Final 350 project

Dependencies:   uzair Camera_LS_Y201 F7_Ethernet LCD_DISCO_F746NG NetworkAPI SDFileSystem mbed

Committer:
shoaib_ahmed
Date:
Mon Jul 31 09:16:35 2017 +0000
Revision:
0:791a779d6220
final project;

Who changed what in which revision?

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shoaib_ahmed 0:791a779d6220 1 /*
shoaib_ahmed 0:791a779d6220 2 * jdmainct.c
shoaib_ahmed 0:791a779d6220 3 *
shoaib_ahmed 0:791a779d6220 4 * Copyright (C) 1994-1996, Thomas G. Lane.
shoaib_ahmed 0:791a779d6220 5 * Modified 2002-2012 by Guido Vollbeding.
shoaib_ahmed 0:791a779d6220 6 * This file is part of the Independent JPEG Group's software.
shoaib_ahmed 0:791a779d6220 7 * For conditions of distribution and use, see the accompanying README file.
shoaib_ahmed 0:791a779d6220 8 *
shoaib_ahmed 0:791a779d6220 9 * This file contains the main buffer controller for decompression.
shoaib_ahmed 0:791a779d6220 10 * The main buffer lies between the JPEG decompressor proper and the
shoaib_ahmed 0:791a779d6220 11 * post-processor; it holds downsampled data in the JPEG colorspace.
shoaib_ahmed 0:791a779d6220 12 *
shoaib_ahmed 0:791a779d6220 13 * Note that this code is bypassed in raw-data mode, since the application
shoaib_ahmed 0:791a779d6220 14 * supplies the equivalent of the main buffer in that case.
shoaib_ahmed 0:791a779d6220 15 */
shoaib_ahmed 0:791a779d6220 16
shoaib_ahmed 0:791a779d6220 17 #define JPEG_INTERNALS
shoaib_ahmed 0:791a779d6220 18 #include "jinclude.h"
shoaib_ahmed 0:791a779d6220 19 #include "jpeglib.h"
shoaib_ahmed 0:791a779d6220 20
shoaib_ahmed 0:791a779d6220 21
shoaib_ahmed 0:791a779d6220 22 /*
shoaib_ahmed 0:791a779d6220 23 * In the current system design, the main buffer need never be a full-image
shoaib_ahmed 0:791a779d6220 24 * buffer; any full-height buffers will be found inside the coefficient or
shoaib_ahmed 0:791a779d6220 25 * postprocessing controllers. Nonetheless, the main controller is not
shoaib_ahmed 0:791a779d6220 26 * trivial. Its responsibility is to provide context rows for upsampling/
shoaib_ahmed 0:791a779d6220 27 * rescaling, and doing this in an efficient fashion is a bit tricky.
shoaib_ahmed 0:791a779d6220 28 *
shoaib_ahmed 0:791a779d6220 29 * Postprocessor input data is counted in "row groups". A row group
shoaib_ahmed 0:791a779d6220 30 * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
shoaib_ahmed 0:791a779d6220 31 * sample rows of each component. (We require DCT_scaled_size values to be
shoaib_ahmed 0:791a779d6220 32 * chosen such that these numbers are integers. In practice DCT_scaled_size
shoaib_ahmed 0:791a779d6220 33 * values will likely be powers of two, so we actually have the stronger
shoaib_ahmed 0:791a779d6220 34 * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.)
shoaib_ahmed 0:791a779d6220 35 * Upsampling will typically produce max_v_samp_factor pixel rows from each
shoaib_ahmed 0:791a779d6220 36 * row group (times any additional scale factor that the upsampler is
shoaib_ahmed 0:791a779d6220 37 * applying).
shoaib_ahmed 0:791a779d6220 38 *
shoaib_ahmed 0:791a779d6220 39 * The coefficient controller will deliver data to us one iMCU row at a time;
shoaib_ahmed 0:791a779d6220 40 * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or
shoaib_ahmed 0:791a779d6220 41 * exactly min_DCT_scaled_size row groups. (This amount of data corresponds
shoaib_ahmed 0:791a779d6220 42 * to one row of MCUs when the image is fully interleaved.) Note that the
shoaib_ahmed 0:791a779d6220 43 * number of sample rows varies across components, but the number of row
shoaib_ahmed 0:791a779d6220 44 * groups does not. Some garbage sample rows may be included in the last iMCU
shoaib_ahmed 0:791a779d6220 45 * row at the bottom of the image.
shoaib_ahmed 0:791a779d6220 46 *
shoaib_ahmed 0:791a779d6220 47 * Depending on the vertical scaling algorithm used, the upsampler may need
shoaib_ahmed 0:791a779d6220 48 * access to the sample row(s) above and below its current input row group.
shoaib_ahmed 0:791a779d6220 49 * The upsampler is required to set need_context_rows TRUE at global selection
shoaib_ahmed 0:791a779d6220 50 * time if so. When need_context_rows is FALSE, this controller can simply
shoaib_ahmed 0:791a779d6220 51 * obtain one iMCU row at a time from the coefficient controller and dole it
shoaib_ahmed 0:791a779d6220 52 * out as row groups to the postprocessor.
