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-rw-r--r--libjpegtwrp/rdtarga.c500
1 files changed, 500 insertions, 0 deletions
diff --git a/libjpegtwrp/rdtarga.c b/libjpegtwrp/rdtarga.c
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+++ b/libjpegtwrp/rdtarga.c
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+/*
+ * rdtarga.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * 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 */
+#ifdef CHAR_IS_UNSIGNED
+typedef char U_CHAR;
+#define UCH(x) ((int) (x))
+#else
+typedef char U_CHAR;
+#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) */
+
+ /* 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 FILE *infile = sinfo->pub.input_file;
+ register int i;
+
+ for (i = 0; i < sinfo->pixel_size; i++) {
+ sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
+ }
+}
+
+
+METHODDEF(void)
+read_rle_pixel (tga_source_ptr sinfo)
+/* Read one Targa pixel from the input file, expanding RLE data as needed */
+{
+ register FILE *infile = sinfo->pub.input_file;
+ 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) getc(infile);
+ }
+}
+
+
+/*
+ * 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 int t;
+ register JSAMPROW ptr;
+ register JDIMENSION col;
+ register JSAMPARRAY colormap = source->colormap;
+
+ 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]);
+ *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 */
+ 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);
+ break;
+ }
+ 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);
+ break;
+ }
+
+ 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);
+ /* 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;
+ }
+
+ 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 (cjpeg_source_ptr) source;
+}
+
+#endif /* TARGA_SUPPORTED */
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