使用Python和百度语音识别生成视频字幕的实现

pip install moviepy

audio_file = work_path + "\out.wav"
video = VideoFileClip(video_file)
video.audio.write_audiofile(audio_file,ffmpeg_params=["-ar","16000","-ac","1"])

pip install pydub

# 这里silence_thresh是认定小于-70dBFS以下的为silence，发现小于 sound.dBFS * 1.3 部分超过 700毫秒，就进行拆分。这样子分割成一段一段的。
sounds = split_on_silence(sound, min_silence_len = 500, silence_thresh= sound.dBFS * 1.3)


sec = 0
for i in range(len(sounds)):
 s = len(sounds[i])
 sec += s
print("split duration is ", sec)
print("dBFS: {0}, max_dBFS: {1}, duration: {2}, split: {3}".format(round(sound.dBFS,2),round(sound.max_dBFS,2),sound.duration_seconds,len(sounds)))

# 通过搜索静音的方法将音频分段
# 参考：https://wqian.net/blog/2018/1128-python-pydub-split-mp3-index.html
timestamp_list = detect_nonsilent(sound,500,sound.dBFS*1.3,1)
 
for i in range(len(timestamp_list)):
 d = timestamp_list[i][1] - timestamp_list[i][0]
 print("Section is :", timestamp_list[i], "duration is:", d)
print("dBFS: {0}, max_dBFS: {1}, duration: {2}, split: {3}".format(round(sound.dBFS,2),round(sound.max_dBFS,2),sound.duration_seconds,len(timestamp_list)))

"""
百度智能云获取 Access Token
"""
def fetch_token():
 params = {"grant_type": "client_credentials",
    "client_id": API_KEY,
    "client_secret": SECRET_KEY}
 post_data = urlencode(params)
 if (IS_PY3):
  post_data = post_data.encode( "utf-8")
 req = Request(TOKEN_URL, post_data)
 try:
  f = urlopen(req)
  result_str = f.read()
 except URLError as err:
  print("token http response http code : " + str(err.errno))
  result_str = err.reason
 if (IS_PY3):
  result_str = result_str.decode()


 print(result_str)
 result = json.loads(result_str)
 print(result)
 if ("access_token" in result.keys() and "scope" in result.keys()):
  print(SCOPE)
  if SCOPE and (not SCOPE in result["scope"].split(" ")): # SCOPE = False 忽略检查
   raise DemoError("scope is not correct")
  print("SUCCESS WITH TOKEN: %s EXPIRES IN SECONDS: %s" % (result["access_token"], result["expires_in"]))
  return result["access_token"]
 else:
  raise DemoError("MAYBE API_KEY or SECRET_KEY not correct: access_token or scope not found in token response")

def asr_raw(speech_data, token):
 length = len(speech_data)
 if length == 0:
  # raise DemoError("file %s length read 0 bytes" % AUDIO_FILE)
  raise DemoError("file length read 0 bytes")


 params = {"cuid": CUID, "token": token, "dev_pid": DEV_PID}
 #测试自训练平台需要打开以下信息
 #params = {"cuid": CUID, "token": token, "dev_pid": DEV_PID, "lm_id" : LM_ID}
 params_query = urlencode(params)


 headers = {
  "Content-Type": "audio/" + FORMAT + "; rate=" + str(RATE),
  "Content-Length": length
 }


 url = ASR_URL + "&＃63;" + params_query
 # print post_data
 req = Request(ASR_URL + "&＃63;" + params_query, speech_data, headers)
 try:
  begin = timer()
  f = urlopen(req)
  result_str = f.read()
  # print("Request time cost %f" % (timer() - begin))
 except URLError as err:
  # print("asr http response http code : " + str(err.errno))
  result_str = err.reason


 if (IS_PY3):
  result_str = str(result_str, "utf-8")
 return result_str

idx = 0
for i in range(len(timestamp_list)):
 d = timestamp_list[i][1] - timestamp_list[i][0]
 data = sound[timestamp_list[i][0]:timestamp_list[i][1]].raw_data
 str_rst = asr_raw(data, token)
 result = json.loads(str_rst)
 # print("rst is ", result)
 # print("rst is ", rst["err_no"][0])


 if result["err_no"] == 0:
  text.append("{0}
{1} --> {2}
".format(idx, format_time(timestamp_list[i][0]/ 1000), format_time(timestamp_list[i][1]/ 1000)))
  text.append( result["result"][0])
  text.append("
")
  idx = idx + 1
  print(format_time(timestamp_list[i][0]/ 1000), "txt is ", result["result"][0])
with open(srt_file,"r+") as f:
 f.writelines(text)