4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1996, Thomas G. Lane.
6 * Modified 2017 by Guido Vollbeding.
7 * libjpeg-turbo Modifications:
8 * Copyright (C) 2018, 2021-2022, D. R. Commander.
9 * For conditions of distribution and use, see the accompanying README.ijg
12 * This file contains routines to read input images in Targa format.
14 * These routines may need modification for non-Unix environments or
15 * specialized applications. As they stand, they assume input from
16 * an ordinary stdio stream. They further assume that reading begins
17 * at the start of the file; start_input may need work if the
18 * user interface has already read some data (e.g., to determine that
19 * the file is indeed Targa format).
21 * Based on code contributed by Lee Daniel Crocker.
24 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
26 #ifdef TARGA_SUPPORTED
29 /* Macros to deal with unsigned chars as efficiently as compiler allows */
31 typedef unsigned char U_CHAR;
32 #define UCH(x) ((int)(x))
35 #define ReadOK(file, buffer, len) \
36 (fread(buffer, 1, len, file) == ((size_t)(len)))
39 /* Private version of data source object */
41 typedef struct _tga_source_struct *tga_source_ptr;
43 typedef struct _tga_source_struct {
44 struct cjpeg_source_struct pub; /* public fields */
46 j_compress_ptr cinfo; /* back link saves passing separate parm */
48 JSAMPARRAY colormap; /* Targa colormap (converted to my format) */
50 jvirt_sarray_ptr whole_image; /* Needed if funny input row order */
51 JDIMENSION current_row; /* Current logical row number to read */
53 /* Pointer to routine to extract next Targa pixel from input file */
54 void (*read_pixel) (tga_source_ptr sinfo);
56 /* Result of read_pixel is delivered here: */
59 int pixel_size; /* Bytes per Targa pixel (1 to 4) */
60 int cmap_length; /* colormap length */
62 /* State info for reading RLE-coded pixels; both counts must be init to 0 */
63 int block_count; /* # of pixels remaining in RLE block */
64 int dup_pixel_count; /* # of times to duplicate previous pixel */
66 /* This saves the correct pixel-row-expansion method for preload_image */
67 JDIMENSION (*get_pixel_rows) (j_compress_ptr cinfo, cjpeg_source_ptr sinfo);
71 /* For expanding 5-bit pixel values to 8-bit with best rounding */
73 static const UINT8 c5to8bits[32] = {
74 0, 8, 16, 25, 33, 41, 49, 58,
75 66, 74, 82, 90, 99, 107, 115, 123,
76 132, 140, 148, 156, 165, 173, 181, 189,
77 197, 206, 214, 222, 230, 239, 247, 255
83 read_byte(tga_source_ptr sinfo)
84 /* Read next byte from Targa file */
86 register FILE *infile = sinfo->pub.input_file;
89 if ((c = getc(infile)) == EOF)
90 ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
96 read_colormap(tga_source_ptr sinfo, int cmaplen, int mapentrysize)
97 /* Read the colormap from a Targa file */
101 /* Presently only handles 24-bit BGR format */
102 if (mapentrysize != 24)
103 ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
105 for (i = 0; i < cmaplen; i++) {
106 sinfo->colormap[2][i] = (JSAMPLE)read_byte(sinfo);
107 sinfo->colormap[1][i] = (JSAMPLE)read_byte(sinfo);
108 sinfo->colormap[0][i] = (JSAMPLE)read_byte(sinfo);
114 * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
118 read_non_rle_pixel(tga_source_ptr sinfo)
119 /* Read one Targa pixel from the input file; no RLE expansion */
123 for (i = 0; i < sinfo->pixel_size; i++) {
124 sinfo->tga_pixel[i] = (U_CHAR)read_byte(sinfo);
130 read_rle_pixel(tga_source_ptr sinfo)
131 /* Read one Targa pixel from the input file, expanding RLE data as needed */
135 /* Duplicate previously read pixel? */
136 if (sinfo->dup_pixel_count > 0) {
137 sinfo->dup_pixel_count--;
141 /* Time to read RLE block header? */
142 if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
143 i = read_byte(sinfo);
144 if (i & 0x80) { /* Start of duplicate-pixel block? */
145 sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
146 sinfo->block_count = 0; /* then read new block header */
148 sinfo->block_count = i & 0x7F; /* number of pixels after this one */
152 /* Read next pixel */
153 for (i = 0; i < sinfo->pixel_size; i++) {
154 sinfo->tga_pixel[i] = (U_CHAR)read_byte(sinfo);
160 * Read one row of pixels.