shoaib_ahmed 0:791a779d6220 53 *
shoaib_ahmed 0:791a779d6220 54 * When need_context_rows is TRUE, this controller guarantees that the buffer
shoaib_ahmed 0:791a779d6220 55 * passed to postprocessing contains at least one row group's worth of samples
shoaib_ahmed 0:791a779d6220 56 * above and below the row group(s) being processed. Note that the context
shoaib_ahmed 0:791a779d6220 57 * rows "above" the first passed row group appear at negative row offsets in
shoaib_ahmed 0:791a779d6220 58 * the passed buffer. At the top and bottom of the image, the required
shoaib_ahmed 0:791a779d6220 59 * context rows are manufactured by duplicating the first or last real sample
shoaib_ahmed 0:791a779d6220 60 * row; this avoids having special cases in the upsampling inner loops.
shoaib_ahmed 0:791a779d6220 61 *
shoaib_ahmed 0:791a779d6220 62 * The amount of context is fixed at one row group just because that's a
shoaib_ahmed 0:791a779d6220 63 * convenient number for this controller to work with. The existing
shoaib_ahmed 0:791a779d6220 64 * upsamplers really only need one sample row of context. An upsampler
shoaib_ahmed 0:791a779d6220 65 * supporting arbitrary output rescaling might wish for more than one row
shoaib_ahmed 0:791a779d6220 66 * group of context when shrinking the image; tough, we don't handle that.
shoaib_ahmed 0:791a779d6220 67 * (This is justified by the assumption that downsizing will be handled mostly
shoaib_ahmed 0:791a779d6220 68 * by adjusting the DCT_scaled_size values, so that the actual scale factor at
shoaib_ahmed 0:791a779d6220 69 * the upsample step needn't be much less than one.)
shoaib_ahmed 0:791a779d6220 70 *
shoaib_ahmed 0:791a779d6220 71 * To provide the desired context, we have to retain the last two row groups
shoaib_ahmed 0:791a779d6220 72 * of one iMCU row while reading in the next iMCU row. (The last row group
shoaib_ahmed 0:791a779d6220 73 * can't be processed until we have another row group for its below-context,
shoaib_ahmed 0:791a779d6220 74 * and so we have to save the next-to-last group too for its above-context.)
shoaib_ahmed 0:791a779d6220 75 * We could do this most simply by copying data around in our buffer, but
shoaib_ahmed 0:791a779d6220 76 * that'd be very slow. We can avoid copying any data by creating a rather
shoaib_ahmed 0:791a779d6220 77 * strange pointer structure. Here's how it works. We allocate a workspace
shoaib_ahmed 0:791a779d6220 78 * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number
shoaib_ahmed 0:791a779d6220 79 * of row groups per iMCU row). We create two sets of redundant pointers to
shoaib_ahmed 0:791a779d6220 80 * the workspace. Labeling the physical row groups 0 to M+1, the synthesized
shoaib_ahmed 0:791a779d6220 81 * pointer lists look like this:
shoaib_ahmed 0:791a779d6220 82 * M+1 M-1
shoaib_ahmed 0:791a779d6220 83 * master pointer --> 0 master pointer --> 0
shoaib_ahmed 0:791a779d6220 84 * 1 1
shoaib_ahmed 0:791a779d6220 85 * ... ...
shoaib_ahmed 0:791a779d6220 86 * M-3 M-3
shoaib_ahmed 0:791a779d6220 87 * M-2 M
shoaib_ahmed 0:791a779d6220 88 * M-1 M+1
shoaib_ahmed 0:791a779d6220 89 * M M-2
shoaib_ahmed 0:791a779d6220 90 * M+1 M-1
shoaib_ahmed 0:791a779d6220 91 * 0 0
shoaib_ahmed 0:791a779d6220 92 * We read alternate iMCU rows using each master pointer; thus the last two
shoaib_ahmed 0:791a779d6220 93 * row groups of the previous iMCU row remain un-overwritten in the workspace.
shoaib_ahmed 0:791a779d6220 94 * The pointer lists are set up so that the required context rows appear to
shoaib_ahmed 0:791a779d6220 95 * be adjacent to the proper places when we pass the pointer lists to the
shoaib_ahmed 0:791a779d6220 96 * upsampler.
shoaib_ahmed 0:791a779d6220 97 *
shoaib_ahmed 0:791a779d6220 98 * The above pictures describe the normal state of the pointer lists.
shoaib_ahmed 0:791a779d6220 99 * At top and bottom of the image, we diddle the pointer lists to duplicate
shoaib_ahmed 0:791a779d6220 100 * the first or last sample row as necessary (this is cheaper than copying
shoaib_ahmed 0:791a779d6220 101 * sample rows around).
shoaib_ahmed 0:791a779d6220 102 *
shoaib_ahmed 0:791a779d6220 103 * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that
shoaib_ahmed 0:791a779d6220 104 * situation each iMCU row provides only one row group so the buffering logic
shoaib_ahmed 0:791a779d6220 105 * must be different (eg, we must read two iMCU rows before we can emit the
shoaib_ahmed 0:791a779d6220 106 * first row group). For now, we simply do not support providing context
shoaib_ahmed 0:791a779d6220 107 * rows when min_DCT_scaled_size is 1. That combination seems unlikely to
shoaib_ahmed 0:791a779d6220 108 * be worth providing --- if someone wants a 1/8th-size preview, they probably
shoaib_ahmed 0:791a779d6220 109 * want it quick and dirty, so a context-free upsampler is sufficient.
