native.cpp

#include "napi.h"
#include "common.h"

#include "whisper.h"

#include <string>
#include <thread>
#include <utility>
#include <vector>
#include <cmath>
#include <cstdint>

struct whisper_params {
    int32_t n_threads = std::min(4, (int32_t) std::thread::hardware_concurrency());
    int32_t n_processors = 1;
    int32_t offset_t_ms = 0;
    int32_t duration_ms = 0;
    int32_t offset_n = 0;
    int32_t max_context = -1;
    int32_t max_len = 0;
    int32_t best_of = 5;
    int32_t beam_size = -1;

    float word_thold = 0.01f;
    float entropy_thold = 2.4f;
    float logprob_thold = -1.0f;

    bool speed_up = false;
    bool translate = false;
    bool diarize = false;
    bool output_txt = false;
    bool output_vtt = false;
    bool output_srt = false;
    bool output_wts = false;
    bool output_csv = false;
    bool print_special = false;
    bool print_colors = false;
    bool print_progress = false;
    bool no_timestamps = false;

    std::string language = "en";
    std::string prompt;
    std::string model = "../../ggml-large.bin";

    std::vector<std::string> fname_inp = {};
    std::vector<std::string> fname_out = {};
};

struct whisper_print_user_data {
    const whisper_params *params;

    const std::vector<std::vector<float>> *pcmf32s;
};

//  500 -> 00:05.000
// 6000 -> 01:00.000
std::string to_timestamp(int64_t t, bool comma = false) {
    int64_t msec = t * 10;
    int64_t hr = msec / (1000 * 60 * 60);
    msec = msec - hr * (1000 * 60 * 60);
    int64_t min = msec / (1000 * 60);
    msec = msec - min * (1000 * 60);
    int64_t sec = msec / 1000;
    msec = msec - sec * 1000;

    char buf[32];
    snprintf(buf, sizeof(buf), "%02d:%02d:%02d%s%03d", (int) hr, (int) min, (int) sec, comma ? "," : ".", (int) msec);

    return std::string(buf);
}

int timestamp_to_sample(int64_t t, int n_samples) {
    return std::max(0, std::min((int) n_samples - 1, (int) ((t * WHISPER_SAMPLE_RATE) / 100)));
}

void
whisper_print_segment_callback(struct whisper_context *ctx, struct whisper_state *state, int n_new, void *user_data) {
    const auto &params = *((whisper_print_user_data *) user_data)->params;
    const auto &pcmf32s = *((whisper_print_user_data *) user_data)->pcmf32s;

    const int n_segments = whisper_full_n_segments(ctx);

    std::string speaker = "";

    int64_t t0;
    int64_t t1;

    // print the last n_new segments
    const int s0 = n_segments - n_new;

    if (s0 == 0) {
        printf("\n");
    }

    for (int i = s0; i < n_segments; i++) {
        if (!params.no_timestamps || params.diarize) {
            t0 = whisper_full_get_segment_t0(ctx, i);
            t1 = whisper_full_get_segment_t1(ctx, i);
        }

        if (!params.no_timestamps) {
            printf("[%s --> %s]  ", to_timestamp(t0).c_str(), to_timestamp(t1).c_str());
        }

        if (params.diarize && pcmf32s.size() == 2) {
            const int64_t n_samples = pcmf32s[0].size();

            const int64_t is0 = timestamp_to_sample(t0, n_samples);
            const int64_t is1 = timestamp_to_sample(t1, n_samples);

            double energy0 = 0.0f;
            double energy1 = 0.0f;

            for (int64_t j = is0; j < is1; j++) {
                energy0 += fabs(pcmf32s[0][j]);
                energy1 += fabs(pcmf32s[1][j]);
            }

            if (energy0 > 1.1 * energy1) {
                speaker = "(speaker 0)";
            } else if (energy1 > 1.1 * energy0) {
                speaker = "(speaker 1)";
            } else {
                speaker = "(speaker ?)";
            }

