/*
* Construct a filter to decode a stream, constraining
* to stream length and decrypting.
*/
static fz_stream *
pdf_open_filter(fz_stream *chain, pdf_xref *xref, fz_obj *stmobj, int num, int gen)
{
fz_obj *filters;
fz_obj *params;
filters = fz_dict_getsa(stmobj, "Filter", "F");
params = fz_dict_getsa(stmobj, "DecodeParms", "DP");
chain = pdf_open_raw_filter(chain, xref, stmobj, num, gen);
if (fz_is_name(filters))
return build_filter(chain, xref, filters, params, num, gen);
if (fz_array_len(filters) > 0)
return build_filter_chain(chain, xref, filters, params, num, gen);
return chain;
}
/*
* Construct a filter to decode a stream, without
* constraining to stream length, and without decryption.
*/
fz_stream *
pdf_open_inline_stream(fz_stream *chain, pdf_xref *xref, fz_obj *stmobj, int length)
{
fz_obj *filters;
fz_obj *params;
filters = fz_dict_getsa(stmobj, "Filter", "F");
params = fz_dict_getsa(stmobj, "DecodeParms", "DP");
/* don't close chain when we close this filter */
fz_keep_stream(chain);
if (fz_is_name(filters))
return build_filter(chain, xref, filters, params, 0, 0);
if (fz_array_len(filters) > 0)
return build_filter_chain(chain, xref, filters, params, 0, 0);
return fz_open_null(chain, length);
}
static fz_error
pdf_load_jpx_image(fz_pixmap **imgp, pdf_xref *xref, fz_obj *dict)
{
fz_error error;
fz_buffer *buf;
fz_colorspace *colorspace;
fz_pixmap *img;
fz_obj *obj;
colorspace = NULL;
error = pdf_load_stream(&buf, xref, fz_to_num(dict), fz_to_gen(dict));
if (error)
return fz_rethrow(error, "cannot load jpx image data");
obj = fz_dict_gets(dict, "ColorSpace");
if (obj)
{
error = pdf_load_colorspace(&colorspace, xref, obj);
if (error)
fz_catch(error, "cannot load image colorspace");
}
error = fz_load_jpx_image(&img, buf->data, buf->len, colorspace);
if (error)
{
if (colorspace)
fz_drop_colorspace(colorspace);
fz_drop_buffer(buf);
return fz_rethrow(error, "cannot load jpx image");
}
if (colorspace)
fz_drop_colorspace(colorspace);
fz_drop_buffer(buf);
obj = fz_dict_getsa(dict, "SMask", "Mask");
if (fz_is_dict(obj))
{
error = pdf_load_image_imp(&img->mask, xref, NULL, obj, NULL, 1);
if (error)
{
fz_drop_pixmap(img);
return fz_rethrow(error, "cannot load image mask/softmask");
}
}
*imgp = img;
return fz_okay;
}
/*
* Scan stream dictionary for an explicit /Crypt filter
*/
static int
pdf_stream_has_crypt(fz_obj *stm)
{
fz_obj *filters;
fz_obj *obj;
int i;
filters = fz_dict_getsa(stm, "Filter", "F");
if (filters)
{
if (!strcmp(fz_to_name(filters), "Crypt"))
return 1;
if (fz_is_array(filters))
{
for (i = 0; i < fz_array_len(filters); i++)
{
obj = fz_array_get(filters, i);
if (!strcmp(fz_to_name(obj), "Crypt"))
return 1;
}
}
}
return 0;
}
static fz_error
pdf_load_image_imp(fz_pixmap **imgp, pdf_xref *xref, fz_obj *rdb, fz_obj *dict, fz_stream *cstm, int forcemask)
{
fz_stream *stm;
fz_pixmap *tile;
fz_obj *obj, *res;
fz_error error;
int w, h, bpc, n;
