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authorJay Berkenbilt <ejb@ql.org>2017-12-26 00:42:33 +0100
committerJay Berkenbilt <ejb@ql.org>2017-12-26 00:42:33 +0100
commit48864b8d6eecc5bbd42029df0e2608621ce7d0bc (patch)
tree205ac0088534d3424605a40e3f663b561225e204 /manual
parent794b649e5b15b193c8682b5a7e67fda3bb719b96 (diff)
downloadqpdf-48864b8d6eecc5bbd42029df0e2608621ce7d0bc.tar.zst
Clarify documentation of advanced parsing options
Diffstat (limited to 'manual')
-rw-r--r--manual/qpdf-manual.xml89
1 files changed, 50 insertions, 39 deletions
diff --git a/manual/qpdf-manual.xml b/manual/qpdf-manual.xml
index 1e907e20..02fe9633 100644
--- a/manual/qpdf-manual.xml
+++ b/manual/qpdf-manual.xml
@@ -865,6 +865,56 @@ outfile.pdf</option>
to be bothered with.
</para>
</sect1>
+ <sect1 id="ref.advanced-parsing">
+ <title>Advanced Parsing Options</title>
+ <para>
+ These options control aspects of how qpdf reads PDF files. Mostly
+ these are of use to people who are working with damaged files.
+ There is little reason to use these options unless you are trying
+ to solve specific problems. The following options are available:
+ <variablelist>
+ <varlistentry>
+ <term><option>--suppress-recovery</option></term>
+ <listitem>
+ <para>
+ Prevents qpdf from attempting to recover damaged files.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>--ignore-xref-streams</option></term>
+ <listitem>
+ <para>
+ Tells qpdf to ignore any cross-reference streams.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ <para>
+ Ordinarily, qpdf will attempt to recover from certain types of
+ errors in PDF files. These include errors in the cross-reference
+ table, certain types of object numbering errors, and certain types
+ of stream length errors. Sometimes, qpdf may think it has
+ recovered but may not have actually recovered, so care should be
+ taken when using this option as some data loss is possible. The
+ <option>--suppress-recovery</option> option will prevent qpdf from
+ attempting recovery. In this case, it will fail on the first
+ error that it encounters.
+ </para>
+ <para>
+ Ordinarily, qpdf reads cross-reference streams when they are
+ present in a PDF file. If <option>--ignore-xref-streams</option>
+ is specified, qpdf will ignore any cross-reference streams for
+ hybrid PDF files. The purpose of hybrid files is to make some
+ content available to viewers that are not aware of cross-reference
+ streams. It is almost never desirable to ignore them. The only
+ time when you might want to use this feature is if you are testing
+ creation of hybrid PDF files and wish to see how a PDF consumer
+ that doesn't understand object and cross-reference streams would
+ interpret such a file.
+ </para>
+ </sect1>
<sect1 id="ref.advanced-transformation">
<title>Advanced Transformation Options</title>
<para>
@@ -976,14 +1026,6 @@ outfile.pdf</option>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>--suppress-recovery</option></term>
- <listitem>
- <para>
- Prevents qpdf from attempting to recover damaged files.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
<term><option>--object-streams=<replaceable>mode</replaceable></option></term>
<listitem>
<para>
@@ -1013,14 +1055,6 @@ outfile.pdf</option>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>--ignore-xref-streams</option></term>
- <listitem>
- <para>
- Tells qpdf to ignore any cross-reference streams.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
<term><option>--preserve-unreferenced</option></term>
<listitem>
<para>
@@ -1143,17 +1177,6 @@ outfile.pdf</option>
You should not use this for &ldquo;production&rdquo; PDF files.
</para>
<para>
- Ordinarily, qpdf will attempt to recover from certain types of
- errors in PDF files. These include errors in the cross-reference
- table, certain types of object numbering errors, and certain types
- of stream length errors. Sometimes, qpdf may think it has
- recovered but may not have actually recovered, so care should be
- taken when using this option as some data loss is possible. The
- <option>--suppress-recovery</option> option will prevent qpdf from
- attempting recovery. In this case, it will fail on the first
- error that it encounters.
- </para>
- <para>
Object streams, also known as compressed objects, were introduced
into the PDF specification at version 1.5, corresponding to
Acrobat 6. Some older PDF viewers may not support files with
@@ -1178,18 +1201,6 @@ outfile.pdf</option>
at least 1.5.
</para>
<para>
- Ordinarily, qpdf reads cross-reference streams when they are
- present in a PDF file. If <option>--ignore-xref-streams</option>
- is specified, qpdf will ignore any cross-reference streams for
- hybrid PDF files. The purpose of hybrid files is to make some
- content available to viewers that are not aware of cross-reference
- streams. It is almost never desirable to ignore them. The only
- time when you might want to use this feature is if you are testing
- creation of hybrid PDF files and wish to see how a PDF consumer
- that doesn't understand object and cross-reference streams would
- interpret such a file.
- </para>
- <para>
The <option>--qdf</option> flag turns on QDF mode, which changes
some of the defaults described above. Specifically, in QDF mode,
by default, stream data is uncompressed, content streams are