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      1 /*
      2  * wrrle.c
      3  *
      4  * This file was part of the Independent JPEG Group's software:
      5  * Copyright (C) 1991-1996, Thomas G. Lane.
      6  * It was modified by The libjpeg-turbo Project to include only code and
      7  * information relevant to libjpeg-turbo.
      8  * For conditions of distribution and use, see the accompanying README file.
      9  *
     10  * This file contains routines to write output images in RLE format.
     11  * The Utah Raster Toolkit library is required (version 3.1 or later).
     12  *
     13  * These routines may need modification for non-Unix environments or
     14  * specialized applications.  As they stand, they assume output to
     15  * an ordinary stdio stream.
     16  *
     17  * Based on code contributed by Mike Lijewski,
     18  * with updates from Robert Hutchinson.
     19  */
     20 
     21 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
     22 
     23 #ifdef RLE_SUPPORTED
     24 
     25 /* rle.h is provided by the Utah Raster Toolkit. */
     26 
     27 #include <rle.h>
     28 
     29 /*
     30  * We assume that JSAMPLE has the same representation as rle_pixel,
     31  * to wit, "unsigned char".  Hence we can't cope with 12- or 16-bit samples.
     32  */
     33 
     34 #if BITS_IN_JSAMPLE != 8
     35   Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
     36 #endif
     37 
     38 
     39 /*
     40  * Since RLE stores scanlines bottom-to-top, we have to invert the image
     41  * from JPEG's top-to-bottom order.  To do this, we save the outgoing data
     42  * in a virtual array during put_pixel_row calls, then actually emit the
     43  * RLE file during finish_output.
     44  */
     45 
     46 
     47 /*
     48  * For now, if we emit an RLE color map then it is always 256 entries long,
     49  * though not all of the entries need be used.
     50  */
     51 
     52 #define CMAPBITS        8
     53 #define CMAPLENGTH      (1<<(CMAPBITS))
     54 
     55 typedef struct {
     56   struct djpeg_dest_struct pub; /* public fields */
     57 
     58   jvirt_sarray_ptr image;       /* virtual array to store the output image */
     59   rle_map *colormap;            /* RLE-style color map, or NULL if none */
     60   rle_pixel **rle_row;          /* To pass rows to rle_putrow() */
     61 
     62 } rle_dest_struct;
     63 
     64 typedef rle_dest_struct * rle_dest_ptr;
     65 
     66 /* Forward declarations */
     67 METHODDEF(void) rle_put_pixel_rows
     68         (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
     69          JDIMENSION rows_supplied);
     70 
     71 
     72 /*
     73  * Write the file header.
     74  *
     75  * In this module it's easier to wait till finish_output to write anything.
     76  */
     77 
     78 METHODDEF(void)
     79 start_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
     80 {
     81   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
     82   size_t cmapsize;
     83   int i, ci;
     84 #ifdef PROGRESS_REPORT
     85   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
     86 #endif
     87 
     88   /*
     89    * Make sure the image can be stored in RLE format.
     90    *
     91    * - RLE stores image dimensions as *signed* 16 bit integers.  JPEG
     92    *   uses unsigned, so we have to check the width.
     93    *
     94    * - Colorspace is expected to be grayscale or RGB.
     95    *
     96    * - The number of channels (components) is expected to be 1 (grayscale/
     97    *   pseudocolor) or 3 (truecolor/directcolor).
