whisper.cpp/examples/main/main.cpp

#include "whisper.h"

// third-party utilities
// use your favorite implementations
#define DR_WAV_IMPLEMENTATION
#include "dr_wav.h"

#include <cmath>
#include <fstream>
#include <cstdio>
#include <string>
#include <thread>
#include <vector>

// Terminal color map. 10 colors grouped in ranges [0.0, 0.1, ..., 0.9]
// Lowest is red, middle is yellow, highest is green.
const std::vector<std::string> k_colors = {
    "\033[38;5;196m", "\033[38;5;202m", "\033[38;5;208m", "\033[38;5;214m", "\033[38;5;220m",
    "\033[38;5;226m", "\033[38;5;190m", "\033[38;5;154m", "\033[38;5;118m", "\033[38;5;82m",
};

//  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);
}

// helper function to replace substrings
void replace_all(std::string & s, const std::string & search, const std::string & replace) {
    for (size_t pos = 0; ; pos += replace.length()) {
        pos = s.find(search, pos);
        if (pos == std::string::npos) break;
        s.erase(pos, search.length());
        s.insert(pos, replace);
    }
}

// command-line parameters
struct whisper_params {
    int32_t seed         = -1; // RNG seed, not used currently
    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 offset_n     = 0;
    int32_t max_context  = -1;
    int32_t max_len      = 0;

    float word_thold = 0.01f;

    bool verbose              = false;
    bool translate            = false;
    bool output_txt           = false;
    bool output_vtt           = false;
    bool output_srt           = false;
    bool output_wts           = false;
    bool print_special_tokens = false;
    bool print_colors         = false;
    bool no_timestamps        = false;

    std::string language  = "en";
    std::string model     = "models/ggml-base.en.bin";

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

void whisper_print_usage(int argc, char ** argv, const whisper_params & params);

bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
    for (int i = 1; i < argc; i++) {
        std::string arg = argv[i];

        if (arg[0] != '-') {
            params.fname_inp.push_back(arg);
            continue;
        }

        if (arg == "-s" || arg == "--seed") {
            params.seed = std::stoi(argv[++i]);
        } else if (arg == "-t" || arg == "--threads") {
            params.n_threads = std::stoi(argv[++i]);
        } else if (arg == "-p" || arg == "--processors") {
            params.n_processors = std::stoi(argv[++i]);
        } else if (arg == "-ot" || arg == "--offset-t") {
            params.offset_t_ms = std::stoi(argv[++i]);
        } else if (arg == "-on" || arg == "--offset-n") {
            params.offset_n = std::stoi(argv[++i]);
        } else if (arg == "-mc" || arg == "--max-context") {
            params.max_context = std::stoi(argv[++i]);
        } else if (arg == "-ml" || arg == "--max-len") {
            params.max_len = std::stoi(argv[++i]);
        } else if (arg == "-wt" || arg == "--word-thold") {
            params.word_thold = std::stof(argv[++i]);
        } else if (arg == "-v" || arg == "--verbose") {
            params.verbose = true;
        } else if (arg == "--translate") {
            params.translate = true;
        } else if (arg == "-l" || arg == "--language") {
            params.language = argv[++i];
            if (whisper_lang_id(params.language.c_str()) == -1) {
                fprintf(stderr, "error: unknown language '%s'\n", params.language.c_str());
                whisper_print_usage(argc, argv, params);
                exit(0);
            }
        } else if (arg == "-otxt" || arg == "--output-txt") {
            params.output_txt = true;
        } else if (arg == "-ovtt" || arg == "--output-vtt") {
            params.output_vtt = true;
        } else if (arg == "-osrt" || arg == "--output-srt") {
            params.output_srt = true;
        } else if (arg == "-owts" || arg == "--output-words") {
            params.output_wts = true;
        } else if (arg == "-ps" || arg == "--print_special") {
            params.print_special_tokens = true;
        } else if (arg == "-pc" || arg == "--print_colors") {
            params.print_colors = true;
        } else if (arg == "-nt" || arg == "--no_timestamps") {
            params.no_timestamps = true;
        } else if (arg == "-m" || arg == "--model") {
            params.model = argv[++i];
        } else if (arg == "-f" || arg == "--file") {
            params.fname_inp.push_back(argv[++i]);
        } else if (arg == "-h" || arg == "--help") {
            whisper_print_usage(argc, argv, params);
            exit(0);
        } else {
            fprintf(stderr, "error: unknown argument: %s\n", arg.c_str());
            whisper_print_usage(argc, argv, params);
            exit(0);
        }
    }

