diff --git a/examples/stream-pcm/README.md b/examples/stream-pcm/README.md index 16d00d42..7b296e0c 100644 --- a/examples/stream-pcm/README.md +++ b/examples/stream-pcm/README.md @@ -1,28 +1,40 @@ # whisper.cpp/examples/stream-pcm -This example performs real-time inference on raw PCM audio streamed via stdin or a pipe. -It mirrors the behavior of `whisper-stream`, but does not require SDL or a microphone device. +This example performs real-time inference on raw PCM audio streamed via stdin, a pipe, or a file. +It is PCM-first (input is consumed once) and does not require SDL or a microphone device. ## Usage -Stream raw PCM (16 kHz, mono) into the tool: +Stream raw PCM (16 kHz, mono) into the tool (non-VAD): ```bash -./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --format s16 --sample-rate 16000 --step 500 --length 5000 +./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --format s16 --sample-rate 16000 --step 1000 --length 10000 --keep 500 +``` + +Enable VAD-based segmentation (optional, recommended for speech bursts): + +```bash +./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --format s16 --sample-rate 16000 --vad --vad-probe-ms 200 --vad-silence-ms 800 --vad-pre-roll-ms 300 --length 8000 ``` You can also read from a named pipe (FIFO): ```bash mkfifo /tmp/whisper.pcm -./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --input /tmp/whisper.pcm --format s16 --sample-rate 16000 --step 500 --length 5000 +./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --input /tmp/whisper.pcm --format s16 --sample-rate 16000 --step 1000 --length 10000 --keep 500 ``` -Example of piping a WAV file using ffmpeg (optional): +Example of piping a WAV file using ffmpeg (optional, `-re` for realtime pacing): ```bash -ffmpeg -i samples/jfk.wav -f s16le -ac 1 -ar 16000 - | \ - ./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --format s16 --sample-rate 16000 --step 500 --length 5000 +ffmpeg -re -i samples/jfk.wav -f s16le -ac 1 -ar 16000 - | \ + ./build/bin/whisper-stream-pcm -m ./models/ggml-base.en.bin --format s16 --sample-rate 16000 --step 1000 --length 10000 --keep 500 +``` + +Windows (PowerShell + `cmd /c`) pipe example: + +```powershell +cmd /c "ffmpeg -re -hide_banner -loglevel error -i samples\jfk.wav -f s16le -ac 1 -ar 16000 - | build-cpu\bin\Release\whisper-stream-pcm.exe -m models\ggml-base.en.bin --format s16 --sample-rate 16000 --step 1000 --length 10000 --keep 500" ``` ## Notes @@ -30,6 +42,8 @@ ffmpeg -i samples/jfk.wav -f s16le -ac 1 -ar 16000 - | \ - Input must be raw PCM, mono, 16 kHz. The tool does not resample. - Supported formats: `f32` or `s16` (little-endian). - Use `--input -` (default) for stdin. +- `--step` must be > 0 unless `--vad` is enabled. +- For VAD, `--vad-probe-ms` should be at least 200 ms; very small probes can fail to trigger. ## Building diff --git a/examples/stream-pcm/stream-pcm.cpp b/examples/stream-pcm/stream-pcm.cpp index 20ceee90..d78fc10a 100644 --- a/examples/stream-pcm/stream-pcm.cpp +++ b/examples/stream-pcm/stream-pcm.cpp @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -47,6 +48,8 @@ struct whisper_params { bool save_audio = false; // save audio to wav file bool use_gpu = true; bool flash_attn = true; + bool debug = false; + bool use_vad = false; std::string language = "en"; std::string model = "models/ggml-base.en.bin"; @@ -55,6 +58,10 @@ struct whisper_params { std::string input = "-"; // "-" = stdin std::string format = "f32"; // f32 or s16 int32_t sample_rate = WHISPER_SAMPLE_RATE; + + int32_t vad_probe_ms = 200; + int32_t