| /* |
| * rdtarga.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1991-1996, Thomas G. Lane. |
| * Modified 2017 by Guido Vollbeding. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2018, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * 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 */ |
| |
| typedef unsigned char U_CHAR; |
| #define UCH(x) ((int)(x)) |
| |
| |
| #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 */ |
| 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 */ |
| 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 int t; |
| register JSAMPROW ptr; |
| register JDIMENSION col; |
| register JSAMPARRAY colormap = source->colormap; |
| int cmaplen = source->cmap_length; |
| |
| 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]); |
| 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 */ |
| 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 */ |
| width == 0 || height == 0) /* image width/height must be non-zero */ |
| 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); |
| 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 (cjpeg_source_ptr)source; |
| } |
| |
| #endif /* TARGA_SUPPORTED */ |