            //printf("is0 = %lld, is1 = %lld, energy0 = %f, energy1 = %f, %s\n", is0, is1, energy0, energy1, speaker.c_str());
        }

        // colorful print bug
        //
        const char *text = whisper_full_get_segment_text(ctx, i);
        printf("%s%s", speaker.c_str(), text);


        // with timestamps or speakers: each segment on new line
        if (!params.no_timestamps || params.diarize) {
            printf("\n");
        }

        fflush(stdout);
    }
}

int run(whisper_params &params, std::vector<std::vector<std::string>> &result) {
    if (params.fname_inp.empty()) {
        fprintf(stderr, "error: no input files specified\n");
        return 2;
    }

    if (params.language != "auto" && whisper_lang_id(params.language.c_str()) == -1) {
        fprintf(stderr, "error: unknown language '%s'\n", params.language.c_str());
        exit(0);
    }

    // whisper init

    struct whisper_context *ctx = whisper_init_from_file(params.model.c_str());

    if (ctx == nullptr) {
        fprintf(stderr, "error: failed to initialize whisper context\n");
        return 3;
    }

    for (int f = 0; f < (int) params.fname_inp.size(); ++f) {
        const auto fname_inp = params.fname_inp[f];
        const auto fname_out = f < (int) params.fname_out.size() && !params.fname_out[f].empty() ? params.fname_out[f]
                                                                                                 : params.fname_inp[f];

        std::vector<float> pcmf32; // mono-channel F32 PCM
        std::vector<std::vector<float>> pcmf32s; // stereo-channel F32 PCM

        if (!::read_wav(fname_inp, pcmf32, pcmf32s, params.diarize)) {
            fprintf(stderr, "error: failed to read WAV file '%s'\n", fname_inp.c_str());
            continue;
        }

        // print system information
        {
            fprintf(stderr, "\n");
            fprintf(stderr, "system_info: n_threads = %d / %d | %s\n",
                    params.n_threads * params.n_processors, std::thread::hardware_concurrency(),
                    whisper_print_system_info());
        }

        // print some info about the processing
        {
            fprintf(stderr, "\n");
            if (!whisper_is_multilingual(ctx)) {
                if (params.language != "en" || params.translate) {
                    params.language = "en";
                    params.translate = false;
                    fprintf(stderr,
                            "%s: WARNING: model is not multilingual, ignoring language and translation options\n",
                            __func__);
                }
            }
            fprintf(stderr,
                    "%s: processing '%s' (%d samples, %.1f sec), %d threads, %d processors, lang = %s, task = %s, timestamps = %d ...\n",
                    __func__, fname_inp.c_str(), int(pcmf32.size()), float(pcmf32.size()) / WHISPER_SAMPLE_RATE,
                    params.n_threads, params.n_processors,
                    params.language.c_str(),
                    params.translate ? "translate" : "transcribe",
                    params.no_timestamps ? 0 : 1);

            fprintf(stderr, "\n");
        }

        // run the inference
        {
            whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);

            wparams.strategy = params.beam_size > 1 ? WHISPER_SAMPLING_BEAM_SEARCH : WHISPER_SAMPLING_GREEDY;

            wparams.print_realtime = false;
            wparams.print_progress = params.print_progress;
            if (!wparams.print_progress)
                fprintf(stderr, "print progress is disabled\n");
            wparams.print_timestamps = !params.no_timestamps;
            wparams.print_special = params.print_special;
            wparams.translate = params.translate;
            wparams.language = params.language.c_str();
            wparams.n_threads = params.n_threads;
            wparams.n_max_text_ctx = params.max_context >= 0 ? params.max_context : wparams.n_max_text_ctx;
            wparams.offset_ms = params.offset_t_ms;
            wparams.duration_ms = params.duration_ms;

            wparams.token_timestamps = params.output_wts || params.max_len > 0;
            wparams.thold_pt = params.word_thold;
            wparams.entropy_thold = params.entropy_thold;
            wparams.logprob_thold = params.logprob_thold;
            wparams.max_len = params.output_wts && params.max_len == 0 ? 60 : params.max_len;

            wparams.speed_up = params.speed_up;

            wparams.greedy.best_of = params.best_of;
            wparams.beam_search.beam_size = params.beam_size;

            wparams.initial_prompt = params.prompt.c_str();

            whisper_print_user_data user_data = {&params, &pcmf32s};

