139 lines
3.0 KiB
C
139 lines
3.0 KiB
C
#include "fitz.h"
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#include "muxps.h"
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#include <jpeglib.h>
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#include <setjmp.h>
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struct jpeg_error_mgr_jmp
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{
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struct jpeg_error_mgr super;
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jmp_buf env;
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char msg[JMSG_LENGTH_MAX];
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};
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static void error_exit(j_common_ptr cinfo)
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{
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struct jpeg_error_mgr_jmp *err = (struct jpeg_error_mgr_jmp *)cinfo->err;
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cinfo->err->format_message(cinfo, err->msg);
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longjmp(err->env, 1);
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}
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static void init_source(j_decompress_ptr cinfo)
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{
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/* nothing to do */
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}
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static void term_source(j_decompress_ptr cinfo)
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{
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/* nothing to do */
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}
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static boolean fill_input_buffer(j_decompress_ptr cinfo)
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{
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static unsigned char eoi[2] = { 0xFF, JPEG_EOI };
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struct jpeg_source_mgr *src = cinfo->src;
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src->next_input_byte = eoi;
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src->bytes_in_buffer = 2;
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return 1;
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}
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static void skip_input_data(j_decompress_ptr cinfo, long num_bytes)
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{
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struct jpeg_source_mgr *src = cinfo->src;
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if (num_bytes > 0)
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{
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src->next_input_byte += num_bytes;
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src->bytes_in_buffer -= num_bytes;
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}
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}
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int
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xps_decode_jpeg(fz_pixmap **imagep, byte *rbuf, int rlen)
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{
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struct jpeg_decompress_struct cinfo;
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struct jpeg_error_mgr_jmp err;
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struct jpeg_source_mgr src;
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unsigned char *row[1], *sp, *dp;
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fz_colorspace *colorspace;
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unsigned int x;
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int k;
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fz_pixmap *image = NULL;
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if (setjmp(err.env))
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{
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if (image)
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fz_drop_pixmap(image);
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return fz_throw("jpeg error: %s", err.msg);
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}
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cinfo.err = jpeg_std_error(&err.super);
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err.super.error_exit = error_exit;
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jpeg_create_decompress(&cinfo);
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cinfo.src = &src;
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src.init_source = init_source;
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src.fill_input_buffer = fill_input_buffer;
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src.skip_input_data = skip_input_data;
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src.resync_to_restart = jpeg_resync_to_restart;
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src.term_source = term_source;
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src.next_input_byte = rbuf;
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src.bytes_in_buffer = rlen;
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jpeg_read_header(&cinfo, 1);
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jpeg_start_decompress(&cinfo);
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if (cinfo.output_components == 1)
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colorspace = fz_device_gray;
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else if (cinfo.output_components == 3)
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colorspace = fz_device_rgb;
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else if (cinfo.output_components == 4)
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colorspace = fz_device_cmyk;
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else
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return fz_throw("bad number of components in jpeg: %d", cinfo.output_components);
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image = fz_new_pixmap_with_limit(colorspace, cinfo.output_width, cinfo.output_height);
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if (!image)
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{
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jpeg_finish_decompress(&cinfo);
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jpeg_destroy_decompress(&cinfo);
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return fz_throw("out of memory");
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}
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if (cinfo.density_unit == 1)
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{
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image->xres = cinfo.X_density;
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image->yres = cinfo.Y_density;
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}
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else if (cinfo.density_unit == 2)
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{
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image->xres = cinfo.X_density * 254 / 100;
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image->yres = cinfo.Y_density * 254 / 100;
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}
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fz_clear_pixmap(image);
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row[0] = fz_malloc(cinfo.output_components * cinfo.output_width);
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dp = image->samples;
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while (cinfo.output_scanline < cinfo.output_height)
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{
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jpeg_read_scanlines(&cinfo, row, 1);
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sp = row[0];
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for (x = 0; x < cinfo.output_width; x++)
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{
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for (k = 0; k < cinfo.output_components; k++)
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*dp++ = *sp++;
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*dp++ = 255;
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}
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}
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fz_free(row[0]);
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jpeg_finish_decompress(&cinfo);
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jpeg_destroy_decompress(&cinfo);
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*imagep = image;
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return fz_okay;
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}
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