piper_impl.hpp

#ifndef PIPER_IMPL_H_
#define PIPER_IMPL_H_

#include "json.hpp"
#include "uni_algo.h"

#include <map>
#include <memory>
#include <optional>
#include <queue>
#include <stdint.h>
#include <string>
#include <vector>

#include <onnxruntime_cxx_api.h>

typedef char32_t Phoneme;
typedef int64_t PhonemeId;
typedef int64_t SpeakerId;
typedef std::map<Phoneme, std::vector<PhonemeId>> PhonemeIdMap;

const PhonemeId ID_PAD = 0; // interleaved
const PhonemeId ID_BOS = 1; // beginning of sentence
const PhonemeId ID_EOS = 2; // end of sentence

const Phoneme PHONEME_PAD = U'_';
const Phoneme PHONEME_BOS = U'^';
const Phoneme PHONEME_EOS = U'$';
const Phoneme PHONEME_SEPARATOR = 0;

const float DEFAULT_LENGTH_SCALE = 1.0f;
const float DEFAULT_NOISE_SCALE = 0.667f;
const float DEFAULT_NOISE_W_SCALE = 0.8f;

const int DEFAULT_HOP_LENGTH = 256;

// onnx
Ort::Env ort_env{ORT_LOGGING_LEVEL_WARNING, "piper"};

// espeak
#define CLAUSE_INTONATION_FULL_STOP 0x00000000
#define CLAUSE_INTONATION_COMMA 0x00001000
#define CLAUSE_INTONATION_QUESTION 0x00002000
#define CLAUSE_INTONATION_EXCLAMATION 0x00003000

#define CLAUSE_TYPE_CLAUSE 0x00040000
#define CLAUSE_TYPE_SENTENCE 0x00080000
#define CLAUSE_TYPE_EOF 0x00010000

#define CLAUSE_INTONATION_TYPE 0x00007000
#define CLAUSE_PAUSE 0x00000FFF

#define CLAUSE_PERIOD (40 | CLAUSE_INTONATION_FULL_STOP | CLAUSE_TYPE_SENTENCE)
#define CLAUSE_COMMA (20 | CLAUSE_INTONATION_COMMA | CLAUSE_TYPE_CLAUSE)
#define CLAUSE_QUESTION (40 | CLAUSE_INTONATION_QUESTION | CLAUSE_TYPE_SENTENCE)
#define CLAUSE_EXCLAMATION                                                     \
    (45 | CLAUSE_INTONATION_EXCLAMATION | CLAUSE_TYPE_SENTENCE)
#define CLAUSE_COLON (30 | CLAUSE_INTONATION_FULL_STOP | CLAUSE_TYPE_CLAUSE)
#define CLAUSE_SEMICOLON (30 | CLAUSE_INTONATION_COMMA | CLAUSE_TYPE_CLAUSE)

#define EXCLAMATION_PAUSE (CLAUSE_EXCLAMATION & CLAUSE_PAUSE)
#define PERIOD_PAUSE (CLAUSE_PERIOD & CLAUSE_PAUSE)
#define SEMICOLON_PAUSE (CLAUSE_SEMICOLON & CLAUSE_PAUSE)
#define COMMA_PAUSE (CLAUSE_COMMA & CLAUSE_PAUSE)

struct piper_synthesizer {
    // From config JSON file
    std::string espeak_voice;
    int sample_rate;
    int num_speakers;
    PhonemeIdMap phoneme_id_map;
    int hop_length = DEFAULT_HOP_LENGTH;

    // Default synthesis settings for the voice
    float synth_length_scale = DEFAULT_LENGTH_SCALE;
    float synth_noise_scale = DEFAULT_NOISE_SCALE;
    float synth_noise_w_scale = DEFAULT_NOISE_W_SCALE;

    // onnx
    std::unique_ptr<Ort::Session> session;
    Ort::AllocatorWithDefaultOptions session_allocator;
    Ort::SessionOptions session_options;
    Ort::Env session_env;

    // synthesize state
    std::queue<std::pair<std::vector<Phoneme>, std::vector<PhonemeId>>>
        phoneme_id_queue;
    std::vector<float> chunk_samples;
    std::vector<int> chunk_phoneme_ids;
    std::vector<Phoneme> chunk_phonemes;
    std::vector<int> chunk_alignments;
    float length_scale = DEFAULT_LENGTH_SCALE;
    float noise_scale = DEFAULT_NOISE_SCALE;
    float noise_w_scale = DEFAULT_NOISE_W_SCALE;
    SpeakerId speaker_id = 0;
};

// Get the first UTF-8 codepoint of a string
std::optional<Phoneme> get_codepoint(std::string s) {
    auto view = una::views::utf8(s);
    auto it = view.begin();

    if (it != view.end()) {
        return *it;
    }

    return std::nullopt;
}

#endif // PIPER_IMPL_H_