vad_silence_ms = 800; + int32_t vad_pre_roll_ms = 300; }; void whisper_print_usage(int argc, char ** argv, const whisper_params & params); @@ -96,6 +103,11 @@ static bool whisper_params_parse(int argc, char ** argv, whisper_params & params else if (arg == "-i" || arg == "--input") { params.input = argv[++i]; } else if (arg == "--format") { params.format = argv[++i]; } else if (arg == "--sample-rate") { params.sample_rate = std::stoi(argv[++i]); } + else if (arg == "--debug") { params.debug = true; } + else if (arg == "--vad") { params.use_vad = true; } + else if (arg == "--vad-probe-ms") { params.vad_probe_ms = std::stoi(argv[++i]); } + else if (arg == "--vad-silence-ms") { params.vad_silence_ms = std::stoi(argv[++i]); } + else if (arg == "--vad-pre-roll-ms") { params.vad_pre_roll_ms = std::stoi(argv[++i]); } else { fprintf(stderr, "error: unknown argument: %s\n", arg.c_str()); @@ -137,6 +149,11 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para fprintf(stderr, " -i PATH, --input PATH [%-7s] input path ('-' for stdin)\n", params.input.c_str()); fprintf(stderr, " --format FMT [%-7s] input format: f32 or s16 (little-endian)\n", params.format.c_str()); fprintf(stderr, " --sample-rate N [%-7d] input sample rate (must be 16000)\n", params.sample_rate); + fprintf(stderr, " --debug [%-7s] enable debug logging\n", params.debug ? "true" : "false"); + fprintf(stderr, " --vad [%-7s] enable VAD-based segmentation\n", params.use_vad ? "true" : "false"); + fprintf(stderr, " --vad-probe-ms N [%-5d] VAD probe chunk size (ms)\n", params.vad_probe_ms); + fprintf(stderr, " --vad-silence-ms N [%-5d] silence duration to end segment (ms)\n", params.vad_silence_ms); + fprintf(stderr, " --vad-pre-roll-ms N[%-5d] audio prepended before VAD trigger (ms)\n", params.vad_pre_roll_ms); fprintf(stderr, "\n"); } @@ -225,6 +242,7 @@ public: std::lock_guard lock(m_mutex); m_audio_pos = 0; m_audio_len = 0; + m_audio_read = 0; return true; } @@ -258,6 +276,39 @@ public: } } + void pop_ms(int ms, std::vector & result) { + result.clear(); + + std::lock_guard lock(m_mutex); + + if (ms <= 0) { + ms = m_len_ms; + } + + size_t n_samples = (m_sample_rate * ms) / 1000; + if (n_samples > m_audio_len) { + n_samples = m_audio_len; + } + + if (n_samples == 0) { + return; + } + + result.resize(n_samples); + + size_t s0 = m_audio_read; + if (s0 + n_samples > m_audio.size()) { + const size_t n0 = m_audio.size() - s0; + memcpy(result.data(), &m_audio[s0], n0 * sizeof(float)); + memcpy(&result[n0], &m_audio[0], (n_samples - n0) * sizeof(float)); + } else { + memcpy(result.data(), &m_audio[s0], n_samples * sizeof(float)); + } + + m_audio_read = (m_audio_read + n_samples) % m_audio.size(); + m_audio_len -= n_samples; + } + size_t available_samples() const { std::lock_guard lock(m_mutex); return m_audio_len; @@ -330,15 +381,21 @@ private: std::lock_guard lock(m_mutex); - if (n_samples > m_audio.size()) { - data += (n_samples - m_audio.size()); - n_samples = m_audio.size(); - } + if (n_samples > m_audio.size()) { + data += (n_samples - m_audio.size()); + n_samples = m_audio.size(); + } - if (m_audio_pos + n_samples > m_audio.size()) { - const size_t n0 = m_audio.size() - m_audio_pos; - memcpy(&m_audio[m_audio_pos], data, n0 * sizeof(float)); - memcpy(&m_audio[0], data + n0, (n_samples - n0) * sizeof(float)); + if (n_samples > m_audio.size() - m_audio_len) { + const size_t drop = n_samples - (m_audio.size() - m_audio_len); + m_audio_read = (m_audio_read + drop) % m_audio.size(); + m_audio_len -= drop; + } + + if (m_audio_pos + n_samples > m_audio.size()) { + const