If the tool qpdf is available in the system, it will be called to manipulate the PDF files (especially to compress the PDF files).
qpdf(input, output, options = "--stream-data=compress")
the path of the input PDF file
the path of the output (if missing, output
will be the
same as input
)
options for qpdf
(default to be
'--stream-data=compress'
, i.e. compress the PDF files)
if ani.options('qpdf')
is non-NULL
, then this function
returns the status of the operation (0
for success; see
system
); otherwise a warning will be issued
This is a wrapper to call qpdf
. The path of qpdf
should
be set via ani.options(qpdf = 'path/to/qpdf')
.
See the reference for detailed usage of qpdf
.
Examples at https://yihui.org/animation/example/qpdf/
qpdf official website https://qpdf.sourceforge.io/