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plt-scheme  4.2.1
wrrle.c
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00001 /*
00002  * wrrle.c
00003  *
00004  * Copyright (C) 1991-1996, Thomas G. Lane.
00005  * This file is part of the Independent JPEG Group's software.
00006  * For conditions of distribution and use, see the accompanying README file.
00007  *
00008  * This file contains routines to write output images in RLE format.
00009  * The Utah Raster Toolkit library is required (version 3.1 or later).
00010  *
00011  * These routines may need modification for non-Unix environments or
00012  * specialized applications.  As they stand, they assume output to
00013  * an ordinary stdio stream.
00014  *
00015  * Based on code contributed by Mike Lijewski,
00016  * with updates from Robert Hutchinson.
00017  */
00018 
00019 #include "cdjpeg.h"         /* Common decls for cjpeg/djpeg applications */
00020 
00021 #ifdef RLE_SUPPORTED
00022 
00023 /* rle.h is provided by the Utah Raster Toolkit. */
00024 
00025 #include <rle.h>
00026 
00027 /*
00028  * We assume that JSAMPLE has the same representation as rle_pixel,
00029  * to wit, "unsigned char".  Hence we can't cope with 12- or 16-bit samples.
00030  */
00031 
00032 #if BITS_IN_JSAMPLE != 8
00033   Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
00034 #endif
00035 
00036 
00037 /*
00038  * Since RLE stores scanlines bottom-to-top, we have to invert the image
00039  * from JPEG's top-to-bottom order.  To do this, we save the outgoing data
00040  * in a virtual array during put_pixel_row calls, then actually emit the
00041  * RLE file during finish_output.
00042  */
00043 
00044 
00045 /*
00046  * For now, if we emit an RLE color map then it is always 256 entries long,
00047  * though not all of the entries need be used.
00048  */
00049 
00050 #define CMAPBITS     8
00051 #define CMAPLENGTH   (1<<(CMAPBITS))
00052 
00053 typedef struct {
00054   struct djpeg_dest_struct pub; /* public fields */
00055 
00056   jvirt_sarray_ptr image;   /* virtual array to store the output image */
00057   rle_map *colormap;        /* RLE-style color map, or NULL if none */
00058   rle_pixel **rle_row;             /* To pass rows to rle_putrow() */
00059 
00060 } rle_dest_struct;
00061 
00062 typedef rle_dest_struct * rle_dest_ptr;
00063 
00064 /* Forward declarations */
00065 METHODDEF(void) rle_put_pixel_rows
00066     JPP((j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
00067         JDIMENSION rows_supplied));
00068 
00069 
00070 /*
00071  * Write the file header.
00072  *
00073  * In this module it's easier to wait till finish_output to write anything.
00074  */
00075 
00076 METHODDEF(void)
00077 start_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
00078 {
00079   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
00080   size_t cmapsize;
00081   int i, ci;
00082 #ifdef PROGRESS_REPORT
00083   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
00084 #endif
00085 
00086   /*
00087    * Make sure the image can be stored in RLE format.
00088    *
00089    * - RLE stores image dimensions as *signed* 16 bit integers.  JPEG
00090    *   uses unsigned, so we have to check the width.
00091    *
00092    * - Colorspace is expected to be grayscale or RGB.
00093    *
00094    * - The number of channels (components) is expected to be 1 (grayscale/
00095    *   pseudocolor) or 3 (truecolor/directcolor).
