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This commit is contained in:
John Whitington
parent
1048bdf1df
commit
8726d3dee0
2
Makefile
2
Makefile
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@ -2,7 +2,7 @@
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MODS = cpdfyojson cpdfxmlm \
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MODS = cpdfyojson cpdfxmlm \
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cpdfunicodedata cpdferror cpdfjson cpdfstrftime cpdfcoord cpdfattach \
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cpdfunicodedata cpdferror cpdfjson cpdfstrftime cpdfcoord cpdfattach \
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cpdfpagespec cpdfposition cpdf cpdfpresent cpdffont cpdftype \
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cpdfpagespec cpdfposition cpdf cpdfpresent cpdffont cpdftype \
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cpdftexttopdf cpdftoc cpdfpad cpdfocg cpdfcommand
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cpdftexttopdf cpdftoc cpdfpad cpdfocg cpdfsqueeze cpdfcommand
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SOURCES = $(foreach x,$(MODS),$(x).ml $(x).mli) cpdfcommandrun.ml
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SOURCES = $(foreach x,$(MODS),$(x).ml $(x).mli) cpdfcommandrun.ml
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244
cpdf.ml
244
cpdf.ml
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@ -49,250 +49,6 @@ let xmp_template =
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<?xpacket end='r'?>|}
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<?xpacket end='r'?>|}
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(* For debugging *)
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let report_pdf_size pdf =
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Pdf.remove_unreferenced pdf;
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Pdfwrite.pdf_to_file_options ~preserve_objstm:false ~generate_objstm:false
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~compress_objstm:false false None false pdf "temp.pdf";
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let fh = open_in_bin "temp.pdf" in
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Printf.printf "Size %i bytes\n" (in_channel_length fh);
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flush stdout;
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close_in fh
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(* Recompress anything which isn't compressed, unless it's metadata. *)
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let recompress_stream pdf = function
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(* If there is no compression, compress with /FlateDecode *)
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| Pdf.Stream {contents = (dict, _)} as stream ->
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begin match
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Pdf.lookup_direct pdf "/Filter" dict,
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Pdf.lookup_direct pdf "/Type" dict
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with
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| _, Some (Pdf.Name "/Metadata") -> ()
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| (None | Some (Pdf.Array [])), _ ->
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Pdfcodec.encode_pdfstream pdf Pdfcodec.Flate stream
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| _ -> ()
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end
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| _ -> assert false
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let recompress_pdf pdf =
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if not (Pdfcrypt.is_encrypted pdf) then
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Pdf.iter_stream (recompress_stream pdf) pdf;
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pdf
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let decompress_pdf pdf =
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if not (Pdfcrypt.is_encrypted pdf) then
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(Pdf.iter_stream (Pdfcodec.decode_pdfstream_until_unknown pdf) pdf);
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pdf
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(* Equality on PDF objects *)
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let pdfobjeq pdf x y =
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let x = Pdf.lookup_obj pdf x
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and y = Pdf.lookup_obj pdf y in
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begin match x with Pdf.Stream _ -> Pdf.getstream x | _ -> () end;
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begin match y with Pdf.Stream _ -> Pdf.getstream y | _ -> () end;
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compare x y
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let really_squeeze pdf =
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let objs = ref [] in
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Pdf.objiter (fun objnum _ -> objs := objnum :: !objs) pdf;
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let toprocess =
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keep
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(fun x -> length x > 1)
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(collate (pdfobjeq pdf) (sort (pdfobjeq pdf) !objs))
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in
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(* Remove any pools of objects which are page objects, since Adobe Reader
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* gets confused when there are duplicate page objects. *)
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let toprocess =
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option_map
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(function
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[] -> assert false
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| h::_ as l ->
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match Pdf.lookup_direct pdf "/Type" (Pdf.lookup_obj pdf h) with
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Some (Pdf.Name "/Page") -> None
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| _ -> Some l)
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toprocess
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in
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let pdfr = ref pdf in
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let changetable = Hashtbl.create 100 in
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iter
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(function [] -> assert false | h::t ->
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iter (fun e -> Hashtbl.add changetable e h) t)
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toprocess;
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(* For a unknown reason, the output file is much smaller if
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Pdf.renumber is run twice. This is bizarre, since Pdf.renumber is
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an old, well-understood function in use for years -- what is
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going on? Furthermore, if we run it 3 times, it gets bigger again! *)
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pdfr := Pdf.renumber changetable !pdfr;
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pdfr := Pdf.renumber changetable !pdfr;
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Pdf.remove_unreferenced !pdfr;
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pdf.Pdf.root <- !pdfr.Pdf.root;
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pdf.Pdf.objects <- !pdfr.Pdf.objects;
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pdf.Pdf.trailerdict <- !pdfr.Pdf.trailerdict
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(* Squeeze the form xobject at objnum.
