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LibCompress: Add a PackBits decoder

This compression scheme was quite popular during the 80's, and we can
still find it in use inside file formats such as TIFF or PDF.
This commit is contained in:
Lucas CHOLLET 2023-12-21 00:16:04 -05:00 committed by Tim Schumacher
parent 5d0fb4bac3
commit d748edd994
5 changed files with 99 additions and 0 deletions

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/*
* Copyright (c) 2023, Lucas Chollet <lucas.chollet@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/Optional.h>
namespace Compress::PackBits {
// This implements the PackBits compression scheme, aka run-length compression
// It is fairly simple and described here: https://web.archive.org/web/20080705155158/http://developer.apple.com/technotes/tn/tn1023.html
// But also in section:
// - 7.4.5 RunLengthDecode Filter of the PDF specification
// - Section 9: PackBits Compression of the TIFF specification
enum class CompatibilityMode {
Original, // 128 is defined as no-op
PDF, // 128 is defined as end of stream
};
ErrorOr<ByteBuffer> decode_all(ReadonlyBytes bytes, Optional<u64> expected_output_size = {}, CompatibilityMode mode = CompatibilityMode::Original);
}