            // this callback is called on each new segment
            if (!wparams.print_realtime) {
                wparams.new_segment_callback = whisper_print_segment_callback;
                wparams.new_segment_callback_user_data = &user_data;
            }

            // example for abort mechanism
            // in this example, we do not abort the processing, but we could if the flag is set to true
            // the callback is called before every encoder run - if it returns false, the processing is aborted
            {
                static bool is_aborted = false; // NOTE: this should be atomic to avoid data race

                wparams.encoder_begin_callback = [](struct whisper_context * /*ctx*/, struct whisper_state * /*state*/,
                                                    void *user_data) {
                    bool is_aborted = *(bool *) user_data;
                    return !is_aborted;
                };
                wparams.encoder_begin_callback_user_data = &is_aborted;
            }

            if (whisper_full_parallel(ctx, wparams, pcmf32.data(), pcmf32.size(), params.n_processors) != 0) {
                fprintf(stderr, "failed to process audio\n");
                return 10;
            }
        }
    }

    const int n_segments = whisper_full_n_segments(ctx);
    result.resize(n_segments);
    for (int i = 0; i < n_segments; ++i) {
        const char *text = whisper_full_get_segment_text(ctx, i);
        const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
        const int64_t t1 = whisper_full_get_segment_t1(ctx, i);

        result[i].emplace_back(to_timestamp(t0, true));
        result[i].emplace_back(to_timestamp(t1, true));
        result[i].emplace_back(text);
    }

    whisper_print_timings(ctx);
    whisper_free(ctx);

    return 0;
}

class Worker : public Napi::AsyncWorker {
public:
    Worker(Napi::Function &callback, whisper_params params)
            : Napi::AsyncWorker(callback), params(std::move(params)) {}

    void Execute() override {
        int response = run(params, result);
        if (response > 0) {
            if (response == 2) {
                SetError("no input files specified");
            } else if (response == 3) {
                SetError("failed to load model");
            } else if (response == 10) {
                SetError("failed to process audio");
            }
        }
    }

    void OnOK() override {
        Napi::HandleScope scope(Env());
        Napi::Object res = Napi::Array::New(Env(), result.size());
        for (uint64_t i = 0; i < result.size(); ++i) {
            Napi::Object tmp = Napi::Array::New(Env(), 3);
            for (uint64_t j = 0; j < 3; ++j) {
                tmp[j] = Napi::String::New(Env(), result[i][j]);
            }
            res[i] = tmp;
        }
        Callback().Call({Env().Null(), res});
    }

private:
    whisper_params params;
    std::vector<std::vector<std::string>> result;
};


Napi::Value whisper(const Napi::CallbackInfo &info) {
    Napi::Env env = info.Env();
    if (info.Length() <= 0 || !info[0].IsObject()) {
        Napi::TypeError::New(env, "object expected").ThrowAsJavaScriptException();
    }
    whisper_params params;