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FIXME: For old PDFs (< v1.2) any resources from the page (or its ancestors in
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the page tree!) are also needed - we must merge them with the ones from the
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xobject itself. However, it it safe for now -- in the unlikely event that the
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resources actually need to be available, the parse will fail, the squeeze of
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this object will fail, and we bail out. *)
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let xobjects_done = ref []
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let squeeze_form_xobject pdf objnum =
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if mem objnum !xobjects_done then () else
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xobjects_done := objnum :: !xobjects_done;
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let obj = Pdf.lookup_obj pdf objnum in
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match Pdf.lookup_direct pdf "/Subtype" obj with
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Some (Pdf.Name "/Form") ->
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let resources =
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match Pdf.lookup_direct pdf "/Resources" obj with
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Some d -> d
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| None -> Pdf.Dictionary []
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in
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begin match
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Pdfops.stream_of_ops
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(Pdfops.parse_operators pdf resources [Pdf.Indirect objnum])
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with
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Pdf.Stream {contents = (_, Pdf.Got data)} ->
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(* Put replacement data in original stream, and overwrite /Length *)
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begin match obj with
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Pdf.Stream ({contents = (d, _)} as str) ->
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str :=
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(Pdf.add_dict_entry d "/Length" (Pdf.Integer (bytes_size data)),
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Pdf.Got data)
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| _ -> failwith "squeeze_form_xobject"
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end
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| _ -> failwith "squeeze_form_xobject"
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end
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| _ -> ()
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(* For a list of indirects representing content streams, make sure that none of
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them are duplicated in the PDF. This indicates sharing, which parsing and
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rewriting the streams might destroy, thus making the file bigger. FIXME: The
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correct thing to do is to preserve the multiple content streams. *)
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let no_duplicates content_stream_numbers stream_numbers =
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not
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(mem false
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(map
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(fun n -> length (keep (eq n) content_stream_numbers) < 2)
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stream_numbers))
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(* Give a list of content stream numbers, given a page reference number *)
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let content_streams_of_page pdf refnum =
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match Pdf.direct pdf (Pdf.lookup_obj pdf refnum) with
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Pdf.Dictionary dict ->
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begin match lookup "/Contents" dict with
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Some (Pdf.Indirect i) -> [i]
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| Some (Pdf.Array x) ->
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option_map (function Pdf.Indirect i -> Some i | _ -> None) x
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| _ -> []
