开源C++智能语音识别库whisper.cpp开发使用入门

whisper.cpp是一个C++编写的轻量级开源智能语音识别库，是基于openai的开源python智能语音模型whisper的移植版本，依赖项少，内存占用低，性能更优，方便作为依赖库集成的到应用程序中提供语音识别功能。

以下基于whisper.cpp的源码利用C++ api来开发实例demo演示读取本地音频文件并转成文字。

项目结构

whispercpp_starter- whisper.cpp-v1.5.0- src|- main.cpp- CMakeLists.txt

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)# this only works for unix, xapian source code not support compile in windows yetproject(whispercpp_starter)set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)add_subdirectory(whisper.cpp-v1.5.0)include_directories(${CMAKE_CURRENT_SOURCE_DIR}/whisper.cpp-v1.5.0${CMAKE_CURRENT_SOURCE_DIR}/whisper.cpp-v1.5.0/examples
)file(GLOB SRCsrc/*.hsrc/*.cpp
)add_executable(${PROJECT_NAME} ${SRC})target_link_libraries(${PROJECT_NAME}commonwhisper # remember to copy dll or so to bin folder
)

main.cpp

#include <cmath>
#include <fstream>
#include <cstdio>
#include <string>
#include <thread>
#include <vector>
#include <cstring>#include "common.h"
#include "whisper.h"#if defined(_MSC_VER)
#pragma warning(disable: 4244 4267) // possible loss of data
#endif// 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);
}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)));
}// 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 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 duration_ms = 0;int32_t progress_step = 5;int32_t max_context = -1;int32_t max_len = 0;int32_t best_of = whisper_full_default_params(WHISPER_SAMPLING_GREEDY).greedy.best_of;int32_t beam_size = whisper_full_default_params(WHISPER_SAMPLING_BEAM_SEARCH).beam_search.beam_size;float word_thold = 0.01f;float entropy_thold = 2.40f;float logprob_thold = -1.00f;bool speed_up = false;bool debug_mode = false;bool translate = false;bool detect_language = false;bool diarize = false;bool tinydiarize = false;bool split_on_word = false;bool no_fallback = false;bool output_txt = false;bool output_vtt = false;bool output_srt = false;bool output_wts = false;bool output_csv = false;bool output_jsn = false;bool output_jsn_full = false;bool output_lrc = false;bool print_special = false;bool print_colors = false;bool print_progress = false;bool no_timestamps = false;bool log_score = false;bool use_gpu = true;std::string language = "en";std::string prompt;std::string font_path = "/System/Library/Fonts/Supplemental/Courier New Bold.ttf";std::string model = "models/ggml-base.en.bin";// [TDRZ] speaker turn stringstd::string tdrz_speaker_turn = " [SPEAKER_TURN]"; // TODO: set from command linestd::string openvino_encode_device = "CPU";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;int progress_prev;
};std::string estimate_diarization_speaker(std::vector<std::vector<float>> pcmf32s, int64_t t0, int64_t t1, bool id_only = false)
{std::string speaker = "";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 = "0";}else if (energy1 > 1.1 * energy0){speaker = "1";}else{speaker = "?";}//printf("is0 = %lld, is1 = %lld, energy0 = %f, energy1 = %f, speaker = %s\n", is0, is1, energy0, energy1, speaker.c_str());if (!id_only){speaker.insert(0, "(speaker ");speaker.append(")");}return speaker;
}
void whisper_print_progress_callback(struct whisper_context* /*ctx*/, struct whisper_state* /*state*/, int progress, void* user_data)
{int progress_step = ((whisper_print_user_data*)user_data)->params->progress_step;int* progress_prev = &(((whisper_print_user_data*)user_data)->progress_prev);if (progress >= *progress_prev + progress_step){*progress_prev += progress_step;fprintf(stderr, "%s: progress = %3d%%\n", __func__, progress);}
}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 = 0;int64_t t1 = 0;// print the last n_new segmentsconst 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){speaker = estimate_diarization_speaker(pcmf32s, t0, t1);}if (params.print_colors){for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j){if (params.print_special == 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() - 1, (int)(std::pow(p, 3) * float(k_colors.size()))));printf("%s%s%s%s", speaker.c_str(), k_colors[col].c_str(), text, "\033[0m");}}else{const char* text = whisper_full_get_segment_text(ctx, i);printf("%s%s", speaker.c_str(), text);}if (params.tinydiarize){if (whisper_full_get_segment_speaker_turn_next(ctx, i)){printf("%s", params.tdrz_speaker_turn.c_str());}}// with timestamps or speakers: each segment on new lineif (!params.no_timestamps || params.diarize){printf("\n");}fflush(stdout);}
