fz_stream *
fz_open_image_decomp_stream(fz_context *ctx, fz_stream *chain, fz_compression_params *params, int *l2factor)
{
switch (params->type)
{
case FZ_IMAGE_FAX:
*l2factor = 0;
return fz_open_faxd(chain,
params->u.fax.k,
params->u.fax.end_of_line,
params->u.fax.encoded_byte_align,
params->u.fax.columns,
params->u.fax.rows,
params->u.fax.end_of_block,
params->u.fax.black_is_1);
case FZ_IMAGE_JPEG:
if (*l2factor > 3)
*l2factor = 3;
return fz_open_dctd(chain, params->u.jpeg.color_transform, *l2factor, NULL);
case FZ_IMAGE_RLD:
*l2factor = 0;
return fz_open_rld(chain);
case FZ_IMAGE_FLATE:
*l2factor = 0;
chain = fz_open_flated(chain, 15);
if (params->u.flate.predictor > 1)
chain = fz_open_predict(chain, params->u.flate.predictor, params->u.flate.columns, params->u.flate.colors, params->u.flate.bpc);
return chain;
case FZ_IMAGE_LZW:
*l2factor = 0;
chain = fz_open_lzwd(chain, params->u.lzw.early_change);
if (params->u.lzw.predictor > 1)
chain = fz_open_predict(chain, params->u.lzw.predictor, params->u.lzw.columns, params->u.lzw.colors, params->u.lzw.bpc);
return chain;
default:
*l2factor = 0;
break;
}
return chain;
}
/*
* Create a filter given a name and param dictionary.
*/
static fz_stream *
build_filter(fz_stream *chain, pdf_document * xref, pdf_obj * f, pdf_obj * p, int num, int gen, pdf_image_params *params)
{
fz_context *ctx = chain->ctx;
char *s = pdf_to_name(f);
int predictor = pdf_to_int(pdf_dict_gets(p, "Predictor"));
int columns = pdf_to_int(pdf_dict_gets(p, "Columns"));
int colors = pdf_to_int(pdf_dict_gets(p, "Colors"));
int bpc = pdf_to_int(pdf_dict_gets(p, "BitsPerComponent"));
if (predictor == 0) predictor = 1;
if (columns == 0) columns = 1;
if (colors == 0) colors = 1;
if (bpc == 0) bpc = 8;
if (!strcmp(s, "ASCIIHexDecode") || !strcmp(s, "AHx"))
return fz_open_ahxd(chain);
else if (!strcmp(s, "ASCII85Decode") || !strcmp(s, "A85"))
return fz_open_a85d(chain);
else if (!strcmp(s, "CCITTFaxDecode") || !strcmp(s, "CCF"))
{
pdf_obj *k = pdf_dict_gets(p, "K");
pdf_obj *eol = pdf_dict_gets(p, "EndOfLine");
pdf_obj *eba = pdf_dict_gets(p, "EncodedByteAlign");
pdf_obj *columns = pdf_dict_gets(p, "Columns");
pdf_obj *rows = pdf_dict_gets(p, "Rows");
pdf_obj *eob = pdf_dict_gets(p, "EndOfBlock");
pdf_obj *bi1 = pdf_dict_gets(p, "BlackIs1");
if (params)
{
/* We will shortstop here */
params->type = PDF_IMAGE_FAX;
params->u.fax.k = (k ? pdf_to_int(k) : 0);
params->u.fax.eol = (eol ? pdf_to_bool(eol) : 0);
params->u.fax.eba = (eba ? pdf_to_bool(eba) : 0);
params->u.fax.columns = (columns ? pdf_to_int(columns) : 1728);
params->u.fax.rows = (rows ? pdf_to_int(rows) : 0);
params->u.fax.eob = (eob ? pdf_to_bool(eob) : 1);
params->u.fax.bi1 = (bi1 ? pdf_to_bool(bi1) : 0);
return chain;
}
return fz_open_faxd(chain,
k ? pdf_to_int(k) : 0,
eol ? pdf_to_bool(eol) : 0,
eba ? pdf_to_bool(eba) : 0,
columns ? pdf_to_int(columns) : 1728,
rows ? pdf_to_int(rows) : 0,
eob ? pdf_to_bool(eob) : 1,
bi1 ? pdf_to_bool(bi1) : 0);
}
else if (!strcmp(s, "DCTDecode") || !strcmp(s, "DCT"))
{
pdf_obj *ct = pdf_dict_gets(p, "ColorTransform");
if (params)
{
/* We will shortstop here */
params->type = PDF_IMAGE_JPEG;
params->u.jpeg.ct = (ct ? pdf_to_int(ct) : -1);
return chain;
}
return fz_open_dctd(chain, ct ? pdf_to_int(ct) : -1);
}
else if (!strcmp(s, "RunLengthDecode") || !strcmp(s, "RL"))
{
if (params)
{
/* We will shortstop here */
params->type = PDF_IMAGE_RLD;
return chain;
}
return fz_open_rld(chain);
}
else if (!strcmp(s, "FlateDecode") || !strcmp(s, "Fl"))
{