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end
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| _ -> []
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(* For each object in the PDF marked with /Type /Page, for each /Contents
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indirect reference or array of such, decode and recode that content stream. *)
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let squeeze_all_content_streams pdf =
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let page_reference_numbers = Pdf.page_reference_numbers pdf in
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let all_content_streams_in_doc =
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flatten (map (content_streams_of_page pdf) page_reference_numbers)
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in
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xobjects_done := [];
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Pdf.objiter
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(fun objnum _ ->
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match Pdf.lookup_obj pdf objnum with
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Pdf.Dictionary dict as d
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when
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Pdf.lookup_direct pdf "/Type" d = Some (Pdf.Name "/Page")
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->
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let resources =
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match Pdf.lookup_direct pdf "/Resources" d with
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Some d -> d
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| None -> Pdf.Dictionary []
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in
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begin try
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let content_streams =
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match lookup "/Contents" dict with
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Some (Pdf.Indirect i) ->
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begin match Pdf.direct pdf (Pdf.Indirect i) with
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Pdf.Array x -> x
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| _ -> [Pdf.Indirect i]
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end
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| Some (Pdf.Array x) -> x
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| _ -> raise Not_found
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in
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if
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no_duplicates
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all_content_streams_in_doc
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(map (function Pdf.Indirect i -> i | _ -> assert false) content_streams)
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then
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let newstream =
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Pdfops.stream_of_ops
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(Pdfops.parse_operators pdf resources content_streams)
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in
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let newdict =
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Pdf.add_dict_entry
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d "/Contents" (Pdf.Indirect (Pdf.addobj pdf newstream))
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in
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Pdf.addobj_given_num pdf (objnum, newdict);
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(* Now process all xobjects related to this page *)
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begin match Pdf.lookup_direct pdf "/XObject" resources with
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Some (Pdf.Dictionary xobjs) ->
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iter
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(function
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(_, Pdf.Indirect i) -> squeeze_form_xobject pdf i
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| _ -> failwith "squeeze_xobject")
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xobjs
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| _ -> ()
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end
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with
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(* No /Contents, which is ok. Or a parsing failure due to
