Adding support for video file sizes

[catagits/App-IdiotBox.git] / lib / Utils / PresentingPerl.pm

package Utils::PresentingPerl;

use strict;
use warnings;

use FLV::File;
#use Data::Dump::Streamer;
use Carp;
use English '-no_match_vars';
use IO::Handle;

# Given a filename, and an arrayref of information keys that we are interested in, returns a hashref with those keys filled in.
# If it cannot determine the information asked for (including if the keys are unknown), it will eventually return a hashref without them filled in.
# Known tags: 'width', 'height'.  Size of video frame.  Does not allow for changing size during the video.
sub get_flv_info {
  my ($filename, $wanted_info) = @_;

  my $file = FLV::File->new;
  
  # We need to use a modified version of FLV::File::parse, or we'll end up parsing the whole file.
  flv_parse($file, $filename);
  
  #Dump $file;
  
  my $info;
  
  # Now, we need to parse out the file, oen bit at at time, until we have what we wanted.
  # This is from FLV::Body::parse
  while (1) {
    my $lastsize = $file->get_bytes(4);
    
    my $tag = FLV::Tag->new;
    $tag->parse($file, {});
    my $payload = $tag->get_payload;
    
    if ($payload->isa('FLV::VideoTag')) {
      $info->{width} = $payload->{width};
      $info->{height} = $payload->{height};
    } else {
      # For the time being, assume that other tags are unimportant.  
      # Could, plasuably, tell somthing about the audio... but what do we care about?
      # Much more plausably, if our file had metadata tags, then we could read them.
      #die "No handler for payload $payload";
    }
    
    for (@$wanted_info) {
      next if !exists $info->{$_};
    }
    
    last;
  }

  return $info;
}

sub flv_parse {
  my $self  = shift;
  my $input = shift;
  my $opts  = shift;
  $opts ||= {};
  
  $self->{header}     = undef;
  $self->{body}       = undef;
  $self->{filename}   = undef;
  $self->{filehandle} = undef;
  $self->{pos}        = 0;
  
  my $eval_result = eval {
    if (ref $input) {
      $self->{filehandle} = $input;
    } else {
      $self->{filename} = $input;
      ## no critic (RequireBriefOpen)
      open my $fh, '<', $self->{filename} or croak q{} . $OS_ERROR;
      binmode $fh or croak 'Failed to set binary mode on file';
      $self->{filehandle} = $fh;
    }
    
    $self->{header} = FLV::Header->new();
    $self->{header}->parse($self);    # might throw exception
    
    $self->{body} = FLV::Body->new();
    # $self->{body}->parse($self, $opts);    # might throw exception
    1;
  };
  if (!$eval_result) {
    die 'Failed to read FLV file: ' . $EVAL_ERROR;
  }
  
  #$self->{filehandle} = undef;              # implicitly close the filehandle
  #$self->{pos}        = 0;
  
  return;
}


'done coding';