    return true;
}

void whisper_print_usage(int argc, char ** argv, const whisper_params & params) {
    fprintf(stderr, "\n");
    fprintf(stderr, "usage: %s [options] file0.wav file1.wav ...\n", argv[0]);
    fprintf(stderr, "\n");
    fprintf(stderr, "options:\n");
    fprintf(stderr, "  -h,       --help           show this help message and exit\n");
    fprintf(stderr, "  -s SEED,  --seed SEED      RNG seed (default: -1)\n");
    fprintf(stderr, "  -t N,     --threads N      number of threads to use during computation (default: %d)\n", params.n_threads);
    fprintf(stderr, "  -p N,     --processors N   number of processors to use during computation (default: %d)\n", params.n_processors);
    fprintf(stderr, "  -ot N,    --offset-t N     time offset in milliseconds (default: %d)\n", params.offset_t_ms);
    fprintf(stderr, "  -on N,    --offset-n N     segment index offset (default: %d)\n", params.offset_n);
    fprintf(stderr, "  -mc N,    --max-context N  maximum number of text context tokens to store (default: max)\n");
    fprintf(stderr, "  -ml N,    --max-len N      maximum segment length in characters (default: %d)\n", params.max_len);
    fprintf(stderr, "  -wt N,    --word-thold N   word timestamp probability threshold (default: %f)\n", params.word_thold);
    fprintf(stderr, "  -v,       --verbose        verbose output\n");
    fprintf(stderr, "            --translate      translate from source language to english\n");
    fprintf(stderr, "  -otxt,    --output-txt     output result in a text file\n");
    fprintf(stderr, "  -ovtt,    --output-vtt     output result in a vtt file\n");
    fprintf(stderr, "  -osrt,    --output-srt     output result in a srt file\n");
    fprintf(stderr, "  -owts,    --output-words   output script for generating karaoke video\n");
    fprintf(stderr, "  -ps,      --print_special  print special tokens\n");
    fprintf(stderr, "  -pc,      --print_colors   print colors\n");
    fprintf(stderr, "  -nt,      --no_timestamps  do not print timestamps\n");
    fprintf(stderr, "  -l LANG,  --language LANG  spoken language (default: %s)\n", params.language.c_str());
    fprintf(stderr, "  -m FNAME, --model FNAME    model path (default: %s)\n", params.model.c_str());
    fprintf(stderr, "  -f FNAME, --file FNAME     input WAV file path\n");
    fprintf(stderr, "\n");
}

void whisper_print_segment_callback(struct whisper_context * ctx, int n_new, void * user_data) {
    const whisper_params & params = *(whisper_params *) user_data;

    const int n_segments = whisper_full_n_segments(ctx);

    // 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) {
            if (params.print_colors) {
                for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
                    if (params.print_special_tokens == false) {
                        const whisper_token id = whisper_full_get_token_id(ctx, i, j);
                        if (id >= whisper_token_eot(ctx)) {
                            continue;
                        }
                    }

                    const char * text = whisper_full_get_token_text(ctx, i, j);
                    const float  p    = whisper_full_get_token_p   (ctx, i, j);

                    const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));

                    printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
                }
            } else {
                const char * text = whisper_full_get_segment_text(ctx, i);
                printf("%s", text);
            }
            fflush(stdout);
        } else {
            const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
            const int64_t t1 = whisper_full_get_segment_t1(ctx, i);

            if (params.print_colors) {
                printf("[%s --> %s]  ", to_timestamp(t0).c_str(), to_timestamp(t1).c_str());
                for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
                    if (params.print_special_tokens == false) {
                        const whisper_token id = whisper_full_get_token_id(ctx, i, j);
                        if (id >= whisper_token_eot(ctx)) {
                            continue;
                        }
                    }

                    const char * text = whisper_full_get_token_text(ctx, i, j);
                    const float  p    = whisper_full_get_token_p   (ctx, i, j);

                    const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));

                    printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
                }
                printf("\n");
            } else {
                const char * text = whisper_full_get_segment_text(ctx, i);

                printf("[%s --> %s]  %s\n", to_timestamp(t0).c_str(), to_timestamp(t1).c_str(), text);
            }
        }
    }
}

bool output_txt(struct whisper_context * ctx, const char * fname) {
    std::ofstream fout(fname);
    if (!fout.is_open()) {
        fprintf(stderr, "%s: failed to open '%s' for writing\n", __func__, fname);
        return false;
    }

    fprintf(stderr, "%s: saving output to '%s'\n", __func__, fname);