int imagemask;
int interpolate;
int indexed;
fz_colorspace *colorspace;
fz_pixmap *mask; /* explicit mask/softmask image */
int usecolorkey;
int colorkey[FZ_MAX_COLORS * 2];
float decode[FZ_MAX_COLORS * 2];
int stride;
unsigned char *samples;
int i, len;
/* special case for JPEG2000 images */
if (pdf_is_jpx_image(dict))
{
tile = NULL;
error = pdf_load_jpx_image(&tile, xref, dict);
if (error)
return fz_rethrow(error, "cannot load jpx image");
if (forcemask)
{
if (tile->n != 2)
{
fz_drop_pixmap(tile);
return fz_throw("softmask must be grayscale");
}
mask = fz_alpha_from_gray(tile, 1);
fz_drop_pixmap(tile);
*imgp = mask;
return fz_okay;
}
*imgp = tile;
return fz_okay;
}
w = fz_to_int(fz_dict_getsa(dict, "Width", "W"));
h = fz_to_int(fz_dict_getsa(dict, "Height", "H"));
bpc = fz_to_int(fz_dict_getsa(dict, "BitsPerComponent", "BPC"));
imagemask = fz_to_bool(fz_dict_getsa(dict, "ImageMask", "IM"));
interpolate = fz_to_bool(fz_dict_getsa(dict, "Interpolate", "I"));
indexed = 0;
usecolorkey = 0;
colorspace = NULL;
mask = NULL;
if (imagemask)
bpc = 1;
if (w == 0)
return fz_throw("image width is zero");
if (h == 0)
return fz_throw("image height is zero");
if (bpc == 0)
return fz_throw("image depth is zero");
if (w > (1 << 16))
return fz_throw("image is too wide");
if (h > (1 << 16))
return fz_throw("image is too high");
obj = fz_dict_getsa(dict, "ColorSpace", "CS");
if (obj && !imagemask && !forcemask)
{
/* colorspace resource lookup is only done for inline images */
if (fz_is_name(obj))
{
res = fz_dict_get(fz_dict_gets(rdb, "ColorSpace"), obj);
if (res)
obj = res;
}
error = pdf_load_colorspace(&colorspace, xref, obj);
if (error)
return fz_rethrow(error, "cannot load image colorspace");
if (!strcmp(colorspace->name, "Indexed"))
indexed = 1;
n = colorspace->n;
}
else
{
n = 1;
}
obj = fz_dict_getsa(dict, "Decode", "D");
if (obj)
{
for (i = 0; i < n * 2; i++)
decode[i] = fz_to_real(fz_array_get(obj, i));
}
else
{
float maxval = indexed ? (1 << bpc) - 1 : 1;
for (i = 0; i < n * 2; i++)
decode[i] = i & 1 ? maxval : 0;
}
obj = fz_dict_getsa(dict, "SMask", "Mask");
if (fz_is_dict(obj))
{
/* Not allowed for inline images */
if (!cstm)
{
error = pdf_load_image_imp(&mask, xref, rdb, obj, NULL, 1);
if (error)
{
if (colorspace)
fz_drop_colorspace(colorspace);
return fz_rethrow(error, "cannot load image mask/softmask");
}
}
}
else if (fz_is_array(obj))
{
usecolorkey = 1;
for (i = 0; i < n * 2; i++)
colorkey[i] = fz_to_int(fz_array_get(obj, i));
}
/* Allocate now, to fail early if we run out of memory */
tile = fz_new_pixmap_with_limit(colorspace, w, h);
if (!tile)
{
if (colorspace)
fz_drop_colorspace(colorspace);
if (mask)
fz_drop_pixmap(mask);
return fz_throw("out of memory");
}
if (colorspace)
fz_drop_colorspace(colorspace);
tile->mask = mask;
tile->interpolate = interpolate;
stride = (w * n * bpc + 7) / 8;
if (cstm)
{
stm = pdf_open_inline_stream(cstm, xref, dict, stride * h);
}
