OXYGENHUB
◆ main openmsx / src / cassette / TsxParser.hh
5.0 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
1 
// Based on code written by:
2 
//   (2017) NataliaPC aka @ishwin74
3 
//   Under GPL License
4
5 
#ifndef TSXPARSER_HH
6 
#define TSXPARSER_HH
7
8 
#include "endian.hh"
9
10 
#include <array>
11 
#include <cstdint>
12 
#include <optional>
13 
#include <span>
14 
#include <string>
15 
#include <vector>
16
17 
class TsxParser {
18 
public:
19 
	// output settings
20 
	static constexpr unsigned TZX_Z80_FREQ       = 3500000; // 3.5MHz (according to TZX spec: not 3.579545MHz)
21 
	static constexpr unsigned OUTPUT_FREQUENCY   = 58900;   // ~ = Z80_FREQ * 4 / T_STATES_MSX_PULSE
22 
	static constexpr float    T_STATES_MSX_PULSE = 238.f;
23
24 
	enum class FileType : uint8_t {
25 
		ASCII, BINARY, BASIC, UNKNOWN,
26 
	};
27
28 
public:
29 
	explicit TsxParser(std::span<const uint8_t> file);
30
31 
	[[nodiscard]] std::vector<int8_t>&& stealOutput() { return std::move(output); }
32 
	[[nodiscard]] std::optional<FileType> getFirstFileType() const { return firstFileType; }
33 
	[[nodiscard]] const std::vector<std::string>& getMessages() const { return messages; }
34
35 
private:
36 
	struct Block10 {
37 
		Endian::UA_L16  pauseMs;     // Pause after this block in milliseconds
38 
		Endian::UA_L16  len;         // Length of data that follow
39 
		//uint8_t       data[];      // Data as in .TAP files
40 
	};
41 
	struct Block11 {
42 
		Endian::UA_L16  pilot;       // Length of PILOT pulse {2168}
43 
		Endian::UA_L16  sync1;       // Length of SYNC first pulse {667}
44 
		Endian::UA_L16  sync2;       // Length of SYNC second pulse {735}
45 
		Endian::UA_L16  zero;        // Length of ZERO bit pulse {855}
46 
		Endian::UA_L16  one;         // Length of ONE bit pulse {1710}
47 
		Endian::UA_L16  pilotLen;    // Length of PILOT tone (number of pulses) {8063 header (flag<128), 3223 data (flag>=128)}
48 
		uint8_t         lastBits;    // Used bits in the last byte (other bits should be 0) {8}
49 
		Endian::UA_L16  pauseMs;     // Pause after this block (ms.) {1000}
50 
		Endian::UA_L24  len;         // Length of data that follow
51 
		//uint8_t       data[];      // Data as in .TAP files
52 
	};
53 
	struct Block12 {
54 
		Endian::UA_L16  len;         // Length of one pulse in T-states
55 
		Endian::UA_L16  pulses;      // Number of pulses
56 
	};
57 
	struct Block13 {
58 
		uint8_t         num;         // Number of pulses
59 
		//Endian::UA_L16 pulses[];   // [Array] Pulses' lengths
60 
	};
61 
	struct Block15 {
62 
		Endian::UA_L16  bitTstates;  // Number of T-states per sample (bit of data)
63 
		Endian::UA_L16  pauseMs;     // Pause after this block (ms.) {1000}
64 
		uint8_t         lastBits;    // Used bits (samples) in last byte of data (1-8)
65 
		Endian::UA_L24  len;         // Length of samples data
66 
		//uint8_t       samples[];   // [Array] Samples data. Each bit represents a state on the EAR port (i.e. one sample). MSb is played first.
67 
	};
68 
	struct Block20 {
69 
		Endian::UA_L16  pauseMs;     // Silence pause in milliseconds
70 
	};
71 
	struct Block21 {
72 
		uint8_t         len;         // Length of the group name string
73 
		//char          name[];      // The group name (ASCII)
74 
	};
75 
	struct Block30 {
76 
		uint8_t         len;         // Length of the text description
77 
		//char          text[];      // [Array] Text description in ASCII format
78 
	};
79 
	struct Block32 {
80 
		Endian::UA_L16  blockLen;    // Length of the whole block (without these two bytes)
81 
		uint8_t         num;         // Number of text strings
82 
		//uint8_t       list[];      // [Array] List of text strings
83 
	};
84 
	struct Block35 {
85 
		std::array<char, 0x10> label;// Identification string (in ASCII)
86 
		Endian::UA_L32  len;         // Length of the custom info
87 
		//uint8_t       data[];      // [Array] Custom info
88 
	};
89 
	struct Block4B {
90 
		Endian::UA_L32  blockLen;    // Block length without these four bytes
91 
		Endian::UA_L16  pauseMs;     // Pause after this block in milliseconds
92 
		Endian::UA_L16  pilot;       // Duration of a PILOT pulse in T-states {same as ONE pulse}
93 
		Endian::UA_L16  pulses;      // Number of pulses in the PILOT tone
94 
		Endian::UA_L16  bit0len;     // Duration of a ZERO pulse in T-states {=2*pilot}
95 
		Endian::UA_L16  bit1len;     // Duration of a ONE pulse in T-states {=pilot}
96 
		uint8_t         bitCfg;
97 
		uint8_t         byteCfg;
98 
		//uint8_t       data[];      // [Array]
99 
	};
100
101 
	void processBlock10(const Block10& b);
102 
	void processBlock11(const Block11& b);
103 
	void processBlock12(const Block12& b);
104 
	void processBlock13(const Block13& b);
105 
	void processBlock15(const Block15& b);
106 
	void processBlock20(const Block20& b);
107 
	void processBlock21(const Block21& b);
108 
	void processBlock30(const Block30& b);
109 
	void processBlock32(const Block32& b);
110 
	void processBlock35(const Block35& b);
111 
	void processBlock4B(const Block4B& b);
112
113 
	void writeSample(uint32_t tStates, int8_t value);
114 
	void writePulse(uint32_t tStates);
115 
	void writePulses(uint32_t count, uint32_t tStates);
116 
	void writeSilence(int s);
117
118 
	template<typename T> std::span<const T> get(size_t count);
119 
	template<typename T> const T& get();
120
121 
	[[noreturn]] void error(std::string msg) const;
122
123 
private:
124 
	// The parsed result is stored here
125 
	std::vector<int8_t> output;
126 
	std::vector<std::string> messages;
127 
	std::optional<FileType> firstFileType;
128
129 
	// The (remaining) part of the input file
130 
	std::span<const uint8_t> buf;
131
132 
	// Intermediate state while writing the waveform
133 
	float  accumBytes = 0.f;
134 
	int8_t currentValue = 127;
135 
};
136
137 
#endif