shoaib_ahmed 0:791a779d6220 110 */
shoaib_ahmed 0:791a779d6220 111
shoaib_ahmed 0:791a779d6220 112
shoaib_ahmed 0:791a779d6220 113 /* Private buffer controller object */
shoaib_ahmed 0:791a779d6220 114
shoaib_ahmed 0:791a779d6220 115 typedef struct {
shoaib_ahmed 0:791a779d6220 116 struct jpeg_d_main_controller pub; /* public fields */
shoaib_ahmed 0:791a779d6220 117
shoaib_ahmed 0:791a779d6220 118 /* Pointer to allocated workspace (M or M+2 row groups). */
shoaib_ahmed 0:791a779d6220 119 JSAMPARRAY buffer[MAX_COMPONENTS];
shoaib_ahmed 0:791a779d6220 120
shoaib_ahmed 0:791a779d6220 121 boolean buffer_full; /* Have we gotten an iMCU row from decoder? */
shoaib_ahmed 0:791a779d6220 122 JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */
shoaib_ahmed 0:791a779d6220 123
shoaib_ahmed 0:791a779d6220 124 /* Remaining fields are only used in the context case. */
shoaib_ahmed 0:791a779d6220 125
shoaib_ahmed 0:791a779d6220 126 /* These are the master pointers to the funny-order pointer lists. */
shoaib_ahmed 0:791a779d6220 127 JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */
shoaib_ahmed 0:791a779d6220 128
shoaib_ahmed 0:791a779d6220 129 int whichptr; /* indicates which pointer set is now in use */
shoaib_ahmed 0:791a779d6220 130 int context_state; /* process_data state machine status */
shoaib_ahmed 0:791a779d6220 131 JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
shoaib_ahmed 0:791a779d6220 132 JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */
shoaib_ahmed 0:791a779d6220 133 } my_main_controller;
shoaib_ahmed 0:791a779d6220 134
shoaib_ahmed 0:791a779d6220 135 typedef my_main_controller * my_main_ptr;
shoaib_ahmed 0:791a779d6220 136
shoaib_ahmed 0:791a779d6220 137 /* context_state values: */
shoaib_ahmed 0:791a779d6220 138 #define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */
shoaib_ahmed 0:791a779d6220 139 #define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */
shoaib_ahmed 0:791a779d6220 140 #define CTX_POSTPONED_ROW 2 /* feeding postponed row group */
shoaib_ahmed 0:791a779d6220 141
shoaib_ahmed 0:791a779d6220 142
shoaib_ahmed 0:791a779d6220 143 /* Forward declarations */
shoaib_ahmed 0:791a779d6220 144 METHODDEF(void) process_data_simple_main
shoaib_ahmed 0:791a779d6220 145 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
shoaib_ahmed 0:791a779d6220 146 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
shoaib_ahmed 0:791a779d6220 147 METHODDEF(void) process_data_context_main
shoaib_ahmed 0:791a779d6220 148 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
shoaib_ahmed 0:791a779d6220 149 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
shoaib_ahmed 0:791a779d6220 150 #ifdef QUANT_2PASS_SUPPORTED
shoaib_ahmed 0:791a779d6220 151 METHODDEF(void) process_data_crank_post
shoaib_ahmed 0:791a779d6220 152 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
shoaib_ahmed 0:791a779d6220 153 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
shoaib_ahmed 0:791a779d6220 154 #endif
shoaib_ahmed 0:791a779d6220 155
shoaib_ahmed 0:791a779d6220 156
shoaib_ahmed 0:791a779d6220 157 LOCAL(void)
shoaib_ahmed 0:791a779d6220 158 alloc_funny_pointers (j_decompress_ptr cinfo)
shoaib_ahmed 0:791a779d6220 159 /* Allocate space for the funny pointer lists.
shoaib_ahmed 0:791a779d6220 160 * This is done only once, not once per pass.
shoaib_ahmed 0:791a779d6220 161 */
shoaib_ahmed 0:791a779d6220 162 {
shoaib_ahmed 0:791a779d6220 163 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 164 int ci, rgroup;
shoaib_ahmed 0:791a779d6220 165 int M = cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 166 jpeg_component_info *compptr;
shoaib_ahmed 0:791a779d6220 167 JSAMPARRAY xbuf;
shoaib_ahmed 0:791a779d6220 168
shoaib_ahmed 0:791a779d6220 169 /* Get top-level space for component array pointers.
shoaib_ahmed 0:791a779d6220 170 * We alloc both arrays with one call to save a few cycles.
shoaib_ahmed 0:791a779d6220 171 */
shoaib_ahmed 0:791a779d6220 172 mainp->xbuffer[0] = (JSAMPIMAGE)
shoaib_ahmed 0:791a779d6220 173 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
shoaib_ahmed 0:791a779d6220 174 cinfo->num_components * 2 * SIZEOF(JSAMPARRAY));
shoaib_ahmed 0:791a779d6220 175 mainp->xbuffer[1] = mainp->xbuffer[0] + cinfo->num_components;
shoaib_ahmed 0:791a779d6220 176
shoaib_ahmed 0:791a779d6220 177 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
shoaib_ahmed 0:791a779d6220 178 ci++, compptr++) {
shoaib_ahmed 0:791a779d6220 179 rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
shoaib_ahmed 0:791a779d6220 180 cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
shoaib_ahmed 0:791a779d6220 181 /* Get space for pointer lists --- M+4 row groups in each list.
shoaib_ahmed 0:791a779d6220 182 * We alloc both pointer lists with one call to save a few cycles.
