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Diffstat (limited to 'libjpegtwrp/wrtarga.c')
| -rw-r--r-- | libjpegtwrp/wrtarga.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/libjpegtwrp/wrtarga.c b/libjpegtwrp/wrtarga.c new file mode 100644 index 000000000..cf104d2de --- /dev/null +++ b/libjpegtwrp/wrtarga.c @@ -0,0 +1,253 @@ +/* + * wrtarga.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 write output images in Targa format. + * + * These routines may need modification for non-Unix environments or + * specialized applications. As they stand, they assume output to + * an ordinary stdio stream. + * + * Based on code contributed by Lee Daniel Crocker. + */ + +#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ + +#ifdef TARGA_SUPPORTED + + +/* + * To support 12-bit JPEG data, we'd have to scale output down to 8 bits. + * This is not yet implemented. + */ + +#if BITS_IN_JSAMPLE != 8 + Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */ +#endif + +/* + * The output buffer needs to be writable by fwrite(). On PCs, we must + * allocate the buffer in near data space, because we are assuming small-data + * memory model, wherein fwrite() can't reach far memory. If you need to + * process very wide images on a PC, you might have to compile in large-memory + * model, or else replace fwrite() with a putc() loop --- which will be much + * slower. + */ + + +/* Private version of data destination object */ + +typedef struct { + struct djpeg_dest_struct pub; /* public fields */ + + char *iobuffer; /* physical I/O buffer */ + JDIMENSION buffer_width; /* width of one row */ +} tga_dest_struct; + +typedef tga_dest_struct * tga_dest_ptr; + + +LOCAL(void) +write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors) +/* Create and write a Targa header */ +{ + char targaheader[18]; + + /* Set unused fields of header to 0 */ + MEMZERO(targaheader, SIZEOF(targaheader)); + + if (num_colors > 0) { + targaheader[1] = 1; /* color map type 1 */ + targaheader[5] = (char) (num_colors & 0xFF); + targaheader[6] = (char) (num_colors >> 8); + targaheader[7] = 24; /* 24 bits per cmap entry */ + } + + targaheader[12] = (char) (cinfo->output_width & 0xFF); + targaheader[13] = (char) (cinfo->output_width >> 8); + targaheader[14] = (char) (cinfo->output_height & 0xFF); + targaheader[15] = (char) (cinfo->output_height >> 8); + targaheader[17] = 0x20; /* Top-down, non-interlaced */ + + if (cinfo->out_color_space == JCS_GRAYSCALE) { + targaheader[2] = 3; /* image type = uncompressed gray-scale */ + targaheader[16] = 8; /* bits per pixel */ + } else { /* must be RGB */ + if (num_colors > 0) { + targaheader[2] = 1; /* image type = colormapped RGB */ + targaheader[16] = 8; + } else { + targaheader[2] = 2; /* image type = uncompressed RGB */ + targaheader[16] = 24; + } + } + + if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18) + ERREXIT(cinfo, JERR_FILE_WRITE); +} + + +/* + * Write some pixel data. + * In this module rows_supplied will always be 1. + */ + +METHODDEF(void) +put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +/* used for unquantized full-color output */ +{ + tga_dest_ptr dest = (tga_dest_ptr) dinfo; + register JSAMPROW inptr; + register char * outptr; + register JDIMENSION col; + + inptr = dest->pub.buffer[0]; + outptr = dest->iobuffer; + for (col = cinfo->output_width; col > 0; col--) { + outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */ + outptr[1] = (char) GETJSAMPLE(inptr[1]); + outptr[2] = (char) GETJSAMPLE(inptr[0]); + inptr += 3, outptr += 3; + } + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + +METHODDEF(void) +put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +/* used for grayscale OR quantized color output */ +{ + tga_dest_ptr dest = (tga_dest_ptr) dinfo; + register JSAMPROW inptr; + register char * outptr; + register JDIMENSION col; + + inptr = dest->pub.buffer[0]; + outptr = dest->iobuffer; + for (col = cinfo->output_width; col > 0; col--) { + *outptr++ = (char) GETJSAMPLE(*inptr++); + } + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + + +/* + * Write some demapped pixel data when color quantization is in effect. + * For Targa, this is only applied to grayscale data. + */ + +METHODDEF(void) +put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, + JDIMENSION rows_supplied) +{ + tga_dest_ptr dest = (tga_dest_ptr) dinfo; + register JSAMPROW inptr; + register char * outptr; + register JSAMPROW color_map0 = cinfo->colormap[0]; + register JDIMENSION col; + + inptr = dest->pub.buffer[0]; + outptr = dest->iobuffer; + for (col = cinfo->output_width; col > 0; col--) { + *outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]); + } + (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); +} + + +/* + * Startup: write the file header. + */ + +METHODDEF(void) +start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) +{ + tga_dest_ptr dest = (tga_dest_ptr) dinfo; + int num_colors, i; + FILE *outfile; + + if (cinfo->out_color_space == JCS_GRAYSCALE) { + /* Targa doesn't have a mapped grayscale format, so we will */ + /* demap quantized gray output. Never emit a colormap. */ + write_header(cinfo, dinfo, 0); + if (cinfo->quantize_colors) + dest->pub.put_pixel_rows = put_demapped_gray; + else + dest->pub.put_pixel_rows = put_gray_rows; + } else if (cinfo->out_color_space == JCS_RGB) { + if (cinfo->quantize_colors) { + /* We only support 8-bit colormap indexes, so only 256 colors */ + num_colors = cinfo->actual_number_of_colors; + if (num_colors > 256) + ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors); + write_header(cinfo, dinfo, num_colors); + /* Write the colormap. Note Targa uses BGR byte order */ + outfile = dest->pub.output_file; + for (i = 0; i < num_colors; i++) { + putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile); + putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile); + putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile); + } + dest->pub.put_pixel_rows = put_gray_rows; + } else { + write_header(cinfo, dinfo, 0); + dest->pub.put_pixel_rows = put_pixel_rows; + } + } else { + ERREXIT(cinfo, JERR_TGA_COLORSPACE); + } +} + + +/* + * Finish up at the end of the file. + */ + +METHODDEF(void) +finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) +{ + /* Make sure we wrote the output file OK */ + fflush(dinfo->output_file); + if (ferror(dinfo->output_file)) + ERREXIT(cinfo, JERR_FILE_WRITE); +} + + +/* + * The module selection routine for Targa format output. + */ + +GLOBAL(djpeg_dest_ptr) +jinit_write_targa (j_decompress_ptr cinfo) +{ + tga_dest_ptr dest; + + /* Create module interface object, fill in method pointers */ + dest = (tga_dest_ptr) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + SIZEOF(tga_dest_struct)); + dest->pub.start_output = start_output_tga; + dest->pub.finish_output = finish_output_tga; + + /* Calculate output image dimensions so we can allocate space */ + jpeg_calc_output_dimensions(cinfo); + + /* Create I/O buffer. Note we make this near on a PC. */ + dest->buffer_width = cinfo->output_width * cinfo->output_components; + dest->iobuffer = (char *) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + (size_t) (dest->buffer_width * SIZEOF(char))); + + /* Create decompressor output buffer. */ + dest->pub.buffer = (*cinfo->mem->alloc_sarray) + ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1); + dest->pub.buffer_height = 1; + + return (djpeg_dest_ptr) dest; +} + +#endif /* TARGA_SUPPORTED */ |