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uninherited resources. FIXME: Add support for inherited
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resources. *)
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Not_found -> ()
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end
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| _ -> ())
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pdf
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(* We run squeeze enough times for the number of objects to not change *)
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let squeeze ?logto ?(pagedata=true) ?(recompress=true) pdf =
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let log x =
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match logto with
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None -> print_string x; flush stdout
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| Some "nolog" -> ()
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| Some s ->
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let fh = open_out_gen [Open_wronly; Open_creat] 0o666 s in
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seek_out fh (out_channel_length fh);
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output_string fh x;
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close_out fh
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in
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try
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let n = ref (Pdf.objcard pdf) in
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log (Printf.sprintf "Beginning squeeze: %i objects\n" (Pdf.objcard pdf));
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while !n > (ignore (really_squeeze pdf); Pdf.objcard pdf) do
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n := Pdf.objcard pdf;
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log (Printf.sprintf "Squeezing... Down to %i objects\n" (Pdf.objcard pdf));
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done;
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if pagedata then
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begin
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log (Printf.sprintf "Squeezing page data and xobjects\n");
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squeeze_all_content_streams pdf;
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end;
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if recompress then
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begin
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log (Printf.sprintf "Recompressing document\n");
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Pdfcodec.flate_level := 9;
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ignore (recompress_pdf pdf)
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end
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with
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e ->
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raise
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(Pdf.PDFError
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(Printf.sprintf
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"Squeeze failed. No output written.\n Proximate error was:\n %s"
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(Printexc.to_string e)))
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type encoding =
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type encoding =
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| Raw
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| Raw
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| UTF8
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| UTF8
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10
cpdf.mli
10
cpdf.mli
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@ -36,14 +36,6 @@ val iter_pages : (int -> Pdfpage.t -> unit) -> Pdf.t -> int list -> unit
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(** Same as [process_pages] but return the list of outputs of the map function. *)
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(** Same as [process_pages] but return the list of outputs of the map function. *)
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val map_pages : (int -> Pdfpage.t -> 'a) -> Pdf.t -> int list -> 'a list
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val map_pages : (int -> Pdfpage.t -> 'a) -> Pdf.t -> int list -> 'a list
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(** Compresses all streams in the PDF document which are uncompressed, using
