rdtarga.c
Go to the documentation of this file.
1 /*
2  * rdtarga.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 read input images in Targa format.
9  *
10  * These routines may need modification for non-Unix environments or
11  * specialized applications. As they stand, they assume input from
12  * an ordinary stdio stream. They further assume that reading begins
13  * at the start of the file; start_input may need work if the
14  * user interface has already read some data (e.g., to determine that
15  * the file is indeed Targa format).
16  *
17  * Based on code contributed by Lee Daniel Crocker.
18  */
19 
20 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
21 
22 #ifdef TARGA_SUPPORTED
23 
24 
25 /* Macros to deal with unsigned chars as efficiently as compiler allows */
26 
27 #ifdef HAVE_UNSIGNED_CHAR
28 typedef unsigned char U_CHAR;
29 #define UCH(x) ((int) (x))
30 #else /* !HAVE_UNSIGNED_CHAR */
31 #ifdef CHAR_IS_UNSIGNED
32 typedef char U_CHAR;
33 #define UCH(x) ((int) (x))
34 #else
35 typedef char U_CHAR;
36 #define UCH(x) ((int) (x) & 0xFF)
37 #endif
38 #endif /* HAVE_UNSIGNED_CHAR */
39 
40 
41 #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
42 
43 
44 /* Private version of data source object */
45 
47 
48 typedef struct _tga_source_struct {
49  struct cjpeg_source_struct pub; /* public fields */
50 
51  j_compress_ptr cinfo; /* back link saves passing separate parm */
52 
53  JSAMPARRAY colormap; /* Targa colormap (converted to my format) */
54 
55  jvirt_sarray_ptr whole_image; /* Needed if funny input row order */
56  JDIMENSION current_row; /* Current logical row number to read */
57 
58  /* Pointer to routine to extract next Targa pixel from input file */
59  JMETHOD(void, read_pixel, (tga_source_ptr sinfo));
60 
61  /* Result of read_pixel is delivered here: */
63 
64  int pixel_size; /* Bytes per Targa pixel (1 to 4) */
65 
66  /* State info for reading RLE-coded pixels; both counts must be init to 0 */
67  int block_count; /* # of pixels remaining in RLE block */
68  int dup_pixel_count; /* # of times to duplicate previous pixel */
69 
70  /* This saves the correct pixel-row-expansion method for preload_image */
71  JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
72  cjpeg_source_ptr sinfo));
74 
75 
76 /* For expanding 5-bit pixel values to 8-bit with best rounding */
77 
78 static const UINT8 c5to8bits[32] = {
79  0, 8, 16, 25, 33, 41, 49, 58,
80  66, 74, 82, 90, 99, 107, 115, 123,
81  132, 140, 148, 156, 165, 173, 181, 189,
82  197, 206, 214, 222, 230, 239, 247, 255
83 };
84 
85 
86 
87 LOCAL(int)
88 read_byte (tga_source_ptr sinfo)
89 /* Read next byte from Targa file */
90 {
91  register FILE *infile = sinfo->pub.input_file;
92  register int c;
93 
94  if ((c = getc(infile)) == EOF)
95  ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
96  return c;
97 }
98 
99 
100 LOCAL(void)
101 read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
102 /* Read the colormap from a Targa file */
103 {
104  int i;
105 
106  /* Presently only handles 24-bit BGR format */
107  if (mapentrysize != 24)
108  ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
109 
110  for (i = 0; i < cmaplen; i++) {
111  sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
112  sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
113  sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
114  }
115 }
116 
117 
118 /*
119  * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
120  */
121 
122 METHODDEF(void)
123 read_non_rle_pixel (tga_source_ptr sinfo)
124 /* Read one Targa pixel from the input file; no RLE expansion */
125 {
126  register FILE *infile = sinfo->pub.input_file;
127  register int i;
128 
129  for (i = 0; i < sinfo->pixel_size; i++) {
130  sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
131  }
132 }
133 
134 
135 METHODDEF(void)
136 read_rle_pixel (tga_source_ptr sinfo)
137 /* Read one Targa pixel from the input file, expanding RLE data as needed */
138 {
139  register FILE *infile = sinfo->pub.input_file;
140  register int i;
141 
142  /* Duplicate previously read pixel? */
143  if (sinfo->dup_pixel_count > 0) {
144  sinfo->dup_pixel_count--;
145  return;
146  }
147 
148  /* Time to read RLE block header? */
149  if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
150  i = read_byte(sinfo);
151  if (i & 0x80) { /* Start of duplicate-pixel block? */
152  sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
153  sinfo->block_count = 0; /* then read new block header */
154  } else {
155  sinfo->block_count = i & 0x7F; /* number of pixels after this one */
156  }
157  }
158 
159  /* Read next pixel */
160  for (i = 0; i < sinfo->pixel_size; i++) {
161  sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
162  }
163 }
164 
165 
166 /*
167  * Read one row of pixels.
