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use strict;
use warnings;
package Data::ParseBinary::Stream::BitReader;
our @ISA = qw{Data::ParseBinary::Stream::Reader Data::ParseBinary::Stream::WrapperBase};
__PACKAGE__->_registerStreamType("Bit");
sub new {
my ($class, $byteStream) = @_;
my $self = bless { buffer => '' }, $class;
$self->_warping($byteStream);
return $self;
}
sub ReadBytes {
my ($self, $count) = @_;
return $self->_readBytesForBitStream($count);
}
sub ReadBits {
my ($self, $bitcount) = @_;
my $current = $self->{buffer};
my $moreBitsNeeded = $bitcount - length($current);
$moreBitsNeeded = 0 if $moreBitsNeeded < 0;
my $moreBytesNeeded = int($moreBitsNeeded / 8) + ($moreBitsNeeded % 8 ? 1 : 0);
#print "BitStream: $bitcount bits requested, $moreBytesNeeded bytes read\n";
my $string = $self->{ss}->ReadBytes($moreBytesNeeded);
$current .= unpack "B*", $string;
my $data = substr($current, 0, $bitcount, '');
$self->{buffer} = $current;
return $data;
}
sub tell {
my $self = shift;
#die "A bit stream is not seekable";
if ($self->{buffer}) {
return "Bit ". (8 - length($self->{buffer}))
} else {
return "Bit 0";
}
}
sub seek {
my ($self, $newpos) = @_;
die "A bit stream is not seekable";
}
sub isBitStream { return 1 };
package Data::ParseBinary::Stream::BitWriter;
our @ISA = qw{Data::ParseBinary::Stream::Writer Data::ParseBinary::Stream::WrapperBase};
__PACKAGE__->_registerStreamType("Bit");
sub new {
my ($class, $byteStream) = @_;
my $self = bless { buffer => '' }, $class;
$self->_warping($byteStream);
return $self;
}
sub WriteBytes {
my ($self, $data) = @_;
return $self->_writeBytesForBitStream($data);
}
sub WriteBits {
my ($self, $bitdata) = @_;
my $current = $self->{buffer};
my $new_buffer = $current . $bitdata;
my $numof_bytesToWrite = int(length($new_buffer) / 8);
my $bytesToWrite = substr($new_buffer, 0, $numof_bytesToWrite * 8, '');
my $binaryToWrite = pack "B".($numof_bytesToWrite * 8), $bytesToWrite;
$self->{buffer} = $new_buffer;
return $self->{ss}->WriteBytes($binaryToWrite);
}
sub Flush {
my $self = shift;
my $write_size = (-length($self->{buffer})) % 8;
$self->WriteBits('0'x$write_size);
return $self->{ss}->Flush();
}
sub tell {
my $self = shift;
return "Bit ". length($self->{buffer});
#die "A bit stream is not seekable";
}
sub seek {
my ($self, $newpos) = @_;
die "A bit stream is not seekable";
}
sub isBitStream { return 1 };
package Data::ParseBinary::Stream::ReversedBitStreamReader;
our @ISA = qw{Data::ParseBinary::Stream::BitReader};
__PACKAGE__->_registerStreamType("ReversedBit");
sub ReadBits {
my ($self, $bitcount) = @_;
my $current = $self->{buffer};
my $moreBitsNeeded = $bitcount - length($current);
if ($moreBitsNeeded > 0) {
my $moreBytesNeeded = int($moreBitsNeeded / 8) + ($moreBitsNeeded % 8 ? 1 : 0);
my $string = $self->{ss}->ReadBytes($moreBytesNeeded);
$string = join '', reverse split '', $string if $moreBytesNeeded > 1;
$current = unpack("B*", $string) . $current;
}
my $data = substr($current, -$bitcount, $bitcount, '');
$data = join '', reverse split '', $data if length($data) > 1;
$self->{buffer} = $current;
return $data;
}
package Data::ParseBinary::Stream::ReversedBitStreamWriter;
our @ISA = qw{Data::ParseBinary::Stream::BitWriter};
__PACKAGE__->_registerStreamType("ReversedBit");
sub WriteBits {
my ($self, $bitdata) = @_;
$bitdata = join '', reverse split '', $bitdata if length($bitdata) > 1;
$self->{buffer} = $bitdata . $self->{buffer};
my $numof_bytesToWrite = int(length($self->{buffer}) / 8);
my $num_of_bits_to_cut = $numof_bytesToWrite * 8;
my $bytesToWrite = substr($self->{buffer}, -$num_of_bits_to_cut, $num_of_bits_to_cut, '');
my $binaryToWrite = pack "B".($numof_bytesToWrite * 8), $bytesToWrite;
$binaryToWrite = join '', reverse split '', $binaryToWrite if $numof_bytesToWrite > 1;
return $self->{ss}->WriteBytes($binaryToWrite);
}
1;
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