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// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
Codecs used by the CHD format
***************************************************************************/
#ifndef MAME_LIB_UTIL_CHDCODEC_H
#define MAME_LIB_UTIL_CHDCODEC_H
#pragma once
#include "utilfwd.h"
#include <cstdint>
#include <memory>
#include <vector>
#define CHDCODEC_VERIFY_COMPRESSION 0
//**************************************************************************
// TYPE DEFINITIONS
//**************************************************************************
// base types
typedef uint32_t chd_codec_type;
// ======================> chd_codec
// common base class for all compressors and decompressors
class chd_codec
{
protected:
// can't create these directly
chd_codec(chd_file &file, uint32_t hunkbytes, bool lossy);
public:
// allow public deletion
virtual ~chd_codec();
// accessors
chd_file &chd() const { return m_chd; }
uint32_t hunkbytes() const { return m_hunkbytes; }
bool lossy() const { return m_lossy; }
// implementation
virtual void configure(int param, void *config);
private:
// internal state
chd_file & m_chd;
uint32_t m_hunkbytes;
bool m_lossy;
};
// ======================> chd_compressor
// base class for all compressors
class chd_compressor : public chd_codec
{
protected:
// can't create these directly
chd_compressor(chd_file &file, uint32_t hunkbytes, bool lossy);
public:
using ptr = std::unique_ptr<chd_compressor>;
// implementation
virtual uint32_t compress(const uint8_t *src, uint32_t srclen, uint8_t *dest) = 0;
};
// ======================> chd_decompressor
// base class for all decompressors
class chd_decompressor : public chd_codec
{
protected:
// can't create these directly
chd_decompressor(chd_file &file, uint32_t hunkbytes, bool lossy);
public:
using ptr = std::unique_ptr<chd_decompressor>;
// implementation
virtual void process(const uint8_t *src, uint32_t complen);
virtual void decompress(const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen) = 0;
};
// ======================> chd_codec_list
// wrapper to get at the list of codecs
class chd_codec_list
{
public:
// create compressors or decompressors
static chd_compressor::ptr new_compressor(chd_codec_type type, chd_file &file);
static chd_decompressor::ptr new_decompressor(chd_codec_type type, chd_file &file);
// utilities
static bool codec_exists(chd_codec_type type) noexcept;
static const char *codec_name(chd_codec_type type) noexcept;
};
// ======================> chd_compressor_group
// helper class that wraps several compressors
class chd_compressor_group
{
public:
// construction/destruction
chd_compressor_group(chd_file &file, chd_codec_type compressor_list[4]);
~chd_compressor_group();
// find the best compressor
int8_t find_best_compressor(const uint8_t *src, uint8_t *compressed, uint32_t &complen);
private:
// internal state
uint32_t m_hunkbytes; // number of bytes in a hunk
chd_compressor::ptr m_compressor[4]; // array of active codecs
std::vector<uint8_t> m_compress_test; // test buffer for compression
#if CHDCODEC_VERIFY_COMPRESSION
chd_decompressor::ptr m_decompressor[4]; // array of active codecs
std::vector<uint8_t> m_decompressed; // verification buffer
#endif
};
//**************************************************************************
// MACROS
//**************************************************************************
constexpr chd_codec_type CHD_MAKE_TAG(char a, char b, char c, char d)
{
return (uint32_t(uint8_t(a)) << 24) | uint32_t(uint8_t((b)) << 16) | uint32_t(uint8_t((c)) << 8) | uint32_t(uint8_t(d));
}
//**************************************************************************
// CONSTANTS
//**************************************************************************
// currently-defined codecs
constexpr chd_codec_type CHD_CODEC_NONE = 0;
// general codecs
constexpr chd_codec_type CHD_CODEC_ZLIB = CHD_MAKE_TAG('z','l','i','b');
constexpr chd_codec_type CHD_CODEC_ZSTD = CHD_MAKE_TAG('z','s','t','d');
constexpr chd_codec_type CHD_CODEC_LZMA = CHD_MAKE_TAG('l','z','m','a');
constexpr chd_codec_type CHD_CODEC_HUFFMAN = CHD_MAKE_TAG('h','u','f','f');
constexpr chd_codec_type CHD_CODEC_FLAC = CHD_MAKE_TAG('f','l','a','c');
// general codecs with CD frontend
constexpr chd_codec_type CHD_CODEC_CD_ZLIB = CHD_MAKE_TAG('c','d','z','l');
constexpr chd_codec_type CHD_CODEC_CD_ZSTD = CHD_MAKE_TAG('c','d','z','s');
constexpr chd_codec_type CHD_CODEC_CD_LZMA = CHD_MAKE_TAG('c','d','l','z');
constexpr chd_codec_type CHD_CODEC_CD_FLAC = CHD_MAKE_TAG('c','d','f','l');
// A/V codecs
constexpr chd_codec_type CHD_CODEC_AVHUFF = CHD_MAKE_TAG('a','v','h','u');
// A/V codec configuration parameters
enum
{
AVHUFF_CODEC_DECOMPRESS_CONFIG = 1
};
#endif // MAME_LIB_UTIL_CHDCODEC_H
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