source: gsdl/trunk/perllib/plugins/RealMediaPlug.pm@ 14705

###########################################################################
#
# RealMediaPlug.pm -- Extract metadata from Real Media files
#
# Original code by Xin Gao
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright (C) 2005 New Zealand Digital Library Project
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

package RealMediaPlug;


use UnknownPlug;
use rm::Header::PurePerl;

use strict;
no strict 'refs'; # make an exception so we can use variables as filehandles


sub BEGIN {
    @RealMediaPlug::ISA = ('UnknownPlug');
}


my $arguments =
    [ { 'name' => "process_exp",
    'desc' => "{BasPlug.process_exp}",
    'type' => "regexp",
    'deft' => &get_default_process_exp(),
    'reqd' => "no" } ];

my $options = { 'name'     => "RealMediaPlug",
        'desc'     => "{RealMediaPlug.desc}",
        'abstract' => "no",
        'inherits' => "yes",
        'args'     => $arguments };


# This plugin processes Real Media files with the suffixes ".rm" and ".rmvb"
sub get_default_process_exp
{
    return q^(?i)(\.rm|rmvb)$^;
}


sub new
{
    my ($class) = shift(@_);
    my ($pluginlist, $inputargs, $hashArgOptLists) = @_;
    push(@$pluginlist, $class);

    if (defined $arguments) { push(@{$hashArgOptLists->{"ArgList"}}, @{$arguments}); }
    if (defined $options) { push(@{$hashArgOptLists->{"OptList"}}, $options); }

    my $self = new UnknownPlug($pluginlist, $inputargs, $hashArgOptLists);
    
    return bless $self, $class;
}


# do plugin specific processing of doc_obj
sub read
{
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $metadata, $processor, $maxdocs, $total_count, $gli) = @_;

    my $outhandle = $self->{'outhandle'};

    #check process and block exps, smart block, etc
    my ($block_status,$filename) = $self->read_block(@_);    
    return $block_status if ((!defined $block_status) || ($block_status==0));

    # Report that we're processing the file
    print STDERR "<Processing n='$file' p='RealMediaPlug'>\n" if ($gli);
    print $outhandle "RealMediaPlug: processing $file\n"
    if ($self->{'verbosity'}) > 1;

    # create a new index document
    my $doc_obj = new doc ($filename, "indexed_doc");
    if ($processor->{'OIDtype'} =~ /^(assigned|dirname)$/) {
    $doc_obj->set_OIDtype ($processor->{'OIDtype'}, $processor->{'OIDmetadata'});
    }
    else {
    $doc_obj->set_OIDtype ("incremental");    # this is done to avoid hashing content of file
    }
    my $top_section = $doc_obj->get_top_section();

    #if there's a leading directory name, eat it...
    $file =~ s/^.*[\/\\]//;
         
    my $url = $file;
  
    # Source (filename) to be consistent with other plugins
    $doc_obj->add_metadata($top_section, "Source", $url);
  
  
    my $text = "";
    my $real_media = rm::Header::PurePerl->new($filename);
    foreach my $key (keys %{$real_media->info})
    {
    my $value = $real_media->info->{$key};
    $doc_obj->add_metadata($top_section, $key, $value);
    $text .= "$key: $value\n";
    }

    $doc_obj->add_utf8_text($top_section, "<pre>\n$text\n</pre>");

    # srclink
    $doc_obj->add_metadata($top_section, "FileFormat", "RealMedia");
    $doc_obj->add_metadata($top_section, "srclink", "<a href=\"_httpprefix_/collect/[collection]/index/assoc/[assocfilepath]/[Source]\">");
    $doc_obj->add_metadata($top_section, "/srclink", "</a>");
    # srcicon (need to include "irmvideo.gif" in the greenstone images directory
    $doc_obj->add_metadata($top_section, "srcicon", "<img src=\"_httpprefix_/images/irmvideo.gif\" title=\"Download\" border=0>");

    # Add the actual file as an associated file
    $doc_obj->associate_file($filename, $file, "RealMedia", $top_section);

    # include any metadata passed in from previous plugins
    my $section = $doc_obj->get_top_section();
    $self->extra_metadata ($doc_obj, $section, $metadata);

    # do plugin specific processing of doc_obj
    return undef unless defined ($self->process (\$text, $pluginfo, $base_dir, $file, $metadata, $doc_obj));

    # do any automatic metadata extraction
    $self->auto_extract_metadata($doc_obj);
    
    # have we found a Title?? is the Title empty??
    if(!defined $doc_obj->get_metadata_element($section, "Title") or $doc_obj->get_metadata_element($section, "Title") eq ""){          
        my $file_derived_title = &BasPlug::filename_based_title($self, $file); 
        if(!defined $doc_obj->get_metadata_element($section, "Title")) {
            $doc_obj->add_metadata ($section, "Title", $file_derived_title);
        }
        else {
            $doc_obj->set_metadata_element ($section, "Title", $file_derived_title);
        }
    } 

    # add an OID
    $doc_obj->set_OID();

    # process the document
    $processor->process($doc_obj);

    $self->{'num_processed'}++;
    return 1;
}

1;