168  *
169  * We provide several different versions depending on input file format.
170  */
171 
172 
175 /* This version is for reading 8-bit grayscale pixels */
176 {
177  tga_source_ptr source = (tga_source_ptr) sinfo;
178  register JSAMPROW ptr;
179  register JDIMENSION col;
180 
181  ptr = source->pub.buffer[0];
182  for (col = cinfo->image_width; col > 0; col--) {
183  (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
184  *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
185  }
186  return 1;
187 }
188 
191 /* This version is for reading 8-bit colormap indexes */
192 {
193  tga_source_ptr source = (tga_source_ptr) sinfo;
194  register int t;
195  register JSAMPROW ptr;
196  register JDIMENSION col;
197  register JSAMPARRAY colormap = source->colormap;
198 
199  ptr = source->pub.buffer[0];
200  for (col = cinfo->image_width; col > 0; col--) {
201  (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
202  t = UCH(source->tga_pixel[0]);
203  *ptr++ = colormap[0][t];
204  *ptr++ = colormap[1][t];
205  *ptr++ = colormap[2][t];
206  }
207  return 1;
208 }
209 
212 /* This version is for reading 16-bit pixels */
213 {
214  tga_source_ptr source = (tga_source_ptr) sinfo;
215  register int t;
216  register JSAMPROW ptr;
217  register JDIMENSION col;
218 
219  ptr = source->pub.buffer[0];
220  for (col = cinfo->image_width; col > 0; col--) {
221  (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
222  t = UCH(source->tga_pixel[0]);
223  t += UCH(source->tga_pixel[1]) << 8;
224  /* We expand 5 bit data to 8 bit sample width.
225  * The format of the 16-bit (LSB first) input word is
226  * xRRRRRGGGGGBBBBB
227  */
228  ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
229  t >>= 5;
230  ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
231  t >>= 5;
232  ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
233  ptr += 3;
234  }
235  return 1;
236 }
237 
240 /* This version is for reading 24-bit pixels */
241 {
242  tga_source_ptr source = (tga_source_ptr) sinfo;
243  register JSAMPROW ptr;
244  register JDIMENSION col;
245 
246  ptr = source->pub.buffer[0];
247  for (col = cinfo->image_width; col > 0; col--) {
248  (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
249  *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
250  *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
251  *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
252  }
253  return 1;
254 }
255 
256 /*
257  * Targa also defines a 32-bit pixel format with order B,G,R,A.
258  * We presently ignore the attribute byte, so the code for reading
259  * these pixels is identical to the 24-bit routine above.
260  * This works because the actual pixel length is only known to read_pixel.
261  */
262 
263 #define get_32bit_row get_24bit_row
264 
265 
266 /*
267  * This method is for re-reading the input data in standard top-down
268  * row order. The entire image has already been read into whole_image
269  * with proper conversion of pixel format, but it's in a funny row order.
270  */
271 
274 {
275  tga_source_ptr source = (tga_source_ptr) sinfo;
277 
278  /* Compute row of source that maps to current_row of normal order */
279  /* For now, assume image is bottom-up and not interlaced. */
280  /* NEEDS WORK to support interlaced images! */
281  source_row = cinfo->image_height - source->current_row - 1;
282 
283  /* Fetch that row from virtual array */
284  source->pub.buffer = (*cinfo->mem->access_virt_sarray)
285  ((j_common_ptr) cinfo, source->whole_image,
286  source_row, (JDIMENSION) 1, FALSE);
287 
288  source->current_row++;
289  return 1;
290 }
291 
292 
293 /*
294  * This method loads the image into whole_image during the first call on
295  * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
296  * get_memory_row on subsequent calls.
297  */
298 
301 {
302  tga_source_ptr source = (tga_source_ptr) sinfo;
303  JDIMENSION row;
305 
306  /* Read the data into a virtual array in input-file row order. */
307  for (row = 0; row < cinfo->image_height; row++) {
308  if (progress != NULL) {
309  progress->pub.pass_counter = (long) row;
310  progress->pub.pass_limit = (long) cinfo->image_height;
311  (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
312  }
313  source->pub.buffer = (*cinfo->mem->access_virt_sarray)
314  ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
315  (*source->get_pixel_rows) (cinfo, sinfo);
316  }
317  if (progress != NULL)
318  progress->completed_extra_passes++;
319 
320  /* Set up to read from the virtual array in unscrambled order */
321  source->pub.get_pixel_rows = get_memory_row;
322  source->current_row = 0;
323  /* And read the first row */
324  return get_memory_row(cinfo, sinfo);
325 }
326 
327 
328 /*
329  * Read the file header; return image size and component count.
