'>></font>cur_method[ci] <font color='#5555FF'>=</font> <font color='#5555FF'>-</font><font color='#979000'>1</font>;
<b>}</b>
<b>}</b>
</pre></body></html>