501 lines
15 KiB
C
501 lines
15 KiB
C
/*
|
|
* rdtarga.c
|
|
*
|
|
* Copyright (C) 1991-1996, Thomas G. Lane.
|
|
* Modified 2017-2019 by Guido Vollbeding.
|
|
* This file is part of the Independent JPEG Group's software.
|
|
* For conditions of distribution and use, see the accompanying README file.
|
|
*
|
|
* This file contains routines to read input images in Targa format.
|
|
*
|
|
* These routines may need modification for non-Unix environments or
|
|
* specialized applications. As they stand, they assume input from
|
|
* an ordinary stdio stream. They further assume that reading begins
|
|
* at the start of the file; start_input may need work if the
|
|
* user interface has already read some data (e.g., to determine that
|
|
* the file is indeed Targa format).
|
|
*
|
|
* Based on code contributed by Lee Daniel Crocker.
|
|
*/
|
|
|
|
#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
|
|
|
|
#ifdef TARGA_SUPPORTED
|
|
|
|
|
|
/* Macros to deal with unsigned chars as efficiently as compiler allows */
|
|
|
|
#ifdef HAVE_UNSIGNED_CHAR
|
|
typedef unsigned char U_CHAR;
|
|
#define UCH(x) ((int) (x))
|
|
#else /* !HAVE_UNSIGNED_CHAR */
|
|
typedef char U_CHAR;
|
|
#ifdef CHAR_IS_UNSIGNED
|
|
#define UCH(x) ((int) (x))
|
|
#else
|
|
#define UCH(x) ((int) (x) & 0xFF)
|
|
#endif
|
|
#endif /* HAVE_UNSIGNED_CHAR */
|
|
|
|
|
|
#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
|
|
|
|
|
|
/* Private version of data source object */
|
|
|
|
typedef struct _tga_source_struct * tga_source_ptr;
|
|
|
|
typedef struct _tga_source_struct {
|
|
struct cjpeg_source_struct pub; /* public fields */
|
|
|
|
j_compress_ptr cinfo; /* back link saves passing separate parm */
|
|
|
|
JSAMPARRAY colormap; /* Targa colormap (converted to my format) */
|
|
|
|
jvirt_sarray_ptr whole_image; /* Needed if funny input row order */
|
|
JDIMENSION current_row; /* Current logical row number to read */
|
|
|
|
/* Pointer to routine to extract next Targa pixel from input file */
|
|
JMETHOD(void, read_pixel, (tga_source_ptr sinfo));
|
|
|
|
/* Result of read_pixel is delivered here: */
|
|
U_CHAR tga_pixel[4];
|
|
|
|
int pixel_size; /* Bytes per Targa pixel (1 to 4) */
|
|
int cmap_length; /* colormap length */
|
|
|
|
/* State info for reading RLE-coded pixels; both counts must be init to 0 */
|
|
int block_count; /* # of pixels remaining in RLE block */
|
|
int dup_pixel_count; /* # of times to duplicate previous pixel */
|
|
|
|
/* This saves the correct pixel-row-expansion method for preload_image */
|
|
JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
|
|
cjpeg_source_ptr sinfo));
|
|
} tga_source_struct;
|
|
|
|
|
|
/* For expanding 5-bit pixel values to 8-bit with best rounding */
|
|
|
|
static const UINT8 c5to8bits[32] = {
|
|
0, 8, 16, 25, 33, 41, 49, 58,
|
|
66, 74, 82, 90, 99, 107, 115, 123,
|
|
132, 140, 148, 156, 165, 173, 181, 189,
|
|
197, 206, 214, 222, 230, 239, 247, 255
|
|
};
|
|
|
|
|
|
|
|
LOCAL(int)
|
|
read_byte (tga_source_ptr sinfo)
|
|
/* Read next byte from Targa file */
|
|
{
|
|
register FILE *infile = sinfo->pub.input_file;
|
|
register int c;
|
|
|
|
if ((c = getc(infile)) == EOF)
|
|
ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
|
|
return c;
|
|
}
|
|
|
|
|
|
LOCAL(void)
|
|
read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
|
|
/* Read the colormap from a Targa file */
|
|
{
|
|
int i;
|
|
|
|
/* Presently only handles 24-bit BGR format */
|
|
if (mapentrysize != 24)
|
|
ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
|
|
|
|
for (i = 0; i < cmaplen; i++) {
|
|
sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
|
|
sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
|
|
sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* read_pixel methods: get a single pixel from Targa file into tga_pixel[]
|
|
*/
|
|
|
|
METHODDEF(void)
|
|
read_non_rle_pixel (tga_source_ptr sinfo)
|
|
/* Read one Targa pixel from the input file; no RLE expansion */
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < sinfo->pixel_size; i++) {