    Napi::Object whisper_params = info[0].As<Napi::Object>();
    int32_t n_threads = whisper_params.Get("n_threads").As<Napi::Number>();
    int32_t n_processors = whisper_params.Get("n_processors").As<Napi::Number>();
    int32_t offset_t_ms = whisper_params.Get("offset_t_ms").As<Napi::Number>();
    int32_t duration_ms = whisper_params.Get("duration_ms").As<Napi::Number>();
    int32_t offset_n = whisper_params.Get("offset_n").As<Napi::Number>();
    int32_t max_context = whisper_params.Get("max_context").As<Napi::Number>();
    int32_t max_len = whisper_params.Get("max_len").As<Napi::Number>();
    int32_t best_of = whisper_params.Get("best_of").As<Napi::Number>();
    int32_t beam_size = whisper_params.Get("beam_size").As<Napi::Number>();
    float word_thold = whisper_params.Get("word_thold").As<Napi::Number>();
    float entropy_thold = whisper_params.Get("entropy_thold").As<Napi::Number>();
    float logprob_thold = whisper_params.Get("logprob_thold").As<Napi::Number>();
    bool speed_up = whisper_params.Get("speed_up").As<Napi::Boolean>();
    bool translate = whisper_params.Get("translate").As<Napi::Boolean>();
    bool diarize = whisper_params.Get("diarize").As<Napi::Boolean>();
    bool output_txt = whisper_params.Get("output_txt").As<Napi::Boolean>();
    bool output_vtt = whisper_params.Get("output_vtt").As<Napi::Boolean>();
    bool output_srt = whisper_params.Get("output_srt").As<Napi::Boolean>();
    bool output_wts = whisper_params.Get("output_wts").As<Napi::Boolean>();
    bool output_csv = whisper_params.Get("output_csv").As<Napi::Boolean>();
    bool print_special = whisper_params.Get("print_special").As<Napi::Boolean>();
    bool print_colors = whisper_params.Get("print_colors").As<Napi::Boolean>();
    bool print_progress = whisper_params.Get("print_progress").As<Napi::Boolean>();
    bool no_timestamps = whisper_params.Get("no_timestamps").As<Napi::Boolean>();

    std::string language = whisper_params.Get("language").As<Napi::String>();
    std::string model = whisper_params.Get("model").As<Napi::String>();
    std::string input = whisper_params.Get("fname_inp").As<Napi::String>();
    std::string output = whisper_params.Get("fname_out").As<Napi::String>();
    std::string prompt = whisper_params.Get("prompt").As<Napi::String>();

    params.language = language;
    params.model = model;
    params.fname_inp.emplace_back(input);
    if (!output.empty())
        params.fname_out.emplace_back(output);
    if (!prompt.empty())
        params.prompt = prompt;
    if (n_threads > 0)
        params.n_threads = n_threads;
    if (n_processors > 0)
        params.n_processors = n_processors;
    if (offset_t_ms > 0)
        params.offset_t_ms = offset_t_ms;
    if (offset_n > 0)
        params.offset_n = offset_n;
    if (duration_ms > 0)
        params.duration_ms = duration_ms;
    if (max_context > 0)
        params.max_context = max_context;
    if (max_len > 0)
        params.max_len = max_len;
    if (best_of > 0)
        params.best_of = best_of;
    if (beam_size > -1)
        params.beam_size = beam_size;
    if (word_thold > 0.01f)
        params.word_thold = word_thold;
    if (entropy_thold > 0.01f)
        params.entropy_thold = entropy_thold;
    if (logprob_thold > 0.01f)
        params.logprob_thold = logprob_thold;
    params.speed_up = speed_up;
    params.translate = translate;
    params.diarize = diarize;
    params.output_txt = output_txt;
    params.output_wts = output_wts;
    params.output_csv = output_csv;
    params.output_srt = output_srt;
    params.output_vtt = output_vtt;
    params.print_progress = print_progress;
    params.print_special = print_special;
    params.print_colors = print_colors;
    params.no_timestamps = no_timestamps;


    Napi::Function callback = info[1].As<Napi::Function>();
    Worker *worker = new Worker(callback, params);
    worker->Queue();
    return env.Undefined();
}


Napi::Object Init(Napi::Env env, Napi::Object exports) {
    exports.Set(
            Napi::String::New(env, "whisper"),
            Napi::Function::New(env, whisper)
    );
    return exports;
}

NODE_API_MODULE(whisper, Init
);