shoaib_ahmed 0:791a779d6220 183 */
shoaib_ahmed 0:791a779d6220 184 xbuf = (JSAMPARRAY)
shoaib_ahmed 0:791a779d6220 185 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
shoaib_ahmed 0:791a779d6220 186 2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW));
shoaib_ahmed 0:791a779d6220 187 xbuf += rgroup; /* want one row group at negative offsets */
shoaib_ahmed 0:791a779d6220 188 mainp->xbuffer[0][ci] = xbuf;
shoaib_ahmed 0:791a779d6220 189 xbuf += rgroup * (M + 4);
shoaib_ahmed 0:791a779d6220 190 mainp->xbuffer[1][ci] = xbuf;
shoaib_ahmed 0:791a779d6220 191 }
shoaib_ahmed 0:791a779d6220 192 }
shoaib_ahmed 0:791a779d6220 193
shoaib_ahmed 0:791a779d6220 194
shoaib_ahmed 0:791a779d6220 195 LOCAL(void)
shoaib_ahmed 0:791a779d6220 196 make_funny_pointers (j_decompress_ptr cinfo)
shoaib_ahmed 0:791a779d6220 197 /* Create the funny pointer lists discussed in the comments above.
shoaib_ahmed 0:791a779d6220 198 * The actual workspace is already allocated (in main->buffer),
shoaib_ahmed 0:791a779d6220 199 * and the space for the pointer lists is allocated too.
shoaib_ahmed 0:791a779d6220 200 * This routine just fills in the curiously ordered lists.
shoaib_ahmed 0:791a779d6220 201 * This will be repeated at the beginning of each pass.
shoaib_ahmed 0:791a779d6220 202 */
shoaib_ahmed 0:791a779d6220 203 {
shoaib_ahmed 0:791a779d6220 204 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 205 int ci, i, rgroup;
shoaib_ahmed 0:791a779d6220 206 int M = cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 207 jpeg_component_info *compptr;
shoaib_ahmed 0:791a779d6220 208 JSAMPARRAY buf, xbuf0, xbuf1;
shoaib_ahmed 0:791a779d6220 209
shoaib_ahmed 0:791a779d6220 210 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
shoaib_ahmed 0:791a779d6220 211 ci++, compptr++) {
shoaib_ahmed 0:791a779d6220 212 rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
shoaib_ahmed 0:791a779d6220 213 cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
shoaib_ahmed 0:791a779d6220 214 xbuf0 = mainp->xbuffer[0][ci];
shoaib_ahmed 0:791a779d6220 215 xbuf1 = mainp->xbuffer[1][ci];
shoaib_ahmed 0:791a779d6220 216 /* First copy the workspace pointers as-is */
shoaib_ahmed 0:791a779d6220 217 buf = mainp->buffer[ci];
shoaib_ahmed 0:791a779d6220 218 for (i = 0; i < rgroup * (M + 2); i++) {
shoaib_ahmed 0:791a779d6220 219 xbuf0[i] = xbuf1[i] = buf[i];
shoaib_ahmed 0:791a779d6220 220 }
shoaib_ahmed 0:791a779d6220 221 /* In the second list, put the last four row groups in swapped order */
shoaib_ahmed 0:791a779d6220 222 for (i = 0; i < rgroup * 2; i++) {
shoaib_ahmed 0:791a779d6220 223 xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i];
shoaib_ahmed 0:791a779d6220 224 xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i];
shoaib_ahmed 0:791a779d6220 225 }
shoaib_ahmed 0:791a779d6220 226 /* The wraparound pointers at top and bottom will be filled later
shoaib_ahmed 0:791a779d6220 227 * (see set_wraparound_pointers, below). Initially we want the "above"
shoaib_ahmed 0:791a779d6220 228 * pointers to duplicate the first actual data line. This only needs
shoaib_ahmed 0:791a779d6220 229 * to happen in xbuffer[0].
shoaib_ahmed 0:791a779d6220 230 */
shoaib_ahmed 0:791a779d6220 231 for (i = 0; i < rgroup; i++) {
shoaib_ahmed 0:791a779d6220 232 xbuf0[i - rgroup] = xbuf0[0];
shoaib_ahmed 0:791a779d6220 233 }
shoaib_ahmed 0:791a779d6220 234 }
shoaib_ahmed 0:791a779d6220 235 }
shoaib_ahmed 0:791a779d6220 236
shoaib_ahmed 0:791a779d6220 237
shoaib_ahmed 0:791a779d6220 238 LOCAL(void)
shoaib_ahmed 0:791a779d6220 239 set_wraparound_pointers (j_decompress_ptr cinfo)
shoaib_ahmed 0:791a779d6220 240 /* Set up the "wraparound" pointers at top and bottom of the pointer lists.
shoaib_ahmed 0:791a779d6220 241 * This changes the pointer list state from top-of-image to the normal state.