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/FlateDecode, leaving out metadata. If the PDF is encrypted, does nothing. *)
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val recompress_pdf : Pdf.t -> Pdf.t
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(** Decompresses all streams in a PDF document, assuming it isn't encrypted. *)
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val decompress_pdf : Pdf.t -> Pdf.t
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val copy_cropbox_to_mediabox : Pdf.t -> int list -> Pdf.t
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val copy_cropbox_to_mediabox : Pdf.t -> int list -> Pdf.t
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(** {2 Metadata and settings} *)
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(** {2 Metadata and settings} *)
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@ -344,8 +336,6 @@ val blackfills : color -> int list -> Pdf.t -> Pdf.t
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(** Remove images from a PDF, optionally adding crossed boxes. *)
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(** Remove images from a PDF, optionally adding crossed boxes. *)
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val draft : string option -> bool -> int list -> Pdf.t -> Pdf.t
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val draft : string option -> bool -> int list -> Pdf.t -> Pdf.t
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(** Squeeze a PDF *)
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val squeeze : ?logto:string -> ?pagedata:bool -> ?recompress:bool -> Pdf.t -> unit
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val remove_all_text : int list -> Pdf.t -> Pdf.t
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val remove_all_text : int list -> Pdf.t -> Pdf.t
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@ -2834,8 +2834,8 @@ let write_pdf ?(encryption = None) ?(is_decompress=false) mk_id pdf =
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None ->
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None ->
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if not is_decompress then
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if not is_decompress then
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begin
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begin
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ignore (Cpdf.recompress_pdf pdf);
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ignore (Cpdfsqueeze.recompress_pdf pdf);
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if args.squeeze then Cpdf.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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if args.squeeze then Cpdfsqueeze.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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end;
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end;
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Pdf.remove_unreferenced pdf;
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Pdf.remove_unreferenced pdf;
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really_write_pdf ~is_decompress mk_id pdf outname
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really_write_pdf ~is_decompress mk_id pdf outname
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@ -2849,8 +2849,8 @@ let write_pdf ?(encryption = None) ?(is_decompress=false) mk_id pdf =
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None ->
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None ->
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if not is_decompress then
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if not is_decompress then
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begin
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begin
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ignore (Cpdf.recompress_pdf pdf);
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ignore (Cpdfsqueeze.recompress_pdf pdf);
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if args.squeeze then Cpdf.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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if args.squeeze then Cpdfsqueeze.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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Pdf.remove_unreferenced pdf
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Pdf.remove_unreferenced pdf
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end;
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end;
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really_write_pdf ~encryption ~is_decompress mk_id pdf temp;
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really_write_pdf ~encryption ~is_decompress mk_id pdf temp;
