asr.py

# coding=utf-8

import sys
import json
import base64
import time
import requests

IS_PY3 = sys.version_info.major == 3


from urllib.request import urlopen
from urllib.request import Request
from urllib.error import URLError
from urllib.parse import urlencode
timer = time.perf_counter

#百度api
API_KEY = ''
SECRET_KEY = ''

# 需要识别的文件
AUDIO_FILE = ''  # 只支持 pcm/wav/amr 格式，极速版额外支持m4a 格式
# 文件格式
FORMAT = "" # 文件后缀只支持 pcm/wav/amr 格式，极速版额外支持m4a 格式

CUID = '123456PYTHON'
# 采样率
RATE = 16000  # 固定值

# 普通版

DEV_PID = 1537  # 1537 表示识别普通话，使用输入法模型。根据文档填写PID，选择语言及识别模型
ASR_URL = 'http://vop.baidu.com/server_api'
SCOPE = 'audio_voice_assistant_get'  # 有此scope表示有asr能力，没有请在网页里勾选，非常旧的应用可能没有

#测试自训练平台需要打开以下信息， 自训练平台模型上线后，您会看见 第二步：“”获取专属模型参数pid:8001，modelid:1234”，按照这个信息获取 dev_pid=8001，lm_id=1234
# DEV_PID = 8001 ;   
# LM_ID = 1234 ;

# 极速版 打开注释的话请填写自己申请的appkey appSecret ，并在网页中开通极速版（开通后可能会收费）

# DEV_PID = 80001
# ASR_URL = 'http://vop.baidu.com/pro_api'
# SCOPE = 'brain_enhanced_asr'  # 有此scope表示有极速版能力，没有请在网页里开通极速版

# 忽略scope检查，非常旧的应用可能没有
# SCOPE = False

class DemoError(Exception):
    pass


"""  TOKEN start """

TOKEN_URL = 'http://aip.baidubce.com/oauth/2.0/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.code))
        result_str = err.read()
    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')

"""  TOKEN end """

def getasr(filename):
    AUDIO_FILE = filename
    FORMAT = AUDIO_FILE[-3:] 

    token = fetch_token()
    speech_data = []
    with open(AUDIO_FILE, 'rb') as speech_file:
        speech_data = speech_file.read()

    length = len(speech_data)
    if length == 0:
        raise DemoError('file %s length read 0 bytes' % AUDIO_FILE)
    speech = base64.b64encode(speech_data)
    speech = str(speech, 'utf-8')
    
    params = {'dev_pid': DEV_PID,
             #"lm_id" : LM_ID,    #测试自训练平台开启此项
              'format': FORMAT,
              'rate': RATE,
              'token': token,
              'cuid': CUID,
              'channel': 1,
              'speech': speech,
              'len': length
              }
    headers={
        "Content-Type":'application/json'
    }
    r=requests.post(url=ASR_URL,headers=headers,data=json.dumps(params))
    work=r.json()
    return(work['result'][0])