00096    *   (could be 2 or 4 if using an alpha channel, but we aren't)
00097    */
00098 
00099   if (cinfo->output_width > 32767 || cinfo->output_height > 32767)
00100     ERREXIT2(cinfo, JERR_RLE_DIMENSIONS, cinfo->output_width, 
00101             cinfo->output_height);
00102 
00103   if (cinfo->out_color_space != JCS_GRAYSCALE &&
00104       cinfo->out_color_space != JCS_RGB)
00105     ERREXIT(cinfo, JERR_RLE_COLORSPACE);
00106 
00107   if (cinfo->output_components != 1 && cinfo->output_components != 3)
00108     ERREXIT1(cinfo, JERR_RLE_TOOMANYCHANNELS, cinfo->num_components);
00109 
00110   /* Convert colormap, if any, to RLE format. */
00111 
00112   dest->colormap = NULL;
00113 
00114   if (cinfo->quantize_colors) {
00115     /* Allocate storage for RLE-style cmap, zero any extra entries */
00116     cmapsize = cinfo->out_color_components * CMAPLENGTH * SIZEOF(rle_map);
00117     dest->colormap = (rle_map *) (*cinfo->mem->alloc_small)
00118       ((j_common_ptr) cinfo, JPOOL_IMAGE, cmapsize);
00119     MEMZERO(dest->colormap, cmapsize);
00120 
00121     /* Save away data in RLE format --- note 8-bit left shift! */
00122     /* Shifting would need adjustment for JSAMPLEs wider than 8 bits. */
00123     for (ci = 0; ci < cinfo->out_color_components; ci++) {
00124       for (i = 0; i < cinfo->actual_number_of_colors; i++) {
00125         dest->colormap[ci * CMAPLENGTH + i] =
00126           GETJSAMPLE(cinfo->colormap[ci][i]) << 8;
00127       }
00128     }
00129   }
00130 
00131   /* Set the output buffer to the first row */
00132   dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
00133     ((j_common_ptr) cinfo, dest->image, (JDIMENSION) 0, (JDIMENSION) 1, TRUE);
00134   dest->pub.buffer_height = 1;
00135 
00136   dest->pub.put_pixel_rows = rle_put_pixel_rows;
00137 
00138 #ifdef PROGRESS_REPORT
00139   if (progress != NULL) {
00140     progress->total_extra_passes++;  /* count file writing as separate pass */
00141   }
00142 #endif
00143 }
00144 
00145 
00146 /*
00147  * Write some pixel data.
00148  *
00149  * This routine just saves the data away in a virtual array.
00150  */
00151 
00152 METHODDEF(void)
00153 rle_put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
00154                   JDIMENSION rows_supplied)
00155 {
00156   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
00157 
00158   if (cinfo->output_scanline < cinfo->output_height) {
00159     dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
00160       ((j_common_ptr) cinfo, dest->image,
00161        cinfo->output_scanline, (JDIMENSION) 1, TRUE);
00162   }
00163 }
00164 
00165 /*
00166  * Finish up at the end of the file.
00167  *
00168  * Here is where we really output the RLE file.
00169  */
00170 
00171 METHODDEF(void)
00172 finish_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
00173 {
00174   rle_dest_ptr dest = (rle_dest_ptr) dinfo;
00175   rle_hdr header;           /* Output file information */
00176   rle_pixel **rle_row, *red, *green, *blue;
00177   JSAMPROW output_row;
00178   char cmapcomment[80];
00179   int row, col;
00180   int ci;
00181 #ifdef PROGRESS_REPORT
00182   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
00183 #endif
00184 
00185   /* Initialize the header info */
00186   header = *rle_hdr_init(NULL);
00187   header.rle_file = dest->pub.output_file;
00188   header.xmin     = 0;
00189   header.xmax     = cinfo->output_width  - 1;
00190   header.ymin     = 0;
00191   header.ymax     = cinfo->output_height - 1;
00192   header.alpha    = 0;
00193   header.ncolors  = cinfo->output_components;
00194   for (ci = 0; ci < cinfo->output_components; ci++) {
00195     RLE_SET_BIT(header, ci);
00196   }
00197   if (cinfo->quantize_colors) {
00198     header.ncmap   = cinfo->out_color_components;
00199     header.cmaplen = CMAPBITS;
00200     header.cmap    = dest->colormap;
00201     /* Add a comment to the output image with the true colormap length. */
00202     sprintf(cmapcomment, "color_map_length=%d", cinfo->actual_number_of_colors);
00203     rle_putcom(cmapcomment, &header);
00204   }
00205 
00206   /* Emit the RLE header and color map (if any) */
00207   rle_put_setup(&header);
00208 
00209   /* Now output the RLE data from our virtual array.