size_t n0 = m_audio.size() - m_audio_pos; + memcpy(&m_audio[m_audio_pos], data, n0 * sizeof(float)); + memcpy(&m_audio[0], data + n0, (n_samples - n0) * sizeof(float)); } else { memcpy(&m_audio[m_audio_pos], data, n_samples * sizeof(float)); } @@ -363,6 +420,7 @@ private: std::vector m_audio; size_t m_audio_pos = 0; size_t m_audio_len = 0; + size_t m_audio_read = 0; std::thread m_thread; }; @@ -398,16 +456,26 @@ int main(int argc, char ** argv) { return 1; } - params.keep_ms = std::min(params.keep_ms, params.step_ms); - params.length_ms = std::max(params.length_ms, params.step_ms); + if (!params.use_vad) { + if (params.step_ms <= 0) { + fprintf(stderr, "error: --step must be > 0 unless --vad is enabled\n"); + return 1; + } + params.keep_ms = std::min(params.keep_ms, params.step_ms); + params.length_ms = std::max(params.length_ms, params.step_ms); + } else { + if (params.length_ms <= 0) { + params.length_ms = 5000; + } + params.keep_ms = 0; + } - const int n_samples_step = (1e-3*params.step_ms )*WHISPER_SAMPLE_RATE; + const bool use_vad = params.use_vad; + const int n_samples_step = use_vad ? 0 : (1e-3*params.step_ms )*WHISPER_SAMPLE_RATE; const int n_samples_len = (1e-3*params.length_ms)*WHISPER_SAMPLE_RATE; const int n_samples_keep = (1e-3*params.keep_ms )*WHISPER_SAMPLE_RATE; const int n_samples_30s = (1e-3*30000.0 )*WHISPER_SAMPLE_RATE; - const bool use_vad = n_samples_step <= 0; // sliding window mode uses VAD - const int n_new_line = !use_vad ? std::max(1, params.length_ms / params.step_ms - 1) : 1; // number of steps to print new line params.no_timestamps = !use_vad; @@ -423,7 +491,15 @@ int main(int argc, char ** argv) { return 1; } - audio.resume(); + auto debug_log = [&](const char * fmt, ...) { + if (!params.debug) { + return; + } + va_list args; + va_start(args, fmt); + vfprintf(stderr, fmt, args); + va_end(args); + }; // whisper init if (params.language != "auto" && whisper_lang_id(params.language.c_str()) == -1){ @@ -479,6 +555,10 @@ int main(int argc, char ** argv) { fprintf(stderr, "\n"); } + debug_log("debug: input='%s' format=%s sample_rate=%d step_ms=%d length_ms=%d keep_ms=%d vad=%d probe_ms=%d silence_ms=%d pre_roll_ms=%d last_ms=%d\n", + params.input.c_str(), params.format.c_str(), params.sample_rate, params.step_ms, params.length_ms, params.keep_ms, + params.use_vad ? 1 : 0, params.vad_probe_ms, params.vad_silence_ms, params.vad_pre_roll_ms, std::max(1, std::min(1000, params.vad_probe_ms / 2))); + int n_iter = 0; bool is_running = true; @@ -503,62 +583,159 @@ int main(int argc, char ** argv) { wavWriter.open(filename, WHISPER_SAMPLE_RATE, 16, 1); } + + audio.resume(); printf("[Start streaming]\n"); fflush(stdout); - auto t_last = std::chrono::high_resolution_clock::now(); - const auto t_start = t_last; + int64_t total_samples = 0; + + // main audio loop + auto run_inference = [&](const std::vector & audio_buf, int64_t seg_start_sample, int64_t seg_end_sample) -> bool { + if (audio_buf.empty()) { + return true; + } + + whisper_full_params wparams = whisper_full_default_params(params.beam_size > 1 ? WHISPER_SAMPLING_BEAM_SEARCH : WHISPER_SAMPLING_GREEDY); + + wparams.print_progress = false; + wparams.print_special = params.print_special; + wparams.print_realtime = false; + wparams.print_timestamps = !params.no_timestamps; + wparams.translate = params.translate; + wparams.single_segment = !use_vad; + wparams.max_tokens = params.max_tokens; + wparams.language = params.language.c_str(); + wparams.n_threads = params.n_threads; + wparams.beam_search.beam_size = params.beam_size; + + wparams.audio_ctx = params.audio_ctx; + + wparams.tdrz_enable = params.tinydiarize; // [TDRZ] + + // disable temperature fallback + //wparams.temperature_inc = -1.0f; + wparams.temperature_inc = params.no_fallback ? 