}bool output_txt(struct whisper_context* ctx, const char* fname, const whisper_params& params, std::vector<std::vector<float>> pcmf32s)
{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);std::string speaker = "";if (params.diarize && pcmf32s.size() == 2){const int64_t t0 = whisper_full_get_segment_t0(ctx, i);const int64_t t1 = whisper_full_get_segment_t1(ctx, i);speaker = estimate_diarization_speaker(pcmf32s, t0, t1);}fout << speaker << text << "\n";}return true;
}int main(int argc, char** argv)
{const std::string model_file_path = "./ggml-base.en.bin";const std::string audio_file_path = "sample.wav"; // should be wav 16bit format// set whisper paramswhisper_params params;params.model = model_file_path;params.fname_inp.emplace_back(audio_file_path);// whisper initstruct whisper_context_params cparams;cparams.use_gpu = params.use_gpu;struct whisper_context* ctx = whisper_init_from_file_with_params(params.model.c_str(), cparams);if (ctx == nullptr){fprintf(stderr, "error: failed to initialize whisper context\n");return 3;}// initialize openvino encoder. this has no effect on whisper.cpp builds that don't have OpenVINO configuredwhisper_ctx_init_openvino_encoder(ctx, nullptr, params.openvino_encode_device.c_str(), nullptr);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 PCMstd::vector<std::vector<float>> pcmf32s; // stereo-channel F32 PCMif (!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__);}}if (params.detect_language){params.language = "auto";}fprintf(stderr, "%s: processing '%s' (%d samples, %.1f sec), %d threads, %d processors, %d beams + best of %d, lang = %s, task = %s, %stimestamps = %d ...\n",__func__, fname_inp.c_str(), int(pcmf32.size()), float(pcmf32.size()) / WHISPER_SAMPLE_RATE,params.n_threads, params.n_processors, params.beam_size, params.best_of,params.language.c_str(),params.translate ? "translate" : "transcribe",params.tinydiarize ? "tdrz = 1, " : "",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;wparams.print_timestamps = !params.no_timestamps;wparams.print_special = params.print_special;wparams.translate = params.translate;wparams.language = params.language.c_str();wparams.detect_language = params.detect_language;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.output_jsn_full || params.max_len > 0;wparams.thold_pt = params.word_thold;wparams.max_len = params.output_wts && params.max_len == 0 ? 60 : params.max_len;wparams.split_on_word = params.split_on_word;wparams.speed_up = params.speed_up;wparams.debug_mode = params.debug_mode;wparams.tdrz_enable = params.tinydiarize; // [TDRZ]wparams.initial_prompt = params.prompt.c_str();wparams.greedy.best_of = params.best_of;wparams.beam_search.beam_size = params.beam_size;wparams.temperature_inc = params.no_fallback ? 0.0f : wparams.temperature_inc;wparams.entropy_thold = params.entropy_thold;wparams.logprob_thold = params.logprob_thold;whisper_print_user_data user_data = { &params, &pcmf32s, 0 };// this callback is called on each new segmentif (!wparams.print_realtime){wparams.new_segment_callback = whisper_print_segment_callback;wparams.new_segment_callback_user_data = &user_data;}if (wparams.print_progress){wparams.progress_callback = whisper_print_progress_callback;wparams.progress_callback_user_data = &user_data;}// examples for abort mechanism// in examples below, 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 racewparams.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;}// the callback is called before every computation - if it returns true, the computation is aborted{static bool is_aborted = false; // NOTE: this should be atomic to avoid data racewparams.abort_callback = [](void* user_data) {bool is_aborted = *(bool*)user_data;return is_aborted;};wparams.abort_callback_user_data = &is_aborted;}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 10;}}// output stuff{printf("\n");// output to text fileif (params.output_txt){const auto fname_txt = fname_out + ".txt";output_txt(ctx, fname_txt.c_str(), params, pcmf32s);}}}// whisper releasewhisper_print_timings(ctx);whisper_free(ctx);return 0;
}

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