330  */
331 
332 METHODDEF(void)
334 {
335  tga_source_ptr source = (tga_source_ptr) sinfo;
336  U_CHAR targaheader[18];
337  int idlen, cmaptype, subtype, flags, interlace_type, components;
338  unsigned int width, height, maplen;
339  boolean is_bottom_up;
340 
341 #define GET_2B(offset) ((unsigned int) UCH(targaheader[offset]) + \
342  (((unsigned int) UCH(targaheader[offset+1])) << 8))
343 
344  if (! ReadOK(source->pub.input_file, targaheader, 18))
345  ERREXIT(cinfo, JERR_INPUT_EOF);
346 
347  /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
348  if (targaheader[16] == 15)
349  targaheader[16] = 16;
350 
351  idlen = UCH(targaheader[0]);
352  cmaptype = UCH(targaheader[1]);
353  subtype = UCH(targaheader[2]);
354  maplen = GET_2B(5);
355  width = GET_2B(12);
356  height = GET_2B(14);
357  source->pixel_size = UCH(targaheader[16]) >> 3;
358  flags = UCH(targaheader[17]); /* Image Descriptor byte */
359 
360  is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
361  interlace_type = flags >> 6; /* bits 6/7 are interlace code */
362 
363  if (cmaptype > 1 || /* cmaptype must be 0 or 1 */
364  source->pixel_size < 1 || source->pixel_size > 4 ||
365  (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
366  interlace_type != 0) /* currently don't allow interlaced image */
367  ERREXIT(cinfo, JERR_TGA_BADPARMS);
368 
369  if (subtype > 8) {
370  /* It's an RLE-coded file */
371  source->read_pixel = read_rle_pixel;
372  source->block_count = source->dup_pixel_count = 0;
373  subtype -= 8;
374  } else {
375  /* Non-RLE file */
376  source->read_pixel = read_non_rle_pixel;
377  }
378 
379  /* Now should have subtype 1, 2, or 3 */
380  components = 3; /* until proven different */
382 
383  switch (subtype) {
384  case 1: /* Colormapped image */
385  if (source->pixel_size == 1 && cmaptype == 1)
386  source->get_pixel_rows = get_8bit_row;
387  else
388  ERREXIT(cinfo, JERR_TGA_BADPARMS);
389  TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
390  break;
391  case 2: /* RGB image */
392  switch (source->pixel_size) {
393  case 2:
394  source->get_pixel_rows = get_16bit_row;
395  break;
396  case 3:
397  source->get_pixel_rows = get_24bit_row;
398  break;
399  case 4:
400  source->get_pixel_rows = get_32bit_row;
401  break;
402  default:
403  ERREXIT(cinfo, JERR_TGA_BADPARMS);
404  break;
405  }
406  TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
407  break;
408  case 3: /* Grayscale image */
409  components = 1;
411  if (source->pixel_size == 1)
412  source->get_pixel_rows = get_8bit_gray_row;
413  else
414  ERREXIT(cinfo, JERR_TGA_BADPARMS);
415  TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
416  break;
417  default:
418  ERREXIT(cinfo, JERR_TGA_BADPARMS);
419  break;
420  }
421 
422  if (is_bottom_up) {
423  /* Create a virtual array to buffer the upside-down image. */
424  source->whole_image = (*cinfo->mem->request_virt_sarray)
426  (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
427  if (cinfo->progress != NULL) {
428  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
429  progress->total_extra_passes++; /* count file input as separate pass */
430  }
431  /* source->pub.buffer will point to the virtual array. */
432  source->pub.buffer_height = 1; /* in case anyone looks at it */
433  source->pub.get_pixel_rows = preload_image;
434  } else {
435  /* Don't need a virtual array, but do need a one-row input buffer. */
436  source->whole_image = NULL;
437  source->pub.buffer = (*cinfo->mem->alloc_sarray)
439  (JDIMENSION) width * components, (JDIMENSION) 1);
440  source->pub.buffer_height = 1;
441  source->pub.get_pixel_rows = source->get_pixel_rows;
442  }
443 
444  while (idlen--) /* Throw away ID field */
445  (void) read_byte(source);
446 
447  if (maplen > 0) {
448  if (maplen > 256 || GET_2B(3) != 0)
449  ERREXIT(cinfo, JERR_TGA_BADCMAP);
450  /* Allocate space to store the colormap */
451  source->colormap = (*cinfo->mem->alloc_sarray)
452  ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
453  /* and read it from the file */
454  read_colormap(source, (int) maplen, UCH(targaheader[7]));
455  } else {
456  if (cmaptype) /* but you promised a cmap! */
457  ERREXIT(cinfo, JERR_TGA_BADPARMS);
458  source->colormap = NULL;
459  }
460 
461  cinfo->input_components = components;
462  cinfo->data_precision = 8;
465 }
466 
467 
468 /*
469  * Finish up at the end of the file.