0.0f : wparams.temperature_inc; + + wparams.prompt_tokens = params.no_context ? nullptr : prompt_tokens.data(); + wparams.prompt_n_tokens = params.no_context ? 0 : prompt_tokens.size(); + + if (whisper_full(ctx, wparams, audio_buf.data(), audio_buf.size()) != 0) { + fprintf(stderr, "%s: failed to process audio\n", argv[0]); + return false; + } + + // print result; + { + if (!use_vad) { + printf("\33[2K\r"); + + // print long empty line to clear the previous line + printf("%s", std::string(100, ' ').c_str()); + + printf("\33[2K\r"); + } else { + const int64_t t0_ms = std::max(0, seg_start_sample * 1000 / WHISPER_SAMPLE_RATE); + const int64_t t1_ms = std::max(0, seg_end_sample * 1000 / WHISPER_SAMPLE_RATE); + + printf("\n"); + printf("### Transcription %d START | t0 = %d ms | t1 = %d ms\n", n_iter, (int) t0_ms, (int) t1_ms); + printf("\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); + + if (params.no_timestamps) { + printf("%s", text); + fflush(stdout); + + if (params.fname_out.length() > 0) { + fout << text; + } + } else { + const int64_t t0 = whisper_full_get_segment_t0(ctx, i); + const int64_t t1 = whisper_full_get_segment_t1(ctx, i); + + std::string output = "[" + to_timestamp(t0, false) + " --> " + to_timestamp(t1, false) + "] " + text; + + if (whisper_full_get_segment_speaker_turn_next(ctx, i)) { + output += " [SPEAKER_TURN]"; + } + + output += "\n"; + + printf("%s", output.c_str()); + fflush(stdout); + + if (params.fname_out.length() > 0) { + fout << output; + } + } + } + + if (params.fname_out.length() > 0) { + fout << std::endl; + } + + if (use_vad) { + printf("\n"); + printf("### Transcription %d END\n", n_iter); + } + } + + ++n_iter; + fflush(stdout); + return true; + }; + + std::vector pre_roll; + std::vector speech_buf; + int64_t segment_start_sample = 0; + size_t silence_samples = 0; + bool in_speech = false; + + const int vad_probe_ms = std::max(1, params.vad_probe_ms); + const int vad_last_ms = std::max(1, std::min(1000, vad_probe_ms / 2)); + const size_t vad_pre_roll_samples = (size_t) (WHISPER_SAMPLE_RATE * std::max(0, params.vad_pre_roll_ms) / 1000); + const size_t vad_silence_samples = (size_t) (WHISPER_SAMPLE_RATE * std::max(0, params.vad_silence_ms) / 1000); + const size_t vad_max_segment_samples = (size_t) n_samples_len; // main audio loop while (is_running && g_running) { - if (audio.is_eof() && audio.available_samples() == 0) { - break; - } - - if (params.save_audio) { - wavWriter.write(pcmf32_new.data(), pcmf32_new.size()); - } - - // process new audio - if (!use_vad) { - bool eof_after_this = false; - while (true) { - if (!g_running) { - is_running = false; - break; - } - - audio.get(params.step_ms, pcmf32_new); - - if ((int) pcmf32_new.size() > 2*n_samples_step) { - fprintf(stderr, "\n\n%s: WARNING: cannot process audio fast enough, dropping audio ...\n\n", __func__); - audio.clear(); + const size_t available = audio.available_samples(); + if (available < (size_t) n_samples_step) { + if (audio.is_eof()) { + if (available == 0) { + break; + } + } else { + std::this_thread::sleep_for(std::chrono::milliseconds(5)); continue; } - - if ((int) pcmf32_new.size() >= n_samples_step) { - audio.clear(); - break; - } - - if (audio.is_eof() && audio.available_samples() > 0) { - // flush remaining samples on EOF - audio.clear(); - eof_after_this = true; - break; - } - - std::this_thread::sleep_for(std::chrono::milliseconds(1)); } - if (!is_running) { - break; + audio.pop_ms(params.step_ms, pcmf32_new); + debug_log("debug: step audio.pop -> %zu samples (available=%zu eof=%d)\n", + pcmf32_new.size(), audio.available_samples(), audio.is_eof() ? 