162 * We provide several different versions depending on input file format.
166 METHODDEF(JDIMENSION)
167 get_8bit_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
168 /* This version is for reading 8-bit grayscale pixels */
170 tga_source_ptr source = (tga_source_ptr)sinfo;
171 register JSAMPROW ptr;
172 register JDIMENSION col;
174 ptr = source->pub.buffer[0];
175 for (col = cinfo->image_width; col > 0; col--) {
176 (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
177 *ptr++ = (JSAMPLE)UCH(source->tga_pixel[0]);
182 METHODDEF(JDIMENSION)
183 get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
184 /* This version is for reading 8-bit colormap indexes */
186 tga_source_ptr source = (tga_source_ptr)sinfo;
188 register JSAMPROW ptr;
189 register JDIMENSION col;
190 register JSAMPARRAY colormap = source->colormap;
191 int cmaplen = source->cmap_length;
193 ptr = source->pub.buffer[0];
194 for (col = cinfo->image_width; col > 0; col--) {
195 (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
196 t = UCH(source->tga_pixel[0]);
198 ERREXIT(cinfo, JERR_TGA_BADPARMS);
199 *ptr++ = colormap[0][t];
200 *ptr++ = colormap[1][t];
201 *ptr++ = colormap[2][t];
206 METHODDEF(JDIMENSION)
207 get_16bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
208 /* This version is for reading 16-bit pixels */
210 tga_source_ptr source = (tga_source_ptr)sinfo;
212 register JSAMPROW ptr;
213 register JDIMENSION col;
215 ptr = source->pub.buffer[0];
216 for (col = cinfo->image_width; col > 0; col--) {
217 (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
218 t = UCH(source->tga_pixel[0]);
219 t += UCH(source->tga_pixel[1]) << 8;
220 /* We expand 5 bit data to 8 bit sample width.
221 * The format of the 16-bit (LSB first) input word is
224 ptr[2] = (JSAMPLE)c5to8bits[t & 0x1F];
226 ptr[1] = (JSAMPLE)c5to8bits[t & 0x1F];
228 ptr[0] = (JSAMPLE)c5to8bits[t & 0x1F];
234 METHODDEF(JDIMENSION)
235 get_24bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
236 /* This version is for reading 24-bit pixels */
238 tga_source_ptr source = (tga_source_ptr)sinfo;
239 register JSAMPROW ptr;
240 register JDIMENSION col;
242 ptr = source->pub.buffer[0];
243 for (col = cinfo->image_width; col > 0; col--) {
244 (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
245 *ptr++ = (JSAMPLE)UCH(source->tga_pixel[2]); /* change BGR to RGB order */
246 *ptr++ = (JSAMPLE)UCH(source->tga_pixel[1]);
247 *ptr++ = (JSAMPLE)UCH(source->tga_pixel[0]);
253 * Targa also defines a 32-bit pixel format with order B,G,R,A.
254 * We presently ignore the attribute byte, so the code for reading
255 * these pixels is identical to the 24-bit routine above.
256 * This works because the actual pixel length is only known to read_pixel.
259 #define get_32bit_row get_24bit_row
263 * This method is for re-reading the input data in standard top-down
264 * row order. The entire image has already been read into whole_image
265 * with proper conversion of pixel format, but it's in a funny row order.
