引言
語音端點檢測最早應用于電話傳輸和檢測系統當中,用于通信信道的時間分配,提高傳輸線路的利用效率.端點檢測屬于語音處理系統的前端操作,在語音檢測領域意義重大.
但是目前的語音端點檢測,尤其是檢測 人聲 開始和結束的端點始終是屬于技術難點,各家公司始終處于 能判斷,但是不敢保證 判別準確性 的階段.

現在基于云端語義庫的聊天機器人層出不窮,其中最著名的當屬amazon的 Alexa/Echo 智能音箱.

國內如雨后春筍般出現了各種搭載語音聊天的智能音箱(如前幾天在知乎上廣告的若琪機器人)和各類智能機器人產品.國內語音服務提供商主要面對中文語音服務,由于語音不像圖像有分辨率等等較為客觀的指標,很多時候憑主觀判斷,所以較難判斷各家語音識別和合成技術的好壞.但是我個人認為,國內的中文語音服務和國外的英文語音服務,在某些方面已經有超越的趨勢.

通常搭建機器人聊天系統主要包括以下三個方面:
語音轉文字(ASR/STT)
在將語音傳給云端API之前,是本地前端的語音采集,這部分主要包括如下幾個方面:
python/76562.html">python 端點檢測
由于實際應用中,單純依靠能量檢測特征檢測等方法很難判斷人聲說話的起始點,所以市面上大多數的語音產品都是使用喚醒詞判斷語音起始.另外加上聲音回路,還可以做語音打斷.這樣的交互方式可能有些傻,每次必須喊一下 喚醒詞 才能繼續聊天.這種方式聊多了,個人感覺會嘴巴疼:-O .現在github上有snowboy喚醒詞的開源庫,大家可以登錄snowboy官網訓練自己的喚醒詞模型.
考慮到用喚醒詞嘴巴會累,所以大致調研了一下,Python擁有豐富的庫,直接import就能食用.這種方式容易受強噪聲干擾,適合一個人在家玩玩.
當檢測到持續時間長度 T1 vad檢測都有語音活動,可以判定為語音起始;
當檢測到持續時間長度 T2 vad檢測都沒有有語音活動,可以判定為語音結束;
完整程序代碼可以從我的github下載
程序很簡單,相信看一會兒就明白了
'''Requirements:+ pyaudio - `pip install pyaudio`+ py-webrtcvad - `pip install webrtcvad`'''import webrtcvadimport collectionsimport sysimport signalimport pyaudiofrom array import arrayfrom struct import packimport waveimport timeFORMAT = pyaudio.paInt16CHANNELS = 1RATE = 16000CHUNK_DURATION_MS = 30 # supports 10, 20 and 30 (ms)PADDING_DURATION_MS = 1500 # 1 sec jugementCHUNK_SIZE = int(RATE CHUNK_DURATION_MS / 1000) # chunk to readCHUNK_BYTES = CHUNK_SIZE 2 # 16bit = 2 bytes, PCMNUM_PADDING_CHUNKS = int(PADDING_DURATION_MS / CHUNK_DURATION_MS)# NUM_WINDOW_CHUNKS = int(240 / CHUNK_DURATION_MS)NUM_WINDOW_CHUNKS = int(400 / CHUNK_DURATION_MS) # 400 ms/ 30ms geNUM_WINDOW_CHUNKS_END = NUM_WINDOW_CHUNKS 2START_OFFSET = int(NUM_WINDOW_CHUNKS CHUNK_DURATION_MS 0.5 RATE)vad = webrtcvad.Vad(1)pa = pyaudio.PyAudio()stream = pa.open(format=FORMAT, channels=CHANNELS, rate=RATE, input=True, start=False, # input_device_index=2, frames_per_buffer=CHUNK_SIZE)got_a_sentence = Falseleave = Falsedef handle_int(sig, chunk): global leave, got_a_sentence leave = True got_a_sentence = Truedef record_to_file(path, data, sample_width): "Records from the microphone and outputs the resulting data to 'path'" # sample_width, data = record() data = pack('<' + ('h' len(data)), data) wf = wave.open(path, 'wb') wf.setnchannels(1) wf.setsampwidth(sample_width) wf.setframerate(RATE) wf.writeframes(data) wf.close()def normalize(snd_data): "Average the volume out" MAXIMUM = 32767 # 16384 times = float(MAXIMUM) / max(abs(i) for i in snd_data) r = array('h') for i in snd_data: r.append(int(i times)) return rsignal.signal(signal.SIGINT, handle_int)while not leave: ring_buffer = collections.deque(maxlen=NUM_PADDING_CHUNKS) triggered = False voiced_frames = [] ring_buffer_flags = [0] NUM_WINDOW_CHUNKS ring_buffer_index = 0 ring_buffer_flags_end = [0] NUM_WINDOW_CHUNKS_END ring_buffer_index_end = 0 buffer_in = '' # WangS raw_data = array('h') index = 0 start_point = 0 StartTime = time.time() print(" recording: ") stream.start_stream() while not got_a_sentence and not leave: chunk = stream.read(CHUNK_SIZE) # add WangS raw_data.extend(array('h', chunk)) index += CHUNK_SIZE TimeUse = time.time() - StartTime active = vad.is_speech(chunk, RATE) sys.stdout.write('1' if active else '_') ring_buffer_flags[ring_buffer_index] = 1 if active else 0 ring_buffer_index += 1 ring_buffer_index %= NUM_WINDOW_CHUNKS ring_buffer_flags_end[ring_buffer_index_end] = 1 if active else 0 ring_buffer_index_end += 1 ring_buffer_index_end %= NUM_WINDOW_CHUNKS_END # start point detection if not triggered: ring_buffer.append(chunk) num_voiced = sum(ring_buffer_flags) if num_voiced > 0.8 NUM_WINDOW_CHUNKS: sys.stdout.write(' Open ') triggered = True start_point = index - CHUNK_SIZE 20 # start point # voiced_frames.extend(ring_buffer) ring_buffer.clear() # end point detection else: # voiced_frames.append(chunk) ring_buffer.append(chunk) num_unvoiced = NUM_WINDOW_CHUNKS_END - sum(ring_buffer_flags_end) if num_unvoiced > 0.90 NUM_WINDOW_CHUNKS_END or TimeUse > 10: sys.stdout.write(' Close ') triggered = False got_a_sentence = True sys.stdout.flush() sys.stdout.write('/n') # data = b''.join(voiced_frames) stream.stop_stream() print(" done recording") got_a_sentence = False # write to file raw_data.reverse() for index in range(start_point): raw_data.pop() raw_data.reverse() raw_data = normalize(raw_data) record_to_file("recording.wav", raw_data, 2) leave = Truestream.close()程序運行方式sudo python vad.py
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持VEVB武林網。
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