shoaib_ahmed 0:791a779d6220 242 */
shoaib_ahmed 0:791a779d6220 243 {
shoaib_ahmed 0:791a779d6220 244 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 245 int ci, i, rgroup;
shoaib_ahmed 0:791a779d6220 246 int M = cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 247 jpeg_component_info *compptr;
shoaib_ahmed 0:791a779d6220 248 JSAMPARRAY xbuf0, xbuf1;
shoaib_ahmed 0:791a779d6220 249
shoaib_ahmed 0:791a779d6220 250 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
shoaib_ahmed 0:791a779d6220 251 ci++, compptr++) {
shoaib_ahmed 0:791a779d6220 252 rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
shoaib_ahmed 0:791a779d6220 253 cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
shoaib_ahmed 0:791a779d6220 254 xbuf0 = mainp->xbuffer[0][ci];
shoaib_ahmed 0:791a779d6220 255 xbuf1 = mainp->xbuffer[1][ci];
shoaib_ahmed 0:791a779d6220 256 for (i = 0; i < rgroup; i++) {
shoaib_ahmed 0:791a779d6220 257 xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i];
shoaib_ahmed 0:791a779d6220 258 xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i];
shoaib_ahmed 0:791a779d6220 259 xbuf0[rgroup*(M+2) + i] = xbuf0[i];
shoaib_ahmed 0:791a779d6220 260 xbuf1[rgroup*(M+2) + i] = xbuf1[i];
shoaib_ahmed 0:791a779d6220 261 }
shoaib_ahmed 0:791a779d6220 262 }
shoaib_ahmed 0:791a779d6220 263 }
shoaib_ahmed 0:791a779d6220 264
shoaib_ahmed 0:791a779d6220 265
shoaib_ahmed 0:791a779d6220 266 LOCAL(void)
shoaib_ahmed 0:791a779d6220 267 set_bottom_pointers (j_decompress_ptr cinfo)
shoaib_ahmed 0:791a779d6220 268 /* Change the pointer lists to duplicate the last sample row at the bottom
shoaib_ahmed 0:791a779d6220 269 * of the image. whichptr indicates which xbuffer holds the final iMCU row.
shoaib_ahmed 0:791a779d6220 270 * Also sets rowgroups_avail to indicate number of nondummy row groups in row.
shoaib_ahmed 0:791a779d6220 271 */
shoaib_ahmed 0:791a779d6220 272 {
shoaib_ahmed 0:791a779d6220 273 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 274 int ci, i, rgroup, iMCUheight, rows_left;
shoaib_ahmed 0:791a779d6220 275 jpeg_component_info *compptr;
shoaib_ahmed 0:791a779d6220 276 JSAMPARRAY xbuf;
shoaib_ahmed 0:791a779d6220 277
shoaib_ahmed 0:791a779d6220 278 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
shoaib_ahmed 0:791a779d6220 279 ci++, compptr++) {
shoaib_ahmed 0:791a779d6220 280 /* Count sample rows in one iMCU row and in one row group */
shoaib_ahmed 0:791a779d6220 281 iMCUheight = compptr->v_samp_factor * compptr->DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 282 rgroup = iMCUheight / cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 283 /* Count nondummy sample rows remaining for this component */
shoaib_ahmed 0:791a779d6220 284 rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight);
shoaib_ahmed 0:791a779d6220 285 if (rows_left == 0) rows_left = iMCUheight;
shoaib_ahmed 0:791a779d6220 286 /* Count nondummy row groups. Should get same answer for each component,
shoaib_ahmed 0:791a779d6220 287 * so we need only do it once.
shoaib_ahmed 0:791a779d6220 288 */
shoaib_ahmed 0:791a779d6220 289 if (ci == 0) {
shoaib_ahmed 0:791a779d6220 290 mainp->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1);
shoaib_ahmed 0:791a779d6220 291 }
shoaib_ahmed 0:791a779d6220 292 /* Duplicate the last real sample row rgroup*2 times; this pads out the
shoaib_ahmed 0:791a779d6220 293 * last partial rowgroup and ensures at least one full rowgroup of context.
shoaib_ahmed 0:791a779d6220 294 */
shoaib_ahmed 0:791a779d6220 295 xbuf = mainp->xbuffer[mainp->whichptr][ci];
shoaib_ahmed 0:791a779d6220 296 for (i = 0; i < rgroup * 2; i++) {
shoaib_ahmed 0:791a779d6220 297 xbuf[rows_left + i] = xbuf[rows_left-1];
shoaib_ahmed 0:791a779d6220 298 }
shoaib_ahmed 0:791a779d6220 299 }
shoaib_ahmed 0:791a779d6220 300 }
shoaib_ahmed 0:791a779d6220 301
shoaib_ahmed 0:791a779d6220 302
shoaib_ahmed 0:791a779d6220 303 /*
shoaib_ahmed 0:791a779d6220 304 * Initialize for a processing pass.