470  */
471 
472 METHODDEF(void)
474 {
475  /* no work */
476 }
477 
478 
479 /*
480  * The module selection routine for Targa format input.
481  */
482 
485 {
486  tga_source_ptr source;
487 
488  /* Create module interface object */
489  source = (tga_source_ptr)
490  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
492  source->cinfo = cinfo; /* make back link for subroutines */
493  /* Fill in method ptrs, except get_pixel_rows which start_input sets */
494  source->pub.start_input = start_input_tga;
495  source->pub.finish_input = finish_input_tga;
496 
497  return (cjpeg_source_ptr) source;
498 }
499 
500 #endif /* TARGA_SUPPORTED */
JSAMPARRAY colormap
Definition: rdtarga.c:53
struct _tga_source_struct tga_source_struct
U_CHAR tga_pixel[4]
Definition: rdtarga.c:62
int c
Definition: autoplay.py:16
char JSAMPLE
Definition: jmorecfg.h:64
JSAMPLE FAR * JSAMPROW
Definition: jpeglib.h:66
#define FALSE
Definition: OPC_IceHook.h:9
JMETHOD(void, read_pixel,(tga_source_ptr sinfo))
png_voidp ptr
Definition: png.h:2063
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:261
JDIMENSION image_height
Definition: jpeglib.h:280
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
#define TRACEMS2(cinfo, lvl, code, p1, p2)
Definition: jerror.h:259
#define TRUE
Definition: OPC_IceHook.h:13
#define SIZEOF(object)
Definition: jinclude.h:80
JDIMENSION buffer_height
Definition: cdjpeg.h:37
#define for
png_uint_32 i
Definition: png.h:2735
static const UINT8 c5to8bits[32]
Definition: rdtarga.c:78
J_COLOR_SPACE in_color_space
Definition: jpeglib.h:282
png_uint_32 int flags
Definition: png.h:1656
jvirt_sarray_ptr whole_image
Definition: rdtarga.c:55
#define JPOOL_IMAGE
Definition: jpeglib.h:749
png_infop png_uint_32 * width
Definition: png.h:2309
int total_extra_passes
Definition: cdjpeg.h:84
struct _tga_source_struct * tga_source_ptr
Definition: rdtarga.c:46
jinit_read_targa(j_compress_ptr cinfo)
Definition: rdtarga.c:484
#define GET_2B(offset)
get_8bit_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:174
get_16bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:211
struct cjpeg_source_struct pub
Definition: rdtarga.c:49
short UINT8
Definition: jmorecfg.h:140
JDIMENSION current_row
Definition: rdtarga.c:56
#define LOCAL(type)
Definition: jmorecfg.h:186
png_infop png_uint_32 png_uint_32 * height
Definition: png.h:2309
get_memory_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:273
get_24bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:239
int source_row
Definition: jpegint.h:373
typedef void(PNGAPI *png_error_ptr) PNGARG((png_structp
preload_image(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:300
t
png_bytepp row
Definition: png.h:1759
JSAMPARRAY buffer
Definition: cdjpeg.h:36
get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:190
struct jpeg_progress_mgr pub
Definition: cdjpeg.h:82
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:67
#define UCH(x)
Definition: rdtarga.c:29
read_colormap(tga_source_ptr sinfo, int cmaplen, int mapentrysize)
Definition: rdtarga.c:101
read_non_rle_pixel(tga_source_ptr sinfo)
Definition: rdtarga.c:123
unsigned char U_CHAR
Definition: rdtarga.c:28
#define GLOBAL(type)
Definition: jmorecfg.h:188
FILE * input_file
Definition: cdjpeg.h:34
#define METHODDEF(type)
Definition: jmorecfg.h:184
FILE * infile
Definition: cdjpeg.h:141
int completed_extra_passes
Definition: cdjpeg.h:83
j_compress_ptr cinfo
Definition: rdtarga.c:51
cd_progress_ptr progress
Definition: cdjpeg.h:147
unsigned int JDIMENSION
Definition: jmorecfg.h:171
struct cdjpeg_progress_mgr * cd_progress_ptr
Definition: cdjpeg.h:89
read_byte(tga_source_ptr sinfo)
Definition: rdtarga.c:88
start_input_tga(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:333
finish_input_tga(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdtarga.c:473
read_rle_pixel(tga_source_ptr sinfo)
Definition: rdtarga.c:136
unsigned char U_CHAR
Definition: rdbmp.c:32
#define ReadOK(file, buffer, len)
Definition: rdtarga.c:41
JDIMENSION image_width
Definition: jpeglib.h:279
#define get_32bit_row
Definition: rdtarga.c:263


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Sat Apr 13 2019 02:14:25