# PDF::API2::Basic::PDF::Filter - phpMan

## NAME
    [PDF::API2::Basic::PDF::Filter] - Abstract superclass for PDF stream
    filters

## SYNOPSIS
        $f = [PDF::API2::Basic::PDF::Filter]->new;
        $str = $f->outfilt($str, 1);
        print OUTFILE $str;

        while (read(INFILE, $dat, 4096))
        { $store .= $f->infilt($dat, 0); }
        $store .= $f->infilt("", 1);

## DESCRIPTION
    A Filter object contains state information for the process of outputting
    and inputting data through the filter. The precise state information
    stored is up to the particular filter and may range from nothing to
    whole objects created and destroyed.

    Each filter stores different state information for input and output and
    thus may handle one input filtering process and one output filtering
    process at the same time.

## METHODS
  [PDF::API2::Basic::PDF::Filter]->new
    Creates a new filter object with empty state information ready for
    processing data both input and output.

  $dat = $f->infilt($str, $isend)
    Filters from output to input the data. Notice that $isend == 0 implies
    that there is more data to come and so following it $f may contain state
    information (usually due to the break-off point of $str not being tidy).
    Subsequent calls will incorporate this stored state information.

    $isend == 1 implies that there is no more data to follow. The final
    state of $f will be that the state information is empty. Error messages
    are most likely to occur here since if there is required state
    information to be stored following this data, then that would imply an
    error in the data.

  $str = $f->outfilt($dat, $isend)
    Filter stored data ready for output. Parallels "infilt".