shoaib_ahmed 0:791a779d6220 305 */
shoaib_ahmed 0:791a779d6220 306
shoaib_ahmed 0:791a779d6220 307 METHODDEF(void)
shoaib_ahmed 0:791a779d6220 308 start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
shoaib_ahmed 0:791a779d6220 309 {
shoaib_ahmed 0:791a779d6220 310 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 311
shoaib_ahmed 0:791a779d6220 312 switch (pass_mode) {
shoaib_ahmed 0:791a779d6220 313 case JBUF_PASS_THRU:
shoaib_ahmed 0:791a779d6220 314 if (cinfo->upsample->need_context_rows) {
shoaib_ahmed 0:791a779d6220 315 mainp->pub.process_data = process_data_context_main;
shoaib_ahmed 0:791a779d6220 316 make_funny_pointers(cinfo); /* Create the xbuffer[] lists */
shoaib_ahmed 0:791a779d6220 317 mainp->whichptr = 0; /* Read first iMCU row into xbuffer[0] */
shoaib_ahmed 0:791a779d6220 318 mainp->context_state = CTX_PREPARE_FOR_IMCU;
shoaib_ahmed 0:791a779d6220 319 mainp->iMCU_row_ctr = 0;
shoaib_ahmed 0:791a779d6220 320 } else {
shoaib_ahmed 0:791a779d6220 321 /* Simple case with no context needed */
shoaib_ahmed 0:791a779d6220 322 mainp->pub.process_data = process_data_simple_main;
shoaib_ahmed 0:791a779d6220 323 }
shoaib_ahmed 0:791a779d6220 324 mainp->buffer_full = FALSE; /* Mark buffer empty */
shoaib_ahmed 0:791a779d6220 325 mainp->rowgroup_ctr = 0;
shoaib_ahmed 0:791a779d6220 326 break;
shoaib_ahmed 0:791a779d6220 327 #ifdef QUANT_2PASS_SUPPORTED
shoaib_ahmed 0:791a779d6220 328 case JBUF_CRANK_DEST:
shoaib_ahmed 0:791a779d6220 329 /* For last pass of 2-pass quantization, just crank the postprocessor */
shoaib_ahmed 0:791a779d6220 330 mainp->pub.process_data = process_data_crank_post;
shoaib_ahmed 0:791a779d6220 331 break;
shoaib_ahmed 0:791a779d6220 332 #endif
shoaib_ahmed 0:791a779d6220 333 default:
shoaib_ahmed 0:791a779d6220 334 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
shoaib_ahmed 0:791a779d6220 335 break;
shoaib_ahmed 0:791a779d6220 336 }
shoaib_ahmed 0:791a779d6220 337 }
shoaib_ahmed 0:791a779d6220 338
shoaib_ahmed 0:791a779d6220 339
shoaib_ahmed 0:791a779d6220 340 /*
shoaib_ahmed 0:791a779d6220 341 * Process some data.
shoaib_ahmed 0:791a779d6220 342 * This handles the simple case where no context is required.
shoaib_ahmed 0:791a779d6220 343 */
shoaib_ahmed 0:791a779d6220 344
shoaib_ahmed 0:791a779d6220 345 METHODDEF(void)
shoaib_ahmed 0:791a779d6220 346 process_data_simple_main (j_decompress_ptr cinfo,
shoaib_ahmed 0:791a779d6220 347 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
shoaib_ahmed 0:791a779d6220 348 JDIMENSION out_rows_avail)
shoaib_ahmed 0:791a779d6220 349 {
shoaib_ahmed 0:791a779d6220 350 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 351 JDIMENSION rowgroups_avail;
shoaib_ahmed 0:791a779d6220 352
shoaib_ahmed 0:791a779d6220 353 /* Read input data if we haven't filled the main buffer yet */
shoaib_ahmed 0:791a779d6220 354 if (! mainp->buffer_full) {
shoaib_ahmed 0:791a779d6220 355 if (! (*cinfo->coef->decompress_data) (cinfo, mainp->buffer))
shoaib_ahmed 0:791a779d6220 356 return; /* suspension forced, can do nothing more */
shoaib_ahmed 0:791a779d6220 357 mainp->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
shoaib_ahmed 0:791a779d6220 358 }
shoaib_ahmed 0:791a779d6220 359
shoaib_ahmed 0:791a779d6220 360 /* There are always min_DCT_scaled_size row groups in an iMCU row. */
shoaib_ahmed 0:791a779d6220 361 rowgroups_avail = (JDIMENSION) cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 362 /* Note: at the bottom of the image, we may pass extra garbage row groups
shoaib_ahmed 0:791a779d6220 363 * to the postprocessor. The postprocessor has to check for bottom
shoaib_ahmed 0:791a779d6220 364 * of image anyway (at row resolution), so no point in us doing it too.
shoaib_ahmed 0:791a779d6220 365 */
shoaib_ahmed 0:791a779d6220 366
shoaib_ahmed 0:791a779d6220 367 /* Feed the postprocessor */
shoaib_ahmed 0:791a779d6220 368 (*cinfo->post->post_process_data) (cinfo, mainp->buffer,
shoaib_ahmed 0:791a779d6220 369 &mainp->rowgroup_ctr, rowgroups_avail,
shoaib_ahmed 0:791a779d6220 370 output_buf, out_row_ctr, out_rows_avail);
shoaib_ahmed 0:791a779d6220 371
shoaib_ahmed 0:791a779d6220 372 /* Has postprocessor consumed all the data yet? If so, mark buffer empty */
shoaib_ahmed 0:791a779d6220 373 if (mainp->rowgroup_ctr >= rowgroups_avail) {
shoaib_ahmed 0:791a779d6220 374 mainp->buffer_full = FALSE;
shoaib_ahmed 0:791a779d6220 375 mainp->rowgroup_ctr = 0;
shoaib_ahmed 0:791a779d6220 376 }
shoaib_ahmed 0:791a779d6220 377 }
shoaib_ahmed 0:791a779d6220 378
shoaib_ahmed 0:791a779d6220 379
shoaib_ahmed 0:791a779d6220 380 /*
shoaib_ahmed 0:791a779d6220 381 * Process some data.
shoaib_ahmed 0:791a779d6220 382 * This handles the case where context rows must be provided.