     98    *   (could be 2 or 4 if using an alpha channel, but we aren't)
     99    */
    100 
    101   if (cinfo->output_width > 32767 || cinfo->output_height > 32767)
    102     ERREXIT2(cinfo, JERR_RLE_DIMENSIONS, cinfo->output_width,
    103              cinfo->output_height);
    104 
    105   if (cinfo->out_color_space != JCS_GRAYSCALE &&
    106       cinfo->out_color_space != JCS_RGB)
    107     ERREXIT(cinfo, JERR_RLE_COLORSPACE);
    108 
    109   if (cinfo->output_components != 1 && cinfo->output_components != 3)
    110     ERREXIT1(cinfo, JERR_RLE_TOOMANYCHANNELS, cinfo->num_components);
    111 
    112   /* Convert colormap, if any, to RLE format. */
    113 
    114   dest->colormap = NULL;
    115 
    116   if (cinfo->quantize_colors) {
    117     /* Allocate storage for RLE-style cmap, zero any extra entries */
    118     cmapsize = cinfo->out_color_components * CMAPLENGTH * sizeof(rle_map);
    119     dest->colormap = (rle_map *) (*cinfo->mem->alloc_small)
    120       ((j_common_ptr) cinfo, JPOOL_IMAGE, cmapsize);
    121     MEMZERO(dest->colormap, cmapsize);
    122 
    123     /* Save away data in RLE format --- note 8-bit left shift! */
    124     /* Shifting would need adjustment for JSAMPLEs wider than 8 bits. */
    125     for (ci = 0; ci < cinfo->out_color_components; ci++) {
    126       for (i = 0; i < cinfo->actual_number_of_colors; i++) {
    127         dest->colormap[ci * CMAPLENGTH + i] =
    128           GETJSAMPLE(cinfo->colormap[ci][i]) << 8;
    129       }
    130     }
    131   }
    132 
    133   /* Set the output buffer to the first row */
    134   dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
    135     ((j_common_ptr) cinfo, dest->image, (JDIMENSION) 0, (JDIMENSION) 1, TRUE);
    136   dest->pub.buffer_height = 1;
    137 
    138   dest->pub.put_pixel_rows = rle_put_pixel_rows;
    139 
    140 #ifdef PROGRESS_REPORT
    141   if (progress != NULL) {
    142     progress->total_extra_passes++;  /* count file writing as separate pass */
    143   }
    144 #endif
    145 }
    146 
    147 
    148 /*
    149  * Write some pixel data.
    150  *
    151  * This routine just saves the data away in a virtual array.
    152  */
    153 
    154 METHODDEF(void)
    155 rle_put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
    156                     JDIMENSION rows_supplied)
    157 {
    158   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
    159 
    160   if (cinfo->output_scanline < cinfo->output_height) {
    161     dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
    162       ((j_common_ptr) cinfo, dest->image,
    163        cinfo->output_scanline, (JDIMENSION) 1, TRUE);
    164   }
    165 }
    166 
    167 /*
    168  * Finish up at the end of the file.
    169  *
    170  * Here is where we really output the RLE file.
    171  */
    172 
    173 METHODDEF(void)
    174 finish_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
    175 {
    176   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
    177   rle_hdr header;               /* Output file information */
    178   rle_pixel **rle_row, *red, *green, *blue;
    179   JSAMPROW output_row;
    180   char cmapcomment[80];
    181   int row, col;
    182   int ci;
    183 #ifdef PROGRESS_REPORT
    184   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
    185 #endif
    186 
    187   /* Initialize the header info */
    188   header = *rle_hdr_init(NULL);
    189   header.rle_file = dest->pub.output_file;
    190   header.xmin     = 0;
    191   header.xmax     = cinfo->output_width  - 1;
    192   header.ymin     = 0;
    193   header.ymax     = cinfo->output_height - 1;
    194   header.alpha    = 0;
    195   header.ncolors  = cinfo->output_components;
    196   for (ci = 0; ci < cinfo->output_components; ci++) {
    197     RLE_SET_BIT(header, ci);
    198   }
    199   if (cinfo->quantize_colors) {
    200     header.ncmap   = cinfo->out_color_components;
    201     header.cmaplen = CMAPBITS;
    202     header.cmap    = dest->colormap;
    203     /* Add a comment to the output image with the true colormap length. */
    204     sprintf(cmapcomment, "color_map_length=%d", cinfo->actual_number_of_colors);
    205     rle_putcom(cmapcomment, &header);
    206   }
    207 
    208   /* Emit the RLE header and color map (if any) */
    209   rle_put_setup(&header);
    210 
    211   /* Now output the RLE data from our virtual array.