|
|
sinfo->tga_pixel[i] = (U_CHAR) read_byte(sinfo);
|
|
}
|
|
}
|
|
|
|
METHODDEF(void)
|
|
read_rle_pixel (tga_source_ptr sinfo)
|
|
/* Read one Targa pixel from the input file, expanding RLE data as needed */
|
|
{
|
|
register int i;
|
|
|
|
/* Duplicate previously read pixel? */
|
|
if (sinfo->dup_pixel_count > 0) {
|
|
sinfo->dup_pixel_count--;
|
|
return;
|
|
}
|
|
|
|
/* Time to read RLE block header? */
|
|
if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
|
|
i = read_byte(sinfo);
|
|
if (i & 0x80) { /* Start of duplicate-pixel block? */
|
|
sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
|
|
sinfo->block_count = 0; /* then read new block header */
|
|
} else {
|
|
sinfo->block_count = i & 0x7F; /* number of pixels after this one */
|
|
}
|
|
}
|
|
|
|
/* Read next pixel */
|
|
for (i = 0; i < sinfo->pixel_size; i++) {
|
|
sinfo->tga_pixel[i] = (U_CHAR) read_byte(sinfo);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Read one row of pixels.
|
|
*
|
|
* We provide several different versions depending on input file format.
|
|
*/
|
|
|
|
METHODDEF(JDIMENSION)
|
|
get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
/* This version is for reading 8-bit grayscale pixels */
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
register JSAMPROW ptr;
|
|
register JDIMENSION col;
|
|
|
|
ptr = source->pub.buffer[0];
|
|
for (col = cinfo->image_width; col > 0; col--) {
|
|
(*source->read_pixel) (source); /* Load next pixel into tga_pixel */
|
|
*ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
METHODDEF(JDIMENSION)
|
|
get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
/* This version is for reading 8-bit colormap indexes */
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
register JSAMPROW ptr;
|
|
register JSAMPARRAY colormap;
|
|
register JDIMENSION col;
|
|
register int t;
|
|
int cmaplen;
|
|
|
|
ptr = source->pub.buffer[0];
|
|
colormap = source->colormap;
|
|
cmaplen = source->cmap_length;
|
|
for (col = cinfo->image_width; col > 0; col--) {
|
|
(*source->read_pixel) (source); /* Load next pixel into tga_pixel */
|
|
t = UCH(source->tga_pixel[0]);
|
|
if (t >= cmaplen)
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
*ptr++ = colormap[0][t];
|
|
*ptr++ = colormap[1][t];
|
|
*ptr++ = colormap[2][t];
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
METHODDEF(JDIMENSION)
|
|
get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
/* This version is for reading 16-bit pixels */
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
register int t;
|
|
register JSAMPROW ptr;
|
|
register JDIMENSION col;
|
|
|
|
ptr = source->pub.buffer[0];
|
|
for (col = cinfo->image_width; col > 0; col--) {
|
|
(*source->read_pixel) (source); /* Load next pixel into tga_pixel */
|
|
t = UCH(source->tga_pixel[0]);
|
|
t += UCH(source->tga_pixel[1]) << 8;
|
|
/* We expand 5 bit data to 8 bit sample width.
|
|
* The format of the 16-bit (LSB first) input word is
|
|
* xRRRRRGGGGGBBBBB
|
|
*/
|
|
ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
|
|
t >>= 5;
|
|
ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
|
|
t >>= 5;
|
|
ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
|
|
ptr += 3;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
METHODDEF(JDIMENSION)
|
|
get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
/* This version is for reading 24-bit pixels */
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
register JSAMPROW ptr;
|
|
register JDIMENSION col;
|
|
|
|
ptr = source->pub.buffer[0];
|
|
for (col = cinfo->image_width; col > 0; col--) {
|
|
(*source->read_pixel) (source); /* Load next pixel into tga_pixel */
|
|
*ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
|
|
*ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
|
|
*ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Targa also defines a 32-bit pixel format with order B,G,R,A.
|
|
* We presently ignore the attribute byte, so the code for reading
|
|
* these pixels is identical to the 24-bit routine above.