shoaib_ahmed 0:791a779d6220 383 */
shoaib_ahmed 0:791a779d6220 384
shoaib_ahmed 0:791a779d6220 385 METHODDEF(void)
shoaib_ahmed 0:791a779d6220 386 process_data_context_main (j_decompress_ptr cinfo,
shoaib_ahmed 0:791a779d6220 387 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
shoaib_ahmed 0:791a779d6220 388 JDIMENSION out_rows_avail)
shoaib_ahmed 0:791a779d6220 389 {
shoaib_ahmed 0:791a779d6220 390 my_main_ptr mainp = (my_main_ptr) cinfo->main;
shoaib_ahmed 0:791a779d6220 391
shoaib_ahmed 0:791a779d6220 392 /* Read input data if we haven't filled the main buffer yet */
shoaib_ahmed 0:791a779d6220 393 if (! mainp->buffer_full) {
shoaib_ahmed 0:791a779d6220 394 if (! (*cinfo->coef->decompress_data) (cinfo,
shoaib_ahmed 0:791a779d6220 395 mainp->xbuffer[mainp->whichptr]))
shoaib_ahmed 0:791a779d6220 396 return; /* suspension forced, can do nothing more */
shoaib_ahmed 0:791a779d6220 397 mainp->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
shoaib_ahmed 0:791a779d6220 398 mainp->iMCU_row_ctr++; /* count rows received */
shoaib_ahmed 0:791a779d6220 399 }
shoaib_ahmed 0:791a779d6220 400
shoaib_ahmed 0:791a779d6220 401 /* Postprocessor typically will not swallow all the input data it is handed
shoaib_ahmed 0:791a779d6220 402 * in one call (due to filling the output buffer first). Must be prepared
shoaib_ahmed 0:791a779d6220 403 * to exit and restart. This switch lets us keep track of how far we got.
shoaib_ahmed 0:791a779d6220 404 * Note that each case falls through to the next on successful completion.
shoaib_ahmed 0:791a779d6220 405 */
shoaib_ahmed 0:791a779d6220 406 switch (mainp->context_state) {
shoaib_ahmed 0:791a779d6220 407 case CTX_POSTPONED_ROW:
shoaib_ahmed 0:791a779d6220 408 /* Call postprocessor using previously set pointers for postponed row */
shoaib_ahmed 0:791a779d6220 409 (*cinfo->post->post_process_data) (cinfo, mainp->xbuffer[mainp->whichptr],
shoaib_ahmed 0:791a779d6220 410 &mainp->rowgroup_ctr, mainp->rowgroups_avail,
shoaib_ahmed 0:791a779d6220 411 output_buf, out_row_ctr, out_rows_avail);
shoaib_ahmed 0:791a779d6220 412 if (mainp->rowgroup_ctr < mainp->rowgroups_avail)
shoaib_ahmed 0:791a779d6220 413 return; /* Need to suspend */
shoaib_ahmed 0:791a779d6220 414 mainp->context_state = CTX_PREPARE_FOR_IMCU;
shoaib_ahmed 0:791a779d6220 415 if (*out_row_ctr >= out_rows_avail)
shoaib_ahmed 0:791a779d6220 416 return; /* Postprocessor exactly filled output buf */
shoaib_ahmed 0:791a779d6220 417 /*FALLTHROUGH*/
shoaib_ahmed 0:791a779d6220 418 case CTX_PREPARE_FOR_IMCU:
shoaib_ahmed 0:791a779d6220 419 /* Prepare to process first M-1 row groups of this iMCU row */
shoaib_ahmed 0:791a779d6220 420 mainp->rowgroup_ctr = 0;
shoaib_ahmed 0:791a779d6220 421 mainp->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size - 1);
shoaib_ahmed 0:791a779d6220 422 /* Check for bottom of image: if so, tweak pointers to "duplicate"
shoaib_ahmed 0:791a779d6220 423 * the last sample row, and adjust rowgroups_avail to ignore padding rows.
shoaib_ahmed 0:791a779d6220 424 */
shoaib_ahmed 0:791a779d6220 425 if (mainp->iMCU_row_ctr == cinfo->total_iMCU_rows)
shoaib_ahmed 0:791a779d6220 426 set_bottom_pointers(cinfo);
shoaib_ahmed 0:791a779d6220 427 mainp->context_state = CTX_PROCESS_IMCU;
shoaib_ahmed 0:791a779d6220 428 /*FALLTHROUGH*/
shoaib_ahmed 0:791a779d6220 429 case CTX_PROCESS_IMCU:
shoaib_ahmed 0:791a779d6220 430 /* Call postprocessor using previously set pointers */
shoaib_ahmed 0:791a779d6220 431 (*cinfo->post->post_process_data) (cinfo, mainp->xbuffer[mainp->whichptr],
shoaib_ahmed 0:791a779d6220 432 &mainp->rowgroup_ctr, mainp->rowgroups_avail,
shoaib_ahmed 0:791a779d6220 433 output_buf, out_row_ctr, out_rows_avail);
shoaib_ahmed 0:791a779d6220 434 if (mainp->rowgroup_ctr < mainp->rowgroups_avail)
shoaib_ahmed 0:791a779d6220 435 return; /* Need to suspend */
shoaib_ahmed 0:791a779d6220 436 /* After the first iMCU, change wraparound pointers to normal state */
shoaib_ahmed 0:791a779d6220 437 if (mainp->iMCU_row_ctr == 1)
shoaib_ahmed 0:791a779d6220 438 set_wraparound_pointers(cinfo);
shoaib_ahmed 0:791a779d6220 439 /* Prepare to load new iMCU row using other xbuffer list */
shoaib_ahmed 0:791a779d6220 440 mainp->whichptr ^= 1; /* 0=>1 or 1=>0 */
shoaib_ahmed 0:791a779d6220 441 mainp->buffer_full = FALSE;
shoaib_ahmed 0:791a779d6220 442 /* Still need to process last row group of this iMCU row, */
shoaib_ahmed 0:791a779d6220 443 /* which is saved at index M+1 of the other xbuffer */
shoaib_ahmed 0:791a779d6220 444 mainp->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 1);
shoaib_ahmed 0:791a779d6220 445 mainp->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 2);
shoaib_ahmed 0:791a779d6220 446 mainp->context_state = CTX_POSTPONED_ROW;
shoaib_ahmed 0:791a779d6220 447 }
shoaib_ahmed 0:791a779d6220 448 }
shoaib_ahmed 0:791a779d6220 449
shoaib_ahmed 0:791a779d6220 450
shoaib_ahmed 0:791a779d6220 451 /*
shoaib_ahmed 0:791a779d6220 452 * Process some data.