268 METHODDEF(JDIMENSION)
269 get_memory_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
271 tga_source_ptr source = (tga_source_ptr)sinfo;
272 JDIMENSION source_row;
274 /* Compute row of source that maps to current_row of normal order */
275 /* For now, assume image is bottom-up and not interlaced. */
276 /* NEEDS WORK to support interlaced images! */
277 source_row = cinfo->image_height - source->current_row - 1;
279 /* Fetch that row from virtual array */
280 source->pub.buffer = (*cinfo->mem->access_virt_sarray)
281 ((j_common_ptr)cinfo, source->whole_image,
282 source_row, (JDIMENSION)1, FALSE);
284 source->current_row++;
290 * This method loads the image into whole_image during the first call on
291 * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
292 * get_memory_row on subsequent calls.
295 METHODDEF(JDIMENSION)
296 preload_image(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
298 tga_source_ptr source = (tga_source_ptr)sinfo;
300 cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;
302 /* Read the data into a virtual array in input-file row order. */
303 for (row = 0; row < cinfo->image_height; row++) {
304 if (progress != NULL) {
305 progress->pub.pass_counter = (long)row;
306 progress->pub.pass_limit = (long)cinfo->image_height;
307 (*progress->pub.progress_monitor) ((j_common_ptr)cinfo);
309 source->pub.buffer = (*cinfo->mem->access_virt_sarray)
310 ((j_common_ptr)cinfo, source->whole_image, row, (JDIMENSION)1, TRUE);
311 (*source->get_pixel_rows) (cinfo, sinfo);
313 if (progress != NULL)
314 progress->completed_extra_passes++;
316 /* Set up to read from the virtual array in unscrambled order */
317 source->pub.get_pixel_rows = get_memory_row;
318 source->current_row = 0;
319 /* And read the first row */
320 return get_memory_row(cinfo, sinfo);
325 * Read the file header; return image size and component count.
329 start_input_tga(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
331 tga_source_ptr source = (tga_source_ptr)sinfo;
332 U_CHAR targaheader[18];
333 int idlen, cmaptype, subtype, flags, interlace_type, components;
334 unsigned int width, height, maplen;
335 boolean is_bottom_up;
337 #define GET_2B(offset) \
338 ((unsigned int)UCH(targaheader[offset]) + \
339 (((unsigned int)UCH(targaheader[offset + 1])) << 8))
341 if (!ReadOK(source->pub.input_file, targaheader, 18))
342 ERREXIT(cinfo, JERR_INPUT_EOF);
344 /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
345 if (targaheader[16] == 15)
346 targaheader[16] = 16;
348 idlen = UCH(targaheader[0]);
349 cmaptype = UCH(targaheader[1]);
350 subtype = UCH(targaheader[2]);
354 source->pixel_size = UCH(targaheader[16]) >> 3;
355 flags = UCH(targaheader[17]); /* Image Descriptor byte */
357 is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
358 interlace_type = flags >> 6; /* bits 6/7 are interlace code */
360 if (cmaptype > 1 || /* cmaptype must be 0 or 1 */
361 source->pixel_size < 1 || source->pixel_size > 4 ||
362 (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
363 interlace_type != 0 || /* currently don't allow interlaced image */
364 width == 0 || height == 0) /* image width/height must be non-zero */
365 ERREXIT(cinfo, JERR_TGA_BADPARMS);
366 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
367 if (sinfo->max_pixels &&
368 (unsigned long long)width * height > sinfo->max_pixels)
369 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
373 /* It's an RLE-coded file */
374 source->read_pixel = read_rle_pixel;
375 source->block_count = source->dup_pixel_count = 0;
379 source->read_pixel = read_non_rle_pixel;