00210    * We assume here that (a) rle_pixel is represented the same as JSAMPLE,
00211    * and (b) we are not on a machine where FAR pointers differ from regular.
00212    */
00213 
00214 #ifdef PROGRESS_REPORT
00215   if (progress != NULL) {
00216     progress->pub.pass_limit = cinfo->output_height;
00217     progress->pub.pass_counter = 0;
00218     (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
00219   }
00220 #endif
00221 
00222   if (cinfo->output_components == 1) {
00223     for (row = cinfo->output_height-1; row >= 0; row--) {
00224       rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
00225         ((j_common_ptr) cinfo, dest->image,
00226         (JDIMENSION) row, (JDIMENSION) 1, FALSE);
00227       rle_putrow(rle_row, (int) cinfo->output_width, &header);
00228 #ifdef PROGRESS_REPORT
00229       if (progress != NULL) {
00230         progress->pub.pass_counter++;
00231         (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
00232       }
00233 #endif
00234     }
00235   } else {
00236     for (row = cinfo->output_height-1; row >= 0; row--) {
00237       rle_row = (rle_pixel **) dest->rle_row;
00238       output_row = * (*cinfo->mem->access_virt_sarray)
00239         ((j_common_ptr) cinfo, dest->image,
00240         (JDIMENSION) row, (JDIMENSION) 1, FALSE);
00241       red = rle_row[0];
00242       green = rle_row[1];
00243       blue = rle_row[2];
00244       for (col = cinfo->output_width; col > 0; col--) {
00245         *red++ = GETJSAMPLE(*output_row++);
00246         *green++ = GETJSAMPLE(*output_row++);
00247         *blue++ = GETJSAMPLE(*output_row++);
00248       }
00249       rle_putrow(rle_row, (int) cinfo->output_width, &header);
00250 #ifdef PROGRESS_REPORT
00251       if (progress != NULL) {
00252         progress->pub.pass_counter++;
00253         (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
00254       }
00255 #endif
00256     }
00257   }
00258 
00259 #ifdef PROGRESS_REPORT
00260   if (progress != NULL)
00261     progress->completed_extra_passes++;
00262 #endif
00263 
00264   /* Emit file trailer */
00265   rle_puteof(&header);
00266   fflush(dest->pub.output_file);
00267   if (ferror(dest->pub.output_file))
00268     ERREXIT(cinfo, JERR_FILE_WRITE);
00269 }
00270 
00271 
00272 /*
00273  * The module selection routine for RLE format output.
00274  */
00275 
00276 GLOBAL(djpeg_dest_ptr)
00277 jinit_write_rle (j_decompress_ptr cinfo)
00278 {
00279   rle_dest_ptr dest;
00280 
00281   /* Create module interface object, fill in method pointers */
00282   dest = (rle_dest_ptr)
00283       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
00284                                   SIZEOF(rle_dest_struct));
00285   dest->pub.start_output = start_output_rle;
00286   dest->pub.finish_output = finish_output_rle;
00287 
00288   /* Calculate output image dimensions so we can allocate space */
00289   jpeg_calc_output_dimensions(cinfo);
00290 
00291   /* Allocate a work array for output to the RLE library. */
00292   dest->rle_row = (*cinfo->mem->alloc_sarray)
00293     ((j_common_ptr) cinfo, JPOOL_IMAGE,
00294      cinfo->output_width, (JDIMENSION) cinfo->output_components);
00295 
00296   /* Allocate a virtual array to hold the image. */
00297   dest->image = (*cinfo->mem->request_virt_sarray)
00298     ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
00299      (JDIMENSION) (cinfo->output_width * cinfo->output_components),
00300      cinfo->output_height, (JDIMENSION) 1);
00301 
00302   return (djpeg_dest_ptr) dest;
00303 }
00304 
00305 #endif /* RLE_SUPPORTED */