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@ -2889,7 +2889,7 @@ let fast_write_split_pdfs
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(stem original_filename) startpage endpage
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(stem original_filename) startpage endpage
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in
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in
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Pdf.remove_unreferenced pdf;
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Pdf.remove_unreferenced pdf;
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if sq then Cpdf.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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if sq then Cpdfsqueeze.squeeze ~pagedata:args.squeeze_pagedata ~recompress:args.squeeze_recompress ?logto:!logto pdf;
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really_write_pdf ~encryption:enc (not (enc = None)) pdf name)
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really_write_pdf ~encryption:enc (not (enc = None)) pdf name)
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(indx pagenums)
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(indx pagenums)
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pagenums
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pagenums
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@ -3261,7 +3261,7 @@ let go () =
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let pdf = get_single_pdf (Some Compress) false in
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let pdf = get_single_pdf (Some Compress) false in
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if args.remove_duplicate_streams then
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if args.remove_duplicate_streams then
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Pdfmerge.remove_duplicate_fonts pdf;
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Pdfmerge.remove_duplicate_fonts pdf;
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write_pdf false (Cpdf.recompress_pdf pdf)
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write_pdf false (Cpdfsqueeze.recompress_pdf pdf)
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| Some RemoveCrop ->
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| Some RemoveCrop ->
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begin match args.inputs, args.out with
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begin match args.inputs, args.out with
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||||||
| (_, pagespec, _, _, _, _)::_, _ ->
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| (_, pagespec, _, _, _, _)::_, _ ->
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||||||
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@ -3736,7 +3736,7 @@ let go () =
|
||||||
(Cpdf.combine_pages args.fast (get_single_pdf args.op false) (pdfread_pdf_of_file None None over) false false true)
|
(Cpdf.combine_pages args.fast (get_single_pdf args.op false) (pdfread_pdf_of_file None None over) false false true)
|
||||||
| Some Encrypt ->
|
| Some Encrypt ->
|
||||||
let pdf = get_single_pdf args.op false in
|
let pdf = get_single_pdf args.op false in
|
||||||
let pdf = Cpdf.recompress_pdf pdf
|
let pdf = Cpdfsqueeze.recompress_pdf pdf
|
||||||
and encryption =
|
and encryption =
|
||||||
{Pdfwrite.encryption_method =
|
{Pdfwrite.encryption_method =
|
||||||
(match args.crypt_method with
|
(match args.crypt_method with
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,246 @@
|
||||||
|
open Pdfutil
|
||||||
|
open Pdfio
|
||||||
|
|
||||||
|
(* For debugging *)
|
||||||
|
let report_pdf_size pdf =
|
||||||
|
Pdf.remove_unreferenced pdf;
|
||||||
|
Pdfwrite.pdf_to_file_options ~preserve_objstm:false ~generate_objstm:false
|
||||||
|
~compress_objstm:false false None false pdf "temp.pdf";
|
||||||
|
let fh = open_in_bin "temp.pdf" in
|
||||||
|
Printf.printf "Size %i bytes\n" (in_channel_length fh);
|
||||||
|
flush stdout;
|
||||||
|
close_in fh
|
||||||
|
|
||||||
|
(* Recompress anything which isn't compressed, unless it's metadata. *)
|
||||||
|
let recompress_stream pdf = function
|
||||||
|
(* If there is no compression, compress with /FlateDecode *)
|
||||||
|
| Pdf.Stream {contents = (dict, _)} as stream ->
|
||||||
|
begin match
|
||||||
|
Pdf.lookup_direct pdf "/Filter" dict,
|
||||||
|
Pdf.lookup_direct pdf "/Type" dict
|
||||||
|
with
|
||||||
|
| _, Some (Pdf.Name "/Metadata") -> ()
|
||||||
|
| (None | Some (Pdf.Array [])), _ ->
|
||||||
|
Pdfcodec.encode_pdfstream pdf Pdfcodec.Flate stream
|
||||||
|
| _ -> ()
|
||||||
|
end
|