    const int n_segments = whisper_full_n_segments(ctx);
    for (int i = 0; i < n_segments; ++i) {
        const char * text = whisper_full_get_segment_text(ctx, i);
        fout << text;
    }

    return true;
}

bool output_vtt(struct whisper_context * ctx, const char * fname) {
    std::ofstream fout(fname);
    if (!fout.is_open()) {
        fprintf(stderr, "%s: failed to open '%s' for writing\n", __func__, fname);
        return 9;
    }

    fprintf(stderr, "%s: saving output to '%s'\n", __func__, fname);

    fout << "WEBVTT\n\n";

    const int n_segments = whisper_full_n_segments(ctx);
    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);

        fout << to_timestamp(t0) << " --> " << to_timestamp(t1) << "\n";
        fout << text << "\n\n";
    }

    return true;
}

bool output_srt(struct whisper_context * ctx, const char * fname, const whisper_params & params) {
    std::ofstream fout(fname);
    if (!fout.is_open()) {
        fprintf(stderr, "%s: failed to open '%s' for writing\n", __func__, fname);
        return false;
    }

    fprintf(stderr, "%s: saving output to '%s'\n", __func__, fname);

    const int n_segments = whisper_full_n_segments(ctx);
    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);

        fout << i + 1 + params.offset_n << "\n";
        fout << to_timestamp(t0, true) << " --> " << to_timestamp(t1, true) << "\n";
        fout << text << "\n\n";
    }

    return true;
}

// karaoke video generation
// outputs a bash script that uses ffmpeg to generate a video with the subtitles
// TODO: font parameter adjustments
bool output_wts(struct whisper_context * ctx, const char * fname, const char * fname_inp, const whisper_params & params, float t_sec) {
    std::ofstream fout(fname);

    fprintf(stderr, "%s: saving output to '%s'\n", __func__, fname);

    // TODO: become parameter
    static const char * font = "/System/Library/Fonts/Supplemental/Courier New Bold.ttf";

    fout << "!/bin/bash" << "\n";
    fout << "\n";

    fout << "ffmpeg -i " << fname_inp << " -f lavfi -i color=size=1200x120:duration=" << t_sec << ":rate=25:color=black -vf \"";

    for (int i = 0; i < whisper_full_n_segments(ctx); i++) {
        const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
        const int64_t t1 = whisper_full_get_segment_t1(ctx, i);

        const int n = whisper_full_n_tokens(ctx, i);

        std::vector<whisper_token_data> tokens(n);
        for (int j = 0; j < n; ++j) {
            tokens[j] = whisper_full_get_token_data(ctx, i, j);
        }

        if (i > 0) {
            fout << ",";
        }

        // background text
        fout << "drawtext=fontfile='" << font << "':fontsize=24:fontcolor=gray:x=(w-text_w)/2:y=h/2:text='':enable='between(t," << t0/100.0 << "," << t0/100.0 << ")'";

        bool is_first = true;

        for (int j = 0; j < n; ++j) {
            const auto & token = tokens[j];

            if (tokens[j].id >= whisper_token_eot(ctx)) {
                continue;
            }

            std::string txt_bg;
            std::string txt_fg; // highlight token
            std::string txt_ul; // underline

            txt_bg = "> ";
            txt_fg = "> ";
            txt_ul = "\\ \\ ";

            {
                int ncnt = 0;
                for (int k = 0; k < n; ++k) {
                    const auto & token2 = tokens[k];

                    if (tokens[k].id >= whisper_token_eot(ctx)) {
                        continue;
                    }

                    const std::string txt = whisper_token_to_str(ctx, token2.id);

                    txt_bg += txt;

                    if (k == j) {
                        for (int l = 0; l < (int) txt.size(); ++l) {
                            txt_fg += txt[l];
                            txt_ul += "_";
                        }
                        txt_fg += "|";
                    } else {
                        for (int l = 0; l < (int) txt.size(); ++l) {
                            txt_fg += "\\ ";
                            txt_ul += "\\ ";
                        }
                    }

                    ncnt += txt.size();
                }

                ::replace_all(txt_bg, "'", "’");
                ::replace_all(txt_bg, "\"", "\\\"");
                ::replace_all(txt_fg, "'", "’");
                ::replace_all(txt_fg, "\"", "\\\"");
            }

            if (is_first) {
                // background text
                fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=gray:x=(w-text_w)/2:y=h/2:text='" << txt_bg << "':enable='between(t," << t0/100.0 << "," << t1/100.0 << ")'";
                is_first = false;
            }

            // foreground text
            fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=lightgreen:x=(w-text_w)/2+8:y=h/2:text='" << txt_fg << "':enable='between(t," << token.t0/100.0 << "," << token.t1/100.0 << ")'";