|
|
* This works because the actual pixel length is only known to read_pixel.
|
|
*/
|
|
|
|
#define get_32bit_row get_24bit_row
|
|
|
|
|
|
/*
|
|
* This method is for re-reading the input data in standard top-down
|
|
* row order. The entire image has already been read into whole_image
|
|
* with proper conversion of pixel format, but it's in a funny row order.
|
|
*/
|
|
|
|
METHODDEF(JDIMENSION)
|
|
get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
JDIMENSION source_row;
|
|
|
|
/* Compute row of source that maps to current_row of normal order */
|
|
/* For now, assume image is bottom-up and not interlaced. */
|
|
/* NEEDS WORK to support interlaced images! */
|
|
source_row = cinfo->image_height - source->current_row - 1;
|
|
|
|
/* Fetch that row from virtual array */
|
|
source->pub.buffer = (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,
|
|
source->whole_image, source_row, (JDIMENSION) 1, FALSE);
|
|
|
|
source->current_row++;
|
|
return 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* This method loads the image into whole_image during the first call on
|
|
* get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
|
|
* get_memory_row on subsequent calls.
|
|
*/
|
|
|
|
METHODDEF(JDIMENSION)
|
|
preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
JDIMENSION row;
|
|
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
|
|
|
|
/* Read the data into a virtual array in input-file row order. */
|
|
for (row = 0; row < cinfo->image_height; row++) {
|
|
if (progress != NULL) {
|
|
progress->pub.pass_counter = (long) row;
|
|
progress->pub.pass_limit = (long) cinfo->image_height;
|
|
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
|
|
}
|
|
source->pub.buffer = (*cinfo->mem->access_virt_sarray)
|
|
((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
|
|
(*source->get_pixel_rows) (cinfo, sinfo);
|
|
}
|
|
if (progress != NULL)
|
|
progress->completed_extra_passes++;
|
|
|
|
/* Set up to read from the virtual array in unscrambled order */
|
|
source->pub.get_pixel_rows = get_memory_row;
|
|
source->current_row = 0;
|
|
/* And read the first row */
|
|
return get_memory_row(cinfo, sinfo);
|
|
}
|
|
|
|
|
|
/*
|
|
* Read the file header; return image size and component count.
|
|
*/
|
|
|
|
METHODDEF(void)
|
|
start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
{
|
|
tga_source_ptr source = (tga_source_ptr) sinfo;
|
|
U_CHAR targaheader[18];
|
|
int idlen, cmaptype, subtype, flags, interlace_type, components;
|
|
unsigned int width, height, maplen;
|
|
boolean is_bottom_up;
|
|
|
|
#define GET_2B(offset) ((unsigned int) UCH(targaheader[offset]) + \
|
|
(((unsigned int) UCH(targaheader[offset+1])) << 8))
|
|
|
|
if (! ReadOK(source->pub.input_file, targaheader, 18))
|
|
ERREXIT(cinfo, JERR_INPUT_EOF);
|
|
|
|
/* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
|
|
if (targaheader[16] == 15)
|
|
targaheader[16] = 16;
|
|
|
|
idlen = UCH(targaheader[0]);
|
|
cmaptype = UCH(targaheader[1]);
|
|
subtype = UCH(targaheader[2]);
|
|
maplen = GET_2B(5);
|
|
width = GET_2B(12);
|
|
height = GET_2B(14);
|
|
source->pixel_size = UCH(targaheader[16]) >> 3;
|
|
flags = UCH(targaheader[17]); /* Image Descriptor byte */
|
|
|
|
is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
|
|
interlace_type = flags >> 6; /* bits 6/7 are interlace code */
|
|
|
|
if (cmaptype > 1 || /* cmaptype must be 0 or 1 */
|
|
width <= 0 || height <= 0 ||
|
|
source->pixel_size < 1 || source->pixel_size > 4 ||
|
|
(UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
|
|
interlace_type != 0) /* currently don't allow interlaced image */
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
|
|
if (subtype > 8) {
|
|
/* It's an RLE-coded file */
|
|
source->read_pixel = read_rle_pixel;
|
|
source->block_count = source->dup_pixel_count = 0;
|
|
subtype -= 8;
