fz_pixmap *
fz_load_jpeg(fz_context *ctx, unsigned char *rbuf, int rlen)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr_jmp err;
struct jpeg_source_mgr src;
unsigned char *row[1], *sp, *dp;
fz_colorspace *colorspace;
unsigned int x;
int k;
fz_pixmap *image = NULL;
fz_var(image);
if (setjmp(err.env))
{
/* SumatraPDF: prevent memory leak */
if (image)
{
fz_drop_pixmap(ctx, image);
image = NULL;
jpeg_finish_decompress(&cinfo);
}
jpeg_destroy_decompress(&cinfo);
fz_throw(ctx, "jpeg error: %s", err.msg);
}
cinfo.err = jpeg_std_error(&err.super);
err.super.error_exit = error_exit;
jpeg_create_decompress(&cinfo);
cinfo.src = &src;
src.init_source = init_source;
src.fill_input_buffer = fill_input_buffer;
src.skip_input_data = skip_input_data;
src.resync_to_restart = jpeg_resync_to_restart;
src.term_source = term_source;
src.next_input_byte = rbuf;
src.bytes_in_buffer = rlen;
jpeg_read_header(&cinfo, 1);
jpeg_start_decompress(&cinfo);
if (cinfo.output_components == 1)
colorspace = fz_device_gray;
else if (cinfo.output_components == 3)
colorspace = fz_device_rgb;
else if (cinfo.output_components == 4)
colorspace = fz_device_cmyk;
else
{
/* SumatraPDF: prevent memory leak */
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fz_throw(ctx, "bad number of components in jpeg: %d", cinfo.output_components);
}
fz_try(ctx)
{
image = fz_new_pixmap(ctx, colorspace, cinfo.output_width, cinfo.output_height);
}
fz_catch(ctx)
{
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fz_throw(ctx, "out of memory");
}
if (cinfo.density_unit == 1)
{
image->xres = cinfo.X_density;
image->yres = cinfo.Y_density;
}
else if (cinfo.density_unit == 2)
{
image->xres = cinfo.X_density * 254 / 100;
image->yres = cinfo.Y_density * 254 / 100;
}
/* cf. http://code.google.com/p/sumatrapdf/issues/detail?id=1963 */
else if (cinfo.density_unit == 0)
{
extract_exif_resolution(rbuf, rlen, &image->xres, &image->yres);
}
if (image->xres <= 0) image->xres = 72;
if (image->yres <= 0) image->yres = 72;
fz_clear_pixmap(ctx, image);
row[0] = fz_malloc(ctx, cinfo.output_components * cinfo.output_width);
dp = image->samples;
while (cinfo.output_scanline < cinfo.output_height)
{
jpeg_read_scanlines(&cinfo, row, 1);
sp = row[0];
for (x = 0; x < cinfo.output_width; x++)
{
for (k = 0; k < cinfo.output_components; k++)
*dp++ = *sp++;
*dp++ = 255;
}
}
fz_free(ctx, row[0]);
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
image->has_alpha = 0; /* SumatraPDF: allow optimizing non-alpha pixmaps */
return image;
}
void
fz_load_jpeg_info(fz_context *ctx, unsigned char *rbuf, int rlen, int *xp, int *yp, int *xresp, int *yresp, fz_colorspace **cspacep)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr err;
struct jpeg_source_mgr src;
fz_try(ctx)
{
cinfo.client_data = ctx;
cinfo.err = jpeg_std_error(&err);
err.error_exit = error_exit;
fz_jpg_mem_init(ctx, &cinfo);
jpeg_create_decompress(&cinfo);
cinfo.src = &src;
src.init_source = init_source;
src.fill_input_buffer = fill_input_buffer;
src.skip_input_data = skip_input_data;
src.resync_to_restart = jpeg_resync_to_restart;
src.term_source = term_source;
src.next_input_byte = rbuf;
src.bytes_in_buffer = rlen;
jpeg_save_markers(&cinfo, JPEG_APP0+1, 0xffff);
jpeg_save_markers(&cinfo, JPEG_APP0+13, 0xffff);
jpeg_read_header(&cinfo, 1);
if (cinfo.num_components == 1)
*cspacep = fz_device_gray(ctx);
else if (cinfo.num_components == 3)
*cspacep = fz_device_rgb(ctx);
else if (cinfo.num_components == 4)
*cspacep = fz_device_cmyk(ctx);
else
fz_throw(ctx, FZ_ERROR_GENERIC, "bad number of components in jpeg: %d", cinfo.num_components);
*xp = cinfo.image_width;
*yp = cinfo.image_height;
if (extract_exif_resolution(cinfo.marker_list, xresp, yresp))
/* XPS prefers EXIF resolution to JFIF density */;
else if (extract_app13_resolution(cinfo.marker_list, xresp, yresp))
/* XPS prefers APP13 resolution to JFIF density */;
else if (cinfo.density_unit == 1)
{
*xresp = cinfo.X_density;
*yresp = cinfo.Y_density;
}
else if (cinfo.density_unit == 2)
{
*xresp = cinfo.X_density * 254 / 100;
*yresp = cinfo.Y_density * 254 / 100;
}
else
{
*xresp = 0;
*yresp = 0;
}
if (*xresp <= 0) *xresp = 96;
if (*yresp <= 0) *yresp = 96;
}
fz_always(ctx)
{
jpeg_destroy_decompress(&cinfo);
fz_jpg_mem_term(&cinfo);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