            // underline
            fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=lightgreen:x=(w-text_w)/2+8:y=h/2+16:text='" << txt_ul << "':enable='between(t," << token.t0/100.0 << "," << token.t1/100.0 << ")'";
        }
    }

    fout << "\" -c:v libx264 -pix_fmt yuv420p -y " << fname_inp << ".mp4" << "\n";

    fout << "\n\n";
    fout << "echo \"Your video has been saved to " << fname_inp << ".mp4\"" << "\n";
    fout << "\n";
    fout << "echo \"  ffplay " << fname_inp << ".mp4\"\n";
    fout << "\n";

    fout.close();

    fprintf(stderr, "%s: run 'source %s' to generate karaoke video\n", __func__, fname);

    return true;
}

int main(int argc, char ** argv) {
    whisper_params params;

    if (whisper_params_parse(argc, argv, params) == false) {
        return 1;
    }

    if (params.seed < 0) {
        params.seed = time(NULL);
    }

    if (params.fname_inp.empty()) {
        fprintf(stderr, "error: no input files specified\n");
        whisper_print_usage(argc, argv, params);
        return 2;
    }

    // whisper init

    struct whisper_context * ctx = whisper_init(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];

        // WAV input
        std::vector<float> pcmf32;
        {
            drwav wav;
            if (!drwav_init_file(&wav, fname_inp.c_str(), NULL)) {
                fprintf(stderr, "%s: failed to open WAV file '%s' - check your input\n", argv[0], fname_inp.c_str());
                whisper_print_usage(argc, argv, {});
                return 4;
            }

            if (wav.channels != 1 && wav.channels != 2) {
                fprintf(stderr, "%s: WAV file '%s' must be mono or stereo\n", argv[0], fname_inp.c_str());
                return 5;
            }

            if (wav.sampleRate != WHISPER_SAMPLE_RATE) {
                fprintf(stderr, "%s: WAV file '%s' must be 16 kHz\n", argv[0], fname_inp.c_str());
                return 6;
            }

            if (wav.bitsPerSample != 16) {
                fprintf(stderr, "%s: WAV file '%s' must be 16-bit\n", argv[0], fname_inp.c_str());
                return 7;
            }

            int n = wav.totalPCMFrameCount;

            std::vector<int16_t> pcm16;
            pcm16.resize(n*wav.channels);
            drwav_read_pcm_frames_s16(&wav, n, pcm16.data());
            drwav_uninit(&wav);

            // convert to mono, float
            pcmf32.resize(n);
            if (wav.channels == 1) {
                for (int i = 0; i < n; i++) {
                    pcmf32[i] = float(pcm16[i])/32768.0f;
                }
            } else {
                for (int i = 0; i < n; i++) {
                    pcmf32[i] = float(pcm16[2*i] + pcm16[2*i + 1])/65536.0f;
                }
            }
        }

        // 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.print_realtime       = false;
            wparams.print_progress       = false;
            wparams.print_timestamps     = !params.no_timestamps;
            wparams.print_special_tokens = params.print_special_tokens;
            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.token_timestamps     = params.output_wts || params.max_len > 0;
            wparams.thold_pt             = params.word_thold;
            wparams.max_len              = params.output_wts && params.max_len == 0 ? 60 : params.max_len;

            // 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 = &params;
            }

            if (whisper_full_parallel(ctx, wparams, pcmf32.data(), pcmf32.size(), params.n_processors) != 0) {
                fprintf(stderr, "%s: failed to process audio\n", argv[0]);
                return 8;
            }
        }

        // output stuff
        {
            printf("\n");

            // output to text file
            if (params.output_txt) {
                const auto fname_txt = fname_inp + ".txt";
                output_txt(ctx, fname_txt.c_str());
            }

            // output to VTT file
            if (params.output_vtt) {
                const auto fname_vtt = fname_inp + ".vtt";
                output_vtt(ctx, fname_vtt.c_str());
            }

            // output to SRT file
            if (params.output_srt) {
                const auto fname_srt = fname_inp + ".srt";
                output_srt(ctx, fname_srt.c_str(), params);
            }

            // output to WTS file
            if (params.output_wts) {
                const auto fname_wts = fname_inp + ".wts";
                output_wts(ctx, fname_wts.c_str(), fname_inp.c_str(), params, float(pcmf32.size() + 1000)/WHISPER_SAMPLE_RATE);
            }
        }
    }

    whisper_print_timings(ctx);
    whisper_free(ctx);

    return 0;
}