||||||
|
| _ -> assert false
|
||||||
|
|
||||||
|
let recompress_pdf pdf =
|
||||||
|
if not (Pdfcrypt.is_encrypted pdf) then
|
||||||
|
Pdf.iter_stream (recompress_stream pdf) pdf;
|
||||||
|
pdf
|
||||||
|
|
||||||
|
let decompress_pdf pdf =
|
||||||
|
if not (Pdfcrypt.is_encrypted pdf) then
|
||||||
|
(Pdf.iter_stream (Pdfcodec.decode_pdfstream_until_unknown pdf) pdf);
|
||||||
|
pdf
|
||||||
|
|
||||||
|
|
||||||
|
(* Equality on PDF objects *)
|
||||||
|
let pdfobjeq pdf x y =
|
||||||
|
let x = Pdf.lookup_obj pdf x
|
||||||
|
and y = Pdf.lookup_obj pdf y in
|
||||||
|
begin match x with Pdf.Stream _ -> Pdf.getstream x | _ -> () end;
|
||||||
|
begin match y with Pdf.Stream _ -> Pdf.getstream y | _ -> () end;
|
||||||
|
compare x y
|
||||||
|
|
||||||
|
let really_squeeze pdf =
|
||||||
|
let objs = ref [] in
|
||||||
|
Pdf.objiter (fun objnum _ -> objs := objnum :: !objs) pdf;
|
||||||
|
let toprocess =
|
||||||
|
keep
|
||||||
|
(fun x -> length x > 1)
|
||||||
|
(collate (pdfobjeq pdf) (sort (pdfobjeq pdf) !objs))
|
||||||
|
in
|
||||||
|
(* Remove any pools of objects which are page objects, since Adobe Reader
|
||||||
|
* gets confused when there are duplicate page objects. *)
|
||||||
|
let toprocess =
|
||||||
|
option_map
|
||||||
|
(function
|
||||||
|
[] -> assert false
|
||||||
|
| h::_ as l ->
|
||||||
|
match Pdf.lookup_direct pdf "/Type" (Pdf.lookup_obj pdf h) with
|
||||||
|
Some (Pdf.Name "/Page") -> None
|
||||||
|
| _ -> Some l)
|
||||||
|
toprocess
|
||||||
|
in
|
||||||
|
let pdfr = ref pdf in
|
||||||
|
let changetable = Hashtbl.create 100 in
|
||||||
|
iter
|
||||||
|
(function [] -> assert false | h::t ->
|
||||||
|
iter (fun e -> Hashtbl.add changetable e h) t)
|
||||||
|
toprocess;
|
||||||
|
(* For a unknown reason, the output file is much smaller if
|
||||||
|
Pdf.renumber is run twice. This is bizarre, since Pdf.renumber is
|
||||||
|
an old, well-understood function in use for years -- what is
|
||||||
|
going on? Furthermore, if we run it 3 times, it gets bigger again! *)
|
||||||
|
pdfr := Pdf.renumber changetable !pdfr;
|
||||||
|
pdfr := Pdf.renumber changetable !pdfr;
|
||||||
|
Pdf.remove_unreferenced !pdfr;
|
||||||
|
pdf.Pdf.root <- !pdfr.Pdf.root;
|
||||||
|
pdf.Pdf.objects <- !pdfr.Pdf.objects;
|
||||||
|
pdf.Pdf.trailerdict <- !pdfr.Pdf.trailerdict
|
||||||
|
|
||||||
|
(* Squeeze the form xobject at objnum.
|
||||||
|
|
||||||
|
FIXME: For old PDFs (< v1.2) any resources from the page (or its ancestors in
|
||||||
|
the page tree!) are also needed - we must merge them with the ones from the
|
||||||
|
xobject itself. However, it it safe for now -- in the unlikely event that the
|
||||||
|
resources actually need to be available, the parse will fail, the squeeze of
|
||||||
|
this object will fail, and we bail out. *)
|
||||||
|
let xobjects_done = ref []
|
||||||
|
|
||||||
|
let squeeze_form_xobject pdf objnum =
|
||||||
|
if mem objnum !xobjects_done then () else
|
||||||
|
xobjects_done := objnum :: !xobjects_done;
|
||||||
|
let obj = Pdf.lookup_obj pdf objnum in
|
||||||
|
match Pdf.lookup_direct pdf "/Subtype" obj with
|
||||||
|
Some (Pdf.Name "/Form") ->
|
||||||
|
let resources =
|
||||||
|
match Pdf.lookup_direct pdf "/Resources" obj with
|
||||||
|
Some d -> d
|
||||||
|
| None -> Pdf.Dictionary []
|
||||||
|
in
|
||||||
|
begin match
|
||||||
|
Pdfops.stream_of_ops
|
||||||
|
(Pdfops.parse_operators pdf resources [Pdf.Indirect objnum])
|
||||||
|
with
|
||||||
|
Pdf.Stream {contents = (_, Pdf.Got data)} ->
|
||||||
|
(* Put replacement data in original stream, and overwrite /Length *)
|
||||||
|
begin match obj with
|
||||||
|
Pdf.Stream ({contents = (d, _)} as str) ->
|
||||||
|
str :=
|
||||||
|
(Pdf.add_dict_entry d "/Length" (Pdf.Integer (bytes_size data)),
|
||||||
|
Pdf.Got data)
|
||||||
|
| _ -> failwith "squeeze_form_xobject"
|
||||||
|
end
|
||||||
|
| _ -> failwith "squeeze_form_xobject"
|
||||||
|
end
|
||||||
|
| _ -> ()
|
||||||
|
|
||||||
|
(* For a list of indirects representing content streams, make sure that none of
|
||||||
|
them are duplicated in the PDF. This indicates sharing, which parsing and
|
||||||
|
rewriting the streams might destroy, thus making the file bigger. FIXME: The
|
||||||
|
correct thing to do is to preserve the multiple content streams. *)
|
||||||
|
let no_duplicates content_stream_numbers stream_numbers =
|
||||||
|
not
|
||||||
|
(mem false
|
||||||
|
(map
|
||||||
|
(fun n -> length (keep (eq n) content_stream_numbers) < 2)
|
||||||
|
stream_numbers))
|
||||||
|
|
||||||
|
(* Give a list of content stream numbers, given a page reference number *)
|
||||||
|
let content_streams_of_page pdf refnum =
|
||||||
|