|
|
} else {
|
|
/* Non-RLE file */
|
|
source->read_pixel = read_non_rle_pixel;
|
|
}
|
|
|
|
/* Now should have subtype 1, 2, or 3 */
|
|
components = 3; /* until proven different */
|
|
cinfo->in_color_space = JCS_RGB;
|
|
|
|
switch (subtype) {
|
|
case 1: /* Colormapped image */
|
|
if (source->pixel_size == 1 && cmaptype == 1)
|
|
source->get_pixel_rows = get_8bit_row;
|
|
else
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
|
|
break;
|
|
case 2: /* RGB image */
|
|
switch (source->pixel_size) {
|
|
case 2:
|
|
source->get_pixel_rows = get_16bit_row;
|
|
break;
|
|
case 3:
|
|
source->get_pixel_rows = get_24bit_row;
|
|
break;
|
|
case 4:
|
|
source->get_pixel_rows = get_32bit_row;
|
|
break;
|
|
default:
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
}
|
|
TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
|
|
break;
|
|
case 3: /* Grayscale image */
|
|
components = 1;
|
|
cinfo->in_color_space = JCS_GRAYSCALE;
|
|
if (source->pixel_size == 1)
|
|
source->get_pixel_rows = get_8bit_gray_row;
|
|
else
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
|
|
break;
|
|
default:
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
}
|
|
|
|
if (is_bottom_up) {
|
|
/* Create a virtual array to buffer the upside-down image. */
|
|
source->whole_image = (*cinfo->mem->request_virt_sarray)
|
|
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
|
|
(JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
|
|
if (cinfo->progress != NULL) {
|
|
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
|
|
progress->total_extra_passes++; /* count file input as separate pass */
|
|
}
|
|
/* source->pub.buffer will point to the virtual array. */
|
|
source->pub.buffer_height = 1; /* in case anyone looks at it */
|
|
source->pub.get_pixel_rows = preload_image;
|
|
} else {
|
|
/* Don't need a virtual array, but do need a one-row input buffer. */
|
|
source->whole_image = NULL;
|
|
source->pub.buffer = (*cinfo->mem->alloc_sarray) ((j_common_ptr) cinfo,
|
|
JPOOL_IMAGE, (JDIMENSION) width * components, (JDIMENSION) 1);
|
|
source->pub.buffer_height = 1;
|
|
source->pub.get_pixel_rows = source->get_pixel_rows;
|
|
}
|
|
|
|
while (idlen--) /* Throw away ID field */
|
|
(void) read_byte(source);
|
|
|
|
if (maplen > 0) {
|
|
if (maplen > 256 || GET_2B(3) != 0)
|
|
ERREXIT(cinfo, JERR_TGA_BADCMAP);
|
|
/* Allocate space to store the colormap */
|
|
source->colormap = (*cinfo->mem->alloc_sarray) ((j_common_ptr) cinfo,
|
|
JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
|
|
source->cmap_length = (int) maplen;
|
|
/* and read it from the file */
|
|
read_colormap(source, (int) maplen, UCH(targaheader[7]));
|
|
} else {
|
|
if (cmaptype) /* but you promised a cmap! */
|
|
ERREXIT(cinfo, JERR_TGA_BADPARMS);
|
|
source->colormap = NULL;
|
|
source->cmap_length = 0;
|
|
}
|
|
|
|
cinfo->input_components = components;
|
|
cinfo->data_precision = 8;
|
|
cinfo->image_width = width;
|
|
cinfo->image_height = height;
|
|
}
|
|
|
|
|
|
/*
|
|
* Finish up at the end of the file.
|
|
*/
|
|
|
|
METHODDEF(void)
|
|
finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
|
|
{
|
|
/* no work */
|
|
}
|
|
|
|
|
|
/*
|
|
* The module selection routine for Targa format input.
|
|
*/
|
|
|
|
GLOBAL(cjpeg_source_ptr)
|
|
jinit_read_targa (j_compress_ptr cinfo)
|
|
{
|
|
tga_source_ptr source;
|
|
|
|
/* Create module interface object */
|
|
source = (tga_source_ptr) (*cinfo->mem->alloc_small)
|
|
((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(tga_source_struct));
|
|
source->cinfo = cinfo; /* make back link for subroutines */
|
|
/* Fill in method ptrs, except get_pixel_rows which start_input sets */
|
|
source->pub.start_input = start_input_tga;
|
|
source->pub.finish_input = finish_input_tga;
|
|
|
|
return &source->pub;
|
|
}
|
|
|
|
#endif /* TARGA_SUPPORTED */
|