382 /* Now should have subtype 1, 2, or 3 */
383 components = 3; /* until proven different */
384 cinfo->in_color_space = JCS_RGB;
387 case 1: /* Colormapped image */
388 if (source->pixel_size == 1 && cmaptype == 1)
389 source->get_pixel_rows = get_8bit_row;
391 ERREXIT(cinfo, JERR_TGA_BADPARMS);
392 TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
394 case 2: /* RGB image */
395 switch (source->pixel_size) {
397 source->get_pixel_rows = get_16bit_row;
400 source->get_pixel_rows = get_24bit_row;
403 source->get_pixel_rows = get_32bit_row;
406 ERREXIT(cinfo, JERR_TGA_BADPARMS);
409 TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
411 case 3: /* Grayscale image */
413 cinfo->in_color_space = JCS_GRAYSCALE;
414 if (source->pixel_size == 1)
415 source->get_pixel_rows = get_8bit_gray_row;
417 ERREXIT(cinfo, JERR_TGA_BADPARMS);
418 TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
421 ERREXIT(cinfo, JERR_TGA_BADPARMS);
426 /* Create a virtual array to buffer the upside-down image. */
427 source->whole_image = (*cinfo->mem->request_virt_sarray)
428 ((j_common_ptr)cinfo, JPOOL_IMAGE, FALSE,
429 (JDIMENSION)width * components, (JDIMENSION)height, (JDIMENSION)1);
430 if (cinfo->progress != NULL) {
431 cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;
432 progress->total_extra_passes++; /* count file input as separate pass */
434 /* source->pub.buffer will point to the virtual array. */
435 source->pub.buffer_height = 1; /* in case anyone looks at it */
436 source->pub.get_pixel_rows = preload_image;
438 /* Don't need a virtual array, but do need a one-row input buffer. */
439 source->whole_image = NULL;
440 source->pub.buffer = (*cinfo->mem->alloc_sarray)
441 ((j_common_ptr)cinfo, JPOOL_IMAGE,
442 (JDIMENSION)width * components, (JDIMENSION)1);
443 source->pub.buffer_height = 1;
444 source->pub.get_pixel_rows = source->get_pixel_rows;
447 while (idlen--) /* Throw away ID field */
448 (void)read_byte(source);
451 if (maplen > 256 || GET_2B(3) != 0)
452 ERREXIT(cinfo, JERR_TGA_BADCMAP);
453 /* Allocate space to store the colormap */
454 source->colormap = (*cinfo->mem->alloc_sarray)
455 ((j_common_ptr)cinfo, JPOOL_IMAGE, (JDIMENSION)maplen, (JDIMENSION)3);
456 source->cmap_length = (int)maplen;
457 /* and read it from the file */
458 read_colormap(source, (int)maplen, UCH(targaheader[7]));
460 if (cmaptype) /* but you promised a cmap! */
461 ERREXIT(cinfo, JERR_TGA_BADPARMS);
462 source->colormap = NULL;
463 source->cmap_length = 0;
466 cinfo->input_components = components;
467 cinfo->data_precision = 8;
468 cinfo->image_width = width;
469 cinfo->image_height = height;
474 * Finish up at the end of the file.
478 finish_input_tga(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
485 * The module selection routine for Targa format input.
488 GLOBAL(cjpeg_source_ptr)
489 jinit_read_targa(j_compress_ptr cinfo)
491 tga_source_ptr source;
493 if (cinfo->data_precision != 8)
494 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
496 /* Create module interface object */
497 source = (tga_source_ptr)
498 (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
499 sizeof(tga_source_struct));
500 source->cinfo = cinfo; /* make back link for subroutines */
501 /* Fill in method ptrs, except get_pixel_rows which start_input sets */
502 source->pub.start_input = start_input_tga;
503 source->pub.finish_input = finish_input_tga;
504 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
505 source->pub.max_pixels = 0;
508 return (cjpeg_source_ptr)source;
511 #endif /* TARGA_SUPPORTED */