1 : 0); + + if (pcmf32_new.empty()) { + if (audio.is_eof()) { + break; + } + continue; + } + + total_samples += pcmf32_new.size(); + + if (params.save_audio && !pcmf32_new.empty()) { + wavWriter.write(pcmf32_new.data(), pcmf32_new.size()); + debug_log("debug: save_audio wrote %zu samples (step)\n", pcmf32_new.size()); } const int n_samples_new = pcmf32_new.size(); - - // take up to params.length_ms audio from previous iteration const int n_samples_take = std::min((int) pcmf32_old.size(), std::max(0, n_samples_keep + n_samples_len - n_samples_new)); pcmf32.resize(n_samples_new + n_samples_take); @@ -571,130 +748,17 @@ int main(int argc, char ** argv) { pcmf32_old = pcmf32; - if (eof_after_this && pcmf32.empty()) { - break; - } - } else { - const auto t_now = std::chrono::high_resolution_clock::now(); - const auto t_diff = std::chrono::duration_cast(t_now - t_last).count(); - - if (t_diff < 2000) { - std::this_thread::sleep_for(std::chrono::milliseconds(100)); - - continue; - } - - audio.get(2000, pcmf32_new); - - if (::vad_simple(pcmf32_new, WHISPER_SAMPLE_RATE, 1000, params.vad_thold, params.freq_thold, false)) { - audio.get(params.length_ms, pcmf32); - } else { - std::this_thread::sleep_for(std::chrono::milliseconds(100)); - - continue; - } - - t_last = t_now; - } - - // run the inference - { - whisper_full_params wparams = whisper_full_default_params(params.beam_size > 1 ? WHISPER_SAMPLING_BEAM_SEARCH : WHISPER_SAMPLING_GREEDY); - - wparams.print_progress = false; - wparams.print_special = params.print_special; - wparams.print_realtime = false; - wparams.print_timestamps = !params.no_timestamps; - wparams.translate = params.translate; - wparams.single_segment = !use_vad; - wparams.max_tokens = params.max_tokens; - wparams.language = params.language.c_str(); - wparams.n_threads = params.n_threads; - wparams.beam_search.beam_size = params.beam_size; - - wparams.audio_ctx = params.audio_ctx; - - wparams.tdrz_enable = params.tinydiarize; // [TDRZ] - - // disable temperature fallback - //wparams.temperature_inc = -1.0f; - wparams.temperature_inc = params.no_fallback ? 0.0f : wparams.temperature_inc; - - wparams.prompt_tokens = params.no_context ? nullptr : prompt_tokens.data(); - wparams.prompt_n_tokens = params.no_context ? 0 : prompt_tokens.size(); - - if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) { - fprintf(stderr, "%s: failed to process audio\n", argv[0]); + if (!run_inference(pcmf32, -1, -1)) { return 6; } - // print result; - { - if (!use_vad) { - printf("\33[2K\r"); - - // print long empty line to clear the previous line - printf("%s", std::string(100, ' ').c_str()); - - printf("\33[2K\r"); - } else { - const int64_t t1 = (t_last - t_start).count()/1000000; - const int64_t t0 = std::max(0.0, t1 - pcmf32.size()*1000.0/WHISPER_SAMPLE_RATE); - - printf("\n"); - printf("### Transcription %d START | t0 = %d ms | t1 = %d ms\n", n_iter, (int) t0, (int) t1); - printf("\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); - - if (params.no_timestamps) { - printf("%s", text); - fflush(stdout); - - if (params.fname_out.length() > 0) { - fout << text; - } - } else { - const int64_t t0 = whisper_full_get_segment_t0(ctx, i); - const int64_t t1 = whisper_full_get_segment_t1(ctx, i); - - std::string