    212    * We assume here that rle_pixel is represented the same as JSAMPLE.
    213    */
    214 
    215 #ifdef PROGRESS_REPORT
    216   if (progress != NULL) {
    217     progress->pub.pass_limit = cinfo->output_height;
    218     progress->pub.pass_counter = 0;
    219     (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
    220   }
    221 #endif
    222 
    223   if (cinfo->output_components == 1) {
    224     for (row = cinfo->output_height-1; row >= 0; row--) {
    225       rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
    226         ((j_common_ptr) cinfo, dest->image,
    227          (JDIMENSION) row, (JDIMENSION) 1, FALSE);
    228       rle_putrow(rle_row, (int) cinfo->output_width, &header);
    229 #ifdef PROGRESS_REPORT
    230       if (progress != NULL) {
    231         progress->pub.pass_counter++;
    232         (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
    233       }
    234 #endif
    235     }
    236   } else {
    237     for (row = cinfo->output_height-1; row >= 0; row--) {
    238       rle_row = (rle_pixel **) dest->rle_row;
    239       output_row = * (*cinfo->mem->access_virt_sarray)
    240         ((j_common_ptr) cinfo, dest->image,
    241          (JDIMENSION) row, (JDIMENSION) 1, FALSE);
    242       red = rle_row[0];
    243       green = rle_row[1];
    244       blue = rle_row[2];
    245       for (col = cinfo->output_width; col > 0; col--) {
    246         *red++ = GETJSAMPLE(*output_row++);
    247         *green++ = GETJSAMPLE(*output_row++);
    248         *blue++ = GETJSAMPLE(*output_row++);
    249       }
    250       rle_putrow(rle_row, (int) cinfo->output_width, &header);
    251 #ifdef PROGRESS_REPORT
    252       if (progress != NULL) {
    253         progress->pub.pass_counter++;
    254         (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
    255       }
    256 #endif
    257     }
    258   }
    259 
    260 #ifdef PROGRESS_REPORT
    261   if (progress != NULL)
    262     progress->completed_extra_passes++;
    263 #endif
    264 
    265   /* Emit file trailer */
    266   rle_puteof(&header);
    267   fflush(dest->pub.output_file);
    268   if (ferror(dest->pub.output_file))
    269     ERREXIT(cinfo, JERR_FILE_WRITE);
    270 }
    271 
    272 
    273 /*
    274  * The module selection routine for RLE format output.
    275  */
    276 
    277 GLOBAL(djpeg_dest_ptr)
    278 jinit_write_rle (j_decompress_ptr cinfo)
    279 {
    280   rle_dest_ptr dest;
    281 
    282   /* Create module interface object, fill in method pointers */
    283   dest = (rle_dest_ptr)
    284       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    285                                   sizeof(rle_dest_struct));
    286   dest->pub.start_output = start_output_rle;
    287   dest->pub.finish_output = finish_output_rle;
    288 
    289   /* Calculate output image dimensions so we can allocate space */
    290   jpeg_calc_output_dimensions(cinfo);
    291 
    292   /* Allocate a work array for output to the RLE library. */
    293   dest->rle_row = (*cinfo->mem->alloc_sarray)
    294     ((j_common_ptr) cinfo, JPOOL_IMAGE,
    295      cinfo->output_width, (JDIMENSION) cinfo->output_components);
    296 
    297   /* Allocate a virtual array to hold the image. */
    298   dest->image = (*cinfo->mem->request_virt_sarray)
    299     ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
    300      (JDIMENSION) (cinfo->output_width * cinfo->output_components),
    301      cinfo->output_height, (JDIMENSION) 1);
    302 
    303   return (djpeg_dest_ptr) dest;
    304 }
    305 
    306 #endif /* RLE_SUPPORTED */
    307