match Pdf.direct pdf (Pdf.lookup_obj pdf refnum) with
|
||||||
|
Pdf.Dictionary dict ->
|
||||||
|
begin match lookup "/Contents" dict with
|
||||||
|
Some (Pdf.Indirect i) -> [i]
|
||||||
|
| Some (Pdf.Array x) ->
|
||||||
|
option_map (function Pdf.Indirect i -> Some i | _ -> None) x
|
||||||
|
| _ -> []
|
||||||
|
end
|
||||||
|
| _ -> []
|
||||||
|
|
||||||
|
(* For each object in the PDF marked with /Type /Page, for each /Contents
|
||||||
|
indirect reference or array of such, decode and recode that content stream. *)
|
||||||
|
let squeeze_all_content_streams pdf =
|
||||||
|
let page_reference_numbers = Pdf.page_reference_numbers pdf in
|
||||||
|
let all_content_streams_in_doc =
|
||||||
|
flatten (map (content_streams_of_page pdf) page_reference_numbers)
|
||||||
|
in
|
||||||
|
xobjects_done := [];
|
||||||
|
Pdf.objiter
|
||||||
|
(fun objnum _ ->
|
||||||
|
match Pdf.lookup_obj pdf objnum with
|
||||||
|
Pdf.Dictionary dict as d
|
||||||
|
when
|
||||||
|
Pdf.lookup_direct pdf "/Type" d = Some (Pdf.Name "/Page")
|
||||||
|
->
|
||||||
|
let resources =
|
||||||
|
match Pdf.lookup_direct pdf "/Resources" d with
|
||||||
|
Some d -> d
|
||||||
|
| None -> Pdf.Dictionary []
|
||||||
|
in
|
||||||
|
begin try
|
||||||
|
let content_streams =
|
||||||
|
match lookup "/Contents" dict with
|
||||||
|
Some (Pdf.Indirect i) ->
|
||||||
|
begin match Pdf.direct pdf (Pdf.Indirect i) with
|
||||||
|
Pdf.Array x -> x
|
||||||
|
| _ -> [Pdf.Indirect i]
|
||||||
|
end
|
||||||
|
| Some (Pdf.Array x) -> x
|
||||||
|
| _ -> raise Not_found
|
||||||
|
in
|
||||||
|
if
|
||||||
|
no_duplicates
|
||||||
|
all_content_streams_in_doc
|
||||||
|
(map (function Pdf.Indirect i -> i | _ -> assert false) content_streams)
|
||||||
|
then
|
||||||
|
let newstream =
|
||||||
|
Pdfops.stream_of_ops
|
||||||
|
(Pdfops.parse_operators pdf resources content_streams)
|
||||||
|
in
|
||||||
|
let newdict =
|
||||||
|
Pdf.add_dict_entry
|
||||||
|
d "/Contents" (Pdf.Indirect (Pdf.addobj pdf newstream))
|
||||||
|
in
|
||||||
|
Pdf.addobj_given_num pdf (objnum, newdict);
|
||||||
|
(* Now process all xobjects related to this page *)
|
||||||
|
begin match Pdf.lookup_direct pdf "/XObject" resources with
|
||||||
|
Some (Pdf.Dictionary xobjs) ->
|
||||||
|
iter
|
||||||
|
(function
|
||||||
|
(_, Pdf.Indirect i) -> squeeze_form_xobject pdf i
|
||||||
|
| _ -> failwith "squeeze_xobject")
|
||||||
|
xobjs
|
||||||
|
| _ -> ()
|
||||||
|
end
|
||||||
|
with
|
||||||
|
(* No /Contents, which is ok. Or a parsing failure due to
|
||||||
|
uninherited resources. FIXME: Add support for inherited
|
||||||
|
resources. *)
|
||||||
|
Not_found -> ()
|
||||||
|
end
|
||||||
|
| _ -> ())
|
||||||
|
pdf
|
||||||
|
|
||||||
|
(* We run squeeze enough times for the number of objects to not change *)
|
||||||
|
let squeeze ?logto ?(pagedata=true) ?(recompress=true) pdf =
|
||||||
|
let log x =
|
||||||
|
match logto with
|
||||||
|
None -> print_string x; flush stdout
|
||||||
|
| Some "nolog" -> ()
|
||||||
|
| Some s ->
|
||||||
|
let fh = open_out_gen [Open_wronly; Open_creat] 0o666 s in
|
||||||
|
seek_out fh (out_channel_length fh);
|
||||||
|
output_string fh x;
|
||||||
|
close_out fh
|
||||||
|
in
|
||||||
|
try
|
||||||
|
let n = ref (Pdf.objcard pdf) in
|
||||||
|
log (Printf.sprintf "Beginning squeeze: %i objects\n" (Pdf.objcard pdf));
|
||||||
|
while !n > (ignore (really_squeeze pdf); Pdf.objcard pdf) do
|
||||||
|
n := Pdf.objcard pdf;
|
||||||
|
log (Printf.sprintf "Squeezing... Down to %i objects\n" (Pdf.objcard pdf));
|
||||||
|
done;
|
||||||
|
if pagedata then
|
||||||
|
begin
|
||||||
|
log (Printf.sprintf "Squeezing page data and xobjects\n");
|
||||||
|
squeeze_all_content_streams pdf;
|
||||||
|
end;
|
||||||
|
if recompress then
|
||||||
|
begin
|
||||||
|
log (Printf.sprintf "Recompressing document\n");
|
||||||
|
Pdfcodec.flate_level := 9;
|
||||||
|
ignore (recompress_pdf pdf)
|
||||||
|
end
|
||||||
|
with
|
||||||
|
e ->
|
||||||
|
raise
|
||||||
|
(Pdf.PDFError
|
||||||
|
(Printf.sprintf
|
||||||
|
"Squeeze failed. No output written.\n Proximate error was:\n %s"
|
||||||
|
(Printexc.to_string e)))
|
||||||
|
|
||||||
|
|
@ -0,0 +1,9 @@
|
||||||
|
(** Compresses all streams in the PDF document which are uncompressed, using
|
||||||
|
/FlateDecode, leaving out metadata. If the PDF is encrypted, does nothing. *)
|
||||||
|
val recompress_pdf : Pdf.t -> Pdf.t
|
||||||
|
|
||||||
|
(** Decompresses all streams in a PDF document, assuming it isn't encrypted. *)
|
||||||
|
val decompress_pdf : Pdf.t -> Pdf.t
|
||||||
|
|
||||||
|
(** Squeeze a PDF *)
|
||||||
|
val squeeze : ?logto:string -> ?pagedata:bool -> ?recompress:bool -> Pdf.t -> unit
|
||||||
Loading…
Reference in New Issue