Add libjpeg dependency

Jay Berkenbilt
1 parent 2d2f6196
Showing 5 changed files with 44 additions and 19 deletions
README
README-what-to-download.txt
configure.ac
libqpdf.pc.in
manual/qpdf-manual.xml
@@ -13,11 +13,11 @@ warranty.
 Prerequisites
 =============
-QPDF depends on the external library "zlib". This are part of every
-Linux distribution and is readily available. Download information
-appears in the documentation. For Windows, you can download pre-built
-binary versions of this libraries for some compilers; see
-README-windows.txt for additional details.
+QPDF depends on the external libraries "zlib" and "jpeg". These are
+part of every Linux distribution and are readily available. Download
+information appears in the documentation. For Windows, you can
+download pre-built binary versions of these libraries for some
+compilers; see README-windows.txt for additional details.
 QPDF requires a C++ compiler that works with STL.  Your compiler must
 also support "long long".  Almost all modern compilers do.  If you are
@@ -34,9 +34,10 @@ you had an otherwise working qpdf.
 Licensing terms of embedded software
 ====================================
-QPDF makes use of zlib for its functionality. This package can be
-downloaded separately from its own download location, or it can be
-downloaded in the external-libs area of the qpdf download site.
+QPDF makes use of zlib and jpeg libraries for its functionality. These
+packages can be downloaded separately from their own download
+locations, or they can be downloaded in the external-libs area of the
+qpdf download site.
 The Rijndael encryption implementation used as the basis for AES
 encryption and decryption support comes from Philip J. Erdelsky's
@@ -147,10 +148,13 @@ sources to the user&#39;s manual can be found in the &quot;manual&quot; directory.
 The software library is just libqpdf, and all the header files are in
 the qpdf subdirectory. If you link statically with -lqpdf, then you
-will also need to link with -lz. The shared qpdf library is linked
-with -lz, and none of qpdf's public header files directly include
-files from libz, so in many cases, qpdf's development files are self
-contained.
+will also need to link with -lz and -ljpeg. The shared qpdf library is
+linked with -lz and -ljpeg, none of qpdf's public header files
+directly include files from libz, and only Pl_DCT.hh includes files
+from libjpeg, so for most cases, qpdf's development files are self
+contained. If you need to use Pl_DCT in your application code, you
+will need to have the header files for some libjpeg distribution in
+your include path.
 To learn about using the library, please read comments in the header
 files in include/qpdf, especially QPDF.hh, QPDFObjectHandle.hh, and
@@ -47,7 +47,10 @@ download.
    If you want to build the external libraries on your own (for
    Windows or anything else), you can download this archive. In
-   addition to including an unmodified distribution zlib, it includes
-   a README file and some scripts to help you build it for Windows.
+   addition to including an unmodified distribution zlib and the jpeg
+   libary, it includes a README file and some scripts to help you
+   build it for Windows. qpdf was built using a binary distribution of
+   libjpeg-turbo for Windows. You will also have to provide those. See
+   README-windows.txt for details.
 If you want to build on Windows, please see also README-windows.txt.
@@ -102,6 +102,8 @@ fi
 if test "$BUILD_INTERNAL_LIBS" = "0"; then
    AC_CHECK_HEADER(zlib.h,,[MISSING_ZLIB_H=1; MISSING_ANY=1])
    AC_SEARCH_LIBS(deflate,z zlib,,[MISSING_ZLIB=1; MISSING_ANY=1])
+   AC_CHECK_HEADER(jpeglib.h,,[MISSING_JPEG_H=1; MISSING_ANY=1])
+   AC_SEARCH_LIBS(jpeg_destroy,jpeg,,[MISSING_JPEG=1; MISSING_ANY=1])
 fi
 if test "x$qpdf_OS_SECURE_RANDOM" = "x1"; then
@@ -471,6 +473,14 @@ if test &quot;$MISSING_ZLIB&quot; = &quot;1&quot;; then
   AC_MSG_WARN(unable to find required library z (or zlib))
 fi
+if test "$MISSING_JPEG_H" = "1"; then
+  AC_MSG_WARN(unable to find required header jpeglib.h)
+fi
+
+if test "$MISSING_JPEG" = "1"; then
+  AC_MSG_WARN(unable to find required library jpeg)
+fi
+
 if test "$MISSING_DOCBOOK_FO" = "1"; then
   AC_MSG_WARN(docbook fo stylesheets are required to build PDF documentation)
 fi
@@ -507,7 +517,7 @@ if test &quot;$USE_EXTERNAL_LIBS&quot; = &quot;1&quot;; then
    # much trouble getting it to work with a different compiler.
    CPPFLAGS="$CPPFLAGS -Iexternal-libs/include"
    LDFLAGS="$LDFLAGS -Lexternal-libs/lib-$BUILDRULES$WINDOWS_WORDSIZE"
-   LIBS="$LIBS -lz"
+   LIBS="$LIBS -lz -ljpeg"
 fi
 AC_OUTPUT
@@ -6,6 +6,6 @@ includedir=@includedir@
 Name: libqpdf
 Description: PDF transformation library
 Version: @PACKAGE_VERSION@
-Requires.private: zlib
+Requires.private: zlib, libjpeg
 Libs: -L${libdir} -lqpdf
 Cflags: -I${includedir}
@@ -93,8 +93,8 @@
   <sect1 id="ref.prerequisites">
    <title>System Requirements</title>
    <para>
-    The qpdf package has only one external dependencies.  In
-    order to build qpdf, the following packages are required:
+    The qpdf package has few external dependencies. In order to build
+    qpdf, the following packages are required:
     <itemizedlist>
      <listitem>
       <para>
@@ -103,6 +103,14 @@
      </listitem>
      <listitem>
       <para>
+       jpeg: <ulink
+       url="http://www.ijg.org/files/">http://www.ijg.org/files/</ulink>
+       or <ulink
+       url="https://libjpeg-turbo.org/">https://libjpeg-turbo.org/</ulink>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
        gnu make 3.81 or newer: <ulink url="http://www.gnu.org/software/make">http://www.gnu.org/software/make</ulink>
       </para>
      </listitem>
@@ -1509,7 +1517,7 @@ outfile.pdf&lt;/option&gt;
    </para>
    <para>
     When linking against the qpdf static library, you may also need to
-    specify <literal>-lz</literal> on your link command.  If
+    specify <literal>-lz -ljpeg</literal> on your link command. If
     your system understands how to read libtool
     <filename>.la</filename> files, this may not be necessary.
    </para>