output = "[" + to_timestamp(t0, false) + " --> " + to_timestamp(t1, false) + "] " + text; - - if (whisper_full_get_segment_speaker_turn_next(ctx, i)) { - output += " [SPEAKER_TURN]"; - } - - output += "\n"; - - printf("%s", output.c_str()); - fflush(stdout); - - if (params.fname_out.length() > 0) { - fout << output; - } - } - } - - if (params.fname_out.length() > 0) { - fout << std::endl; - } - - if (use_vad) { - printf("\n"); - printf("### Transcription %d END\n", n_iter); - } - } - - ++n_iter; - - if (!use_vad && (n_iter % n_new_line) == 0) { + if (n_iter % n_new_line == 0) { printf("\n"); // keep part of the audio for next iteration to try to mitigate word boundary issues - pcmf32_old = std::vector(pcmf32.end() - n_samples_keep, pcmf32.end()); + if (n_samples_keep > 0 && (int) pcmf32.size() >= n_samples_keep) { + pcmf32_old = std::vector(pcmf32.end() - n_samples_keep, pcmf32.end()); + } // Add tokens of the last full length segment as the prompt if (!params.no_context) { @@ -709,7 +773,80 @@ int main(int argc, char ** argv) { } } } - fflush(stdout); + } else { + const size_t available = audio.available_samples(); + if (available == 0) { + if (audio.is_eof()) { + if (in_speech && !speech_buf.empty()) { + const int64_t seg_end_sample = segment_start_sample + (int64_t) speech_buf.size(); + if (!run_inference(speech_buf, segment_start_sample, seg_end_sample)) { + return 6; + } + speech_buf.clear(); + in_speech = false; + } + break; + } + std::this_thread::sleep_for(std::chrono::milliseconds(5)); + continue; + } + + audio.pop_ms(vad_probe_ms, pcmf32_new); + debug_log("debug: vad probe audio.pop -> %zu samples (available=%zu eof=%d)\n", + pcmf32_new.size(), audio.available_samples(), audio.is_eof() ? 1 : 0); + + if (pcmf32_new.empty()) { + continue; + } + + total_samples += pcmf32_new.size(); + + if (params.save_audio && !pcmf32_new.empty()) { + wavWriter.write(pcmf32_new.data(), pcmf32_new.size()); + debug_log("debug: save_audio wrote %zu samples (probe)\n", pcmf32_new.size()); + } + + const bool silence = ::vad_simple(pcmf32_new, WHISPER_SAMPLE_RATE, vad_last_ms, params.vad_thold, params.freq_thold, false); + debug_log("debug: vad silence=%d (last_ms=%d)\n", silence ? 1 : 0, vad_last_ms); + + if (!in_speech) { + if (!silence) { + in_speech = true; + silence_samples = 0; + speech_buf.clear(); + if (!pre_roll.empty()) { + speech_buf.insert(speech_buf.end(), pre_roll.begin(), pre_roll.end()); + } + speech_buf.insert(speech_buf.end(), pcmf32_new.begin(), pcmf32_new.end()); + segment_start_sample = total_samples - (int64_t) speech_buf.size(); + debug_log("debug: vad speech start (segment_start_sample=%lld)\n", (long long) segment_start_sample); + } + } else { + speech_buf.insert(speech_buf.end(), pcmf32_new.begin(), pcmf32_new.end()); + if (!silence) { + silence_samples = 0; + } else { + silence_samples += pcmf32_new.size(); + } + + if (speech_buf.size() >= vad_max_segment_samples || silence_samples >= vad_silence_samples) { + const int64_t seg_end_sample = segment_start_sample + (int64_t) speech_buf.size(); + if (!run_inference(speech_buf, segment_start_sample, seg_end_sample)) { + return 6; + } + speech_buf.clear(); + in_speech = false; + silence_samples = 0; + debug_log("debug: vad speech end (segment_end_sample=%lld)\n", (long long) seg_end_sample); + } + } + + if (vad_pre_roll_samples > 0) { + pre_roll.insert(pre_roll.end(), pcmf32_new.begin(), pcmf32_new.end()); + if (pre_roll.size() > vad_pre_roll_samples) { + pre_roll.erase(pre_roll.begin(), pre_roll.end() - vad_pre_roll_samples); + } + } } }