shoaib_ahmed 0:791a779d6220 453 * Final pass of two-pass quantization: just call the postprocessor.
shoaib_ahmed 0:791a779d6220 454 * Source data will be the postprocessor controller's internal buffer.
shoaib_ahmed 0:791a779d6220 455 */
shoaib_ahmed 0:791a779d6220 456
shoaib_ahmed 0:791a779d6220 457 #ifdef QUANT_2PASS_SUPPORTED
shoaib_ahmed 0:791a779d6220 458
shoaib_ahmed 0:791a779d6220 459 METHODDEF(void)
shoaib_ahmed 0:791a779d6220 460 process_data_crank_post (j_decompress_ptr cinfo,
shoaib_ahmed 0:791a779d6220 461 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
shoaib_ahmed 0:791a779d6220 462 JDIMENSION out_rows_avail)
shoaib_ahmed 0:791a779d6220 463 {
shoaib_ahmed 0:791a779d6220 464 (*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL,
shoaib_ahmed 0:791a779d6220 465 (JDIMENSION *) NULL, (JDIMENSION) 0,
shoaib_ahmed 0:791a779d6220 466 output_buf, out_row_ctr, out_rows_avail);
shoaib_ahmed 0:791a779d6220 467 }
shoaib_ahmed 0:791a779d6220 468
shoaib_ahmed 0:791a779d6220 469 #endif /* QUANT_2PASS_SUPPORTED */
shoaib_ahmed 0:791a779d6220 470
shoaib_ahmed 0:791a779d6220 471
shoaib_ahmed 0:791a779d6220 472 /*
shoaib_ahmed 0:791a779d6220 473 * Initialize main buffer controller.
shoaib_ahmed 0:791a779d6220 474 */
shoaib_ahmed 0:791a779d6220 475
shoaib_ahmed 0:791a779d6220 476 GLOBAL(void)
shoaib_ahmed 0:791a779d6220 477 jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
shoaib_ahmed 0:791a779d6220 478 {
shoaib_ahmed 0:791a779d6220 479 my_main_ptr mainp;
shoaib_ahmed 0:791a779d6220 480 int ci, rgroup, ngroups;
shoaib_ahmed 0:791a779d6220 481 jpeg_component_info *compptr;
shoaib_ahmed 0:791a779d6220 482
shoaib_ahmed 0:791a779d6220 483 mainp = (my_main_ptr)
shoaib_ahmed 0:791a779d6220 484 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
shoaib_ahmed 0:791a779d6220 485 SIZEOF(my_main_controller));
shoaib_ahmed 0:791a779d6220 486 cinfo->main = &mainp->pub;
shoaib_ahmed 0:791a779d6220 487 mainp->pub.start_pass = start_pass_main;
shoaib_ahmed 0:791a779d6220 488
shoaib_ahmed 0:791a779d6220 489 if (need_full_buffer) /* shouldn't happen */
shoaib_ahmed 0:791a779d6220 490 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
shoaib_ahmed 0:791a779d6220 491
shoaib_ahmed 0:791a779d6220 492 /* Allocate the workspace.
shoaib_ahmed 0:791a779d6220 493 * ngroups is the number of row groups we need.
shoaib_ahmed 0:791a779d6220 494 */
shoaib_ahmed 0:791a779d6220 495 if (cinfo->upsample->need_context_rows) {
shoaib_ahmed 0:791a779d6220 496 if (cinfo->min_DCT_v_scaled_size < 2) /* unsupported, see comments above */
shoaib_ahmed 0:791a779d6220 497 ERREXIT(cinfo, JERR_NOTIMPL);
shoaib_ahmed 0:791a779d6220 498 alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */
shoaib_ahmed 0:791a779d6220 499 ngroups = cinfo->min_DCT_v_scaled_size + 2;
shoaib_ahmed 0:791a779d6220 500 } else {
shoaib_ahmed 0:791a779d6220 501 ngroups = cinfo->min_DCT_v_scaled_size;
shoaib_ahmed 0:791a779d6220 502 }
shoaib_ahmed 0:791a779d6220 503
shoaib_ahmed 0:791a779d6220 504 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
shoaib_ahmed 0:791a779d6220 505 ci++, compptr++) {
shoaib_ahmed 0:791a779d6220 506 rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
shoaib_ahmed 0:791a779d6220 507 cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
shoaib_ahmed 0:791a779d6220 508 mainp->buffer[ci] = (*cinfo->mem->alloc_sarray)
shoaib_ahmed 0:791a779d6220 509 ((j_common_ptr) cinfo, JPOOL_IMAGE,
shoaib_ahmed 0:791a779d6220 510 compptr->width_in_blocks * ((JDIMENSION) compptr->DCT_h_scaled_size),
shoaib_ahmed 0:791a779d6220 511 (JDIMENSION) (rgroup * ngroups));
shoaib_ahmed 0:791a779d6220 512 }
shoaib_ahmed 0:791a779d6220 513 }