if (params)
{
/* We will shortstop here */
params->type = PDF_IMAGE_FLATE;
params->u.flate.predictor = predictor;
params->u.flate.columns = columns;
params->u.flate.colors = colors;
params->u.flate.bpc = bpc;
return chain;
}
chain = fz_open_flated(chain);
if (predictor > 1)
chain = fz_open_predict(chain, predictor, columns, colors, bpc);
return chain;
}
else if (!strcmp(s, "LZWDecode") || !strcmp(s, "LZW"))
{
pdf_obj *ec = pdf_dict_gets(p, "EarlyChange");
if (params)
{
/* We will shortstop here */
params->type = PDF_IMAGE_LZW;
params->u.lzw.predictor = predictor;
params->u.lzw.columns = columns;
params->u.lzw.colors = colors;
params->u.lzw.bpc = bpc;
params->u.lzw.ec = (ec ? pdf_to_int(ec) : 1);
return chain;
}
chain = fz_open_lzwd(chain, ec ? pdf_to_int(ec) : 1);
if (predictor > 1)
chain = fz_open_predict(chain, predictor, columns, colors, bpc);
return chain;
}
else if (!strcmp(s, "JBIG2Decode"))
{
fz_buffer *globals = NULL;
pdf_obj *obj = pdf_dict_gets(p, "JBIG2Globals");
if (obj)
globals = pdf_load_stream(xref, pdf_to_num(obj), pdf_to_gen(obj));
/* fz_open_jbig2d takes possession of globals */
return fz_open_jbig2d(chain, globals);
}
else if (!strcmp(s, "JPXDecode"))
return chain; /* JPX decoding is special cased in the image loading code */
else if (!strcmp(s, "Crypt"))
{
pdf_obj *name;
if (!xref->crypt)
{
fz_warn(ctx, "crypt filter in unencrypted document");
return chain;
}
name = pdf_dict_gets(p, "Name");
if (pdf_is_name(name))
return pdf_open_crypt_with_filter(chain, xref->crypt, pdf_to_name(name), num, gen);
return chain;
}
fz_warn(ctx, "unknown filter name (%s)", s);
return chain;
}
/*
* Create a filter given a name and param dictionary.
*/
static fz_stream *
build_filter(fz_stream *chain, pdf_xref * xref, fz_obj * f, fz_obj * p, int num, int gen)
{
fz_error error;
char *s;
s = fz_to_name(f);
if (!strcmp(s, "ASCIIHexDecode") || !strcmp(s, "AHx"))
return fz_open_ahxd(chain);
else if (!strcmp(s, "ASCII85Decode") || !strcmp(s, "A85"))
return fz_open_a85d(chain);
else if (!strcmp(s, "CCITTFaxDecode") || !strcmp(s, "CCF"))
return fz_open_faxd(chain, p);
else if (!strcmp(s, "DCTDecode") || !strcmp(s, "DCT"))
return fz_open_dctd(chain, p);
else if (!strcmp(s, "RunLengthDecode") || !strcmp(s, "RL"))
return fz_open_rld(chain);
else if (!strcmp(s, "FlateDecode") || !strcmp(s, "Fl"))
{
fz_obj *obj = fz_dict_gets(p, "Predictor");
if (fz_to_int(obj) > 1)
return fz_open_predict(fz_open_flated(chain), p);
return fz_open_flated(chain);
}
else if (!strcmp(s, "LZWDecode") || !strcmp(s, "LZW"))
{
fz_obj *obj = fz_dict_gets(p, "Predictor");
if (fz_to_int(obj) > 1)
return fz_open_predict(fz_open_lzwd(chain, p), p);
return fz_open_lzwd(chain, p);
}
else if (!strcmp(s, "JBIG2Decode"))
{
fz_obj *obj = fz_dict_gets(p, "JBIG2Globals");
if (obj)
{
fz_buffer *globals;
error = pdf_load_stream(&globals, xref, fz_to_num(obj), fz_to_gen(obj));
if (error)
fz_catch(error, "cannot load jbig2 global segments");
chain = fz_open_jbig2d(chain, globals);
fz_drop_buffer(globals);
return chain;
}
return fz_open_jbig2d(chain, NULL);
}
else if (!strcmp(s, "JPXDecode"))
return chain; /* JPX decoding is special cased in the image loading code */
else if (!strcmp(s, "Crypt"))
{
fz_obj *name;
if (!xref->crypt)
{
fz_warn("crypt filter in unencrypted document");
return chain;
}
name = fz_dict_gets(p, "Name");
if (fz_is_name(name))
return pdf_open_crypt_with_filter(chain, xref->crypt, fz_to_name(name), num, gen);
return chain;
}
fz_warn("unknown filter name (%s)", s);
return chain;
}