else
{
error = pdf_open_stream(&stm, xref, fz_to_num(dict), fz_to_gen(dict));
if (error)
{
fz_drop_pixmap(tile);
return fz_rethrow(error, "cannot open image data stream (%d 0 R)", fz_to_num(dict));
}
}
samples = fz_calloc(h, stride);
len = fz_read(stm, samples, h * stride);
if (len < 0)
{
fz_close(stm);
fz_free(samples);
fz_drop_pixmap(tile);
return fz_rethrow(len, "cannot read image data");
}
/* Make sure we read the EOF marker (for inline images only) */
if (cstm)
{
unsigned char tbuf[512];
int tlen = fz_read(stm, tbuf, sizeof tbuf);
if (tlen < 0)
fz_catch(tlen, "ignoring error at end of image");
if (tlen > 0)
fz_warn("ignoring garbage at end of image");
}
fz_close(stm);
/* Pad truncated images */
if (len < stride * h)
{
fz_warn("padding truncated image (%d 0 R)", fz_to_num(dict));
memset(samples + len, 0, stride * h - len);
}
/* Invert 1-bit image masks */
if (imagemask)
{
/* 0=opaque and 1=transparent so we need to invert */
unsigned char *p = samples;
len = h * stride;
for (i = 0; i < len; i++)
p[i] = ~p[i];
}
fz_unpack_tile(tile, samples, n, bpc, stride, indexed);
fz_free(samples);
if (usecolorkey)
pdf_mask_color_key(tile, n, colorkey);
if (indexed)
{
fz_pixmap *conv;
fz_decode_indexed_tile(tile, decode, (1 << bpc) - 1);
conv = pdf_expand_indexed_pixmap(tile);
fz_drop_pixmap(tile);
tile = conv;
}
else
{
fz_decode_tile(tile, decode);
}
*imgp = tile;
return fz_okay;
}
pdf_link *
pdf_load_link(pdf_xref *xref, fz_obj *dict)
{
fz_obj *dest;
fz_obj *action;
fz_obj *obj;
fz_rect bbox;
pdf_link_kind kind;
fz_context *ctx = xref->ctx;
dest = NULL;
obj = fz_dict_gets(ctx, dict, "Rect");
if (obj)
bbox = pdf_to_rect(ctx, obj);
else
bbox = fz_empty_rect;
obj = fz_dict_gets(ctx, dict, "Dest");
if (obj)
{
kind = PDF_LINK_GOTO;
dest = resolve_dest(xref, obj);
}
action = fz_dict_gets(ctx, dict, "A");
/* fall back to additional action button's down/up action */
if (!action)
action = fz_dict_getsa(ctx, fz_dict_gets(ctx, dict, "AA"), "U", "D");
if (action)
{
obj = fz_dict_gets(ctx, action, "S");
if (fz_is_name(ctx, obj) && !strcmp(fz_to_name(ctx, obj), "GoTo"))
{
kind = PDF_LINK_GOTO;
dest = resolve_dest(xref, fz_dict_gets(ctx, action, "D"));
}
else if (fz_is_name(ctx, obj) && !strcmp(fz_to_name(ctx, obj), "URI"))
{
kind = PDF_LINK_URI;
dest = fz_dict_gets(ctx, action, "URI");
}
else if (fz_is_name(ctx, obj) && !strcmp(fz_to_name(ctx, obj), "Launch"))
{
kind = PDF_LINK_LAUNCH;
dest = fz_dict_gets(ctx, action, "F");
}
else if (fz_is_name(ctx, obj) && !strcmp(fz_to_name(ctx, obj), "Named"))
{
kind = PDF_LINK_NAMED;
dest = fz_dict_gets(ctx, action, "N");
}
else if (fz_is_name(ctx, obj) && (!strcmp(fz_to_name(ctx, obj), "GoToR")))
{
kind = PDF_LINK_ACTION;
dest = action;
}
else
{
dest = NULL;
}
}
if (dest)
{
pdf_link *link = fz_malloc(ctx, sizeof(pdf_link));
link->kind = kind;
link->rect = bbox;
link->dest = fz_keep_obj(dest);
link->next = NULL;
return link;
}
return NULL;
}
