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
55typedef 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
64typedef rle_dest_struct * rle_dest_ptr;
65
66/* Forward declarations */
67METHODDEF(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
78METHODDEF(void)
79start_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
154METHODDEF(void)
155rle_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
173METHODDEF(void)
174finish_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
277GLOBAL(djpeg_dest_ptr)
278jinit_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