百度語音識別API的python使用示例

百度給的樣例程序，不論C還是Java版，都分為method1和method2兩種

前者稱為隱式（post的是json串，音頻數據編碼到json里），后者稱為顯式（post的就是音頻數據）

一開始考慮到python wave包處理的都是“字符串”，擔心跟C語言的數組不一致，所以選擇低效但保險的method1，

即先將音頻數據base64編碼，再加上采樣率、通道數等信息匯集成dict，最后總體編碼成json串

結果老是報：

3300 輸入參數不正確

先后試過urllib2和pycurl包，都是上面情況

不得已換用method2，成功（看來wave包對音頻的存儲并不是“字符串”）

    #encoding=utf-8


import wave  
import urllib, urllib2, pycurl  
import base64  
import json  
## get access token by api key & secret key  

def get_token():  
    apiKey = "xxxxxxxx"  
    secretKey = "xxxxxxxxx"  

    auth_url = "https://openapi.baidu.com/oauth/2.0/token?grant_type=client_credentials&client_id=" + apiKey + "&client_secret=" + secretKey;  

    res = urllib2.urlopen(auth_url)  
    json_data = res.read()  
    return json.loads(json_data)['access_token']  

def dump_res(buf):  
    print buf  


## post audio to server  
def use_cloud(token):  
    fp = wave.open('vad_0.wav', 'rb')  
    nf = fp.getnframes()  
    f_len = nf * 2  
    audio_data = fp.readframes(nf)  

    cuid = "xxxxxxxxxx" #my xiaomi phone MAC  
    srv_url = 'http://vop.baidu.com/server_api' + '?cuid=' + cuid + '&token=' + token  
    http_header = [  
        'Content-Type: audio/pcm; rate=8000',  
        'Content-Length: %d' % f_len  
    ]  

    c = pycurl.Curl()  
    c.setopt(pycurl.URL, str(srv_url)) #curl doesn't support unicode  
    #c.setopt(c.RETURNTRANSFER, 1)  
    c.setopt(c.HTTPHEADER, http_header)   #must be list, not dict  
    c.setopt(c.POST, 1)  
    c.setopt(c.CONNECTTIMEOUT, 30)  
    c.setopt(c.TIMEOUT, 30)  
    c.setopt(c.WRITEFUNCTION, dump_res)  
    c.setopt(c.POSTFIELDS, audio_data)  
    c.setopt(c.POSTFIELDSIZE, f_len)  
    c.perform() #pycurl.perform() has no return val  

if __name__ == "__main__":  
    token = get_token()  
    use_cloud(token)  </pre> 


 運行結果
{"corpus_no":"6150045491002357923","err_msg":"success.","err_no":0,"result":["播放小蘋果，"],"sn":"243903724071431919050"}