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