121 lines
2.0 KiB
C
121 lines
2.0 KiB
C
//
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// Created by bruno on 13. 7. 2026.
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//
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#ifndef AUDIOCODER_DECODER_H
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#define AUDIOCODER_DECODER_H
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#define MAX_BITS 16
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#define PREAMBLE_SYMBOLS 128
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#define DECODER_SAMPLE_HISTORY 262144
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#include <SDL_audio.h>
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#include <SDL_render.h>
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#include <stdint.h>
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#include "goertzel.h"
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typedef enum {
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RX_SEARCH,
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RX_ALIGN,
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RX_SYNC,
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RX_LOCKED
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} RxState;
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typedef struct {
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uint8_t bitCount;
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uint16_t startFreq;
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uint16_t endFreq;
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uint16_t dataSpacing;
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uint16_t clock0;
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uint16_t clock1;
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uint32_t symbolSamples;
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uint32_t sampleCount;
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float sampleHistory[DECODER_SAMPLE_HISTORY];
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uint32_t sampleHistoryWrite;
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uint32_t sampleHistoryCount;
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uint64_t totalSamples;
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Goertzel tones[MAX_BITS * 2 + 2];
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uint8_t currentByte;
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uint8_t bitIndex;
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uint8_t buffer[1024*1024*8];
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uint32_t bufferSize;
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bool lastClock;
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float energies[MAX_BITS * 2 + 2];
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float maxEnergy;
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float clockEnergy0;
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float clockEnergy1;
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float clockRatio;
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uint8_t lastDecodedByte;
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int bestSyncScore;
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int bestSyncPhase;
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RxState rxState;
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bool expectedClock;
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float lastClockEnergy;
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uint32_t goodClocks;
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uint32_t syncIndex;
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uint32_t badClocks;
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uint64_t phaseSearchStart;
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uint32_t phaseWait;
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int phaseOffset;
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bool phaseSearchReady;
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uint32_t searchOffset;
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uint32_t syncOffset;
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uint8_t clockHistory;
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uint8_t clockCount;
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bool locked;
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SDL_Renderer *renderer;
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} Decoder;
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void decoder_init(
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Decoder *dec
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);
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void decoder_process(
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Decoder *dec,
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float *samples,
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uint32_t count
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);
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void decoder_rebuild_tones(
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Decoder *dec
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);
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extern Decoder decoder;
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extern SDL_AudioDeviceID inputDev;
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extern const uint8_t syncBytes[4];
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// Internal audio bus for loopback
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#define INTERNAL_BUFFER_SIZE 262144
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extern float internalBusSamples[INTERNAL_BUFFER_SIZE];
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extern volatile uint32_t internalBusWrite;
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extern volatile uint32_t internalBusRead;
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void initAudioDecoder(SDL_Renderer *renderer);
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#endif //AUDIOCODER_DECODER_H
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